experimental investigation of the entrained flow gasification ......• experimental investigation...
TRANSCRIPT
M.Sc. Andreas Geißler, M.Sc. Markus Steibel, M.Sc. Federico Botteghi,
Prof. Hartmut Spliethoff
Institute for Energy Systems
Technical University of Munich
8th International Freiberg Conference on IGCC & Xtl Technologies
Experimental Investigation of the
Entrained Flow Gasification of a
Bituminous Coal and a Lignite
2
1 Motivation and Aim of this Work
3 Experimental Equipment and Experiment Matrix
5 Conclusion and Future Aspect
• Pressurized High Temperature Entrained Flow Reactor (PiTER)
Agenda
4 Results
• High Pressure Thermogravimetric Analyzer (PTGA)
2 Experimental Procedure
3
1 Motivation and Aim of this Work
Motivation
• Entrained flow gasification for high conversion rates
• Fuel properties (e.g. coal rank) and gasification conditions influence conversion
behavior
• Detailed knowledge of occurring phenomena during gasification important for
design and performance of efficient gasifiers
Experimental data for coals of different rank at conditions comparable to
industrial gasifiers necessary for understanding the conversion process and
designing gasifiers
CO2
CxHy
CO
H2O
Soot
H2
Tars Ash
Reaction gas
Fuel
CO2
H2O
O2
CO H2
Synthesis gas
Pyrolysis Gasification
Aim of this work
• Experimental investigation of entrained flow gasification for two fuels at high
temperatures (up to 1600 °C) and high pressures (up to 2.0 MPa)
• Comparison of devolatilization and gasification behavior (overall conversion)
• Focus on char properties (reactivity and surface area) of the collected samples
Comparison of char surface area at different pyrolysis conditions
Comparison of intrinsic kinetic data of representative char samples
determined in thermogravimetric analyzers (Regime I)
Determine and compare the behavior of the fuels in regard to thermal
annealing
4
TGA: Intrinsic
Parameters
Entrained Flow
Conditions
Obtain insights of the gasification behavior of
two fuels at condition comparable to industrial
scale gasifiers
1 Motivation and Aim of this Work
5
2 Experimental Procedure
Char Sample
Lab Analysis
• Proximate and Ultimate Analysis
• Surface Area Measurement
Thermogravimetric Analyzers
• Char gasification kinetics
• Obtain intrinsic kinetic data for different
gasification agents
Pressurized Entrained Flow Reactor
Devolatilization and Gasification Experiments
FuelAsh
ContentMoisture
Volatile
ContentCarbon Hydrogen Nitrogen Sulfur
wt% (dry) wt% (ar) wt% (dry) wt% (dry) wt% (dry) wt% (dry) wt% (dry)
Bit. Coal 8.44 4.35 38.46 68.14 4.82 1.37 0.64
Lignite 5.77 10.07 52.90 63.43 4.77 0.62 0.75
6
Fuel Feeding
Gas inlet
QuenchSampling probe
Technical Data
Gasification AgentsAr, N2, O2, CO2,
H2O
Max. Temperature 1800 °C
Max. Pressure 5.0 MPaReaction
tube
Ga
s P
reh
ea
tin
gR
ea
ctio
n z
on
e
3 Experimental Equipment
Pressurized High Temperature Entrained Flow Reactor (PiTER)
Evaluation: Ash-Tracer-Method
𝑋𝑂𝑣𝑒𝑟𝑎𝑙𝑙 =𝑚0,𝑑𝑎𝑓 −𝑚 𝑑𝑎𝑓
𝑚0,𝑑𝑎𝑓=
1 −𝑥0,𝐴𝑠ℎ𝑥 𝐴𝑠ℎ
1 − 𝑥0,𝐴𝑠ℎ
7
3 Experimental Equipment
Thermogravimetric Analyzer
Technical Data
Gasification AgentsAr, N2, O2, H2,
CO2, H2O, CO
Max. Temperature 1000 °C
Max. Pressure 5.0 MPa
Gas
inlet
Heating
Element
Sample
Beam Balance
Up to 100 % vol. of gasification agent
concentration
𝑟𝑜𝑏𝑠 = −1
𝑚𝑡
𝑑𝑚𝑡
𝑑𝑡
𝑋 𝑡 =𝑚0 − 𝑚𝑡
𝑚0
8
3 Experiment Matrix
PiTER:
• Pyrolysis experiment: Gas residence time between 0.4–2.4 s in N2
• Gasification experiments:
Constant O/C-Ratio of 1
CO2-Gasification: Constant partial pressure of 0.2 MPa
Thermogravimetric Analyzers:
• PTGA:
Lignite and Bit. Coal char from PiTER experiments at similar conditions
Investigated temperatures determined by heating rate experiments
• ATGA (atmospheric):
Pyrolysis chars: 5% O2; constant temperature: 375 °C Lignite, 425 °C Bit. Coal
Reactivities in relation to reactivity of reference char (according to DIN 51720)
9
4 Results
Pyrolysis Experiments at Different Pressures and Temperatures
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3
Ove
rall
Co
nve
rsio
n [
-]
Residence Time [s]
Bit. Coal - Pyrolysis
1200 °C; 0.5 MPa
1200 °C; 1.0 MPa
1200 °C; 2.0 MPa
1400 °C; 0.5 Mpa
• Higher volatile content of lignite
• Bit. Coal: Release of volatiles completed for every investigated residence time
• Lignite: Influence of temperature and residence time detectable
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3
Ove
rall
Co
nve
rsio
n [
-]
Residence Time [s]
Lignite - Pyrolysis
1200 °C; 1.0 Mpa
1200 °C; 2.0 Mpa
1400 °C; 0.5 Mpa
1400 °C; 1.0 Mpa
1400 °C; 2.0 Mpa
1600 °C; 0.5 Mpa
10
4 Results
Pyrolysis Experiments at Different Pressures and Temperatures
0
50
100
150
200
250
300
350
400
450
500
0 1 2 3
Spe
cifi
c su
rfac
e a
rea
[m2/g
]
Residence Time [s]
Bit. Coal - Surface area
1200 °C; 0.5 MPa
1200 °C; 1.0 MPa
1200 °C; 2.0 MPa
1400 °C; 0.5 MPa
• Surface areas decrease with increasing residence time
• Bit. Coal: Higher temperature leads to a lower surface area
• Lignite: Chars more sensititve to reaction conditions
0
50
100
150
200
250
300
350
400
450
500
0 1 2 3
Spe
cifi
c su
rfac
e a
rea
[m2 /
g]
Residence Time [s]
Lignite - Surface area
1200 °C; 1.0 MPa
1200 °C; 2.0 MPa
1400 °C; 0.5 MPa
1400 °C; 1.0 MPa
1400 °C; 2.0 MPa
1600 °C; 0.5 MPa
11
4 Results
O2-Gasification at Different Temperatures:
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3
Ove
rall
Co
nve
rsio
n [
-]
Residence Time [s]
Lignite - O2-Gasification
1000 °C; 0.5 MPa
1400 °C; 0.5 MPa
1600 °C; 0.5 MPa
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3
Ove
rall
Co
nve
rsio
n [
-]
Residence Time [s]
Bit. Coal - O2-Gasification
1200 °C; 0.5 MPa
1400 °C; 0.5 MPa
1600 °C; 0.5 MPa
• Temperature and residence time influence detectable
• Bit. Coal: Overall conversion of 80% reached
• Lignite: Overall conversion of 95% reached
12
4 Results
CO2-Gasification at Different Pressures and Temperatures:
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3
Ove
rall
Co
nve
rsio
n [
-]
Residence Time [s]
Lignite - CO2-Gasification
1000 °C; 0.5 Mpa
1000 °C; 1.0 MPa
1000 °C; 2.0 MPa
1400 °C; 0.5 Mpa
1400 °C; 1.0 MPa
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 1 2 3
Ove
rall
Co
nve
rsio
n [
-]
Residence Time [s]
Bit. Coal - CO2-Gasification
1200 °C; 0.5 MPa
1400 °C; 0.5 MPa
• Temperature and residence time influence detectable
• Bit. Coal: Temperature of 1200 °C too low for the CO2-Gasification
• Lignite: More reactive than Bit. Coal
13
4 Results
• Determine intrinsic kinetic data
• Modeling with Arrhenius- and Power-Law Approach
• Heating rate experiment for determining temperatures for isothermal experiments:
• Reactivity of Lignite significantly higher than for Bit. Coal
• Reactivity towards H2O-gasification for both fuels higher than to CO2-gasification
HPTGA: Char from PiTER-Experiments (2.0 MPa, 1200 °C, 2.5 s)
𝑟𝑜𝑏𝑠𝑒𝑟𝑣𝑒𝑑 𝑋, 𝑇, 𝑝𝑖 = 𝑆 𝑋 ∙ 𝑟𝑖𝑛𝑡 𝑇 ∙ 𝑝𝑖𝑛 = 𝑆 𝑋 ∙ 𝑘0 exp −
𝐸𝐴
𝑅∙𝑇∙ 𝑝𝑖
𝑛
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 200 400 600 800 1000 1200
r ose
rved
(g/g
/min
)
Temperature [°C]
Heating rate experiment CO2
KOL
TBK
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 200 400 600 800 1000
r ose
rve
d(g
/g/m
in)
Temperature [°C]
Heating rate experiment H2O
KOL
TBK
14
4 Results
HPTGA: Char from PiTER-Experiments (2.0 MPa, 1200 °C, 2.5 s)
FuelActivation Energy [kJ/mol] Reaction order [-]
CO2 H2O CO2 H2O
Bit. Coal 205 212 0.70 0.43
Lignite 187 166 0.47 0.24
• Reaction order: Bit. Coal more sensitive to partial pressure of gasification agent
• Activation energy: Less temperature dependency of the reaction with lignite
00.10.20.30.40.50.60.70.80.9
1
0 100 200 300 400 500
Car
bo
n C
on
vers
ion
[-]
Residence time [min]
Lignite: CO2-Gasification (675 °C, 2.0 MPa)
0.5 MPa
1.0 MPa
2.0 MPa
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 100 200 300 400 500 600
Car
bo
n c
on
vers
ion
[-]
Residence time [min]
Bit. Coal: CO2-Gasification (800 °C, 2.0 MPa)
0.5 MPa
1.0 MPa
2.0 MPa
15
4 Results
ATGA: Thermal Annealing of Different Pyrolysis Chars
0
20
40
60
80
100
120
140
160
0 1 2 3
r in
trin
sic/
r Ref
,intr
insi
c
Residence time
Lignite - Annealing
1000 °C; 2.0 MPa
1200 °C; 1.0 MPa
1400 °C; 0.5 MPa
1400 °C; 1.0 MPa
1400 °C; 2.0 MPa
1600 °C; 0.5 MPa
• Reactivity reduced with increasing temperature and residence time during pyrolysis
• Lignite much more sensitive to temperature and residence time influence
• No pressure influence detectable
0
1
2
3
4
5
6
0 1 2 3
r in
trin
sic/
r Ref
,intr
insi
c
Residence time
Bit. Coal - Annealing
1200 °C; 0.5 MPa
1200 °C; 1.0 MPa
1200 °C; 2.0 MPa
1400 °C; 0.5 MPa
Reactivites of char samples is reduced by thermal annealing:
16
5 Conclusion and Future Aspects
Future Aspects
• Transfer intrinsic kinetic data with effectiveness-factor approach to entrained flow
conditions (Regime II and III)
• Use data for model validation
• Test further coals (other ranks such as anthracite) or biomass
• Create databank with kinetic data and further parameters relevant for gasification
• Data of experiments at high temperature and pressure are presented
• Pyrolysis behavior and surface area development shows higher sensitivity to
operation parameters for the lignite than for the bituminous coal
• Higher reactivity of lignite → Higher conversion of the lignite at equal conditions
Obtained data can be used for designing large scale applications
according to the fuel rank
Conclusion
17
Thank you for your Attention!
M.Sc. Andreas Geißler
+49 (0) 89 287 16263
Institute for Energy Systems
Technical University of Munich
This work is part of a project supported by the German Federal Ministry of Economics and Technology and
industrial partners (AirLiquide, RWE, EnBW, Vattenfall and Siemens Fuel Gasification) under the
Contract Number: 0327773A.