Integration of CO2 capture in a complete and detailed
IGCC power station simulation model has been studied in
order to calculate the final efficiency. In this study a precise
representation of the process is performed in order to
ARTICLE IN PRESS
Table 5
IGCC performances with and without CO2 capture—pre-combustion
Units IGCC
[16] [2] [19] [1] [1] [1] [17] This work
Fuel Coal Coal Coal Coal Coal Coal Coal Coal
Reactor HTW Prenflo KRW Texaco Texaco Texaco Prenflo
T inlet turbine C 1070 1190 1280 1280 1280 1400 1120
T outlet turbine C 600 539
Net power output MWe 320 370 411 403 403 403 344 315
Efficiency yi % 45 46.2 36.6 45.9 45.9 45.9 46.4 43.5
Solvent for CO2
capture
NMP Methanol Glycol Selexol Selexol Selexol DEA–MDEA
25–25%
Methanol
Regeneration Flash under
vaccum
Thermal
regeneration
nc Flash Flash Flash Thermal
regeneration
Thermal
regeneration
P bar 19 23 50 50 50 20 23
T C 5 28 25 25 25 30
P storage bar 60 1.3 145 80 80 80 80 150
CO conversion rate mol% 90 95 95.5 85.5 49.4 90 91.9
CO2 absorption rate mol% 98 96 95.5 92.3 92.3 95
Capture rate mol% 86.6 88 91.7 81.7 45.6 83
Emission g/
kWh
227 70 146 409 130 112
CO2 capture and
compression
MWe 24 22.7 20 12.7
Other auxiliaries MWe 44.9 41.4 40.9 39.6
Net power output MWe 320 300 373 358 361.9 373 287.8 293.4
Efficiency with capture
yf
% 38.6 39.7 33.2 38.7 40.44 42.8 38.8 34.6
Dy ¼ yf yi % 6.4 6.2 3.4 7.1 5.42 3.1 7.6 8.9
Table 6
IGCC performances with and without CO2 capture—post-combustion
Units PC NGCC
[18] [20]
Fuel Coal Natural gas
T inlet turbine C Not available Not available
T outlet turbine C Not available Not available
Net power output MWe 320 735
Efficiency yi % 44.3 52.4
Solvent for CO2 capture MEA 30% MEA 25%
P bar 1.2
T C 40
P storage bar 140 50
Capture rate mol% 90 84
Emission g/kWh 120.3
CO2 capture and compression MWe 24
Net power output MWe 237.3 634
Efficiency with capture yf % 32.7 45.2
Dy ¼ yf yi % 11.6 7.2
880 C. Descamps et al. / Energy 33 (2008) 874–881
represent and have the possibility to modify all the
parameters. The order of magnitude of the results is equal
to published results for similar absorption processes, but
the calculated efficiency decrease is lower in this work.
Objective comparisons are difficult because of the lack of
details in published works concerning the integration of the
different mass and energy fluxes with the combined cycle as
well as details of CO2 capture thermodynamic modeling.
An important aspect of CO2 capture is the energy amount
required by auxiliary systems. This energy consumption
reduces the overall efficiency of power generation, typically,
by 8–12% (difference between the efficiencies without
and with CO2 capture), which is a substantial price to pay
for capturing CO2. One attraction of the methanol process
is that the required energy consumptions are moderate for
this operation compared to chemical absorption. There is a
continual research to reduce energy consumption for the
overall process. The use of the new technologies of gas
turbines operating with high turbine inlet temperature will
increase the power production with similar fuel flow rate
and so for the electric net efficiency which is a complimentary
way to reduce fossil fuel consumption and therefore
the CO2 emission. Research on the CO shift conversion
could also reduce the steam consumption.