Heat integration of natural gas combined cycle power plant integrated with post-combustion CO2 capture and compression

Abstract

Carbon capture for fossil fuel power generation draws an increasing attention because of significant challenges of global climate change. This study aims to explore the integration of a 453 MWe natural gas combined cycle (NGCC) power plant with an MEA-based post-combustion carbon capture (PCC) process and CO2 compression train. The steady state models of the NGCC power plant, the PCC process and compression train were developed using Aspen Plus® and were validated with the published data and experimental data. The interfaces between NGCC and PCC were discussed. Exhaust gas recirculation (EGR) was also investigated. With EGR, a great size reduction of the absorber and the stripper was achieved. An advanced supersonic shock wave compressor was adopted for the CO2 compression and its heat integration was studied. The case study shows net efficiency based on low heating value (LHV) decreases from 58.74% to 49.76% when the NGCC power plant is integrated with the PCC process and compression. Addition of EGR improves the net efficiency to 49.93% and two compression heat integration options help to improve the net efficiency to 50.25% and 50.47% respectively. This study indicates NGCC including EGR integrated with PCC and supersonic shock wave compression with new heat integration opportunity would be the future direction of carbon capture deployment for NGCC power plant.