New Performance Indicators for Evaluation of Adsorbents for CO2 Capture with PSA processes

Abstract

Pressure swing adsorption (PSA) process is one of the candidate processes for C02 capture. The interest has led to the development of various adsorbents such as modified zeolite materials and metal-organic frameworks (MOFs). Performance of the developed adsorbents is evaluated through lab-scale methods based on simple measures like working capacity and selectivity. However, these performance indices are not entirely reflective of the performance in a PSA process. In this work, we propose new performance indices that are better reflective of actual process-level performance: efficiency and purity. Both are derived for an ideal PSA process, which means they serve as the limits of the best achievable performance of a PSA process with target adsorbents. For simple calculation and quick evaluation, the performance indices are derived as explicit analytical expressions. Case study involving the evaluation of zeolite 13X, activated carbon and Cu-BTC is presented to show the use of the new performance indicators, and the results are compared with rigorous simulation results.