Efficiency Analysis of Warm Gas Clean up in Integrated Gasification Fuel Cell (IGFC) System

Abstract

This study investigates the energy consumption of two kinds of pre-combustion CO2 capture technologies, the conventional Selexol process and the elevated temperature pressure swing adsorption (ET-PSA) process, in an integrated gasification fuel cell (IGFC) power plant. Power plant models with and without CO2 capture are built in Aspen Plus and the simulation of ET-PSA process is realized in gPROMS. Specific primary energy consumption for CO2 avoided (SPECCA), a function related to CO2 emission rate and electric efficiency, is used to quantitatively evaluate the CO2 capture energy consumption. ET-PSA technology purifies the syngas at over 150 °C, avoiding the efficiency penalty caused by cooling and reheating processes in conventional purification methods. Adding reflux and rinse to ET-PSA procedures is proved to be effective ways to improve H2 recovery. When the CO2 capture rate is 90% and 99%, the SPECCA of ET-PSA is 1.80 and 2.72 kJ/kg, respectively, while the corresponding outcomes of Selexol is 3.46 and 3.66 kJ/kg, respectively. The reduction of energy consumption is mainly attributed to the saving of sensible heat in the syngas.