Economic analysis of amine based carbon dioxide capture system with bi-pressure stripper in supercritical coal-fired power plant

Abstract

Post-combustion CO2 capture and storage is among the most mature technologies to capture, compress, transport and store CO2 from flue gas in coal-fired power plant. This paper presents the simulation of monoethanolamine (MEA) based CO2 capture and compression process integrated within a 600MWe supercritical coal-fired power plant using chemical process simulators. Comparison between bi-pressure stripper and single-pressure stripper reveals that improved CO2 capture system with bi-pressure stripper minimizes energy penalty of CO2 capture and compression by up to 6.3% at full unit load. The study also explores optimization of some important process parameters affecting the performance of coal-fired power plant by taking into account both CO2 capture process and CO2 compression at full unit load. These parameters include operating stripper pressure, CO2 capture efficiency and steam extraction location. Results show that the optimal stripper pressure is within the range of 1.9–2.1bar and feasible CO2 capture efficiency is between 60% and 90%. Results also show that low-pressure steam extraction reduces energy penalty. Evaluation of improved CO2 capture system is also performed at part flue gas load ranging from 40% to 90%. The study reveals that operating at part flue gas load, as compared with full load, increases energy penalty of carbon capture. Not only energy penalty but also lean solution flow rate and plant efficiency are studied at different flue load levels in this paper. In addition, results show that bi-pressure stripper configuration is also effective in reducing energy penalty at part unit load.