IGCC is an emerging clean coal technology with the potential to produce electricity without damaging the ecosystem. However, efficiency enhancement of the IGCC when pollutant emissions are included in the system is a critical issue that should be evaluated further. In this paper, a large-scale IGCC system is modeled and simulated in three configurations: IGCC without CO2 capture, IGCC with pre-combustion capture, and IGCC with post-combustion capture. The validated model of CO2 capture based on a blended solution of ammonia and AMP is integrated with the IGCC to evaluate system performance in terms of net power produced, efficiency penalty due to CO2 capture, and energy losses in various sections of the IGCC. Moreover, an exergy analysis is carried out to investigate the loss of useful work in major sections of the IGCC for three cases (IGCC without capture, IGCC with pre-capture and IGCC with post-capture). The results indicated that the chemical absorption-based blended solution of AMP and NH3 is an attractive option due to its high CO2 loading capacity and low heat duty requirement; it can also be applied to both the IGCC with pre-combustion capture and IGCC with post-combustion capture. However, IGCC with post-combustion capture is more efficient because the net power produced from IGCC with post-combustion capture (561 MW) is greater than the power obtained from IGCC with pre-combustion capture (518 MW). The efficiency loss due to CO2 was 1.1% for post-combustion capture and 4.3% for pre-combustion capture. Furthermore, about 65% of the total exergy loss was observed in the gasifier and gas turbine combustor only, whereas 41.5% of the total power produced was consumed in the gas turbine compressor and air separation unit.
- CO capture
- Climate change