2010‐05‐10
Chalmers University of Technology
Chalmers pilot gasifier an overview
Henrik Thunman
Division of Energy Technology
Chalmers University of Technology
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Background
Local utility company Göteborg Energi has a goal that they will replace all natural gas they use and sell with a substitute based on biomass (SNG)
First step toward this goal is to build a 20 MW SNG‐plant together with E.ON to be taken into operation at the end of 2012
Second step is to take a 80 MW SNG unit into operation to the end of 2015. In parallel E.ON has the ambition to build a 200 MW SNG unit within the same time frame.
Henrik Thunman Division of Energy Technology
1
2010‐05‐10
Chalmers University of Technology
Indirect Gasification, 4‐8 MWfuel/m2
(0.8‐1.6 ton/h m2)
Dry N2 free
product gas QG
Waste water (liq), Xw
QCL
Tquench > Tsat
Fuel
Air
Q
Drying
QGL
Flue gas Tchimny>Tmin
Flue gas Steam QGH+QCH
Product gas
Steam
QCH
Drying
Devolatilization
Combustion
Evaporated and Pre‐heating of
waste water
Qevap
Steam QGH
Heat
Char
Fluidized Bed
Gasification
Steam
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Energy Balance Indirect Gasification QG
Optimized gasifier
Q (LHV)
Q(HHV)
Fuel 50% moist, Qfuel
100.0
123.0
Fuel 20% moist, Qfuel,dried
111.2
123.0
97.9
109.7
Steam prod. gasi., QGH
6.4
6.4
Steam prod. comb., QCH
2.9
2.9
Product gas, QG
Low temp heat, gasi., QGL
3.7
3.7
Low temp heat, comb., QCL
Low temp heat, comb.,
0.3
0.3
111.2
123.0
11.2
11.2
9.3
9.3
11.2
11.2
Heat demand drying
QGH+QCH
QGH+QCH+0.5QGL
QGL
Qfuel,dried
QCL
QGH
QCH
Drying
Xw=0.15
Devolatilization
Combustion
Air pre‐heated
to 53 % of max
Heat
Char
Gasification
Steam
Qfuel,dry
QGH+QCH
xQGL
Drying
Qfuel
Henrik Thunman Division of Energy Technology
2
2010‐05‐10
Chalmers University of Technology
Pressurizing of Product Gas
Alternative 1
Alternative 2
Fl Gas
Flue
G
CO2
Flue Gas
QCL, QCH2
QCG, QCG
Qfuel
QP
Drying
Product Gas
Air
Product Gas
QCL
QGL
QGH
QCH
Qevap
Filter
Qfuel
Air
Qevap
Water
Filter
Combustion
QCH1
Heat
Char
Drying
y g
Drying
y g
Devolatilization
Devolatilization
Gasification
Combustion
Heat
Char
Gasification
Steam
Steam
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Poly‐Generation Concept of Chalmers Heat, Electricity and Biofuels
• Increased stability of the gasification process
• Less need of refractory walls
• Possibility to take full advantage of the low temperature heat demand connected to the drying
• Take advantage of the low alkali content in the char
• Production unit can produce heat and power even if the biofuel
production has low availability
Henrik Thunman Division of Energy Technology
3
2010‐05‐10
Chalmers University of Technology
Poly‐Generation Unit
3,50
3,00
QCH ((T>150 °C)
50 )
QCL (T<150 °C)
2,50
Q/QF0
QG (product gas)
QGH (T>300 °C)
QGL (T<300 °C)
2,00
QF Fuel to combustor
1,50
QCH+QGH High Temp Heat
Qb
Wood 10 % most
10 % most.
QFG
Wood 40 % moist
QF
1,00
QCL+QGL Low Temp Heat
Boiler Qb
0,50
0,00
4,0
3,5
3,0
2,5
2,0
1,5
1,0
0,5
Steam
0,0
Air
QFG/QF0
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Market Introduction
The gasification route has so far not been Economically Feasible, however present and expected requirements on the introduction of renewable fuels in large scale are slowly changing this To use Existing Boiler Infrastructure for solid fuels ‐ at present producing heat and power ‐ to also produce gas is a low risk option for the introduction of biofuels via gasification
Henrik Thunman Division of Energy Technology
4
2010‐05‐10
Chalmers University of Technology
Concept
Circulating fluidized bed (CFB)
Heat, Electricity, Steam
Combustible Gas
H
Hot Bed Material
Fuel, e.g. Biomass or Coal Hot Bed Material
Heat, Electricity, Steam
Fuel, e.g. Biomass or Coal Air
Fuel
Steam
Air
Before Reconstruction
After Reconstruction
Circulating bed
Bubbling beds
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Chalmers Research‐Gasifier
Chalmers 12 MW CFB boiler
Heat, Electricity, Steam
Flue Gas
Fuel, e.g. g
Biomass Waste or Coal
Hott Bed Material
Gas
Air
Combustible Gas
Hot Bed Material
Fuel
Steam, Flue Gas
Or Air
Steam, Flue Gas
or Air
Henrik Thunman Division of Energy Technology
5
2010‐05‐10
Chalmers University of Technology
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Henrik Thunman Division of Energy Technology
6
2010‐05‐10
Chalmers University of Technology
Wood Chips vs Pellets
100%
4,26
4,20
11,69
11,74
14,62
15,93
90%
3,99
3,93
11,11
11,29
18,32
17,54
80%
70%
C3H8 vol-%
C2H6 vol-%
60%
C2H4 vol-%
C2H2 vol-%
50%
26,96
33,33
32,46
40%
CH4 vol-%
28,14
CO2 vol-%
CO vol-%
H2 vol-%
30%
20%
27,00
21,07
18,74
830°C Flis
780°C Flis
10%
23,35
0%
830°C Pellets
780°C Pellets
Henrik Thunman Division of Energy Technology
Chalmers University of Technology
Specification of Chalmers Gasifier
Variation possibilities
•
•
Product gas composition
g
p
•
Solid flux
•
Fuel feed
•
Temperatures
•
Pressures
•
In plant gas and bed sampling
‐ Dry pellets (tested: Wood and Bark)
‐ Wet biomass (tested: Wood chips)
•
Extraction of gas slip flow
Bed material (tested: silica sand)
Accumulated Time of Operation
Fuel load 0 – 4 MW (0 Fuel load 0 4 MW (0 ‐ 1 ton/h) 1 ton/h)
–
•
(tested: 0‐2.3 MW)
Optional fluidization media
‐ Steam
‐ Flue gases
‐ Air (not yet tested)
•
Temperature in Gasifier 550‐950 °C (tested 725 ‐ 860 °C)
•
Residence time
•
Fuel
•
Measurements
‐ Adjustable solid flux ‐ Adjustable bed height (Not yet applied)
Adjustable bed height (Not yet applied)
with fuel ~650 h
without fuel ~4300 h
Henrik Thunman Division of Energy Technology
7
2010‐05‐10
Chalmers University of Technology
Conclusions
• Indirect gasification is an energy efficient process to produce a product gas from biomass in mid‐ and large scale, up to several h d d f MW f l i
hundreds of MW fuel input
t
• Pressurizing of product gas can easily be integrated into the process without any significant energy penalty
• Poly‐generation of gas with heat and power production from solid biomass simplify construction and operation. It also utilize the low temperature heat demand of the process and enable higher steam temperature
heat demand of the process and enable higher steam
data from biomass. • Chalmers gasifier show a significant different gas composition than corresponding unit in Güssing
Henrik Thunman Division of Energy Technology
8