1. Biomass Based Net CO2-negative
Cogeneration – Performance
Study Using ASPEN Plus®
Kuntal Jana and Sudipta De*
Department of Mechanical Engineering
Jadavpur University
Kolkata- 700032
India

4. Some future options with fossil fuels………
• IGCC with carbon capture (pre-combustion
or post-combustion)
Oxy-fuel combustion and CO2 capture and
storage
Membranes specific for certain gases –
O2, CO2, H2 etc. and integration with existing
technology

6. Global Primary Bioenergy Supply
Global Bioenergy Electricity Generation 2000-10

7. Possible options ………..…..
• Biomass based power (CO2 – neutral).
• Improving energy efficiency and environment
performance (Cogeneration, Gasification)
• Reducing CO2 emission even more (net CO2 –
negative)
• Combining all these – possible future
sustainable options with efficient and net
CO2- negative power generation units.
• Challenges – technology maturity, scaling up….

8. Objective of the Present Work
Objective
• Model development of biomass integrated
gasification combined cogeneration (BIGCC) with
CO2 capture
• Simulation of the model by using ASPEN Plus®
• Defining a non-dimensional thermodynamic
performance parameter- capture performance
• Finding the optimum degree of CO2
capture,
based
on
thermodynamic
performance, i.e., capture performance

9. Schematic of biomass integrated gasification combined cogeneration with
post-combustion CO2 capture
GT-Cycle
Gasification
Water
HEATER
SYNGAS COMPRESSOR
SYNGAS CLEANER
GASIFIER
DRIER
Biomass
CO2 CAPTURE
Syngas
Air
ECONOMIZEREVAPORATOR
GAS
COOLER
Ash
CO2
SUPERHEATERREHEATER
GAS
TURBINE
COMBUSTOR
STEAM
TURBINE
PUMP
Air
AIR COMPRESSOR
CONDENSER
ST-Cycle
Steam
Vent
gas

10. Schematic of amine based CO2 capture process
Make-up amine
AMINE TREATMENT PLANT
Vent-gas
CO2
CO
Product2
Product
o
Amine (40 C)
ABSORBER
RICH-LEAN AMINE
HEAT EXCHANGER
o
Flue gas (40 C)
CONDENSER
PUMP
Rich-amine solution
FLUE GAS
COOLER
STRIPPER
SOX REMOVAL
UNIT
Lean-amine solution
Flue gas
Reboiler

11. B20
FLU-EXHS
TO-ATMP
FLU-EXIT
ECO-EVA
GAS-SEP
AMONI A
WATER
H2S
DRI ER
GT-SYN
W
RYI ELD
HP-WRK
SYN-COMW
HOT-BI O
HP-ST
SYN-COMP
RSTOIC
GAS-TURB
COMB-GAS
WET-BIO
DRY-BI O
BIOMASS
ECO-IN
W
GT-WORK
GIBS-OUT
COMP-SYN
DRY-FLSH
SPH-OUT
RH-IN
SPH-IN
Q
PUMP
FLUE-OUT
GT-AIR
Q-DECOMP
COMP-WRK
SEPARATE
HOT-FLUE
PUMP-W RK
GT-COMB
DECOMP
SPRH
SYN-GAS
Q-COND
FEED-WTR
SOLI D
RGIBBS
COMP-AI R
SYN-OUT
GASI -AIR
B18
LP-ST
COND
RH-OUT
LP-WRK
W
S3
C-SEP
PR-WTRI N
S5
LP-OUT
AIR-COMP
C-ASH
COLD-SYN
PRO-HT
PRW TROUT
S48
ASPEN Plus® model of BIGCC
CO2OUT
STRIPIN
STRIP
PUMP
TREATGAS
AB
COL-MEA
LEANMEA
POUT
Q
Q-MEA
RICHMEA
COL-FLU
HX
HOUT
HEATER
COOLER
Q-REB
FLUEGAS
MEAOUT
H2O-IN
H2O-OUT
Q
ASPEN Plus® model of Post-combustion CO2 capture

12. Model development & Simulation
• Simulation Software – ASPEN Plus ® (Developed by
MIT, DOE – USA)
• Biomass feed rate – 1000 kg/hr of sugarcane bagasse
• Property methods:
1. Gasification and GT-power generation - Peng-Robinson
equation of state with Boston Mathias alpha function (PRBM)
2. Carbon capture process - Electrolyte Non Random Two
Liquid (ELECNRTL)
3. Steam turbine power generation and process-steam
generation - Steam table (STEAM TA)

13. Operating Parameters
Configurations
Reaction in gasification
Air compression,
Syngas compression
Combustion air
Parameters
Pressure
Equivalence ratio
Pressure ratio
Isentropic efficiency
Mass flow rate
Value
1atm
25% of stoichiometric air
14
0.9
25% excess of stoichiometric air
Gas cleaning
Separation efficiency of solids particles
85%
Gas turbine combustor
Pressure
Heat duty
Discharge pressure
Isentropic efficiency
HP stage temperature
HP stage pressure
LP stage temperature
LP stage pressure
Temperature
Pressure
Isentropic efficiency
LP-ST discharge pressure
Temperature
Pressure
Amine concentration
CO2/amine (mole basis)
14atm
0
1atm
0.9
5380C
12.4MPa
5000C
3.2MPa
250C
1atm
0.92
0.07MPa
400C
1.7 bar
30% by mass
32%
Calculation type
No. of stages
Condenser type
Condenser pressure
Reboiler type
Distillate rate
Reflux ratio
Equilibrium
20
Partial vapor
10 psia
Kettle
1000 Kg/hr
0.10
Gas turbine
Superheater-Reheater
Feed water for ST cycle
HP and LP Steam turbine
Lean amine solution
Lean loading
Stripper column

14. Results
2.5
2
1.5
1
0.5
0
NET GT-POWER (MW)
LPST-POWER (MW)
HPST-POWER (MW)
TOTAL POWER (MW)
Power output of BIGCC with postcombustion CO2 capture
Variation of net-reboiler heat duty
with carbon capture efficiency
0.4
0.2
0
-0.2
-0.4
-0.6
-0.8
REBOILER HEAT
DUTY (MW)
UTILITY HEAT
(MW)
NET REBOILER
HEAT DUTY
(MW)
Heat consumption, Utility heat and net
reboiler heat of BIGCC with postcombustion CO2 capture

15. Variation of capture performance with carbon capture efficiency

16. Conclusions
• Reboiler heat duty increases sharply beyond
50% of CO2 capture
• For plants with CO2 capture, utility heat may be
utilized for CO2 capture process
• For net CO2 negative plant, operational
condition may be thermodynamically optimized
with selection of suitable carbon capture
efficiency (say, for this study 0-0.5).