(617f) Simplified Models for Rapid Evaluation of Adsorption Processes for CO2 Capture from Flue Gas and Ambient Air

Optimizing adsorption processes is a complex, time-consuming task. This work advances a simplified Batch Adsorber Analogue Model (BAAM) to quantify key performance metrics such as purity, recovery, and energy trends [1].The BAAM assumes the column is isothermal and is well mixed with no spatial gradients of intensive process variables. This allows process equations to be simplified to coupled ordinary differential equations independent of time and space, thus allowing for unique graphical capabilities and elimination of cyclic steady-state calculations. This study focuses on the visualization and rapid screening of 4 different pressure swing adsorption (PSA) processes, including complex cycles with pressure equalization steps. A method for predicting if a given process will meet U.S. Department of Energy purity-recovery requirements is also proposed. The extended BAAM was able to predict energy consumption trends instantaneously. We demonstrate the need for choosing optimal operating pressure ranges through process optimization using the extended BAAM. The rapid screening abilities of the BAAM are used to compare various process configurations and the performance of multiple adsorbents. Additionally, the principles used to develop the PSA BAAM are applied to a direct air capture temperature swing adsorption (TSA) cycle with a steam desorption step and used to predict the purity of CO₂, specific energy, and CO₂ productivity [2]. The comparison of the simplified models with detailed ones and their ability to screen materials and optimize process operation will be illustrated.

[1] V. Subramanian Balashankar, A. K. Rajagopalan, R. de Pauw, A. M. Avila, and A. Rajendran, “Analysis of a batch adsorber analogue for rapid screening of adsorbents for postcombustion CO2 capture,” Ind. Eng. Chem. Res., vol. 58, no. 8, pp. 3314–3328, Feb. 27, 2019.

[2] V. Stampi-Bombelli, M. van der Spek, and M. Mazzotti, “Analysis of direct capture of CO2 from ambient air via steam-assisted temperature–vacuum swing adsorption,” Adsorption, vol. 26, no. 7, pp. 1183–1197, Oct. 1, 2020.