Technische Universität München
The Role of Solid Fuel Conversion in Future
Power Generation
Hartmut Spliethoff
FINNISH-SWEDISH FLAME DAYS 2013
“Focus on Combustion and Gasification Research”
Jyväskylä, April, 17th and 18th 2013
Technische Universität München
Content
1. Future Developments
1. Worldwide
2. Germany
2. Power Station Requirements
3. Technologies - What Power Plants are required?
4. Research Demand for Solid Fuels
5. IFRF Research
6. EF Gasification Research at TUM
Technische Universität München
1. Future
Primary Energy – World, New Policies Scenario
IEA, WEO 2011
Technische Universität München
1. Future
Importance of Coal – Worlwide
IEA, WEO 2012
Technische Universität München
1. Future
Importance of Biomass – Worlwide
IEA, WEO 2012
Technische Universität München
1. Future
Energy concept 2010 (Germany) – Power Generation
Technische Universität München
2. Requirements
Power requirements – Situation Germany 2010
Today (2010): Share of renewables 16 %, Wind 26 GW, PV 17 GW
Source: Spliethoff: et. al, CIT 2011
Technische Universität München
2. Requirements
Power Requirements – Germany 2020
2020: Wind 46 GW, PV 50 GW, Constant consumption
Requirement for low minimum load
Source: Spliethoff: et. al, CIT 2011
Technische Universität München
2. Requirements
Power Station Requirements
Efficiency
Investment costs
Flexibility
• Future:
• Operational hours ↓  Investment costs ↓
• Flexibility:
• Start-up time ↓ , minimal load ↓
• Load change capability ↑
• Efficiency ??
Technische Universität München
3. Technologies
Technologies for the future
- Storage technologies:
- Long term: chemical storage
- Power to heat
- Flexible conventional power generation for balancing
- Combined Cycle the preferred technologies
- Pulverized Coal Power Station with low investment costs
- Integration of storage technologies
- Renewables:
- Biomass
- Waste
Source: Spliethoff: et. al, CIT 2011
Technische Universität München
3. Technologies
Comparison Flexibility: CC versus PC
Combined
Cycle (new)
Pulverized Coal
Power Station
new
old
Load Change
3-6 % / min
3-6 % / min
2-4 % / min
Minimum
load
25 % (2 GT)
20 %
40 %
0,5 – 1 h
1- 1.5 h
1-2 h
3h
2h
4-5 h
Start-up
hot (8h)
warm (48 h)
Source: Spliethoff: et. al, CIT 2011
Technische Universität München
3. Technologies
Ongoing developments - PC
•
•
Reduction minimum load
– Firing stability determines
minimum load:
– Requirement: safe operation in
case of a mill failure
– Bituminous coal: Reduction for
pure coal firing: 35-40 %  20
%
– Brown coal: Reduction from
appr. 50 % to 20 % by predrying
Operation without power production
Source: Spliethoff: et. al, CIT 2011
Technische Universität München
3. Technologies
Gasification - challenges and opportunities
Gasification
+ High efficiency
- Costly
- Low availability
Power Production
(IGCC)
Efficient CO2separation
Flexibility in the
context of increasing
renewables
Chemicals and energy
carriers/ polygeneration
Technische Universität München
3. Technologies
Gasification - challenges and opportunities
Electrolysis
Gasifier
Storage
for SNG and FT
fuels
infrastructures
are already
present
Chemical
Synthesis
•
•
•
Methanol
SNG
FT liquids
19
Technische Universität München
3. Technologies
IGCC-EPI: Excess Power Integration
100%
Coal
Entrained flow
gasifier
Quench/
HRSG
Rectisol
Exhaust gas
0-100%
ASU
50-100%
Gasturbine
Steam
turbine cycle
HRSG
0-100%
0-100%
O2
El.
Energy
El. Energy
El. Energy
H2S
Synthesis
O2-storage
O2
0-100%
Electrolysis
Excess power
H2
SNG
H2-storage
H2
Gas grid
Technische Universität München
3. Technologies
Waste
Zella Mehlis, Germany
Electrical Efficiency
- Europe, average:
- new conventional plants:
13 %
18 %
Technische Universität München
3. Technologies
Biomass
Entrained
Flow
gasification
Biomass CxHyOz
Source: hs energieanlagen gmbh
Fluidized bed
gasification
Source: www.skymeshgroup.com
Gas cleaning,
tar, sulphur,…
Methanation
SNG
23
Technische Universität München
4. Research Demand
Conversion
H2O
Volatiles
Volatiles
combustion
CO2, H2O
Raw coal
Heating/ drying
Step
Pyrolysis
Demand
Char combustion
Examples
Pyrolysis
2
Kinetics, composition, impact on char structure
Volatile comb.
3
Gas phase combustion
Char
combustion
1
Kinetics for O2, CO2, H2O, char structure and reactivity
Ash
Technische Universität München
4. Research Demand
Emission – Example NOx emission
N2
s
atile
l
o
V
til
ola
V
raw coal
-
NO
char
N
Fuel
nitrogen
-
N
d
fixe
N
coal char
N2
Demand: extensive research in the past and secondary measures lower
research demand
Key: Distribution volatile N and char-N
Technische Universität München
4. Research Demand
Ash related issues
-
-
Ash makes the difference to gas
combustion
Operational problems such as
slagging, fouling and corrosion are
Nucleation
Coagulation
domnination design and operation
anorganic
Research demand:
vapours
Ash formation
heterogeneous
Ash chemistry
condensation
Evaporation
……..
Mineral
inclusions
I
superfine
particle
(0,1 µm)
II
agglomerated
ash particle
(0,1 - 10 µm)
ash
particle
fragmentation
coal
particle
Tail coke
particle
char
combustion
III
flyash
(1 - 20 µm)
Technische Universität München
4. Research Demand
Gasification
• Gasification is an old technology ↔ knowledge base is low
Conventional
•
Membrane reactor
•
CCS power plant today is based on available technologies
Gasifier
Gas
cleaning
High T
shift
Low T
shift
CO2
separation
H2
Coal
CO2
- with CCS η < 40 %
- without CCS η ≤ 50%
Gasification offers a high potential (integration, membranes)
Gasifier
Coal
Gas
cleaning
Membrane
shift
H2
CO2
KEY for future development: Knowledge of coal behaviour including mineral
matter/ trace components at highest temp./ pressures and reducing conditions
Technische Universität München
4. Research Demand
Fuel characterization and CFD-modelling
Requirement for design and operation: to know the impact of
fuel quality and
combustion conditions
on
Combustion behaviour,
Emissions
Slagging, fouling and corrosion
Approach:
•
•
Fuel Characterization: Advanced FC, which consider large scale
combustion conditions
CFD modelling: data of fuels and ashes required
Technische Universität München
5. IFRF Research
IFRF - Fuel characterization
•
•
•
Characterise solid fuels
– to fill data gaps for numerical model validation
& application
– includes fuels that are environmentally and
economically significant
• Biomass, Wastes, Blends with coals
• In atmospheres that reflect O2/RFG
approach, temperatures and pressures of
current interest to members and other
sponsors (steam, CO2)
Establish protocols for solid fuels
combustion/gasification characterisation
Produce and maintain DATABASES (IFRF Solid
Fuel Database- http://sfdb.ifrf.net
Technische Universität München
5. IFRF Research
The IFRF Isothermal Plug Flow Reactor (Livorno – Italy)
•
•
•
•
Length 4 m, ID 0.15 m
8 modules, 19 feed ports
quenched collector probe
60 kW burner, 54 kW
resistances
• 700-1400°C
• 5-1500 ms residence time
• carrier gas (O2, N2, CO2 mix)
conditions similar to those of
full scale plants
Technische Universität München
Technische Universität München
5. IFRF Research
IPFR Qualification:
CFD modeling
Issues:
• Temperature is really isothermal?
• Particles residence time
distribution – trajectories
• Partciles actual T vs time history
CFD modeling can help to correctly
analyze and interpretate the raw
data produced by IPFR.
Technische Universität München
5. IFRF Research
Materials
•
•
•
•
Straw pellets (Denmark)
Torrefied Spruce (BE 2020)
Sofwood pellets (BE 2020)
DDGS (TUD)
•
•
•
Palm Kernel Shell (+ torrified) (KTH & Poland)
Lignine (Italy)
Sunflower seeds (Italy)
Technische Universität München
5. IFRF Research
IPFR - Conversion versus time/ T, gas composition
experimental data with error bars and sub-model fitting
Technische Universität München
6. Gasification Research at TUM
Research Project Industry Partner: Siemens, Air Liquide, RWE, EnBW, Vattenfall
Research Partner: TUM, TUB Freiberg, FZ Jülich, GTT
Gasification
Kinetics
CFD
Simulations
IGCC
Concepts
In-situ
Monitoring
Trace Species
Condensation
Technische Universität München
6. Gasification Research at TUM
Coal Gasification Kinetics
Technische Universität München
6. Gasification Research at TUM
Experimental Procedure
Technische Universität München
6. Gasification Research at TUM
Pressurized High Temperature EF Reactor (PiTER)
• Experiments at pressure
• Gasification in CO2/H2O/O2
• Pyrolysis in inert atmospheres
7m
• Char and gas analysis
Technical Data
Temperature:
Pressure:
Residence time:
Feed:
Fuel mass flow:
Gas vol. flow:
Gas composition:
1m
Reactor height:
Reaction tube
length:
inner diameter:
up to 1800°C
up to 5.0 MPa
0.5 – 5 s
pulverized coal
up to 5 kg/h
max. 100 mN³/h
N2,H2O,CO2,H2,
O2,CO
7000 mm
2200 mm
70 mm
Technische Universität München
6. Gasification Research at TUM
Experimental facilities – Babiter, WMR and PTGA
PWMR
(a)
(b)
1100°C, 5.0 MPa
PTGA
1600°C, 5.0 MPa
Sample
Temperature [°C]
1200
0.1 MPa
1000
(c)
BabiTER
1600°C, atmospheric
Gas
preheater
Pressurized
heating system
Coal
feeder
Heating
zones
1.0 MPa
2.5 MPa
800
5.0 MPa
600
400
200
Optical
ports
Balance system
0
0
1
2
3
4
Time [s]
5
6
Water
quench
Sampling
probe
Gas
analysis
Char
filter
Technische Universität München
6. Gasification Research at TUM
Reaction kinetics in a technical EF Gasifier
Technische Universität München
Conclusions
•
•
•
•
Relative decrease of coal utilization in the medium
and long-term, but absolute increase in the short
and medium term
Importance of biomass and waste fuels
Increase of fluctuating renewables requires flexible
power plants
Research in solid fuels is still required