Cycle synthesis and optimization of a VSA process for postcombustion CO₂ capture

Abstract

A systematic analysis of several vacuum swing adsorption (VSA) cycles with Zeochem zeolite 13X as the adsorbent to capture CO 2 from dry, flue gas containing 15% CO 2 in N 2 is reported. Full optimization of the analyzed VSA cycles using genetic algorithm has been performed to obtain purity‐recovery and energy‐productivity Pareto fronts. These cycles are assessed for their ability to produce high‐purity CO 2 at high recovery. Configurations satisfying 90% purity‐recovery constraints are ranked according to their energy‐productivity Pareto fronts. It is shown that a 4‐step VSA cycle with light product pressurization gives the minimum energy penalty of 131 kWh/tonne CO 2 captured at a productivity of 0.57 mol CO 2 /m 3 adsorbent/s. The minimum energy consumption required to achieve 95 and 97% purities, both at 90% recoveries, are 154 and 186 kWh/tonne CO 2 captured, respectively. For the proposed cycle, it is shown that significant increase in productivity can be achieved with a marginal increase in energy consumption. © 2013 American Institute of Chemical Engineers AIChE J , 59: 4735–4748, 2013