Pre-combustion CO_2 capture in low rank coal gasification combined cycle power plants

摘要

This study aims at investigating different pre-combustion CO_2 capture options based on gasification of low grade coals. Two main IGCC process schemes with different CO_2 capture technologies are presented and their performance is evaluated. The first scheme is based on the commercial available HTW gasification process utilising a physical absorption unit for CO_2 capture. The second process scheme is based on a novel steam gasification process where in-situ CO_2 capture and steam reforming are taken part in a single reactor with the aid of calcined limestone. In this study possible plant configurations for the selected gasification technologies integrated to a modern gas turbine combine cycle are presented and detailed simulation with Aspen Plus software of alternative CO_2 capture scenarios is performed. Assuming a 90% carbon capture efficiency, plant efficiencies between 36-38% are seem to be possible for both the concepts examined.