Mitigation of GHG Emission:
New Technology and other nontechnological measures
7 January 2008
By K.S. Lam
PolyU
References

IPCC Fourth Assessment Report- Climate Change
2007: Mitigation of Climate Change
–
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Greenhouse Gas Emission Control Study
–

2007, IPCC Second Assessment Report
2000, Environmental Protection Department
International Conference on Climate Change, 2007,
Hong Kong
Declaration

In this presentation, most information
- are extracted from IPCC reports and EPD report;
- show the numbers of technology reducing GHG
emissions;
- do not include the cost of technology;
- do not include the barrier of technology;
- do not include the mitigation options with vulnerability,
adaptation and sustainable development
GHG emissions in 2000 (by sector)
Waste
3% Other energy
related
Agriculture
5% Industry
14%
14%
Land Use
18%
Buildings
8%
Power
24%
Transport
14%
Mitigation Approach

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To stabilize GHG at 550ppm, GHG needs to be cut by
80% from today’s level.
No one single technology can achieve this reduction.
Mitigation has to be achieved in all sectors.
GHG can be cut in 4 ways:
– Increased efficiency
– Reducing demand
– Action on non-energy emissions
– Switch to low-carbon technologies
1. Increase Efficiency and
Reduce Demand
1.1 Increase efficiency in Power Generation

Change from coal fired to gas fired.
Schematic of Gas fired Plant
Gas - Natural Gas (Less carbon-intensive
sources of energy)

Efficiency of coal fired power Plants: about 35%
Efficiency of gas fired power Plants: can reach 56%

CO2 emission of gas fired is 57% of coal fired

1.2. Increase efficiency in Transport
–
–
–
–
(1) Aviation
(2) Rail
(3) Road transport
(4) Shipping
Aviation

Fuel efficiency improvement by
(1) Aerodynamic improvements
(2) weight reductions
(3) engine fuel efficient development
Air traffic control
Open more air corridor, shortest path saves energy

Alternative fuel - HYDROGEN

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Rail

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Energy efficiency technologies for railways are
discussed in http://www.railwayenergy.org/tfee/index.php
Aims of technology
(1) Reducing aerodynamic resistance
(2) Reducing train weight
(3) Regenerative braking
(4) Higher efficiency propulsion system
Road Transport

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Incremental improvements in current vehicle
technologies
Advanced technologies: greater use of electricdrive technologies (hybrid electric power trains,
fuel cells and battery electric vehicles)
Alternative fuels: natural gas, biofuels, electricity,
hydrogen
Increase Efficiency in Transport

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Electronic road price system.
Electronic real-time traffic volume information
dissemination.
Increase Efficiency in Transport

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Flying cars in the future?
Levitation in the future?
1.3 Building GHG mitigation options
1.
Overview of energy efficiency principles
- Reduce heating, cooling and lighting loads
(structural insulation panel, glazing layer)
- Increase efficiency of appliances, heating and
cooling equipment and ventilation
1.3 Building GHG mitigation options
1.
Overview of energy efficiency principles
- Improve operations and maintenance
- Change behaviour
- Utilize active solar energy and other
environmental heat sources and sinks
- Utilize system approaches to building design
- Consider building form, orientation and related
attributes
- Minimize halocarbon emissions
Building GHG mitigation options
2.
3.
Thermal envelope
- Refers to the shell of the building as a barrier to
unwanted heat or mass transfer between the interior of
the building and the outside conditions
- Insulation material
- Thermal performance of windows (e.g. multiple
glazing layers, low-emissivity coastings, use of framing
material)
- Air leakage (seals leaks)
Heating systems
- Passive solar heating
- Space heating systems
Building GHG mitigation options
4.
5.
Radiant Cooling Panel
Cooling and cooling loads
- Reducing the cooling load, 25.5C rather than 20C
- Natural ventilation
Heating, ventilation and air conditioning (HVAC)
system
for commercial buildings, 2 alternatives:
Radiant chilled-ceiling cooling,
Displacement ventilation
6.
Building energy management systems (BEMS)
(2)
Building GHG mitigation options
7.
8.
Active collection and transformation of solar energy
- Building-integrated Photovoltaic (BiPV)
- Solar thermal energy for heating water
Domestic hot water
- use of water saving fixtures
- use of more efficient and better insulated water heaters
- use of tankless water heaters
- recovery of heat from warm waste water
- use of air-sources or exhaust-air heat pumps
Building GHG mitigation options
9.
Household appliances, consumer electronics and
office equipment
1.3 Increase Efficiency of A/C

Change A/C from air cool
to water cool, save >20%
electricity.
Building GHG mitigation options
9.
Lighting systems
- natural light, light well,
light pipe
Increase efficiency of Lighting


Change light bulb to fluorescence to LED.
Incandescent Watt = 6 * fluorescent Watt = 12* LED Watt
Incandescent
Fluorescent
LED
Increase efficiency of Lighting

Future:
–
–
Building will use LED
PV/LED, use solar energy to power LED lighting
Increase efficiency in Lift

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One for low floors and one for high floors?
Odd/Even floors vs all floors?
Double deck?
1.4. Industry
Measures for reducing GHG emissions
 Management practices
 Energy efficiency
 Fuel switching, including the use of waste materials
 Heat and power recovery
 Renewable energy
 Material efficiency and recycling
 Carbon dioxide capture and storage (CCS), including
oxy-fuel combustion
Most technologies are discussed in the previous sections
1.5 General principles to reduce Demand

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Reduce population.
Reduce waste.
Use only when it is needed.
Purchase energy efficient products.
Reduce size of products.
Walk – bicycle – mass transit – motor vehicle.
Satellite city: home near office.
Work at home? Home office?
2. Action on Non-Energy Emissions
2.1 Mitigating GHG emissions from
agricultural ecosystems

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Cropland management
Grazing land management/pasture improvement
Management of organic soil
Restoration of degraded land
Livestock management
Manure/biosolid management
Bioenergy
Source: IPCC 2007 Assessment Report:
Mitigation of Climate Chnage
2.2. Forestry

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1m3 of wood stores 0.92tCO2
Mitigation Activities
(1) Maintaining or increasing the forest area
(2) Maintaining or increasing the carbon density
(3) Increasing off-site carbon stocks in wood
products and enhancing product and fuel
substitution
2.3. Methane from Landfill Site
(1) landfilling with
landfill gas recovery
(CH4)
- Active landfill gas
extraction system
Methane from Landfill Site
Tai Kwu Ling Landfill Site Plant
2.3. Waste Management
(2) post-consumer
recycling
- reduce
- recycling
- re-use
2.3 Waste Management
(3) Composting of selected waste fractions
- Fluorinated gases (CFCs and HCFCs)
(4) Processes that reduce GHG generation compared to
landfilling
- incineration
- production of refuse-derived fuel
- industrial co-combustion
- Biological treatment (compositing, anaerobic
digestion and mechanical biological treatment)
- wastewater and sludge treatment
3. Low Carbon Emission
Technologies
3.1
Carbon Dioxide Capture and Storage (CCS)


CCS - an approach to mitigating global warming
by capturing carbon dioxide (CO2) from large
point sources such as fossil fuel power plants and
subsequently storing it instead of releasing it into
the atmosphere
CO2 Storage: (1) geological storage, (2) ocean
storage, (3) mineral storage
Carbon Dioxide Capture and Storage
1.1 Integrated gasification combined cycle
IGCC

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Clean coal technology – coal gasification and
combined cycle.
Coal gasification – coal is partially combusted
with oxygen and steam to produce syngas. The
syngas then is cleaned before entering gas turbine.
Combine cycle – syngas drive gas turbine first,
the residual heat then make steam which drive
steam turbine. Consume less fuel per kWhr.
Geological Storage
Ocean Storage
Emissions to air from plants with or
without CCS (kg/(MW·h))
Natural gas
combined cycle
Pulverized coal
Integrated
gasification
combined cycle
CO2
43 (-89%)
107 (−87%)
97 (−88%)
NOX
0.11 (+22%)
0.77 (+31%)
0.1 (+11%)
SOX
---
0.001 (−99.7%)
0.33 (+17.9%)
Ammonia
0.002 (before: 0) 0.23 (+2200%)
---
Source: IPCC special report 2005
Between brackets the increase or decrease compared to a similar plant without CCS
Examples of power plants with CCS

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StatoilHydro – Natural gas Field
(http://www.statoilhydro.com/no/Pages/default.as
px)
FutureGen Alliance – Coal-fueled power plant
(http://www.futuregenalliance.org/news/releases/p
r_12-18-07.stm)
3.2. Low Carbon Power Generation
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Nuclear: Uranium, Uranium recycle, Fusion
Renewable:
–
–
–
–
–
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Hydro,
Wind,
Solar PV,
Biomass,
Geothermal,
Ocean.
Nuclear Energy
Nuclear Power
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It is considered as a non-renewable energy
Little GHG emissions.
Total life-cycle GHG emissions per unit of electricity
produced from nuclear power are below 40gCO2eq/kWh.
It is considered to be the short to medium term solution
for mitigation of CO2 emission.
As of December 2006, 442 nuclear power plants were
in operation with a total installed capacity of about
370GWe
In 2005, 2626 TWh of electricity (16% of the world
total) was generated by nuclear power
Daya Bay Nuclear Power Plant
Renewable Energies
Renewable energy

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Renewable energy accounted for over 15% of world
energy supply in 2004
Renewable: Hydro, Wind, Biomass, Geothermal,
Solar PV, Ocean
Technology of renewable energy

Category (A): Large and small hydro, woody
biomass combustion, Geothermal, landfill gas,
crystalline silicon PV solar water heating,
onshore wind, bioethanol from sugars and
starch
Technology of renewable energy

Category (B): Municipal solid waste-to-energy,
anaerobic digestion, biodiesel, co-firing of
biomass, concentrating solar dishes and troughs,
solar-assisted air conditioning, mini- and microhydro, offshore wind
Technology of renewable energy
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Category (C): thin-film PV, concentrating PV,
tidal range and currents, wave power, biomass
gasification and pyrolysis, bioethanol from lignocellulose, solar thermal tower
Category (D): organic and inorganic
nanotechnology solar cells, artificial
photosynthesis, biological hydrogen production
involving biomass, algae and bacteria,
biorefineries, ocean thermal and saline gradients,
ocean currents
Hydropower
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emissions-free,
reliable energy source,
zero CO2-emissions,
Hydropower's fuel—water—is essentially infinite and is
not depleted in the production of energy.
preserve our nation's independence from supply
disruptions overseas.
hydropower excels at preserving the stability and
reliability of the electrical grid due to its unique operating
characteristics.
Wind Energy
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The wind push a
propeller to rotate. The
motor that attach to the
propeller generates
electricity.
Can be small scale.
Solar technologies
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Passive
Active
Photovoltaics
Solar thermal electric
A passive solar house. Sunlight streams into the house
during low sun of winter months. The overhead sun is
blocked in summer months. Interior walls absorbs
energy and emit heat all the time.
Active solar systems

Active solar systems generally employ rooftop
panels that collect heat from sunlight and store it
in water or some other medium. This solar
energy can then be used to heat domestic hot
water or to heat the interior of the building
Medium temperature
Concentrating Parabolic Collector
Photovoltaics

Thin wafers of materials such as silicon that emits
electrons when struck by sunlight.
Array of photovoltaic cells. It is like thousands
of batteries connected together.
PV Solar Panel in Hong Kong
Solar Thermal Electric
Solar thermal electric
using parabolic
reflectors. It heat up
oil filled tubes and in
turn heat water to
produce steam.
High temperature
Roof Collector
Biomass Energy

Biomass is organic matter such as wood or crop
wastes that can be burned or converted into
gaseous or liquid fuels.
Geothermal Energy
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Geothermal energy is a renewable resource
created primarily from magma, molten rock
beneath the crust.
It is an enormous, underused heat and power
resource that is clean (emits little or no
greenhouse gases), reliable (average system
availability of 95%), and homegrown.
Geothermal Energy
Simple application case
Ocean Energy
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Tidal energy schemes capture water at high tide
and release it at low tide.
Wave energy: the oscillating motion of an
incoming and outgoing wave is used to drive
turbines that generate electricity.
Ocean thermal energy conversion uses the
difference in temperature between warm surface
water and cold deep ocean water to make
electricity.
Tidal Energy
Dam of a Tidal power generation
station.
The dam opens during high tide to
allow water level to raise.
The close when tidal started to ebb
and lock the water level.
The side gate then release water at
low tides to generate electricity.
How it works
Second-generation tidal power plants
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Two types- vertical axis and horizontal axis
Harness the energy of tidal streams
More efficient because they allow for energy production on
both the ebbing and surging tides
One site has potential to equal the generating power of 3
nuclear power plants
3.4 Low Carbon Emission Vehicles
Alternative fuels
- Natural Gas (CNG/LNG/LTL)
- Biofuels
- Electric vehicles
- Hydrogen / Fuel Cells
4. Advance Technologies
and Latest Development
4.1. Future Technologies
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Integration of different technologies
Hydrogen Fuel
Fuel Cells
Nuclear Fusion
Waste-to Energy Facility (WEF)
Enhanced anaerobic digestion for Municipal Solid
Waste
Sludge incineration
Integration of Technologies
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Hybrid vehicles:
–
Electric drive + gasoline
Integration of Technologies
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Hybrid vehicles:
–
gasoline + Hydrogen
Hydrogen Fuel
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Over 70% of earth’s surface is ocean.
The problem is how to collect enough solar
power to convert water to H2 fuel.
This approach could completely solve the GHG
emission problem.
E.g. Outerspace/desert/tundra PV plants.
Outerspace Power Stations
Space-based solar power offers energy from an
unending source with no emissions and very little
environmental impact
FUEL CELL

Reversed Electrolysis
Device
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Pt coated electrodes

Use air as a source of O2
How Does it Work

Electrolyte- protonexchange-membrane (PEM),
Phosphoric Acid

Combines Fuel and Oxygen

Produces H20 (l), heat, CO2
Fuel Cell
Fuel Cell can be used in small or large
scale applications
Useful Links
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IPCC special report on carbon dioxide capture and storage
(http://www.ipcc.ch/ipccreports/special-reports.htm)
IPCC forth assessment report : Mitigation of Climate
Change (http://www.ipcc.ch/ipccreports/ar4-wg3.htm)
Greenhouse Gas Emission Control Study
(http://www.epd.gov.hk/epd/english/environmentinhk/air/s
tudyrpts/greenhouse_gas_study.html)
4.2. Eco-City / Carbon Neutral City
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Dongtan Eco-city (near Shanghai)
An island with 500,000 people.
40% land used for building, others to green space and
farmland.
Integrate all aspects of sustainability.
Low energy consumption that is as close to carbon neutral
as possible, most energy derive from solar, wind and
biomass.
Pedestrian, bicycle and fuel cell transport.
Recycled city waste organic farming self-sufficient in water
and food sourced from the surrounding farmland.
Another city is Sseesamirembe (Uganda)
4.2. Eco-City / Carbon Neutral City

Dontang Eco-city (near Shanghai)
End