Incorporating IGCC and CaO sorption-enhanced process for power generation with CO2 capture

Integrated gasification combined cycle (IGCC) is a power generation technology to convert solid fuels into electricity. IGCC with CCS is regarded as a promising option to mitigate CO2 emission. In this paper, the CaO sorption-enhanced process is incorporated downstream with coal gasification to produce a hydrogen-rich stream for electricity production and CO2 separation. A WGS-absorber substitutes the high- and low-temperature water-gas shift reactors and desulfurization units in conventional IGCC-CCS to produce a hydrogen-rich stream, which is sent onto a gas turbine. CaO is used as the sorbent to enhance hydrogen production and for CO2 capture. Regeneration of CaO is completed via calcination in a regenerator vessel. The IGCC with CaO sorption-enhanced process is modeled and simulated using Aspen Plus software. Two commercial available gasification technologies. Shell and Texaco, are integrated with the sorption-enhanced process. The results showed IGCC with CaO sorption-enhanced process has a satisfactory system performance. Even though the net electricity efficiency is not as high as expected, just around 30-33%, the system has a high CO2 capture efficiency similar to 97% and low pollutant emissions. Moreover, compared with conventional IGCC-CCS, the schematic diagram of the IGCC-CCS process is simplified. Parameters that affect the plant performance are analyzed in the sensitive analysis, including WGS-absorber temperature, H2O/CO ratio, pressure, etc. Some challenges to the system are also discussed. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.