Design and Performance Evaluation of Multisorbent Vacuum-Swing Adsorption Processes for Postcombustion Carbon Capture
Adam Ward, Ronny Pini
Abstract
High Resolution Image Download MS PowerPoint Slide We present the design and performance evaluation of a novel multisorbent process for CO 2 /N 2 separation based on vacuum-swing adsorption (VSA). We study two process configurations: (i) layered-bed processes, wherein two distinct adsorbent materials are arranged in sequential layers within the adsorption bed, and (ii) mixed-bed processes, wherein two distinct adsorbent materials are homogeneously mixed within the adsorption bed. We develop, validate, and deploy a high-fidelity dynamic adsorption column model for the multisorbent process configurations and apply Bayesian optimization to design processes that achieve maximum separation effectiveness in terms of CO 2 purity and recovery with an application to postcombustion carbon capture (PCC) on a coal-fired power plant. We find that the multisorbent process configurations achieve improved CO 2 /N 2 separation effectiveness compared to benchmark classical single-adsorbent processes, increasing the CO 2 recovery by up to 5% while achieving high CO 2 purity. When operating in compliance with widely adopted performance targets for PCC (Pu CO 2 ≥ 95%, Re CO 2 ≥ 90%), we find that the multisorbent process configurations reduce the energy usage of the separation by approximately 35%. We use the modeling framework to analyze the subcolumn scale adsorption dynamics and identify that the observed improvements in performance are associated with the positioning of the CO 2 adsorption front under optimized operating conditions, leading to favorable dynamic interactions with the operation of the VSA process cycle.