Modelling, Simulation and Optimisation of an Integrated Two-Stage P/VSA Process for Post-Combustion CO2 Capture Using Combinations of Adsorbents

Abstract

Abstract This work presents a systematic model-based approach for the simulation and optimisation of an integrated two-stage pressure/vacuum swing adsorption (P/VSA) process used for the reduction of CO2 emissions from dry flue gas. According to systematic comparative simulation studies, all possible combinations of two promising adsorbents (zeolite 13X and Mg-MOF-74) have been considered, to study the effect of adsorbent type on key process performance indicators of the process under consideration at nearly atmospheric feed pressures without using deep vacuum. Furthermore, dynamic optimisation studies for different combinations of adsorbents in the first and second stage (zeolite 13X – Mg-MOF-74 and zeolite 13X – zeolite 13X) have been performed to minimize energy consumption for specified minimum requirements in CO2 purity and CO2 recovery. The optimisation results indicate that the minimum requirements of 95% in CO2 purity and 90% in CO2 recovery are met for the integrated two-stage P/VSA process, for both combinations of adsorbents under different operating conditions, thus resulting in different energy requirements and CO2 productivities.