Comparative studies of stripper overhead vapor integration-based configurations for post-combustion CO2 capture

Abstract

In this study, five absorption/stripping process configurations, including a conventional process, split flow with overhead exchanger, simple vapor recompression, and two new configurations-split flow with vapor recompression (SFVR), and improved split flow with vapor recompression (ISFVR) using 30wt% aqueous monoethanolamine (MEA) for CO2 capture from a 300MW power plant were simulated and compared, usingthe ProMax3.2 program. In the SFVR and ISFVR, the heat from the stripper overhead vapor and CO2compression system were recovered to the stripping column in order to reduce the reboiler duty and overall energy consumption. Sensitivity analyses were carried out to evaluate the effects of key parameters (e.g. lean CO2 loading and feed fraction) with regards to energy consumption. The simulation results showed that the innovative configurations SFVR and ISFVR could fully utilize the latent heat of the stripper overhead vapor and decreased the total equivalent works by 17.21% and 17.52%, respectively, compared with those of the conventional configuration. The minimal total equivalent works were 0.808GJ/tCO2 and 0.805GJ/t CO2, respectively. The split stripping with overhead heat exchanger process is the third with a total equivalent work of 0.86GJ/tCO2, while the simple vapor recompression configuration provided no reduction when compared with the conventional process.