IGCC process intensification for simultaneous power generation and CO₂ capture

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.