IGCC process intensification for simultaneous power generation and CO2 capture

Abstract

In this study IGCC process which is a commercial example of pre-combustion technique has been developed in order to analyze the overall plant output with CO2 capture while discussing the process economics. Three different schemes with consistent and transparent methodology have been proposed in order to ensure fair evaluation of analysis. First two cases use water gas shift (WGS) reactions scheme with sour shift catalysis process. The resulted syngas rich of CO2 is treated by CO2 capture unit producing a syngas almost free of CO2 which can be either combusted by air or O2. The first case uses air as an oxidant for burning H2 and the combustor temperature is controlled by air as well. In the second case, O2 is used as an oxidizing agent for H2 combustion and combustion temperature is controlled by recycling the captured CO2. In the third case, WGS reactor and CO2 capture units are removed. The syngas composed of CO and H2 is sent directly for combustion with high purity O2 making it similar to an oxy-fuel combustion process and CO2 is recovered while condensing steam from the flue gas. All the results are compared in terms of both power plant efficiencies and economics.