ICSC/323 AUGUST 2022
POTENTIAL ROLE OF
AMMONIA IN A CLEAN
ENERGY TRANSITION
DR QIAN ZHU
POTENTIAL ROLE OF
AMMONIA IN A CLEAN
ENERGY TRANSITION
INTERNATIONAL CENTRE FOR SUSTAINABLE CARBON
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INTERNATIONAL CENTRE FOR SUSTAINABLE CARBON
POTENTIAL ROLE OF AMMONIA IN A CLEAN ENERGY TRANSITION
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PREFACE
This report has been produced by the International Centre for Sustainable Carbon (ICSC) and is based on
a survey and analysis of published literature and on information gathered in discussions with interested
organisations and individuals. Their assistance is gratefully acknowledged. It should be understood that the
views expressed in this report are our own and are not necessarily shared by those who supplied the
information, nor by our member organisations.
The International Centre for Sustainable Carbon was established in 1975 and has contracting parties and
sponsors from Australia, China, Italy, Japan, South Africa, and the USA.
The overall objective of the International Centre for Sustainable Carbon is to continue to provide our
members, the International Energy Agency (IEA) Working Party on Fossil Energy and other interested
parties with definitive and policy relevant independent information on how various carbon-based energy
sources can continue to be part of a sustainable energy mix worldwide. The energy sources include, but
are not limited to coal, biomass and organic waste materials. Our work is aligned with the UN Sustainable
Development Goals (SDGs), which includes the need to address the climate targets as set out by the
United Nations Framework Convention on Climate Change (UNFCCC). We consider all aspects of solid
carbon production, transport, processing and utilisation, within the rationale for balancing security of
supply, affordability and environmental issues. These include efficiency improvements, lowering
greenhouse and non-greenhouse gas emissions, reducing water stress, financial resourcing, market issues,
technology development and deployment, ensuring poverty alleviation through universal access to
electricity, sustainability, and social licence to operate. Our operating framework is designed to identify
and publicise the best practice in every aspect of the carbon production and utilisation chain, so helping
to significantly reduce any unwanted impacts on health, the environment and climate, to ensure the
wellbeing of societies worldwide.
The International Centre for Sustainable Carbon is a Technology Collaboration Programme organised
under the auspices of the International Energy Agency (IEA) but is functionally and legally autonomous.
Views, findings and publications of the International Centre for Sustainable Carbon do not necessarily
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Neither the International Centre for Sustainable Carbon nor any of its employees nor any supporting
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INTERNATIONAL CENTRE FOR SUSTAINABLE CARBON
POTENTIAL ROLE OF AMMONIA IN A CLEAN ENERGY TRANSITION
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ABSTRACT
Some properties of ammonia make it suitable for use as an energy storage medium, a hydrogen carrier
and as a fuel. Ammonia is the second most produced chemical in the world. Technologies for
production, safe handling, transport and storage of ammonia are mature and global supply and
distribution infrastructure already exists. Therefore, ammonia could form the basis of an integrated
energy storage and distribution solution, and be a low-carbon fuel for power generation, transport and
industrial processes as well as a valuable feedstock to produce fertiliser, explosives, pharmaceuticals
and textiles.
Ammonia could be burnt directly in internal combustion engines (ICE), gas turbines, coal boilers and
furnaces with minor modifications, or fed to fuel cells (FC) to produce electricity. Extensive research
and development (R&D) is underway and developments in ammonia combustion technologies are
progressing rapidly. Significant progress in cofiring ammonia and coal for power generation has been
made in Japan and commercial demonstration of 20% ammonia cofiring at a 1000 MWe coal power
unit is scheduled for 2023-24. Ammonia-gas cofiring technologies for gas-fired power generation are
in development and could be commercially available by 2025. Several projects are ongoing to
demonstrate ammonia-powered commercial shipping vessels in 2024-25. Analyses show that
substituting fossil fuels with low-carbon ammonia for power generation can reduce life cycle carbon
dioxide (CO2) emissions, and hence, contribute to decarbonising the power sector. This report
explores the potential role of ammonia in a clean energy transition with a focus on ammonia as a clean
fuel. It provides an overview of existing technologies for ammonia manufacture, and the latest
developments in low-carbon ammonia production. Recent developments in ammonia combustion
technologies for power generation, transport and industrial processes are reviewed. The challenges
and opportunities of ammonia fuel use, the potential CO2 emission reductions that can be achieved
including life cycle analysis are discussed, and the impacts of firing/cofiring ammonia on electricity
costs are analysed. Overall, ammonia has the potential to become a key element of a net zero emissions
energy mix, especially in energy-intensive sectors such as power generation, transport and some
industrial processes.
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ACRONYMS AND ABBREVIATIONS
ABS
American Bureau of Shipping
ADNOC
Abu Dhabi National Oil Company
AIST
National Institute of Advanced Industrial Science and Technology, Japan
BAT
best available technologies
BECCS
biomass energy with carbon capture and storage
BEIS
Department for Business, Energy and Industrial Strategy, UK
Capex
capital expenditure
CCGT
combined cycle gas turbine
CCS
carbon capture and storage
CCUS
carbon capture, utilisation and storage
CRIEPI
Central Research Institute of Electric Power Industry, Japan
EOR
enhanced oil recovery
EU
European Union
FC
fuel cell
GE
General Electric Company
GHG
greenhouse gas
GWP
global warming potential
HHV
higher heating value
ICE
internal combustion engine
ICSC
International Centre of Sustainable Carbon
IDEA
Inventory Database for Environmental Analysis
IEA
International Energy Agency
IEEJ
Institute of Energy Economics, Japan
IMO
International Maritime Organization
IPCC
Intergovernmental Panel on Climate Change
ISPT
Institute for Sustainable Process Technology
J-ENG
Japan Engine Corporation
LCA
life cycle analysis
LCOE
levelised cost of electricity
LHV
lower heating value
LNG
liquefied natural gas
MAN ES
MAN Energy Solutions
MEA
monoethanolamine
MHI
Mitsubishi Heavy Industries Group
MoU
Memorandum of Understanding
NG
natural gas
NGCC
natural gas combined cycle
NEDO
New Energy and Industrial Technology Development Organization, Japan
NMRI
National Maritime Research Institute, Japan
NZE
net zero emissions
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POTENTIAL ROLE OF AMMONIA IN A CLEAN ENERGY TRANSITION
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Opex
operating expenditure
PEM
polymer electrolyte membrane
PV
photovoltaic
R&D
research and development
REFUEL
Renewable Energy to Fuels through Utilisation of Energy-Dense Liquids
SABIC
Saudi Basic Industries Corporation
SCR
selective catalytic reduction (of NOx)
SDARI
Shanghai Merchant Ship Design & Research Institute
SDG
Sustainable Development Goal
SEP
Strategic Energy Plan
SIP
Cross-ministerial Strategic Innovation Promotion Program, Japan
SMR
steam methane reforming
SOEC
solid oxide electrolysis cells
SOFC
solid oxide fuel cells
TEU
twenty-foot equivalent unit
UN
United Nations
WGS
water-gas shift
UNITS
CHEMICALS
gCO2-eq
grammes of CO2 equivalent
CO
carbon monoxide
GWe
gigawatt electric
CO2
carbon dioxide
kilogramme per cubic metre
CH4
methane
kt
kilotonnes
H2
hydrogen
kWh
kilowatt-hour
H2O
water
kW/L
kilowatt per litre
N2
nitrogen
kW/t
kilowatt per tonne
N2O
nitrous oxide
kWth
kilowatt thermal
NH3
ammonia
L
litre
NMC
nickel manganese cobalt oxide
MPa
megapascal
NOx
nitrogen oxides
Mt
million tonnes
O2
oxygen
Mt/y
million tonnes per year
MW
megawatt
MWe
megawatt electric
MWth
megawatt thermal
ppm
parts per million
vol%
volume per cent
wt%
weight per cent
kg/m
3
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CONTENTS
P REF AC E
4
A BS TR AC T
5
A CR O N Y MS A N D AB BR E V I A TI O N S
6
C O NT E NT S
8
L I S T O F F I G UR E S
10
L I S T O F T AB LE S
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E X EC UT I VE S UM MA R Y
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1
I N T RO DU C T IO N
15
A M MO N IA TO F UE L FU T UR E C LE AN EN ER GY
Ammonia as an energy vector
Ammonia as a carbon-free fuel
Sustainability
Health and safety issues and environmental impacts
Summary
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2
2.1
2.2
2.3
2.4
2.5
3
A M MO N IA VA L UE C HA I N
3.1 Production
3.1.1 Technologies
3.1.2 Production and supply
3.2 Transport and distribution systems
3.3 Utilisation
3.3.1 Fertiliser and chemicals
3.3.2 Energy and hydrogen carrier
3.3.3 Fuel
3.4 Summary
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25
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28
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35
35
4
A M MO N IA AS A F UE L
4.1 Fundamental studies on ammonia combustion and laboratory scale R&D
4.2 Power generation
4.2.1 Cofiring ammonia with coal in boilers
4.2.2 Cofiring ammonia in combustion turbines
4.3 Transport
4.3.1 Ammonia-fuelled ICE for shipping vessels
4.3.2 Ammonia-fuelled ICE for road vehicles
4.3.3 Ammonia fuel cell powered vehicles
4.4 Industrial process heat and steam
4.5 Summary
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C H A L LE N GE S AN D O PP O R TU N I T IES
5.1 Challenges
5.1.1 Costs
5.1.2 Demand and supply
5.1.3 Environmental and social impacts
5.1.4 Policy and regulations
5.2 Opportunities
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5.3 Potential CO2 emissions reduction from coal power generation using ammonia fuel
5.3.1 Life cycle analyses
5.4 Economic assessment of power generation based on low-carbon ammonia
5.5 Summary
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D I S C US S IO N A N D CO N C L US IO NS
6.1 Policies
6.2 Role of CCUS and ammonia in power generation
6.3 Conclusions
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65
R EFER E N CE S
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LIST OF FIGURES
Figure 1
The volumetric energy density of a range of fuels
Figure 2 Estimated costs for transport of hydrogen and ammonia by lorry, rail and ship
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20
Figure 3 Clean energy transition enabled by renewable ammonia
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Figure 4 Indicative life cycle GHG emissions from different ammonia production processes
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Figure 5 A simplified schematic of the natural gas SMR-based Haber-Bosch process
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Figure 6 A simplified schematic of coal gasification-based Haber-Bosch process
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Figure 7
30
Ammonia production capacity map
Figure 8 Global ammonia shipping infrastructure
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Figure 9 Ammonia pipeline distribution networks in the USA
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Figure 10 Flame observation: a) ammonia-air combustion; b) ammonia-coal-air combustion
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Figure 11
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Ammonia-coal cofiring burner developed by IHI Corporation
Figure 12 Boiler retrofit concept for Unit 4 of Hekinan power plant, Japan
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Figure 13 An ammonia-fuelled NGCC power plant concept evaluated by Mitsubishi Power
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Figure 14 Comparison of costs and CO2 intensities of ammonia production via different routes
50
Figure 15 The system boundary of the analysed life cycle
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Figure 16 Life cycle CO2 emissions of ammonia and fossil-fuelled power generation
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Figure 17 LCOE comparison of low-carbon electricity from renewable ammonia, fossil fuels with
CCS, nuclear and BECCS
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Figure 18 LCOE of low-carbon electricity at various power plant capacity factors
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POTENTIAL ROLE OF AMMONIA IN A CLEAN ENERGY TRANSITION
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LIST OF TABLES
Table 1
Ammonia properties
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Table 2
Safe exposure limits for ammonia in selected countries
24
Table 3
Comparative energy consumption and carbon footprint of different ammonia production
processes and feedstocks
27
Table 4
Comparison of the water electrolysis technologies
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Table 5
Regional and global production, trade and consumption of ammonia, 2019
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Table 6
Renewable ammonia projects
30
Table 7
Possible applications of ammonia as a fuel in the transport, power and industrial sectors
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Table 8
Comparison of fuel properties
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Table 9
Estimated costs of conventional and renewable ammonia production in the USA
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Table 10
Comparison of LCOE of cofiring imported low-carbon ammonia and renewable ammonia
at Japanese coal power plants in 2030
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EXECUTIVE SUMMARY
EXECUTIVE SUMMARY
AMMONIA AS A CARBON-FREE FUEL
Ammonia (NH3) has certain properties that make it suitable for use as an energy storage medium, a
hydrogen carrier and as a fuel. As it is carbon free, ammonia combustion does not emit CO 2. Ammonia
is currently the second most produced chemical; around 180 Mt/y of ammonia is manufactured
worldwide for use as a feedstock for fertiliser and other chemicals. Nearly 90% of ammonia is produced
and consumed locally while the remaining 10%, around 20 Mt, is traded globally. Therefore,
technologies for its production, safe handling, transport and storage are mature and global supply and
distribution infrastructure already exists, although not on a massive scale. These factors mean that
ammonia could form the basis of an integrated energy storage and distribution solution, and be a lowcarbon fuel for power generation, transport and industrial processes. Ammonia combustion as an
alternative approach to decarbonising power generation, may be particularly important for countries
that depend on thermal power plants to provide key flexibility and other system services.
There are three main commercial technological routes for ammonia production: steam methane
reforming (SMR) accounting for 72% of global ammonia production, coal gasification accounting for
26%, and the water electrolysis-based Haber-Bosch process produces less than 1%. Ammonia
production processes are energy intensive and create emissions of large volumes of CO2 as almost all
ammonia is currently produced from unabated fossil fuels. When using ammonia as a fuel for
decarbonisation the options include producing renewable ammonia via electrolysis using renewable
energy to power the entire production process. However, this is a nascent commercial activity and
currently not competitive with the other two options of ammonia production. The alternative is to
produce low-carbon ammonia by combining a fossil fuel-based process with carbon capture and storage
(CCS).
Ammonia can be directly burnt with minor modifications in internal combustion engines (ICE), gas
turbines, and coal-fired boilers, or be fed to a fuel cell (FC) to produce electricity. There are technical
challenges to burning ammonia in existing combustion systems due to its relatively low energy content
and low reactivity, and the likely increase in emissions of nitrogen oxides (NOx) and nitrous oxide
(N2O); they can be overcome using existing technologies, improved engineering designs and system
optimisation. Extensive R&D on ammonia combustion technologies is progressing fast. Several
projects are developing ammonia-coal cofiring technologies for power generation; commercial
demonstration of 20% ammonia-coal cofiring at a 1000 MW coal power unit is scheduled for 2023-24
at the Hekinan plant in Japan. Ammonia-gas cofiring technologies for gas power generation are in
development and could be commercialised by 2025.
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EXECUTIVE SUMMARY
Projects are underway to demonstrate that ammonia can deliver power to shipboard systems safely
and effectively. The first commercial vessels propelled by ammonia fuel or using large FCs running on
ammonia are expected to launch in 2024-25. Road vehicles driven by ammonia-fuelled ICE and FC
systems are in development and some have been demonstrated. However, they are not competitive
with rival technologies such as batteries and hydrogen-fuelled FC, so there is less progress. Ammonia
as a fuel in industrial furnaces has been explored with some positive results.
CHALLENGES AND OPPORTUNITIES
A major barrier to using clean ammonia as a fuel is its high cost. In general, renewable ammonia costs
more than double conventional ammonia and it is likely to remain expensive for some years. Lowcarbon ammonia costs around 25% more than conventional ammonia due to the additional cost of
carbon capture.
Another serious challenge is the future demand for clean ammonia. The increased use of ammonia as
an energy source could create a market many times larger than current global total production capacity.
This would require a massive scale-up of ammonia production, port, storage, and distribution facilities.
However, the low production rate of renewable ammonia constrains its use as a clean fuel. Low-carbon
ammonia could offer a quicker and cheaper route to a low-carbon energy transition.
In addition, ammonia is a toxic gas and can damage human health. Large-scale combustion of ammonia
could have a negative environmental impact due to the likely increase in emissions of N 2O, NOx, and
ammonia. New safety protocols and regulations, emission standards and clean fuel standards are
needed to extend the use of ammonia as fuel.
Appropriate policies need to be established to kick-start the use of ammonia as a clean fuel. For
example, policies in the form of development strategies, roadmaps, action plans and mandates with
targets for clean fuel uptake and/or carbon emissions reduction can inspire companies and investors
to capitalise in the clean energy business. Policy support such as emission charges and tax credits, and
incentives and financial support are also important to overcome the high cost of clean ammonia fuel.
More R&D is needed to lower the cost of clean ammonia.
The expansion of ammonia production, transport and distribution infrastructure to enable the
extended use of ammonia as a fuel requires large capital investment, which poses another challenge
but also provides opportunities for investors as the market may be huge.
AMMONIA TO FUEL FUTURE CLEAN ENERGY
Substituting fossil fuels with clean ammonia in existing combustion systems can reduce CO2 emissions
over the life cycle of the fuel. For coal power generation, substituting coal with clean ammonia could
reduce CO2 emissions by 80–95%. Ammonia combustion/cocombustion and ammonia FC
technologies may be commercially available within 5–10 years; it is likely that power generation and
INTERNATIONAL CENTRE FOR SUSTAINABLE CARBON
POTENTIAL ROLE OF AMMONIA IN A CLEAN ENERGY TRANSITION
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EXECUTIVE SUMMARY
maritime transport will be early deployers of clean ammonia fuel. The first large-scale uptake of
ammonia fuel use is likely to be based on lower-cost low-carbon ammonia, which can offer a quicker
and cheaper start to decarbonisation than renewable ammonia. Appropriate policies are key to the
successful deployment and use of clean ammonia fuel. Overall, ammonia has the potential to become
a key element of a net zero emissions energy mix, especially in energy-intensive sectors such as power
generation, transport and some industrial processes.
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INTRODUCTION
1
INTRODUCTION
According to the Intergovernmental Panel on Climate Change (IPCC, 2018), to limit global warming
to below 2°C above pre-industrial levels with at least 66% probability, global net anthropogenic CO 2
emissions need to decline by 25% by 2030 from the 2010 level and reach net zero around 2070. If we
wish to control global warming to ≤1.5°C, the world will need to cut CO2 emissions by 45% by 2030
and to net zero by around 2050. Recently, many countries, including some of the world’s largest
economies such as the European Union (EU), Japan, South Korea and the UK have announced
ambitious plans to reach net zero emissions (NZE) by 2050, while China and Indonesia have set NZE
targets for 2060, and India for 2070. President Biden also announced in April 2021 that the USA would
aim to achieve a 50–52% reduction in greenhouse gas (GHG) emissions by 2030 from 2005 levels, and
to reach NZE no later than 2050 (White House, 2021). To meet the climate change objectives, the
power sector, industry, transport and other sectors such as buildings and agriculture must decarbonise
within the next few decades. This will need innovative solutions, technologies and policies.
The need to address climate change is driving a fundamental change in power systems globally. There
has been a rapid expansion in the deployment of renewable energy sources such as solar, wind and
biomass in recent years. Many developed countries such as Germany, other EU member states and the
UK, have deadlines for the closure of all coal-fired power plants. In the USA, 28% of coal power
generation capacity totalling 88.7 GW was shuttered between 2011 and 2020, and 2.7 GW of coal
power capacity was due to retire in 2021 (US EIA, 2021a,b). As part of its efforts to decarbonise, Japan
plans to phase out inefficient coal power plants and reduce coal’s share in power generation from 31%
in 2020 to 26% by 2030 (Kumagai, 2021). However, despite the rapid development in renewable
power and the recent closure of a large number of coal power plants worldwide (especially the smaller,
inefficient and polluting ones in China and India), coal remains the dominant fuel for power generation.
Globally, coal’s share of electricity generation was 35.1% in 2020 (bp, 2021). On the one hand, in the
short- to medium-term, dispatchable thermal power plants are needed to provide flexibility, enabling
power systems worldwide to integrate the maximum levels of variable renewable power. On the other
hand, in many parts of the world coal power generation has, and will continue to play, an important
role in providing secure, reliable and affordable electricity to fuel economic development and lift
people out of poverty. There are many reasons why countries continue to rely on coal for power
generation and these relate to their individual circumstances. The reasons include enhancing national
energy security and reducing energy imports, using indigenous energy resources, and maintaining a
diverse energy mix (Mills, 2021). In the last two decades, many new coal power plants have been
commissioned in Asia, Africa and other parts of the world. As of September 2021, new coal power
plants totalling nearly 130 GW capacity are under construction, and coal power plants with a total
capacity of about 184 GW are planned (S&P Global, 2021). In addition, countries such as China, India,
Bangladesh and Vietnam have a relatively young coal fleet, with an average age of less than 15 years
which will be in service for many years (coal power plants have a service life of 30–50 years).
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INTRODUCTION
According to the International Energy Agency (IEA, 2019), around 1250 GW of coal power plants
worldwide in operation or under construction in 2019 could not only still be in service by 2030, but
could also still have a remaining lifetime of at least 20 years. Therefore, it is vital to cut CO2 emissions
from these plants as part of meeting environmental targets and achieving NZE.
There are various technological routes to reduce CO2 emissions from coal power generation such as
improving energy efficiency and carbon capture, utilisation and storage (CCUS). Cofiring of
low-carbon fuels, traditionally biomass, in coal power plants has been shown to reduce carbon
emissions with relatively low investment. In recent years, the use of ammonia as a carbon-free fuel for
power has received more attention. Combustion of ammonia produces mainly water (H2O) and
nitrogen (N2), two components that are benign to the environment. Replacing part or all of the fossil
fuel in boilers or combustion turbines with ammonia can lower CO2 emissions from power plants
proportionate to the reduced amount of fossil fuel used. There is also increasing interest worldwide in
the use of ammonia as an energy vector. In several recent studies, the IEA recognises that, as an energy
carrier, ammonia is much cheaper than hydrogen to transport and store and thus, it is the most
economically competitive alternative to hydrogen for distribution (IEA, 2017, 2019, 2021a). The IEA
has also identified technologies to produce clean ammonia using renewable energy and for its use as a
low-carbon fuel in various applications such as power generation, road and maritime transport. The
development and deployment of ammonia as an energy vector also provides a pathway to reach the
United Nations’ (UN) Sustainable Development Goals (SDGs). The UN has instigated 17 SDGs as a
‘blueprint to achieve a better and more sustainable future for all’. The use of ammonia as a medium for
energy storage, a hydrogen carrier and a carbon-free fuel could lead to a reduction in CO2 emissions,
which forms part of SDG 13 that calls for urgent action to combat climate change and its impacts. The
use of ammonia will necessitate R&D and deployment of technologies for clean ammonia production,
transport, distribution and utilisation, as well as the building of necessary infrastructure. Widespread
ammonia utilisation also requires close collaboration between governments, research institutes and
industries, and companies from different sectors and countries, and creates new businesses and
employment in clean energy field. These activities contribute to achieving SDGs 9, 17 and 8 to ‘build
resilient infrastructure, promote inclusive and sustainable industrialisation and foster innovation’ (SDG 9),
‘strengthen the means of implementation and revitalise the global partnership for sustainable development’
(SDG 17), and ‘promote sustained, inclusive and sustainable economic growth, full and productive
employment and decent work for all’ (SDG 8).
The efforts from many parties and international organisations to raise awareness and promote
investment in the development of clean ammonia production and utilisation, have resulted in various
R&D projects and progress has been made. In particular, developments in cofiring ammonia with coal
for power generation have been made in Japan, where work is underway to demonstrate cofiring 20%
of ammonia at a 1000 MW coal-fired power unit. When fully developed and commercialised, the
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INTRODUCTION
technology could play a crucial role in decarbonising coal power generation in Asian countries and
beyond where coal power plants provide key flexibility and other system services.
This report explores the potential role of ammonia in a clean energy transition. The focus is on the use
of ammonia fuel to decarbonise heavy emitting sectors, particularly coal power generation. Chapter 2
explains the possible use of ammonia as an energy storage medium, a hydrogen carrier and as a fuel,
and its potential role in a future circular, zero emissions economy. The sustainability of ammonia
production and use, health and safety considerations and the environmental impacts of ammonia are
also discussed in Chapter 2. Chapter 3 provides an overview of ammonia production, transport,
distribution, and utilisation, as well as reviews of existing technologies for ammonia manufacture, and
the latest developments in the production of clean ammonia. Recent developments in ammonia
combustion technologies for power generation, transportation and industrial processes are reviewed
in Chapter 4. In Chapter 5, the challenges and opportunities of using ammonia as a fuel, the potential
CO2 emission reductions that can be achieved by substituting fossil fuels with ammonia for power
generation including life cycle analysis are discussed, and the impacts on electricity costs of
firing/cofiring ammonia are analysed. After some discussion, conclusions are drawn in Chapter 6.
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AMMONIA TO FUEL FUTURE CLEAN ENERGY
2
AMMONIA TO FUEL FUTURE CLEAN ENERGY
Ammonia is both a chemical energy store and a fuel, like fossil fuels. Although ammonia itself is
carbon-free, the life cycle of ammonia from feedstock extraction and processing, transport,
manufacturing to use, and waste disposal, can involve significant CO2 emissions depending on the
technologies employed for the processes within the cycle. There are various technological routes to
synthesise ammonia (see Section 3.1.1), each of which has its own carbon footprint. Depending on the
carbon footprint, the following terms are used for the ammonia produced from the different methods:
•
conventional ammonia: ammonia made using unabated fossil fuels such as natural gas and
coal as the feedstock which therefore, has a large carbon footprint;
•
low-carbon ammonia: ammonia produced using fossil fuels or biomass as the feedstock with
CCUS to reduce the carbon footprint;
•
renewable ammonia: ammonia synthesised using water and air as feedstock with the entire
process being powered by renewable energy so its production is carbon free; and
•
clean ammonia: clean ammonia includes low-carbon and renewable ammonia.
In this chapter the role ammonia could play in an energy transition and in a future circular,
zero-emission economy is discussed. Its sustainability is considered, taking into account the whole
supply chain, as well as health and safety considerations and the environmental impacts of ammonia
production and use.
2.1
AMMONIA AS AN ENERGY VECTOR
Ammonia has several characteristics that make it suitable as a potential energy storage medium. At
ambient temperature and atmospheric pressure, ammonia is a colourless, pungent gas. It can be easily
liquefied under mild conditions, either by compression to 10 times atmospheric pressure (1 MPa) or
cooled to -33°C, which are similar properties to liquefied natural gas (LNG) (Royal Society, 2020).
This means that ammonia can be stored in liquid phase in a simple, inexpensive pressure vessel, and
distributed by various means such as pipelines, railways, barges, ships, road trailers and storage depots.
Some physical and chemical properties of ammonia are shown in Table 1. Liquid ammonia has an
energy density of about 3 kWh/L, which is lower than, but comparable to, fossil fuels, as shown in
Figure 1. The combination of a relatively high energy density and easy storage and transport are
desirable characteristics for a chemical used as a medium for energy storage. If wind and solar power
could be cost-effectively converted into ammonia, then the ammonia could serve as a practical and
economic medium for storing excess or remotely generated variable renewable power. The energy
could then be sent to where it is needed and/or be stored for days, weeks, or months before being
converted back into electricity on demand.
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TABLE 1
AMMONIA PROPERTIES (THOMAS AND PARKS, 2006)
Molecular weight
17.03
Critical pressure, MPa
11.3
Boiling point, °C
-33.5
Critical temperature, °C
132.4
Melting point, °C
-78
Water solubility, vol/vol
862 (0.1 MPa at 0°C)
H2 weight fraction, wt.%
17.65
Liquid density, kg/m3
682 (0.1 MPa at boiling point)
H2 volume density, kg/L
0.105
Gas density, kg/m3
0.86 (0.1 MPa at boiling point)
Figure 1 The volumetric energy density of a range of fuels (Royal Society, 2020)
In comparison, hydrogen is also a gas at atmospheric pressure and room temperature. However, for
large-scale storage hydrogen needs to be compressed to around 35 to 70 MPa, or cryogenically cooled
to -253°C. Consequently, it is more difficult, energy-intensive and expensive to transport and store
hydrogen than ammonia, hence it can be cheaper to use ammonia for the transport and long-term
storage of hydrogen. The estimated transport costs of ammonia and hydrogen are compared in
Figure 2. Ammonia has a large weight fraction of hydrogen of 17.65 wt%. Liquid ammonia contains
50% more hydrogen by volume than liquid hydrogen does (Royal Society, 2020). In addition, ammonia
can be catalytically decomposed (or cracked) into hydrogen and nitrogen gases. These properties,
along with ease of storage and transport, make ammonia an attractive candidate as a hydrogen carrier.
Importantly, ammonia is also less flammable than hydrogen and hence, safer to handle and transport.
Its pungent smell makes early detection of an ammonia leak (even at parts per million, ppm, level)
possible, a feature not found in pure hydrogen. Furthermore, technologies for the safe handling,
transport and storage of ammonia are mature after over a century of development. Ammonia is traded
internationally and infrastructure, although modest compared to what will be required in the transition
to NZE, is already in place including regulations for its handling, storage and transport. This means
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that ammonia as an energy carrier is the most economically competitive alternative to hydrogen for
distribution, rather than a competitor.
Figure 2 Estimated costs for transport of hydrogen and ammonia by lorry, rail and ship
(Royal Society, 2020)
2.2
AMMONIA AS A CARBON-FREE FUEL
The main component of natural gas is methane (CH4), which has four C-H bonds that can be broken
to release energy. Similarly, ammonia (NH3) has three N-H bonds that can be broken to release energy.
The crucial difference is that ammonia does not contain any carbon. Combustion of NH 3 produces
H2O and N2, whilst combustion of CH4 releases CO2 and H2O. There are several power technologies
that work well with ammonia or ammonia-derived hydrogen as a fuel. Ammonia can be burnt directly
in internal combustion engines (ICE), gas turbines and coal-fired furnaces, or it can be reacted with
oxygen from the air in a fuel cell (FC) to produce electricity. For deep ocean vessels and heavy-duty
vehicles that are difficult to electrify, switching to a carbon-free fuel or using ammonia or
hydrogen-fuelled FC to drive the motor provides the best options for decarbonisation. Large marine
vessels and trains may be best positioned to use ammonia-fuelled ICE and combustion turbines
because they can accommodate heavier engines and larger fuel tanks more easily than road vehicles,
and ammonia fuelling stations can be built at ports and railway stations (Lewis, 2018). Several recent
studies on reducing the shipping sector’s GHG emissions have all identified fuel-switching to ammonia
as one of the most compelling options for limiting the sector’s contribution to global warming (Lloyd’s
Register and UMAS, 2020; ITF, 2018; ICS, 2018). Using ammonia as a fuel for ICE dates back to the
early 1900s and there was a surge in its use as an alternative fuel during World War II when stockpiles
of oil ran low (Carioscia, 2021). R&D is ongoing to develop and optimise engine and turbine designs
for burning pure ammonia and for cofiring ammonia with, for instance, petroleum fuel or natural gas
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for road and marine transport and power generation. Recent advances in FC technologies are proving
that ammonia can be a viable fuel for FC.
Cofiring a small volume of ammonia and coal has recently been successfully demonstrated in Japan at
small scale and work is underway to demonstrate ammonia-coal cofiring at a commercial coal-fired
power plant in Japan (see Section 4.2.1). Test results showed that cofiring ammonia reduced CO2
emissions at the coal power plant (Kimoto and others, 2019; Nagatani and others, 2020; Tamura and
others, 2020). Studies are being carried out to better understand the fundamentals of ammonia
oxidation or combustion. These studies and extensive R&D may open new fields of investigation,
leading to wider exploitation of ammonia as a fuel. A detailed review of recent developments in
ammonia combustion technologies can be found in Chapter 4, and the potential reduction of CO2
emissions that can be achieved by substituting fossil fuels with clean ammonia is assessed in Section 5.3.
As a carbon-free fuel, ammonia could play a part in a future energy mix and have a place in NZE
strategies. In a recent study, researchers from a Dutch consortium comprising universities, energy,
utility and industrial companies evaluated the concept of using renewable ammonia for energy storage
and power generation (ISPT, 2017). Their vision of a clean energy transition enabled by renewable
ammonia as shown in Figure 3, is a good example, illustrating the potentially important role of
ammonia in decarbonising the power sector and in a future circular net-zero economy.
Figure 3 Clean energy transition enabled by renewable ammonia (Lewis, 2018)
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2.3
SUSTAINABILITY
The choice of technology for ammonia production is most important for using ammonia as a fuel to
decarbonise the heavy emitting sectors and to achieve a net global reduction in CO2 emissions. The
production and use of renewable ammonia is environmentally sustainable because only the water and
nitrogen in the air used to synthesise ammonia will be released back into the atmosphere when the
ammonia is burnt, and the production processes are powered by renewable energy. As a result, cofiring
renewable ammonia with fossil fuel can lead to a net CO2 emissions reduction from the fuel
combustion which is proportional to the amount of fossil fuel it replaces. Technologies for renewable
ammonia synthesis exist but in their current form they are expensive and have limitations. Extensive
R&D is ongoing to advance the existing technologies and develop innovative ones. It is anticipated that
technological development and further expansion of renewable power capacities will enable the largescale production of affordable renewable ammonia in the future.
Ammonia synthesis using fossil fuels is proven and well-established technologies currently dominate
global ammonia production (see Section 3.1.1). These processes are energy-intensive and have high
carbon emissions. However, low-carbon ammonia can be manufactured from fossil fuels by combining
existing technologies with CCUS. Technologies for carbon capture are mature and ready for
commercial rollout (Global CCS Institute, 2021; Kelsall, 2020). In a recent analysis, Stocks and others
(2020) found that CO2 emissions associated with ammonia production including energy input, could
be reduced by 75%, when the ammonia was produced by steam methane reforming (SMR) using best
available technologies (BAT) with 90% carbon capture. It should be noted that the 90% capture rate is
an artificial limit based on the current economics of carbon capture. There are no technical barriers to
increasing the capture rate to higher than 99% (IEAGHG, 2019). Figure 4 compares the total GHG
emissions (including upstream emissions of CO2 and methane from fuel extraction, processing and
transport) of ammonia from fossil fuels, with and without carbon capture, and the GHG emissions
from different technologies. It is evident from Figure 4 that with the employment of all the BAT,
substantial global GHG life cycle emission reductions can be achieved through the production and
utilisation of clean ammonia.
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Figure 4 Indicative life cycle GHG emissions from different ammonia production processes
(IEA, 2021a)
2.4
HEALTH AND SAFETY ISSUES AND ENVIRONMENTAL
IMPACTS
Ammonia is a toxic gas if inhaled, an irritant to the eyes and respiratory system, and can be fatal upon
exposure to high concentrations. Contact with liquid ammonia and anhydrous ammonia can cause skin
damage. In addition, ammonia is flammable and poses a risk of fire and explosion if the concentration
of ammonia vapour in the air is within the range of 15% to 33.6% (Public Health England, 2019).
Nevertheless, as the second most-produced chemical that is traded globally, ammonia is considered a
relatively safe chemical. Extensive safety protocols and guidelines for industrial practices have been
developed over the past century of industrial use to mitigate its toxicity risk. Table 2 shows the safe
exposure limits for ammonia set in selected countries and regions.
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TABLE 2
SAFE EXPOSURE LIMITS FOR AMMONIA IN SELECTED COUNTRIES (DGUV, ND)
Limit value – eight hours
Limit value – short term
ppm
mg/m3
ppm
mg/m3
Australia
25
17
35
24
China
n/a
20
n/a
30a
EU
20
14
50a
36a
Japan
25
17
n/a
n/a
UK
25
18
35
25
USA – NIOSHb
25
18
35a
27a
USA – OSHAc
50
35
n/a
n/a
a: 15-minute average value.
b: Recommended exposure limits by the National Institute for Occupational Safety and Health (NIOSH) for hazardous
substances or conditions in the workplace.
c: Enforceable Permissible Exposure Limits set by the Occupational Safety and Health Administration (OSHA), an agency of
the US Department of Labour to protect workers against the health effects of exposure to hazardous substances.
n/a – not available.
The likely increase in emissions of unburnt ammonia, nitrogen and nitrous oxides (NOx and N2O,
by-products of ammonia combustion) can be mitigated using existing technologies. Standards for NOx
emissions control from the combustion of fossil fuels are established in many countries and can be
extended to the combustion of ammonia fuel. The impacts of ammonia utilisation on air quality and
the environment merit further investigation.
2.5
SUMMARY
Ammonia possesses certain properties that make it suitable for use as an energy storage medium, a
hydrogen carrier and as a fuel. The health and safety risks and air pollution associated with ammonia
fuel appear to be comparable to those of other more commonplace fuels such as gasoline, and similarly
manageable. Ammonia is highly flexible as an energy product and could play an important role in
addressing decarbonisation challenges across sectors and in a circular economy. With its relatively
high-energy density and existing global transport and storage infrastructure, ammonia could form the
basis of an integrated energy storage and distribution solution, and a low-carbon energy source for
power generation, transport and industrial processes.
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AMMONIA VALUE CHAIN
3
AMMONIA VALUE CHAIN
This chapter provides an overview of the ammonia value chain from production and supply, transport
and distribution to utilisation. Existing technologies for ammonia production from fossil fuels and
water electrolysis are described. The latest developments in clean ammonia production are reviewed.
3.1
PRODUCTION
3.1.1
Technologies
For over a century, commercial ammonia production has been predominantly based on the
Haber-Bosch process to catalytically synthesise nitrogen and hydrogen under pressures of 10–25 MPa
and temperatures of 400–500°C (IEAGHG, 2017). The nitrogen is obtained from compressed air or
an air separation unit. The hydrogen may be obtained by SMR of natural gas and gasification (partial
oxidation) of coal or heavy fuel oil. The modern ammonia manufacturing process is highly integrated
comprising two main functional steps: hydrogen production and ammonia synthesis. Natural gas is
typically used as the feedstock for producing hydrogen, accounting for approximately 70% of global
ammonia production (Brightling, 2018). The remainder is made up mainly of coal (essentially in
China) and heavy fuel oil. Other materials such as petroleum coke and biomass can also be used as
feedstock for ammonia manufacture via the gasification route.
Natural gas SMR-based Haber-Bosch process. Figure 5 shows a simplified schematic overview of the
natural gas-based SMR plus Haber-Bosch process for ammonia production.
Figure 5 A simplified schematic of the natural gas SMR-based Haber-Bosch process
In a natural gas-fed ammonia production process, the gas stream first goes through a desulphurisation
unit to remove any sulphur compounds present which are poisonous to most of the catalysts used
downstream. The gas stream then enters SMR vessels in which CH4 is decomposed and reformed into
H2 and CO (carbon monoxide) using pressure and high-temperature steam. Next, a water-gas shift
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process converts the CO into CO2, which accounts for about two-thirds of the total CO2 produced
during the SMR process (Lewis, 2018). This process CO2 is separated and removed from the gas stream,
ready to be compressed, transported and stored relatively inexpensively. The H2 produced, along with
N2 in a H2:N2 ratio of 3:1, is sent to the Haber-Bosch reactor for NH3 synthesis. The remaining CO2
emissions associated with SMR occur when natural gas is burnt to generate heat and steam required
by the process. If this CO2 (about one-third of the total) is also subject to carbon capture and storage
(CCS), the hydrogen and the subsequent ammonia produced are low-carbon hydrogen and low-carbon
ammonia.
Figure 6 A simplified schematic of coal gasification-based Haber-Bosch process
Coal gasification-based Haber-Bosch process. A simplified gasification-based Haber-Bosch process for
coal-fed ammonia production is shown in Figure 6. In a coal-based ammonia production process, coal
is prepared and then enters a gasifier in which it is partially oxidised in the presence of H2O to generate
a syngas of mainly CO and H2. After removal of particulates, sulphur and other impurities, the syngas
is upgraded by converting the CO to CO2 and more H2 using the water-gas shift reaction. Similar to the
SMR process, the CO2 is separated and removed from the system as a stream of pure CO2 ready for
utilisation or sequestration. The H2 generated is sent to a Haber-Bosch reactor for NH3 synthesis. As
in the gas-fed ammonia synthesis process, low-carbon hydrogen and low-carbon ammonia can be
produced from coal by combining the gasification process with CCUS.
There are various SMR and gasification technologies, process configurations and designs for ammonia
production from gas or coal as a feedstock with varying energy efficiencies (Pattabathula and
Richardson, 2016; Brightling, 2018). Detailed descriptions of low-carbon hydrogen production using
combined coal gasification and CCUS technologies can be found in a recent ICSC study by Kelsall
(2021). Overall, conventional ammonia production processes are energy-intensive and have high
emissions of CO2 if carried out without CCUS. In particular, hydrogen generation, the first stage in the
ammonia production process, has a high energy demand. Two-thirds of the energy consumption and
around 90% of the CO2 emissions from the total process result from the hydrogen production step.
The type of feedstock used also has significant impacts on energy consumption (and cost) and CO2
emissions from the hydrogen and ammonia production process. Table 3 compares the energy
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consumption and carbon footprint of BAT for different fossil fuel-based ammonia production
processes and feedstocks. The natural gas SMR-based Haber-Bosch process is considered the best
choice of technology from the viewpoint of energy use and CO2 emissions.
TABLE 3
COMPARATIVE ENERGY CONSUMPTION AND CARBON FOOTPRINT OF DIFFERENT AMMONIA
PRODUCTION PROCESSES AND FEEDSTOCKS (BRIGHTLING, 2018)
Feedstock
Process
Energy, GJ/tNH3
CO2 emissions, tCO2/tNH3
Natural gas
SMR
28
1.6
Naphtha
SMR
35
2.5
Heavy fuel oil
Gasification
38
3.0
Coal
Gasification
42
3.8
Electrolysis-based Haber-Bosch process. More recently, different technological pathways are being
explored for renewable hydrogen and renewable ammonia production. The best known is electrolysis
which uses electricity to split water into hydrogen and oxygen. Water electrolysis for hydrogen
production is a mature technology but is yet to be widely adopted as it is not competitive with fossil
fuel-based technologies. At present, there are three main electrolyser technologies: alkaline
electrolysis, polymer electrolyte membrane (PEM) electrolysis, and solid oxide electrolysis cells
(SOEC). Alkaline electrolysers are the most mature technology; several alkaline electrolysers with a
capacity of up to 165 MWe have been built in the past and powered by large hydropower resources
(IEA, 2019). PEM is also a mature technology and is becoming the preferred choice as several
small-scale PEM electrolysers have been built recently (Zhu, 2021). PEM electrolysers operate at high
pressure and have some advantages over alkaline electrolysers such as a faster response to a variable
power load, the production of compressed hydrogen with higher purity and a smaller footprint.
However, PEM electrolysers have lower efficiency and higher cost than alkaline electrolysers.
SOEC are still under development. SOEC operate at high temperatures of up to 1000°C and use steam
for electrolysis. The waste heat from ammonia synthesis processes can be recovered to produce steam
for SOEC to improve the overall system efficiency. SOEC has the potential to become a lower-cost and
high-efficiency electrolysis technology with electrical energy efficiency of 90% being achievable. The
three electrolysis technologies are compared in Table 4. When renewable energy such as solar and
wind power is used to drive water electrolysis there are no CO2 emissions from the hydrogen
generation process. Other processes such as nitrogen generation and ammonia synthesis can be
powered entirely by electricity. Consequently, renewable ammonia can be synthesised using a system
running on water, air and renewable energy.
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TABLE 4
COMPARISON OF THE WATER ELECTROLYSIS TECHNOLOGIES (MODIFIED FROM ZHU, 2021)
Alkaline
PEM
SOEC
Operating temperature, °C
63–70
50–80
650–1000
Operating pressure, MPa
0.1–3
3–8
0.1
Electrical efficiency, %
63–70
56–60
74–81
Load range, %
10–110
0–160
20–100
Hydrogen purity, %
99.9–99.9998
99.9–99.9999
99.9
Plant footprint, m2/kW
0.095
0.048
Not available
Capital costs (stack)
minimum 1 MW ($/kW)
270
400
>2000
Electrolysis, however, is more energy-intensive and has a lower overall efficiency than fossil
fuel-based ammonia production processes. The average energy consumption for electrolysis is
between 52.5–70.1 kWh/kgH2, compared to 45.8–50 kWh/kgH2 for SMR (Patonia and Poudineh,
2020). In all-electric ammonia plants, electrolysers account for over 90% of the electricity
consumption (IEA, 2017). Also, electrolysers have high costs representing about 67% of the total
capital expenditure for an all-electric ammonia plant, although the recent cost evolution of alkaline
electrolysers has brought this ratio closer to half. The high energy consumption, low production
efficiency and expensive electrolysers lead to higher costs per tonne of ammonia produced via water
electrolysis than those of ammonia synthesised using conventional fossil fuel-fed processes.
Extensive research is underway to develop alternative ammonia synthesis pathways to SMR and
electrolysis such as electrochemical, photocatalytic, plasma catalytic and homogeneous molecular
catalytic ammonia synthesis. The focus of the investigation is on converting water and nitrogen
directly into ammonia, thereby avoiding the intermediate step of hydrogen production, which could
potentially reduce energy use substantially. These technologies are in an early stage of development.
For interested readers, recent reviews of the latest development of the technologies are available
(Hasan and others, 2021; Li and others, 2020).
3.1.2
Production and supply
Ammonia is the second most-produced chemical in the world. In 2019, a total of 183 million tonnes
(Mt) of ammonia was manufactured worldwide (IFASTAT, 2021). China, Russia, the USA and India
are the top four producing countries, accounting for more than half of global ammonia production.
Table 5 shows the regional and global production, trade and consumption of ammonia in 2019.
Ammonia supplies are widely available as ammonia plants are broadly distributed across the world, as
shown in Figure 7. Nearly 90% of ammonia was produced and consumed locally while 10% of
production, or around 20 Mt, was traded globally.
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Almost all ammonia is produced from fossil fuels with natural gas SMR accounting for 72% of global
ammonia production (IEA, 2021a). Approximately 26% of ammonia is manufactured from coal
gasification, about 1% from oil products and less than 1% from electrolysis. The use of coal and fuel oil
for ammonia production is largely restricted to China. China dominates ammonia production,
accounting for 30% of the global total in 2019. Around 80% of ammonia plants in China are coal
gasification-based which accounts for 95% of global coal-fed ammonia production capacity (Brightling,
2018). In some plants, a fraction (up to 40%) of the CO2 produced is captured and used in combination
with ammonia to manufacture urea, a nitrogen fertiliser (IEA, 2017). In general, current ammonia
production is unabated and responsible for about 420 MtCO2/y emissions, which is more than 1% of
global energy-related CO2 emissions.
TABLE 5
REGIONAL AND GLOBAL PRODUCTION, TRADE AND CONSUMPTION OF AMMONIA, 2019 (IFASTAT, 2021)
Region
Production, kt
Import, kt
Export, kt
Consumption, kt
Western Europe
10,934
4,434
1,305
14,063
Central Europe
4,868
696
238
5,325
Eastern Europe & Central
Asia
25,666
804
4,696
21,773
North America
21,182
2,495
1,387
22,291
Latin America
7,104
1,571
4,552
4,123
Africa
9,546
1,917
1,901
9,563
West Asia
17,242
1,340
2,994
15,589
South Asia
19,607
2,785
53
22,339
East Asia
64,742
3,457
2,148
66,052
Oceania
1,965
63
301
1,725
0
14
0
14
182,855
19,574
19,574
182,855
Other regions
World total
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Figure 7 Ammonia production capacity map (Hatfield, 2020)
TABLE 6
RENEWABLE AMMONIA PROJECTS (MODIFIED FROM AYVALI AND OTHERS, 2021; TULLO, 2021;
BIOENERGY, 2021)
Capacity,
t/y
Energy
source
Start
year
Porsgrunn,
Norway
~5,000
Hydroelectric
grid
2022
The first small step towards
carbon-free fertiliser production by
installing 5 MW electrolyser
corresponding to 1% of the
hydrogen production in Porsgrunn
Yara
Porsgrunn,
Norway
500,000
Hydroelectric
grid
2026
Yara wants to sell the ammonia as
a fuel for ships and is seeking
incentives from the Norwegian
government before it moves
forward
Haldor Topsøe
Foulum,
Denmark
300
Wind
2025
Demonstration of direct ammonia
production from water and air
using solid oxide fuel cells (SOFC)
without air separation unit
Air Products,
ACWA Power,
Thyssenkrupp,
Haldor Topsøe,
NEOM
Red Sea
coast, Saudi
Arabia
1.2 Mt/y
Wind, solar
2025
Production of renewable ammonia
at oil and gas scale and distribute
it globally, crack it back to
‘carbon-free hydrogen’ at the point
of use, supplying hydrogen
refuelling stations
OCP Group
Jorf Lasfar,
Morocco
700
Solar
TBD
Fertiliser production and supply as
fuel to marine vessels
Enaex
Antofagasta,
Chile
20,000 and
350,000
Solar
TBD
Feasibility study. Pilot plant has
capacity of 64 MW solar power
and 47 MW electrolyser, full-scale
plant has 1030 MW solar power
and 778 MW electrolyser
Developers
Location
Yara
Notes
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TABLE 6 – CONTINUED
Capacity,
t/y
Energy
source
Start
year
GoereeOverflakkee,
The
Netherlands
20,000
Wind, tidal
TBD
Part of regional renewable
hydrogen economy roadmap
Siemens Gamesa,
Energifonden
Skive
Skive,
Denmark
TBD
Wind
TBD
Ammonia production as a way to
store surplus electricity from wind
turbines
Ballance AgriNutrients,
Hiringa Energy
Kapuni, New
Zealand
~5,000
Wind
TBD
The $50 million showcase project
as a catalyst for the development
of a sustainable renewable
hydrogen market
Queensland
Nitrates,
Incitec Pivot,
Wesfarmers JV,
Neoen, Worley
Moura,
Australia
20,000
Solar
TBD
Determining the technical and
economic feasibility of producing
renewable ammonia at a
commercial scale
Dyno Nobel
Moranbah,
Australia
60,000
Solar
TBD
Feasibility study to decarbonise
their nitrogen-based commodity
production facility
Yara
Pilbara,
Australia
25,000
Solar
TBD
Feasibility study for carbon-free
fertiliser production
H2U,
Thyssenkrupp
Port Lincoln,
Australia
20,000
Wind, solar
TBD
Business case demonstration for
renewable energy exports
(Hydrogen Hubs)
ACME Group
Duqm,
Oman
~900,000
Wind, solar
2022
India’s ACME Group signed a
land agreement with the Oman
Government in 2021 to set up the
project in the Special Economic
Zones at Duqm Port in Oman. The
plant will be an integrated facility
using 3 GW of solar and 0.5 GW
of wind energy to produce
2400 t/d of renewable ammonia
for export. ACME will be
conducting field studies of the
project in the first phase. The first
facility is likely to be
commissioned by the end of 2022
Developers
Location
Proton Ventures,
Siemens, Yara
Notes
TBD ─ to be determined
The pressing need to decarbonise the energy sector and industrial processes to combat climate change
and to meet governments’ and/or companies’ CO2 reduction targets are driving many companies to
invest in clean ammonia production. In September 2020, Saudi Aramco and the Institute of Energy
Economics of Japan (IEEJ), in partnership with Saudi Basic Industries Corporation (SABIC, Aramco’s
ammonia and methanol producing subsidiary), successfully demonstrated the production and
shipment of the world’s first cargo of 40 tonnes of low-carbon ammonia from Saudi Arabia to Japan
for use in power generation (Aramco, 2020). The ammonia was produced using SMR and the
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Haber-Bosch process combined with CCUS. Thirty tonnes of the process CO2 were supplied to a
nearby methanol plant, and 20 tCO2 were captured for EOR at Aramco’s Uthmaniyah field (TGS, nd).
Aramco also plans to expand and intensify cooperation with China in the R&D of low-carbon hydrogen
and ammonia production (Ratcliffe, 2021). In October 2021, Japan’s Mitsui & Co announced a plan to
invest more than 100 billion yen ($899 million) in building a low-carbon ammonia production plant
in Western Australia with a capacity of 1 Mt/y (Nikkei Asia, 2021). CO2 generated during ammonia
production will be stored in a nearby waste gas field. A similar project is under development in Canada.
In November 2021, Abu Dhabi National Oil Company (ADNOC) and holding company ADQ signed an
agreement with Japan’s Mitsui & Co and South Korea’s GS Energy to develop a low-carbon ammonia
project in partnership with Ta’ziz and Fertiglobe (Gnana, 2021). The plant will have an ammonia
production capacity of 1 Mt/y and will be located in the UAE’s downstream hub in Ruwais.
Various renewable ammonia projects are also in development. Table 6 lists some of the projects that
have been announced worldwide. The Norwegian fertiliser giant Yara recently announced its intention
to change the source of hydrogen for its ammonia plant in Porsgrunn, Norway, from hydrocarbons to
water electrolysis powered by renewable energy (Tullo, 2020, 2021). The primary use of the ammonia
will be as fuel rather than as fertiliser, if the project is completed as planned in 2026. The conversion
of the plant, which has a 500 ktNH3/y capacity, would reduce CO2 emissions by 800 kt/y. Yara has
also announced several pilot projects, including (Grabowiec and others, 2021):
•
70 kt/y of renewable ammonia production at its Sluiskil plant in the Netherlands, using offshore
wind to produce hydrogen. The project is at the feasibility study stage;
•
20 kt/y of renewable ammonia production capacity at the Porsgrunn plant in Norway.
Electrolysers with 5 MWe power input will be installed in collaboration with NEL Hydrogen, and
an electrolysis plant with 20 MWe input is under tender; and
•
a 3.5 kt/y renewable ammonia production facility at the Pilbara plant in Australia using solar
power, in collaboration with France-based Engie. Both projects are at the concept design stage.
Similarly, Dutch chemicals producer OCI N.V. has announced several projects to enable the
production of clean ammonia and methanol, including a pilot renewable ammonia project in Egypt that
is currently (2021) at the feasibility study stage. OCI is also teaming up with German energy company
RWE to produce renewable hydrogen using electrolysers directly linked to RWE’s wind farms to
reduce the intake of natural gas at some of its ammonia plants (Grabowiec and others, 2021). In
Australia, the ammonium nitrate producers Dyno Nobel and Queensland Nitrates are looking into
building facilities with 9 kt/y and 20 kt/y of renewable ammonia output, respectively. Pilot projects
are also underway in New Zealand and Chile (Tullo, 2021). In the USA, CF Industries has announced
that it will spend $100 million to install electrolysers with 20 ktNH3/y capacity at its Donaldsonville
Nitrogen Complex, Louisiana. The company is also planning CCUS projects to convert about one-third
of its ammonia output to low-carbon ammonia.
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Saudi Arabia has the largest project at $5 billion, developed in partnership with the US company Air
Products and Chemicals, a local company ACWA Power, and NEOM. Scheduled for completion in
2025, the plant will be located at the Red Sea coast and powered by 4 GWe solar and wind power
plants. The hydrogen will be fed into a traditional Haber-Bosch plant to produce 1.2 Mt/y of renewable
ammonia (Energy & Utilities, 2021; Tullo, 2021). This ammonia will be distributed globally to provide
carbon-free fuel at the point of use.
3.2
TRANSPORT AND DISTRIBUTION SYSTEM S
After more than a century of widespread use as a feedstock for fertilisers and continuous development,
technologies for the safe handling, transport and storage of ammonia are mature. Global trading of
ammonia means that international shipping routes are well established and there is a network of
around 120 ports equipped with ammonia terminals (Tullo, 2021; Royal Society, 2020). Figure 8 shows
the global ammonia shipping infrastructure including a heat map of liquid ammonia carriers and
existing ammonia port facilities. This infrastructure could enable the quick start of ammonia fuel use
and if developed further it could facilitate adoption of large-scale transport of ammonia as an energy
vector and fuel.
Figure 8 Global ammonia shipping infrastructure (Royal Society, 2020)
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Figure 9 Ammonia pipeline distribution networks in the USA (Soloveichik, 2021)
In the USA, there are over 10,000 ammonia storage sites. Ammonia is transported by road, rail, river
and pipeline. There are approximately 4950 kilometres of ammonia pipeline (see Figure 9) which are
proven to operate safely and cost-effectively (Royal Society, 2020; IEA, 2021a). These pipelines
connect 11 states and carry around 2 Mt/y ammonia from production sites to terminals serving
distributors and end-users (primarily farmers).
3.3
UTILISATION
3.3.1
Fertiliser and chemicals
Ammonia can serve a variety of end-uses in many sectors. Its key role has been as a feedstock for
fertilisers. Today, around 80% of the ammonia produced is used as fertiliser that supports food
production for around half of the world’s population (Quick, 2021). In addition, ammonia is an
efficient refrigerant that has been used extensively since the 1930s in industrial cold stores, food
processing industry applications and increasingly in large-scale air-conditioning (Royal Society, 2020).
Ammonia is also used in the pharmaceutical, textile and explosives industries, and as a reagent or key
component for NOx emissions control from power plants and vehicles.
3.3.2 Energy and hydrogen carrier
Recently, increasing attention has been turned to the use of ammonia as an energy and hydrogen
carrier. Ammonia can provide flexible, long-term energy storage at large scale. For example, ammonia
can be produced using excess renewable power and stored for use as a fuel to cover seasonal demands
such as heating buildings in the winter. Therefore, it can be an effective energy carrier for nascent
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regional and international sustainable energy supply chains to strengthen the economic opportunities
for the maximal adoption of renewable energy.
3.3.3 Fuel
Ammonia is itself a carbon-free fuel. A suite of technologies used in the transport, power and industrial
sector such as ICE, boilers, gas turbines and fuel cells can convert ammonia into energy. Table 7 shows
the possible applications and technologies for using ammonia as a fuel in various sectors.
TABLE 7
POSSIBLE APPLICATIONS OF AMMONIA AS A FUEL IN THE TRANSPORT, POWER AND INDUSTRIAL
SECTORS (MODIFIED FROM LEWIS, 2018)
Energy end-use
Ammonia conversion technology
Heavy-duty transport
On/off road
ICE and possibly direct ammonia fuel cells
Rail
ICE and possibly direct ammonia fuel cells
Marine
ICE and possibly ammonia fuel cells
Light duty transport
Automobiles
ICE and possibly direct ammonia fuel cells
Power generation
Centralised power generation
Combustion turbines, boilers
Distributed power generation
ICE
Variable renewable energy complements for grid
balancing
ICE
Industrial process heat
Electric/steam/gaseous heat
Boilers and industrial furnaces
Recent developments in utilising ammonia as a fuel are reviewed in Chapter 4.
3.4
SUMMARY
There are three main technological routes for ammonia production: steam methane reforming (SMR),
coal gasification, and water electrolysis. Commercial processes for manufacturing ammonia via these
three routes are well established. However, the water electrolysis route is a nascent commercial
activity as it is currently not competitive with the other two routes. While today’s ammonia
production is predominantly fossil fuel-based using the Haber-Bosch process and is generally unabated,
carbon capture technologies are ready for commercial rollout to produce low-carbon ammonia. When
renewable power is used to drive the water electrolysis and ammonia synthesis process, renewable
ammonia can be produced with no CO2 being formed and/or released during the processes.
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Ammonia has been produced by the fertiliser industry for over a century. It has also found application
in many sectors such as the pharmaceutical, textile and explosives industries. Ammonia is a
well-established sector with production, transport and distribution infrastructure in existence
worldwide. There is increased awareness of the potential role of ammonia as an energy and hydrogen
carrier and as a fuel in a clean energy transition, together with growing interest in ammonia utilisation.
As a result, initiatives are underway in several countries by energy and utility companies, industries,
and governments to promote R&D and deployment of clean ammonia production, and to develop the
ammonia value chain and market.
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4
AMMONIA AS A FUEL
This chapter provides a detailed review of the latest progress in R&D and the deployment of ammonia
as a fuel in power generation, transport, and industrial processes. Fundamental studies have been
carried out to better understand the mechanisms of ammonia combustion, and the combustion
characteristics of ammonia cofired with other fuels such as hydrogen, natural gas, and coal. Small-scale
experiments of ammonia combustion have been conducted by researchers worldwide and commercial
ammonia firing and cofiring technologies are being developed based on this work, which is discussed
briefly in the next section.
4.1
FUNDAMENTAL STUDIES ON AMMONIA COMBUSTION AND
LABORATORY SCALE R&D
Using ammonia as a fuel has drawbacks compared to common hydrocarbon fuels. Table 8 shows some
of the major differences in thermal properties and combustion characteristics of ammonia compared
to hydrogen and some common hydrocarbon fuels. Due to its relatively low energy content and
reactivity, the heat of ammonia combustion and the velocity of an ammonia/air flame are much lower
than those of typical hydrocarbon fuels. Also, ammonia has low flammability as indicated by its narrow
flammability limit, higher ignition energy and ignition temperature. Ammonia/air flame temperature
and the radiation heat transfer rate from the flame are also lower than those of hydrocarbon flames
because of the absence of CO2 in the products. Furthermore, ammonia has a high heat of vaporisation,
which results in a significant temperature drop when it is evaporated from liquid to gas leading to
problems such as lowering of the in-cylinder temperature and possible freezing of injection nozzles.
Another problem of ammonia combustion is the corrosion of materials used in the existing engines
and turbines such as copper, aluminium, zinc, and magnesium alloys. An additional challenge of
ammonia combustion relates to the high fuel NOx emissions although this problem can be solved with
a modified selective catalytic NOx reduction (SCR) catalyst (Kobayashi and others, 2019;
Klüssmannand others, 2020). Consequently, challenges will arise when using ammonia in existing
combustion systems that are designed to burn fuels such as gasoline, natural gas, and coal.
Studies have been conducted to improve understanding of the mechanisms of ammonia combustion,
and the combustion characteristics of NH3-H2, NH3-CH4 and NH3-coal mixture. For interested readers,
there are several recent reviews of the fundamental studies of ammonia combustion available
(Kobayashi and others, 2019; Erdemir and Dincer, 2020; Lee and Lee, 2021; Valera-Medina and others,
2021).
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TABLE 8
COMPARISON OF FUEL PROPERTIES (MODIFIED FROM KOBAYASHI AND OTHERS, 2019; KLÜSSMANN
AND OTHERS, 2020; ERDEMIR AND DINCER, 2021)
Gasoline
Diesel
Natural gas
(CH4)
Hydrogen
Ammonia
Lower heating value,
MJ/kg
44.5
43.5
50.0
120.0
18.6
Flash point, °C
-42.7
73.8
-184.4
n/a
-33.4
Flammability limits, vol%
0.6–8
0.43–0.87
5–15
4–75
15–28
Minimum auto-ignition
temperature, °C
300
177–329
537
530
650
Minimum autoignition
energy, MJ
0.14
0.23
n/a
0.016
8
Flame velocity, m/s
0.58
0.8–0.87
8.45
3.5
0.07
Latent heat of
vaporisation, kJ/kg
71.78
47.86
104.8
n/a
1369
n/a –not available
A research team at Cardiff University (UK) has been investigating the use of ammonia as a hydrogen
carrier and as a fuel for direct combustion in gas turbines for power generation (Valera-Medina and
others, 2017, 2019; Bozo and others, 2019). Cocombustion of ammonia and hydrogen or ammonia and
methane was tested using a gas turbine model combustor with swirl burners. The hydrogen was
generated in a precombustion ammonia cracker. The researchers demonstrated that stable combustion
could be obtained when burning a fuel blend of NH3-H2 at a ratio of 70:30 (vol.%) under swirling
conditions. They also showed that the injection of steam into a cocombustion gas turbine reduced NOx
emissions.
In cooperation with the National Institute of Advanced Industrial Science and Technology, Japan
(AIST), Professor Hideaki Kobayashi at Tohoku University in Japan developed the world’s first
technology for the direct combustion of ammonia in a gas turbine (Iki and others, 2016; Okafor and
others, 2019; 2021; Ito and others, 2020). The combustion and power generation system with a power
output of 50 kW was developed by remodelling the combustor of Toyota’s micro gas turbine. In
September 2015, 41.8 kW power output was reached using a mixture of methane and ammonia, and
subsequently, the same output power was generated with 100% ammonia. Although the continuing
R&D has focused on NOx emissions control, their latest published work reported the development of
a system for burning liquid ammonia by spraying it directly into a combustor (Okafor and others,
2021).
Also in Japan, under the Cross-Ministerial Strategic Innovation Promotion Program (SIP) Energy
Carrier initiative, a team at Osaka University carried out a detailed study on the combustion behaviour
of pulverised coal and ammonia during cofiring in a laminar counter-current burner (Fukui and others,
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2016). Researchers at Hokkaido University investigated the combustion characteristics of ammonia
during coal-ammonia cofiring under turbulent flow conditions (Xia and others, 2021; Hadi and others,
2021). Engineers at IHI Corporation tested ammonia combustion using a bench-scale 1.2 MWth
pulverised coal furnace (Tamura and others 2020). The results showed that ammonia can be burnt in
a coal-firing furnace; with proper design, low NOx emissions from pure ammonia combustion in a coal
furnace can be achieved; and NOx emissions from both ammonia-coal cofiring and pure ammonia
firing can be controlled by air staging. A Japanese coal combustion research institute, the Central
Research Institute of Electric Power Industry (CRIEPI), performed coal-ammonia cofiring tests with
an ammonia ratio of up to 20% using both single and multi-burner furnaces (Kimoto and others, 2019).
The test results showed that by adjusting the injection point and feed rate of ammonia into the furnaces,
NOx emissions could be contained and controlled, and although N2O might be formed in the
combustion process, none was detected in the exhaust gas.
Experimental work on ammonia combustion in gas turbines and cofiring ammonia with coal in
coal-fired boilers has also been conducted at the Korea Institute of Energy Research (Lee and Lee,
2021). An experimental rig with a 5 kWth (kilowatt thermal) capacity, which is designed as a model
of a gas turbine combustor, is used to test cofiring of ammonia with bituminous coal with a ratio of
10–50% ammonia. Ammonia-coal cocombustion flames were observed in the study and reported. The
study showed that coal particles burnt well in an ammonia flame, which has a relatively low flame
temperature. The ammonia-coal cofiring produced a longer flame compared to the combustion of
ammonia alone, as shown in Figure 10. This is attributed to the longer time required for volatile matter
and coal char combustion. In future work, the researchers plan to build an experimental device with
coal-fired burners and to investigate the effects of burner type, coal type and coal particle size on
ammonia-coal cofiring.
Figure 10 Flame observation: a) ammonia-air combustion; b) ammonia-coal-air combustion
(Lee and Lee, 2021)
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4.2
POWER GENERATION
4.2.1 Cofiring ammonia with coal in boilers
Based on the outcomes of the studies by Japanese researchers described in Section 4.1, the Chugoku
Electric Power Company of Japan conducted demonstration tests of coal-ammonia cofiring at the
156 MWe Unit 2 of its commercial coal-fired Mizushima Thermal Power Station (Yoshizaki, 2019;
Kimoto and others, 2019). The test results showed that the ammonia was completely burnt with no
ammonia being detected outside the plant. NOx emissions were not significantly different from those
of 100% coal-firing, and the Japanese environmental standards were met. Although the ratio of
ammonia was only 0.6 to 0.8 wt% due to the limited capacity of the ammonia vapouriser, the most
significant achievement of the demonstration was the confirmation that the coal-ammonia cofiring
technology can be applied to coal-fired power plants in commercial operations as a measure to reduce
CO2 emissions. Following this demonstration, IHI developed a coal-ammonia cofiring burner
(see Figure 11) that can be attached to an existing coal-fired boiler and can minimise incremental NOx
emissions (Nagatani and others, 2020; Ito and others, 2019). After installing its cofiring burners, IHI
analysed the changes in heat transfer characteristics in the boiler when an ammonia-coal mixture is
burnt. This study was carried out as there was a concern that the heat distribution on the furnace wall
inside a boiler may change as the ammonia flame temperature is lower, and cofiring with ammonia
reduces the amount of burning soot and coal particles in the furnace which produces radiative heat.
Earlier studies found that the ammonia/coal ratio and injection methods are two important parameters
to consider in ammonia cofiring. With a 60% ammonia cofiring ratio, the radiative component of heat
transfer was observed to decrease significantly, although total heat transfer to the walls was lowered
by only 3% (Valera-Medina and others, 2021). Also, the nitrogen contained in ammonia could lead to
increased NOx emissions. The test results showed that NOx emissions could be reduced to the level
that occurs with 100% coal combustion, and the heat collection performance of the boiler did not
change significantly. At a 20% ammonia/coal cofiring ratio, CO2 emissions decreased by 20%. In
addition, an evaluation based on these test results concluded that cofiring ammonia with coal is a
low-cost CO2 reduction technology as it does not require major system modifications including NOx
control equipment, and therefore, maximises the use of existing coal-fired power generation facilities
(Sakoya, 2018).
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Figure 11 Ammonia-coal cofiring burner developed by IHI Corporation (Ito and others, 2019)
Japan’s JERA Co and IHI are working together on a demonstration project to cofire 20% ammonia at
the large, commercial coal-fired Hekinan Thermal Power Station. The project will run for
approximately four years from June 2021 to March 2025. Ammonia cofiring tests at a lower ratio began
in October 2021 at the 1000 MWe Unit 5 of the Hekinan plant to develop cofiring burners for use in
later, higher ratio ammonia cofiring tests at the 1000 MWe Unit 4 (JERA, 2021a,b). During the tests,
two of the 48 coal burners at Unit 5 will be replaced with test burners to examine the effects of
different burner materials and combustion times to identify the optimal conditions for cofiring burners.
The approximate 200 tonnes of ammonia required for the tests will be supplied to the test burners
from the liquid ammonia tanks on the power station site. JERA and IHI will progress through the steps
of the demonstration project to achieve an ammonia cofiring rate of 20% at Hekinan Unit 4 in 2023, a
year earlier than originally planned (Kumagai, 2022). Figure 12 outlines the boiler retrofit concept for
Hekinan Unit 4.
Figure 12 Boiler retrofit concept for Unit 4 of Hekinan power plant, Japan (JERA, 2021b)
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In a parallel eight-year project started in January 2022 and founded by the New Energy and Industrial
Technology Development Organization (NEDO) under the Green Innovation Fund programme, JERA
has teamed up with Japan’s Mitsubishi Heavy Industries Group (MHI) to develop and demonstrate
dedicated ammonia burners that can increase the ammonia cofiring rate to 50% or more for coal boilers
manufactured by MHI (JERA and MHI, 2022). The project aims to develop an ammonia single-fuel
burner suitable for coal-fired boilers by 2024 and to demonstrate the operation of the burner at actual
coal boilers. By 2028, the developers aim to verify cofiring with at least 50% ammonia at two units
with different types of boilers.
China Energy Investment Corporation has recently demonstrated cofiring 35% ammonia with coal at
a 40 MW coal power unit (Xie, 2022). NOx emissions were reportedly lower than burning pure coal,
and only 0.01% of ammonia fuel was left unburnt.
4.2.2 Cofiring ammonia in combustion turbines
Existing gas turbine systems can be used with minor modifications to burn other fuels including
ammonia (Nose and others, 2021; IEA, 2021a). Such systems can either combust hydrogen derived
from ammonia, blends of ammonia and hydrogen or methane or 100% ammonia directly. The
modifications required are mainly adjustments of the gas turbine combustion components and fuel
supply systems. The ammonia-fuelled combustion turbine technology has a lower technology
readiness level compared to the hydrogen cofiring turbine technology. Using ammonia as fuel benefits
from the easier storage of ammonia than hydrogen, but it poses additional technical challenges due to
its toxic and corrosive nature. Technology is also being developed to supply liquid ammonia directly
to the gas turbine without vapourisation, which would reduce costs and increase efficiency. Cracking
part of the ammonia back to hydrogen, and combusting the unseparated mixture of ammonia,
hydrogen and nitrogen would be one way to achieve combustion characteristics more similar to
hydrocarbon fuels.
IHI has been developing a low emission combustor for ammonia-natural gas cofiring (Ito and others,
2020, IHI, 2021). Based on the technology developed at Tohoku University and AIST to spray liquid
ammonia directly into combustors, and IHI’s expertise in aero engine development, IHI successfully
tested cofiring up to 20% (based on heat input) of ammonia with natural gas using a 2 MW-class gas
turbine at IHI Yokohama Works. Stable operation was achieved during the tests with improved overall
thermal efficiency compared to natural gas firing. NOx emissions at the turbine outlet increased as a
result of ammonia cofiring. However, a SCR unit could reduce NOx emissions to around 6 ppm or
lower, a level that can meet the most stringent emission standards in the world. The ammonia cofiring
ratio was later increased to 70%, and 100% ammonia-firing using this technology was also achieved in
some of the tests (IHI, 2021). In June 2021, General Electric (GE) and IHI signed a Memorandum of
Understanding (MoU) for the collaborative development of an ammonia gas turbine business roadmap
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(GE, 2021). The ammonia roadmap will support the use of ammonia as a carbon-free fuel to lower
carbon emissions from both existing and new gas-fired power plants in Japan and across Asia.
Recently, Mitsubishi Power, a subsidiary of MHI, has begun to develop a 40 MW-class gas turbine
system for small- to medium-scale power plants that will use 100% ammonia as a fuel for power
generation (Nose and others, 2021). Again, the main challenge is the increase in NOx emissions.
Mitsubishi Power is trying to resolve the problem using a gas turbine system that combines a SCR unit
with a new low-NOx ammonia combustor. This is being applied to the H-25 series gas turbines with a
40 MW power output, which the developers aim to commercialise in, or around, 2025.
Figure 13 An ammonia-fuelled NGCC power plant concept evaluated by Mitsubishi Power
(Nose and others, 2021)
Mitsubishi Power is also working on the combustion of ammonia in large-frame gas turbines used in
natural gas combined cycle (NGCC) power plants (Nose and others, 2021). Unlike small- and
medium-sized systems, large-frame gas turbines have more restrictions on the expansion of the
combustor size, which is required for the complete combustion of ammonia, and it is more difficult to
control NOx emissions due to the high combustion temperature. Mitsubishi Power is investigating the
use of waste heat from gas turbines in NGCC systems to decompose ammonia into hydrogen and
nitrogen as shown in Figure 13. Cofiring of natural gas and ammonia decomposition gas comprising
20 vol% of hydrogen, 6.7 vol% of nitrogen, 73.3 vol% of natural gas and a trace amount of ammonia
was tested at a turbine inlet temperature of 1650°C. Results showed that stable combustion could be
attained, and NOx formation increased with increasing ammonia concentration in the fuel gas mixture.
4.3
TRANSPORT
4.3.1 Ammonia-fuelled ICE for shipping vessels
Ammonia is a suitable fuel for transport, especially for heavy goods vehicles, trains and deep-sea
shipping, where large amounts of energy are required for extended periods and where batteries or
direct electrical connections are not practical or cost-effective. Ammonia can be used as a fuel in both
purposely designed and modified ICE, either in a pure form or in a blend with other fuels such as
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petroleum. Ammonia has an energy density of about one-half that of gasoline and diesel, but an
ammonia-fuelled ICE can provide about 20% more power than gasoline and diesel engines due to the
higher compression ratio needed for ammonia combustion (Lewis, 2018). However, burning ammonia
has challenges due to its relatively low reactivity making it difficult to ignite. The low combustion rate
of ammonia causes combustion to be inconsistent under low engine load and/or high engine speed
operating conditions. Most existing combustion engines that use ammonia as fuel typically require a
combustion promoter (known as secondary fuel or ignition fuel) such as hydrogen, gasoline or diesel
for ignition, operation at low engine loads and/or high engine speed. Also, emissions of NOx and N2O
from ammonia combustion need to be controlled. Although the use of ammonia as a fuel for ICE started
over a century ago, there was limited research on ICE (both compression ignition and spark ignition
engines) using ammonia as fuel until the 2010s. The use of ammonia as a marine fuel has been
researched more extensively since 2007 (Carioscia, 2021). In 2008, Caterpillar of the USA filed a
patent for an ammonia-fuelled engine and ancillary system (Kim and others, 2020). Since 2019, MAN
Energy Solutions (MAN ES) of Germany has been developing a two-stroke engine that operates on
ammonia (MAN ES, 2020). MAN ES is to integrate existing technology in the ammonia-based
propulsion system while designing the ammonia fuel injection, combustion components, exhaust gas
after-treatment system, and engine components. In addition, MAN ES will provide the engine test-bed
and conduct the engine trial run. This project is now supported by the Innovation Fund Denmark and
the first ammonia engine is scheduled to be installed in a commercial vessel in 2024. In 2019, MAN ES,
Shanghai Merchant Ship Design & Research Institute (SDARI) and the American Bureau of Shipping
(ABS) initiated a joint project to develop an ammonia-fuelled feeder container vessel using the
dual-fuel technology of MAN ES (Hansson and others, 2020). In the same year, Lloyd’s Register (2019)
of the UK granted Approval in Principle to the Chinese Dalian Shipbuilding Industry Company and
MAN ES for an ammonia-fuelled 23,000 TEU (twenty-foot equivalent unit) ultra-large container ship
(ULCS) concept design, the first of its kind in China.
In Japan, a consortium comprising five Japanese heavyweights in the shipping industry and MAN ES,
is collaborating on a project to develop ships designed to use ammonia as fuel and to go beyond
onboard ship technology to include ‘owning and operating the ships, supplying ammonia fuel and
developing ammonia supply facilities’. MAN ES’ ammonia-fuelled engine will be used as the prime
mover (Suda, 2020). In 2019, the Japan Engine Corporation (J-ENG) announced the launch of a new
R&D programme in collaboration with the National Maritime Research Institute (NMRI), focusing on
developing an engine for the combustion of carbon-free fuels including hydrogen and ammonia
(Brown, 2019). In their earlier work, a diesel engine was modified to operate on a dual fuel mix of light
oil and 20% ammonia (by energy content). In addition, NMRI developed an exhaust gas aftertreatment
device to mitigate emissions of nitrous oxide, NOx, and unburnt ammonia. Due to the lower energy
density, ammonia weighs about twice as much and requires over 2.5 times more space to contain the
same amount of energy as heavy fuel oil; a factor to consider in the design phase. Therefore, NMRI
also examined ship design from the perspective of fuel storage. In August 2020, NYK Line, Japan
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Marine United Corporation and Nippon Kaiji Kyokai (ClassNK) signed a joint R&D agreement to
commercialise an ammonia-fuelled ammonia gas carrier. It would use ammonia as the main fuel, in
addition to an ammonia floating storage and regasification barge for offshore bunkering and stable
supply of ammonia fuel (NYK Line, 2020).
The Finnish technology group Wärtsilä started full-scale tests on ammonia-fuelled marine combustion
engines in early 2020 with some encouraging results. In one test, the engine performed well when
running on a fuel mix containing 70% ammonia at a typical marine load range (Wärtsilä, 2021). Testing
will continue with the aim of defining feasible ICE-based solutions for power plant and marine
applications. Wärtsilä later announced that it would begin testing ammonia in a marine four-stroke
combustion engine in Norway, as part of the DEMO2000 programme that is supported by the
Norwegian Research Council. Wärtsilä is also developing ammonia storage and supply systems as part
of the EU’s ShipFC project. The company has already gained significant experience with ammonia from
designing cargo handling systems for liquid petroleum gas carrier vessels, many of which are used to
transport ammonia. Norway’s Color Line also has plans to pilot ammonia as a marine fuel. A 16-party
consortium has been launched to conduct the case study with Color Fantasy, the world’s largest
roll-on/roll-off cruise liner (Brown, 2020). Color Fantasy currently burns around 25,000 t/y of bunker
fuel and, if the vessel is converted, it will require around 60,000 tNH3/y, which would need to be
stored and distributed locally.
Overall, the number of published tests on ammonia-fuelled marine engines is limited. At present, no
propulsion technologies for ammonia have been commercialised for marine operation. However, the
latest assessment of the availability of alternative fuel technologies for shipping predicts that the first
demonstration of ammonia-fuelled ICE for onboard use will begin in 2024 and the technology will
become commercial within 10 years (DNV, 2021).
4.3.2 Ammonia-fuelled ICE for road vehicles
Ammonia-fuelled road vehicles operate in a similar way to gasoline-fuelled vehicles, which means that
ammonia-fuelled vehicles can generally be built and maintained in the same way as the current vehicle
fleet. Most vehicles on the road could be modified to run on a mixture of ammonia and petroleum, and
engines that could run on 100% ammonia are in development. In 2007, an ammonia-fuelled truck was
developed which drove across the USA powered by a mix of ammonia and gasoline. In 2013, South
Korean researchers successfully road-tested a dual fuel passenger car that ran on a mixture of ammonia
and gasoline in a ratio of 70:30, and an ammonia-gasoline hybrid sports car was displayed at the Geneva
Motor Show (NH3 Fuel Association, 2013a,b). Based on research carried out at the University of
Michigan, a US company, Raso Enterprises, develops and manufactures conversion kits, NH3CAR, for
cars to run on ammonia. The NH3CAR conversions are automotive dual fuel (gasoline and anhydrous
ammonia) systems that provide additional ammonia fuel to the engine depending on its operating
conditions (https://www.rasoenterprises.com/index.php/ammonia/26-manufacturers/15-nh3car).
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In 2019, Canadian company TFX International announced a CAN$2 million ($1.5 million) project to
convert two diesel-fuelled generators and transport trucks to use ammonia fuel over three years
(Vezina, 2019). The multi-fuel engine retrofit systems developed by Ontario-based Hydrofuel Inc will
be used. After the conversion, the trucks will operate on a dual fuel basis in either a ‘low emission’
configuration that uses diesel and ammonia or a ‘zero emission’ configuration that uses
hydrogen/oxygen assisted ammonia fuel. The project partners anticipate that lower ongoing fuel and
maintenance costs will pay for the upfront investment in engine conversion and fuelling logistics.
Ammonia dual-fuel combustion in ICE currently suffers from relatively high unburnt ammonia, and
N2O and NOx emissions because of the fuel-bound nitrogen, and hence, after-treatment systems are
required (Dimitriou and Javaid, 2020). Research has progressed to show that engine performance and
emissions can be improved with optimised engine design and systematic tuning. More specifically,
studies have shown the importance of combustor inlet temperature, injection port location, fuel blend,
and air injection rate on NOx and ammonia emissions. Reviews of recent R&D on ammonia-fuelled
ICE and developments in advanced injection strategies are available (Dimitriou and Javaid, 2020;
Mounaïm-Rousselle and Brequigny, 2020).
Despite all the advances in ammonia-fuelled ICE technologies, the future of ammonia in the car market
is uncertain because battery-powered electric vehicles are currently more economical than renewable
ammonia-ICE-driven cars and are already an established technology.
4.3.3 Ammonia fuel cell powered vehicles
Interest has been growing in developing ammonia-powered FC technology for electric vehicles and
shipping. Hydrogen- and ammonia-based FC can have higher energy efficiency than conventional
combustion engines, while effectively reducing or eliminating emissions and noise. FC can have other
potential benefits such as reduced maintenance, modular and flexible design, and improved part-load
operation efficiency (DNV, 2021). Depending on whether decomposition of ammonia occurs,
ammonia FC can be either direct or indirect. Indirect ammonia FC involve decomposing ammonia to
release hydrogen which is fed into the FC for power generation. In direct ammonia FC, ammonia is
directly supplied to the FC for conversion of the chemical energy of ammonia to electric energy. This
leads to savings in capital and operating costs and improved overall efficiency. High-temperature
SOFC are usually regarded as the most efficient method for power generation and are one of the most
studied types of ammonia-fed fuel cell technology. Various types of direct or indirect ammonia-fed
SOFC have been investigated and tested with major developments being achieved (Jeerh and others,
2021). In January 2020, the ShipFC consortium of 14 European companies and institutions received
€10 million ($11 million) in funding from the EU to install the world’s first ammonia-powered FC on
a vessel, Viking Energy (Maritime Executive, 2020). A large 2 MW ammonia FC will be retrofitted on
Viking Energy in late 2023, allowing it to sail solely on the clean fuel for up to 3000 hours annually.
The SOFC system is being developed and tested on land in a parallel project and the construction will
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be undertaken by the developer Prototech. Wärtsilä is to supply the onboard power technology and
systems for ammonia storage and distribution. Yara will supply the renewable ammonia. The project
aims to demonstrate that long-range zero-emission voyages with high power on larger ships are
possible. The goal is also to ensure that a large fuel cell can deliver total electric power to shipboard
systems safely and effectively. Also in January 2021, several European companies including Alfa Laval,
DTU Energy, and Haldor Topsøe entered into a joint project, SOFC4Maritime, to accelerate the
development of SOFC technology for marine vessels with ammonia-based SOFC as the starting point
(Green Car Congress, 2021).
Low-temperature alkaline FC such as molten alkaline ammonia FC and alkaline membrane-based FC
as well as microbial ammonia FC have also been explored. Compared to high-temperature FC, lowand medium-temperature FC are more tolerant to dynamic load variations. Researchers at the
University of Delaware, USA, reported on progress they made on direct ammonia-fed alkaline
membrane FC technology for passenger cars (Gobesfeld, 2017). However, significant developments
are needed before these technologies can reach commercial applications. FC technologies come with
significant disadvantages related to their cost and durability. Also, direct ammonia FC are less
developed than hydrogen FC. The FC-powered electric vehicles on the road today, including cars,
buses and trucks, are mainly fuelled by hydrogen.
Despite extensive studies on direct and indirect ammonia FC systems and the emerging ammonia
SOFC technology for shipping, the development of ammonia FC for road transport is limited.
4.4
INDUSTRIAL PROCESS HEAT AND STEAM
One of the challenges of using ammonia as a fuel in industrial furnaces is the reduced radiative heat
transfer and lower ammonia flame temperature. In the study at Osaka University, Japan, using a 10 kW
class model furnace, it was found that enhanced flame radiation from oxygen-enriched combustion
and multi-stage combustion to achieve uniform flame temperature could overcome such problems in
both 100% ammonia combustion and cofiring of ammonia-methane in a ratio of 30:70 (Murai and
others, 2019). The same results were also obtained in a demonstration test using a 100 kW class model
furnace, which is close to the practical scale of industrial furnaces.
In a project supported by Japan’s SIP Energy Carriers initiative, this technology was applied to a
degreasing furnace used in the pretreatment process for hot-dip galvanised steel sheet production
(Numata and others, 2019). An impinge jet burner for using ammonia as a fuel was developed and
several types of burner design were evaluated during ammonia-methane cofiring tests at varying
ammonia ratios. The tests were conducted by a research team from Nippon Steel Nisshin Company
and Taiyo Nippon Sanso Company at one of Nippon Steel Nisshin’s production lines to verify the
applicability of this technology. The impinge jet burners performed well in the industrial furnace as
expected. The optimal burner arrangement for uniform heating was determined during the tests. The
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results also showed that by mixing conventional methane fuel with 30% of ammonia to heat the
furnace, CO2 emissions were reduced by 30%.
4.5
SUMMARY
Ammonia as a fuel can be burnt in ICE, gas turbines, coal boilers and industrial furnaces with minor
modifications. There are challenges when burning ammonia in existing combustion systems designed
for hydrocarbon fuels. Preliminary studies and small-scale research into ammonia combustion
revealed that slow flame velocity, slower heat release, and the combustion characteristics of ammonia
posed no major obstacle to combustion in these systems. The challenges related to low flammability,
low radiation intensity of ammonia combustion and high NOx emissions could be overcome with
improved engineering designs and system optimisation. Extensive R&D to develop technologies for
ammonia cofiring and pure ammonia combustion are progressing fast. Several projects are ongoing or
under development to demonstrate ammonia cofiring technologies at coal-fired power plants at a
commercial scale. Projects are also underway to demonstrate that ammonia can deliver power to
shipboard systems safely and effectively. The first commercial vessels propelled by ammonia fuel
using two- or four-stroke engines designed to operate on ammonia, or using large fuel cells running on
ammonia are expected to start sailing in 2024-25. Ammonia-gas cofiring technologies for gas power
generation have been developed and could be commercialised as early as 2025.
Road vehicles driven by ammonia-fuelled ICE and FC systems are in development and some have been
demonstrated. Despite the extensive R&D activity and some ongoing projects to convert existing
transport vehicles to ammonia-diesel dual fuel, developments in ammonia-fuelled road vehicles are
limited due to a lack of competitiveness with rival technologies such as batteries and hydrogen-fuelled
FC. Efforts have also been made to explore the use of ammonia fuel in industrial furnaces. The work
is preliminary and is being carried out mostly in Japan with some positive results. It can be anticipated
that the first deployment of ammonia combustion technologies at a commercial scale will take place
in shipping and the coal power generation sector to reduce CO2 emissions.
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5
CHALLENGES AND OPPORTUNITIES
The challenges of firing ammonia as a fuel, and the efforts and progress made to tackle the challenges
have been discussed in Chapter 4. Apart from technical issues, there are other challenges to the
utilisation of ammonia in a clean energy transition. In some cases, the challenges also represent
opportunities. The following sections discuss the challenges and opportunities of using ammonia as a
low-carbon fuel. Techno-economic analysis and an evaluation of the impacts of ammonia fuel use on
reducing CO2 emissions are also conducted.
5.1
CHALLENGES
5.1.1
Costs
A major barrier to the utilisation of clean ammonia as a fuel is the cost. The production costs of
conventional ammonia depend on the price of gas or coal and electricity (as feedstock and fuel) and
are largely influenced by plant size (Patonia and Poudineh, 2020). There is also a wide regional
variation in the production costs due to the different costs of natural gas, coal, electricity and labour
in each region. Table 9 compares the estimated costs in the USA of conventional ammonia production
from SMR and renewable ammonia by electrolysers and Haber-Bosch with different plant capacities.
In China, the costs of conventional ammonia from coal would be comparable to those of ammonia
from SMR as the higher capital expenditure of the coal gasification route for ammonia synthesis is
offset by lower operating costs relative to natural gas due to the abundance of coal.
TABLE 9
ESTIMATED COSTS OF CONVENTIONAL AND RENEWABLE AMMONIA PRODUCTION IN THE USA (PATONIA AND
POUDINEH, 2020)
~2000 (Large)
Production
process
SMR
Costs, $/tNH3
Plant size, tNH3/d
~545 (Medium)
Electricity
~91 (Small)
Electricity
Electricity
SMR
Electrolysis
H-B
SMR
Electrolysis
H-Ba
Electrolysis
H-B
Feedstock/
energy
93
441
67
93
441
67
93
441
67
Capital
55
33
32
88
33
51
113
33
66
O&Mb
22
41
13
62
41
36
133
41
77
Total
170
627
243
669
339
725
a: Haber–Bosch; b: operation and maintenance
It can be seen from Table 9 that the costs of renewable ammonia production could be more than
2–3.6 times higher than conventional ammonia depending on the plant size. This is consistent with
the estimates by CF Industries, one of the world’s largest ammonia producers (Tullo, 2020, 2021).
CF Industries estimated that the cost of making renewable ammonia would be about 500 $/t, which is
3.3 times higher than the approximate 150 $/t for making conventional ammonia. The company
considers that renewable ammonia could be sold for 2200 $/t as a fuel in the alternative energy
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marketplace, which is more than 6 times higher than CF’s average selling price of about 350 $/t for
conventional ammonia for fertiliser in 2019. Commodity market specialists at Argus (2021) recently
modelled a weekly price for renewable ammonia delivered to northwest Europe based on a theoretical
‘typical’ production plant in the Middle East. Their model yielded a notional value of 1196 $/tNH3,
which is significantly higher than the market price of conventional ammonia and is nearly four times
the cost of fossil fuel-based marine shipping fuels when compared on an energy content basis.
The costs for making low-carbon ammonia will be higher than conventional ammonia production due
to the added costs of CCS; they are estimated to increase by 10–25% for the natural gas-based routes
and by 15% for the coal-gasification routes (IEA, 2021b). Hiraoka and others (2018) evaluated the
costs of importing natural gas-based ammonia from the UAE for use as a fuel in a coal power plant in
Japan. They found the total delivered cost (including production, transport, unloading, re-evaporation
and distribution costs) of low-carbon ammonia would be 392 $/tNH3, compared to 310 $/tNH3 for
conventional ammonia. The 26.5% increase in the total costs resulted from decarbonisation of
conventional ammonia making low-carbon ammonia a potentially viable choice of clean fuel. Similar
costs were derived by the IEA (2021a) in recent case studies which found that in 2030, the production
costs of natural gas-based low-carbon ammonia in Saudi Arabia would be 210–310 $/tNH3, while the
renewables-based electrolytic ammonia in Chile would cost 400–540 $/tNH3. Figure 14 compares the
estimated costs and CO2 intensities of ammonia production via different technological routes.
Figure 14 Comparison of costs and CO2 intensities of ammonia production via different routes
(IEA, 2019)
In an analysis by IEEJ (Kawakami and others, 2019), the costs of low-carbon ammonia production
(SMR + Haber-Bosch + CCS) in Saudi Arabia and other Gulf States as well as North America, and the
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costs of transporting ammonia from the producing countries to Japan by ocean using large gas carrier
vessels were estimated based on the following assumptions:
•
construction of a new ammonia production plant with an annual capacity of 1.1 Mt;
•
natural gas feedstock priced at 3.00 $/MBtu (million British thermal units) (2.84 $/GJ); and
•
10% equity internal rate of return as supplier profit.
The analysis found that it could be profitable for producers if the low-carbon ammonia was sold at
prices between 276 $/tNH3 (for producers in Saudi Arabia) or 300 $/tNH3 (for the other regions).
The logistics would cost 40 $/tNH3 from the Middle East to Japan and 80 $/tNH3 from North America
to Japan. If the captured CO2 is sold for enhanced oil recovery (EOR) at around 20 $/tCO2, the
production cost of low-carbon ammonia could be reduced by about 35 $/tNH3; this factor was taken
into account in the cost estimation of the low-carbon ammonia produced in the USA. The analysts
concluded that: 1) the cost of low-carbon ammonia arriving in Japan could be around 350 $/t; and 2)
until around 2030, the cost of natural gas-based low-carbon ammonia would be considerably cheaper
than that of renewable hydrogen.
It should be noted that most of the cost analyses discussed here were conducted when gas prices were
low. Since the beginning of 2022, the price of conventional ammonia has doubled due to substantial
increases in the cost of natural gas (Argus, 2022).
5.1.2
Demand and supply
Global ammonia production stands at around 180 Mt with 10% of it traded internationally and around
80% of it used as fertiliser. There is generally a substantial stock of existing ammonia supply that is
widely available geographically, so ammonia supply is rarely a market constraint (Hatfield, 2020).
However, if ammonia is to play a significant role in decarbonising power generation, transport and the
industrial sector, much larger volumes will be needed. As an indication, cofiring 20% ammonia at a
1000 MW coal power plant would consume 0.5 MtNH3/y (Hirata and Ito, 2021). If all coal-fired power
plants in Japan were to cofire 20% ammonia, 20 MtNH3/y would be required for cofiring in Japan alone,
an amount comparable to the current volume globally traded. The Road Map for Fuel Ammonia
published by Japan’s Ministry of Economy, Trade and Industry (METI) in 2021 promotes the use of
ammonia in Japan in thermal power plants and as a shipping fuel. Japan expects to import 3 Mt/y of
clean ammonia by 2030, with demand rising to 30 Mt/y by 2050. In addition, if ammonia is to be used
as a marine fuel to help meet the International Maritime Organization’s (IMO) target of reducing GHG
emissions from international shipping by 50% by 2050 from a 2008 base, 500 Mt/y of ammonia would
be required in the long term to satisfy shipping demand (IEA, 2019). This is almost three times the
volume of current global production and nearly thirty times the volume of ammonia currently traded.
Specialists at Argus (2020) estimated that the potential use of ammonia as an energy source and energy
carrier in a range of applications could create a one billion tonnes per year market, a volume many
times more than today’s global total production capacity.
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Since existing ammonia production capacity is already largely utilised, the likely significant increase
in future demand for ammonia will require a massive scale-up of ammonia production, port, storage,
and distribution facilities. Although there exists a worldwide ammonia distribution system that meets
current demand and supply, to extend the use of ammonia as a fuel, the existing ammonia distribution
network will need to be expanded significantly. This will enable it to meet the increasing distribution
volume and to connect production and storage sites to all end users. Such an expansion will require a
huge amount of capital investment. As new projects normally take several years to plan, finance and
execute, early decisions and action on new construction are needed to establish and expand a supply
chain of clean ammonia that can meet future demand.
From a capital cost perspective, an important factor to consider is the plant size. While economies of
scale favour conventional ammonia plants, most of the renewable ammonia projects focus on
small-scale ammonia production (see Table 6) in tens of thousands of tonnes per year rather than the
half-million tonnes or more per year that a conventional ammonia plant produces. This is because the
average size of wind and solar power plants could not support a standard Haber-Bosch ammonia plant.
As a result, renewable ammonia projects will have higher capital intensity compared with conventional
ammonia plants, although the gap is expected to narrow in the medium to long term with decreasing
electrolysis unit costs and technological advances. Also, the current renewable power generation
capacity is insufficient to supply the grid while supporting renewable ammonia production. Therefore,
the availability (production volume) and costs of renewable ammonia may constrain its use as a clean
fuel. However, in the short to medium term, low-carbon ammonia could be produced at large scales
with lower costs by retrofitting the existing ammonia plants with carbon capture facilities and building
new ammonia plants with CCUS. The production and use of low-carbon ammonia could enable the
early adoption of clean ammonia as an energy carrier and fuel and facilitate the transition towards
increased utilisation of renewable ammonia in the longer term.
5.1.3
Environmental and social impacts
Ammonia is a toxic gas and prolonged exposure to high concentrations of it can damage human health.
Great care is required to prevent and control it from leaking or spilling. The greater use of ammonia
means that small leaks or spills should be expected and they could have a cumulative effect on airborne
ammonia levels in the immediate vicinity. Also, a pervasive odour surrounding high-use areas such as
filling stations may be a nuisance and a cause of public health and safety concerns. Therefore, health
and safety aspects of the potential use of ammonia in the transport, energy and other sectors should
be evaluated and new safety protocols and regulations need to be established to minimise the risks of
using ammonia. Discussions are taking place within the IMO to start developing standards for the
design of marine engines; the countries involved are already conducting analyses and forecasts for the
eventual implementation of ammonia fuel in the sector (Valera-Medina and others, 2021).
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Large-scale combustion of ammonia could lead to increased emissions of N2O, NOx, and ammonia.
The impacts of ammonia use as a fuel on air quality and the environment require further analysis.
Experts are working to better understand the extent to which ammonia is emitted by the many
participants in the ammonia value chain, and to determine what the current emissions and control
practices might imply regarding emissions risks in a future context where ammonia is commonly used
as fuel (Valera-Medina and others, 2021; Lewis, 2018). Strict limiting values of NOx emissions from
fossil fuel combustion have been set in many countries, and similar standards should, and can, be
established and applied to ammonia combustion.
5.1.4 Policy and regulations
Large-scale deployment of ammonia utilisation as a clean fuel will not happen without appropriate
policies and regulations in place. Successful uptake of ammonia fuel use depends on the development
of supportive policies, incentives, national and corporate GHG reduction targets, and requires the
establishment of efficient safety legislation for extending ammonia use as a fuel in various sectors.
Policies and regulations could play a pivotal role in the adoption of clean ammonia fuel, similar to how
they incentivised investments in renewables. They could include development strategies, mandates,
direct carbon pricing, carbon taxes (such as the 45Q adopted in the USA), and low- and/or zero-carbon
fuel standards. The current policies that promote the development and deployment of ammonia fuel
use are discussed in the next chapter. New financing mechanisms and short-term financial support
such as through investment in foundational infrastructure, subsidies to encourage end-use adoption
and drives to scale-up are also critical to attract and de-risk investment.
5.2
OPPORTUNITIES
Extending the use of ammonia as a fuel into power, transport and other industrial sectors means that
large investment will be required for the substantial expansion of the infrastructure of ammonia
production, storage and distribution. This poses a challenge but also provides an opportunity for
investors as the market is potentially huge. The successful investors will be in an advantageous position
across the value chain of clean ammonia production, supply and distribution. To ensure the
establishment of a clean ammonia supply chain, Japanese firms (which have been recently joined by
Korean ones) are already collaborating with companies in the Gulf States, Australia, Norway and Asia,
while promoting the use of ammonia in other sectors and countries. Equipment manufacturers who
have developed ammonia combustion technologies will be able to expand their business into the clean
energy field while fossil-fuelled applications are under pressure to phase down or phase out.
5.3
POTENTIAL CO 2 EMISSIONS REDUCTION FROM COAL POWER
GENERATION USING AMMONIA FUEL
Ammonia is carbon-free and hence, the combustion of ammonia does not generate any CO2. As a result,
replacing fossil fuels with ammonia in, for example, boilers, combustion turbines, and ICE will reduce
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CO2 emissions in proportion to the decreased amount of fossil fuels being burnt. Currently, Japan’s
power generation sector emits about 400 MtCO2/y (ANRE, 2021). It is estimated that cofiring 20%
ammonia at a 1000 MW coal power generating unit could avoid 1 MtCO2/y emissions. Cofiring 20%
ammonia at all coal-fired power plants owned by Japanese major power companies could result in a
decrease in CO2 emissions of 40 Mt/y. If all coal power plants in Japan were to convert to 100%
ammonia firing, the emissions from coal power generation would be eliminated resulting in 200 Mt/y
CO2 emission savings. In a recent analysis, IEA (2021a) concluded that substituting coal with ammonia
for power generation could lead to about an 80% reduction in CO2 emissions when ammonia is
produced from fossil fuels with 95% carbon capture, and to 90–95% CO2 emissions reduction when
ammonia is produced from wind and solar power.
5.3.1
Life cycle analyses
While combustion of ammonia does not emit any CO2, the raw material extraction and processing,
ammonia production and transport could result in large GHG emissions depending on the feedstock
and technologies used. Therefore, it is important to evaluate the life cycle carbon footprint of ammonia
produced via different routes when considering substituting fossil fuels with ammonia as an approach
to sectoral decarbonisation. A life cycle analysis (LCA) is a systematic analysis of the potential
environmental impacts of a product or service during its entire life cycle from raw materials extraction,
processing and transport through product production and use to recycling and final disposal of wastes.
With increasing interest in ammonia use as an energy vector, there have been several LCA on its
carbon and nitrogen footprint as well as other impacts on the environment (such as eutrophication
and abiotic depletion) and human health (Cox and Treyer, 2015; Bicer and Dincer, 2018; Xue and
others, 2019; Ozawa and others, 2019; Boero and others, 2021). The studies show that ammonia
production is the main contributor to the life cycle environmental impacts of ammonia fuel use. In
these studies, global warming potential (GWP) is often used to compare the environmental impacts of
different fuels. GWP measures the heat absorbed by any greenhouse gas in the atmosphere over a
given period (usually 100 years), relative to that of CO2. The larger the GWP, the more that a given
gas warms the earth compared to CO2 over that time period. CO2 is used as the reference so by
definition, has a GWP of 1. As a comparison, methane is estimated to have a GWP of 28-36 and nitrous
oxide of 265-298, over 100 years (US EPA, nd).
Bicer and Dincer (2018) compared life cycle GHG emissions from city transport and power generation
using fossil fuels with those using renewable ammonia produced by wind power-driven water
electrolysis. They found that GHG emissions from an ammonia-fuelled vehicle are around 100 g CO2
equivalent per kilometre (gCO2-eq/km), which is considerably lower than the 270 and
230 gCO2-eq/km for gasoline- and diesel-driven vehicles, respectively. Using ammonia in power plants
also has a lower total GWP (about 60%) compared to a natural gas-fired power plant.
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Boero and others (2021) assessed the life cycle environmental impacts of ammonia-based electricity
generation in the UK using ammonia produced via different pathways. Their results show that
electricity generation using renewable and nuclear power-driven electrolysis-based ammonia has the
lowest GWP, fossil fuel depletion potential, and ozone depletion potential. Electricity generation from
ammonia produced via SMR with CCS also has a lower GWP compared to a reference natural gas
power plant. Ammonia-fuelled combined heat and power production can further reduce the carbon
footprint by over 29%. In addition, the results show that ammonia from electrolysis powered by grid
electricity that has higher fractions of fossil-fuelled power will have a larger carbon footprint than the
unabated reference plant.
Ozawa and others (2019) evaluated the life cycle emissions of CO2 from a 1000 MW power plant in
Japan operating at a 70% capacity factor fuelled by:
•
100% ammonia with 53.0% energy efficiency (HHV based);
•
100% coal using ultrasupercritical steam condition with 39.6% efficiency;
•
100% natural gas using a combined cycle gas turbine with 53.0% efficiency;
•
ammonia-coal cofiring at a ratio of 20:80 with 39.6% efficiency; and
•
ammonia-gas cofiring at a ratio of 20:80 with 53.0% efficiency.
Figure 15 depicts the life cycle of the various fuels for the power plant that are assessed. Data used in
the analysis are from a literature survey, Inventory Database for Environmental Analysis (IDEA), and
the Japanese life cycle inventory database. The researchers assumed that the ammonia was
manufactured in the UAE and imported to Japan by ship. Ammonia is synthesised via SMR without
(NG-1) or with CCS (NG-2), or via water electrolysis powered by a solar power plant that is newly
constructed and dedicated to water electrolysis. In the case of NG-2, all process CO2 and 91% of utility
CO2 are captured (see Figure 16). A monoethanolamine (MEA)-based chemical absorption system is
used for capturing CO2 emissions from both ammonia production and power generation. Methane
emissions from coal mining have been taken into account in the analyses.
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Figure 15 The system boundary of the analysed life cycle (Ozawa and others, 2019)
Figure 16 Life cycle CO2 emissions of ammonia and fossil-fuelled power generation (Ozawa
and others, 2019)
The analyses show that ammonia production is responsible for over 80% of life cycle CO2 emissions
of ammonia. Adding CCS to a natural gas-fed ammonia production plant could reduce ammonia life
cycle CO2 emissions from 2.0 to 0.3 kgCO2/kgNH3, while ammonia from solar power-driven water
electrolysis has life cycle CO2 emissions of around 1 kgCO2/kgNH3. For 100% ammonia-fuelled power
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generation, the life cycle CO2 emissions of conventional ammonia is 608 gCO2/kWh, which could be
reduced by 84% to 96 gCO2/kWh when low-carbon ammonia is burnt for power production. For 20%
ammonia-coal cofired without CCS, using low-carbon ammonia could lower life cycle CO2 emissions
of power generation from 928 to 786 gCO2/kWh. Post-combustion CCS capturing 90% CO2 from the
power plant could cut the total emissions further to 238 gCO2/kWh, compared to the life cycle
emissions of 278 gCO2/kWh from a coal-fired power plant with CCS. The life cycle CO2 emissions of
ammonia- and fossil fuel-fired power generation are compared in Figure 16.
The IEA (2021a) studied the role of low-carbon fuels in power sector clean energy transitions and
concluded that substantial GHG life cycle emissions reductions could be achieved by substituting fossil
fuels with low-carbon hydrogen and ammonia fuel in thermal power plants.
5.4
ECONOMIC ASSESSMENT OF POWER GENERATION BASED
ON LOW-CARBON AMMONIA
Scientists at Oxford University have conducted a techno-economic analysis to forecast the levelised
cost of electricity (LCOE) from renewable ammonia based on near- and long-term technological
developments to 2040 (Cesaro and others, 2021). Their analysis included various assumptions:
•
solar PV provides the electricity required, which is integrated with batteries for night-time
operation;
•
hydrogen is produced via water electrolysis when solar power is available and stored on-site
to allow for a constant hydrogen supply to the Haber-Bosch process;
•
technological advances will make the Haber-Bosch process more flexible, so two days of
hydrogen storage in 2020 will be reduced to one day in 2040 with a reduction in the
associated costs.
A 100 MW ammonia-to-power combined cycle gas turbine was selected for LCOE evaluation.
Cesaro and others (2021) predict that the combustion technologies will progress over time from
100% hydrogen with a plant efficiency of 52% in phase I to blends of hydrogen and ammonia in
phase II, and to 100% ammonia with a plant efficiency of 60% in phase III. The hydrogen is
generated at the power plant by ammonia cracking at 99% conversion efficiency. They predict that
the levelised cost of solar-powered ammonia production would decline from 771 $/kgNH3 in 2020
to 494 $/kgNH3 in 2030 and reduce further to 380 $/kgNH3 by 2040. Based on the ammonia costs,
the estimated LCOE of renewable ammonia-based electricity at a 25% capacity factor and the
changes with technological developments over time are shown in Figure 17, where they are
compared with those of fossil fuel power with CCS, nuclear power and biomass energy with CCS
(BECCS). The LCOE at varying power plant capacity factors are compared in Figure 18. The results
indicate that with technological advances, renewable ammonia could become competitive with
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fossil fuels for low-carbon power generation, especially when the power plant operates at low
capacity factors. They conclude that:
‘RENEWABLE AMMONIA IS A TECHNICALLY VIABLE AND
ECONOMICALLY COMPETITIVE FUEL FOR
DECARBONI SATION OF THE ELECTRICITY SECTOR VIA
HIGH EFFICIENCY GAS TURBINE POWER PLANTS BY
2040’.
However, there are large uncertainties in the production costs of renewable ammonia primarily due
to the lack of reliable learning curve data for the cost of electrolysers. In addition, the total cost will
be largely influenced by economic and political factors which are difficult to predict.
Figure 17 LCOE comparison of low-carbon electricity from renewable ammonia, fossil fuels
with CCS, nuclear and BECCS (Cesaro and others, 2021)
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Figure 18 LCOE of low-carbon electricity at various power plant capacity factors (Cesaro and
others, 2021)
TABLE 10
COMPARISON OF LCOE OF COFIRING IMPORTED LOW-CARBON AMMONIA AND RENEWABLE AMMONIA
AT JAPANESE COAL POWER PLANTS IN 2030 (IEA, 2021A)
70%
CF
Transport
Production
Transport
210–320
50–70
400–540
60–85
~95–139
~114–160
15%
CF
Production
~99–144
~118–165
70%
CF
Renewable ammonia
111–161
166–224
15%
CF
20% NH3
60% NH3
LCOE, $/MWh
Cost, $/tNH3
Low carbon ammonia
119–172
174–234
Coal
52–78
100%
coal
88–127
CF – capacity factor
Case studies using existing Japanese coal power plants were carried out by the IEA (2021a) to evaluate
the cost impacts of cofiring coal with natural gas-based low-carbon ammonia from Saudi Arabia, and
with renewable ammonia from Chile in 2030. It was assumed that in 2030, Japan would have a carbon
price of 66–98 $/tCO2, and coal plants in Japan would operate at 44% plant efficiency. The estimated
LCOEs are compared in Table 10. The cost of ammonia, which was the base for calculating the LCOEs,
are also given in Table 10. The results show that cofiring clean ammonia at coal power plants will lead
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to an increase in the LCOE, which rises with the increasing share of ammonia in cofiring. The increases
are larger for renewable ammonia due to its higher cost. Also, the increase in costs would be higher if
the plant were operated under peak-load mode only (at 15% capacity factor), but the electricity
generated is also likely to be sold at higher prices during peak-load times. Importantly, the cost
increase was largely offset by higher carbon price due to reductions in emissions prices.
A case study of the cost impacts of cofiring coal with low-carbon ammonia from Saudi Arabia on
existing coal power plants in Indonesia was also performed by the IEA (2021a). Similar to Japan, the
Saudi Arabian low-carbon ammonia would cost 210–320 $/tNH3 and transporting it by sea to
Indonesia would cost 45–60 $/tNH3. It was assumed that in 2030, the coal price in Indonesia would
be 35–50 $/t; coal power plants would operate at 40% efficiency, and the government would not
introduce a carbon price. The analysis found that the LCOE for an existing coal power plant would be
23–29 $/MWh in 2030. Cofiring 60% of ammonia at a capacity factor of 70% would significantly
increase the LCOE to 91–130 $/MWh, as the cost increase from using expensive low-carbon ammonia
would not be offset by lower emission costs due to the lack of a carbon price. Operating the plant on
peak-load mode at a 15% capacity factor would increase the LCOE further to 99–142 $/MWh. The IEA
(2021a) work demonstrates that the impact of ammonia fossil fuel cofiring on the LCOE of an existing
power plant depends on many local factors including the type and efficiency of the power plant, the
cost of plant modification, the ratio of cofiring, the average capacity factor and the carbon price. A
high carbon price can significantly reduce the gap between the LCOEs from cofiring and the energy
market value.
5.5
SUMMARY
Utilising clean ammonia as a fuel faces several challenges. The greatest challenge is its high cost.
Renewable ammonia costs more than double that of conventional ammonia and is likely to remain
significantly high for at least the short- to medium-term. The cost of low-carbon ammonia is around
25% higher than that of conventional ammonia. Another large challenge is to meet the potential
substantial demand for clean ammonia. As more ammonia is used as an energy source, significant
development of ammonia production, transport and distribution infrastructure is required to connect
the producers to the end-users. Currently, the production of renewable ammonia through electrolysis
powered by renewable electricity is not yet of a viable scale compared to conventional processes.
Therefore, from a technical and economical viewpoint, low-carbon ammonia could offer a quicker and
cheaper route to a low-carbon energy transition. Supportive policies, incentives and safety legislation
for extending the use of ammonia are needed. Societal acceptance of ammonia use may also be an issue
due to safety concerns. The massive expansion of ammonia production, transport and distribution
infrastructure that is required to enable the extended use of ammonia as a fuel demands large capital
investment, which poses another challenge but also provides opportunities to investors as the
potential market may be huge.
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Techno-economic analyses have shown that substituting fossil fuel with clean ammonia for power
generation can lead to life cycle reduction in GHG emissions. Cofiring clean ammonia at power plants
will increase LCOE but that increase can be largely offset by supportive policies such as a carbon price.
With continued technological developments and falling costs of renewable electricity, it is anticipated
that at some point renewable ammonia may become a technically viable and economically competitive
fuel for decarbonising power generation.
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6
DISCUSSION AND CONCLUSIONS
6.1
POLICIES
Ammonia is portable, storable, energy-dense, and it also possesses certain properties that make it
suitable for use as an energy storage medium, a hydrogen carrier and as a fuel. Technologies for the
production, safe handling, transport and storage of ammonia are mature, and infrastructure is already
in place. Therefore, ammonia could form the basis of an integrated energy storage and distribution
solution, and be a clean fuel for power generation, transport and industrial processes. However, R&D
and deployment of ammonia utilisation require supportive policies. In recognising the potential of
ammonia as an energy vector, the Cross-ministerial Strategic Innovation Promotion Program (SIP) of
Japan introduced a hydrogen and ammonia-related technology roadmap, the Strategic Plan for
Hydrogen Utilisation in 2017, and promoted the R&D of ammonia direct combustion/cocombustion
and utilisation (Shiozawa, 2018). A 22-member Green Ammonia Consortium led by Tokyo Gas was
created in 2017, seeking to demonstrate hydrogen, ammonia and hydrides as building blocks of a
hydrogen economy and to develop an ammonia value chain (JST, 2017). At the end of 2020, Japan’s
Ministry of Economy, Trade and Industry (METI) announced that it had selected the fuel ammonia
industry as one area to prioritise in its ‘Green growth strategy’ action plan (ITO, 2021). The Road Map
for Fuel Ammonia published by METI in 2021 promotes the use of ammonia in Japan in thermal power
plants and as a shipping fuel. Japan expects to import 3 Mt/y of clean ammonia by 2030. As an island
country with limited mineral resources, Japan relies on imports for almost all its oil, natural gas and
coal supply. Japan’s energy policy is based on fundamental principles of safety, energy security,
economic efficiency, and environmental suitability, which recognises the importance of coal in a
secure and reliable primary energy supply. In the 6th Strategic Energy Plan (SEP) published in October
2021, coal’s role in power generation beyond 2030 is clearly defined (METI, 2021). The 6 th SEP sets
targets to increase the energy efficiency of coal power plants and to cofire 20% ammonia with coal by
2030 to achieve the decarbonisation goals of coal power generation. This incentivises Japanese power
generators and gives them the confidence to set their own carbon emissions reduction targets and
invest in technologies to achieve decarbonisation. Driven by the policies and supported by
government funding, Japanese researchers and engineers are actively collaborating and have made
significant progress in developing ammonia combustion technologies for power generation and
transport (see Section 4.2). As a result, Japan leads the way in R&D and deployment of clean ammonia
fuel. Japan’s power generator JERA is working to demonstrate 20% ammonia-coal cofiring at a
commercial 1000 MWe coal power unit in 2023. JERA has pledged to commercialise its ammonia
cofiring power generation by 2030 as part of its aim to start using 100% ammonia as a fuel in the 2040s
for its 2050 carbon neutrality target. Plans to commercialise ammonia-firing gas turbines by 2025 for
power generation have also been announced by Japanese turbine manufacturers. Japan is currently
collaborating with other companies and investing in countries rich in renewable and fossil energy
resources such as Australia, Gulf States, Norway and North America to promote the establishment of
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a low-carbon ammonia supply chain and market. It is anticipated that clean ammonia fuel will be
commercially applied to power generation around 2030 in Japan to decarbonise the sector.
South Korea has also launched policy roadmaps to achieve carbon neutrality by 2050. In 2021, South
Korea announced an action plan to use renewable ammonia and hydrogen as a key power generation
fuel to reduce demand for coal and natural gas for electricity production (Lee, 2021). A task force has
been formed to carry out R&D and deployment of ammonia-fuelled power generation. It plans to
complete research and testing processes for using ammonia for power production by 2027, and to start
commercialising ammonia-fuelled power generation from 2030. South Korea plans to raise the portion
of ammonia in power generation to 3.6%, or 22.1 TWh by 2030. GS Energy of South Korea has agreed
with Japan’s Mitsui & Co to take stakes in a 1 Mt/y low-carbon ammonia plant being developed in the
UAE to secure a supply of 200,000 t/y of low-carbon ammonia from 2025.
With strong market signals from Japan, the Energy Council of the Australian government published
the National Hydrogen Strategy in 2019, and a new chapter of the ammonia fuel association was
opened which aims to work closely with the hydrogen fuel community to increase awareness of the
use of ammonia for energy storage and power generation (Horrocks and others, 2020; Valera-Medina
and others, 2018).
Many countries have established hydrogen-related strategies and roadmaps to achieve net zero
emission targets, which have motivated R&D of technologies for the production and utilisation of clean
ammonia due to its potential as a hydrogen carrier. In the USA, the Renewable Energy to Fuels through
Utilisation of Energy-Dense Liquids (REFUEL) program was launched to develop scalable technologies
for converting electrical energy from renewable sources into energy-dense carbon-neutral liquid fuels
and back into electricity or hydrogen on demand (ARPA-E, 2016). Funding of $32.7 million was
provided in 2016 to 13 R&D projects on the synthesis and use of ammonia under the REFUEL program.
The UK has also shown strong interest and several studies on the use of ammonia as a fuel or for energy
storage have been carried out by companies and universities such as Siemens, Oxford University,
Cardiff University and Ecuity Consulting (Royal Society, 2020; Jackson and others, 2020). Currently,
the Ammonia to Green Hydrogen Project, supported by the UK’s Department for Business, Energy
and Industrial Strategy (BEIS), is being conducted by a consortium of companies and the UK’s Science
& Technology Facilities Council (STFC) to demonstrate a new ammonia cracking technology. In the
EU, the Netherlands leads in promoting the production and utilisation of ammonia (ISPT, 2017).
Funded by the Dutch Ministry of Economic Affairs and led by the Institute for Sustainable Process
Technology (ISPT), a consortium comprising universities, energy, utility and industrial companies
carried out the Power-to-Ammonia project to investigate the value chains and business cases to
produce CO2-free ammonia suitable for various market applications, in particular, energy storage and
power generation. Initiatives have also been taken by energy and utility companies, industries, and
governments in countries such as China, New Zealand, Norway and Saudi Arabia to promote R&D and
deployment of clean ammonia production and utilisation, and to develop an ammonia value chain and
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market. Currently, there are several clean ammonia production projects under development. However,
action plans and/or goals for clean fuel utilisation, similar to those seen in Japan and South Korea,
should be established in these countries and other parts of the world, combined with mandates or
targets of carbon emissions reduction to promote large-scale uptake of ammonia fuel use.
Supportive policies such as direct carbon pricing and carbon taxes are also required to help overcome
the high costs of clean fuels. The case studies by the IEA discussed in Section 5.4 illustrated clearly
how supportive policies could help offset some of the increase in the levelised cost of electricity due
to the higher price of clean ammonia fuel. Financial support and subsidies are also critical, especially
in the early days of ammonia fuel deployment, to attract investment and reduce the risks.
6.2
ROLE OF CCUS AND AMMONIA IN POWER GENERATION
Low-carbon ammonia can be produced by capturing both process and utility CO2 from ammonia
production. Capturing and storing process CO2, a pure stream of CO2 generated from the SMR process,
is easy as it is ready for sequestration (see Section 3.1.1). Capturing utility CO2 which is the CO2
emitted during the generation of steam, heat and electricity needed by ammonia production, requires
the installation of carbon capture equipment with added cost. For ammonia producers that use grid
electricity to power the production process, collaboration with a power generator will be needed to
decarbonise power generation to minimise the carbon footprint of the ammonia. The industry has
experience in CCS over decades with many commercial demonstration CCS projects in operation and
more commercial CCS plants under construction around the world. Carbon capture technologies have
been evolving and are ready to roll out. In addition, measures should be taken to reduce the emissions
of carbon and fugitive methane (also a GHG) during extraction, processing and transport of fossil fuel
feedstock to minimise the life cycle environmental impacts of ammonia utilisation.
Analyses by scientists around the world have shown that substituting fossil fuel with clean ammonia
for power generation can lead to a reduction in life cycle GHG emissions. For coal power generation,
substituting coal with clean ammonia can lead to an 80–95% reduction in CO2. Therefore,
ammonia-coal cofiring technology can provide an alternative approach to decarbonising power
generation. This is especially important for countries or regions that have a young coal fleet or have
limited available low-carbon dispatchable resources. For power plants where CCUS is not a viable
option, for example, due to a lack of easy access to carbon storage sites or having a limited remaining
life which restricts the potential return on investment, ammonia combustion/cocombustion can
provide a means to reduce emissions of CO2. Cofiring ammonia can reduce the risk of existing power
plants becoming stranded assets by allowing them to continue operating even when climate change
mitigation regulations are tightened. This is particularly the case for east and southeast Asia.
The widespread deployment of ammonia as a clean fuel will depend on several factors such as fuel
prices, fuel availability, distribution and storage infrastructure, policy and incentives for uptake, and
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cost of technology. In comparison, the cost of low-carbon ammonia is around 25% higher than that of
conventional ammonia, which can be offset by incentives or supporting policies, for example, carbon
prices and tax credits such as the 45Q used in the USA. Therefore, low-carbon ammonia can offer a
quicker and cheaper option for bridging an immediate least-cost start to a long-term zero-carbon goal.
The uptake could also be slowed by insufficient ammonia availability resulting from constrained access
to capital and infrastructure such as renewable power capacity for the required expansion of ammonia
production and distribution. Therefore, implementing CCUS to fossil fuel-based ammonia production
is critical to large-scale clean ammonia utilisation. It is essential to start planning and investing in
building new ammonia production capacity with CCUS now and retrofitting carbon capture devices to
existing ammonia plants in order to meet the projected increasing demand for low-carbon ammonia.
Again, policies are required to drive and encourage companies and investors to act. Increased efforts,
new regulations and standards, and supporting policies are needed to overcome the barriers to a
successful uptake of clean ammonia fuel utilisation. More R&D is also needed to bring down the cost
of clean ammonia.
6.3
CONCLUSIONS
Substituting unabated fossil fuels with clean ammonia in combustion systems can result in reduced
emissions of CO2 over the life cycle of the fuel. Ammonia combustion/cocombustion and ammonia-fed
fuel cell technologies are in development and can be expected to be commercially available within
5-10 years. It is likely that power generation and maritime transport will be among the first to deploy
clean ammonia fuel to decarbonise the sector. Ammonia combustion technologies may be particularly
important for countries and regions that depend on thermal power plants to provide key flexibility
and other system services, providing them with an alternative approach to decarbonising power
generation.
The uptake of ammonia fuel can be very sensitive to its price as well as local and global availability,
which depend on the cost of production and development of infrastructure. Due to the current high
cost and limited availability of renewable ammonia, the early large-scale uptake of ammonia fuel use
is likely to be based on lower-cost low-carbon ammonia, which can offer a quicker and cheaper start
for a gradual transition to renewable ammonia utilisation.
Policies are key to the successful deployment and use of clean ammonia fuel. Policies in the form of,
for instance, development strategies, roadmaps, action plans and mandates with targets or goals for
clean fuel uptake and/or carbon emissions reduction such as those seen in Japan can inspire companies
and investors to capitalise in clean energy business. Policy support such as emission charges and tax
credits, and incentives are also important in order to overcome the high cost of clean ammonia fuel.
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Overall, ammonia has the potential to become a key element of a net zero emissions energy mix,
especially in energy-intensive sectors such as power generation, transport and some industrial
processes.
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