Multiscale, Techno-economic Evaluation of Isoreticular Series of CALF-20 for Biogas Upgrading using a Pressure/Vacuum Swing Adsorption (PVSA) Process

TL;DR

This paper presents a multiscale evaluation combining molecular simulations, process optimization, and techno-economic analysis of CALF-20 MOF series for biogas upgrading via PVSA, highlighting the most cost-effective material.

Contribution

It introduces an integrated framework for assessing adsorbent materials for biogas upgrading, combining molecular data with process and economic optimization.

Findings

CALF-20 achieves >97% CH4 purity at $4.31/kg CH4

Energy consumption is 9.35 kWh per kg of CH4

Distinct cost performance differences among CALF-20 derivatives

Abstract

Cyclic swing adsorption processes, such as pressure/vacuum swing adsorption (PVSA), are a promising technology for upgrading biogas by separating carbon dioxide (CO2) from methane (CH4). The rational design of adsorbent materials with tailored properties is important for the deployment of high-performance PVSA technology. Metal-organic frameworks (MOFs), particularly the CALF-20 isoreticular series, have attracted interest due to their high CO2 selectivity, thermal, and water stability. In this study, we report a multiscale assessment of CALF-20 and its isoreticular five derivatives by integrating molecular simulations with PVSA process optimization and techno-economic analysis. Structural and adsorption characteristics were calculated and employed to assess how each material performs in terms of energy efficiency and cost. The analysis reveals distinct differences in cost performance among the CALF-20 series, with CALF-20 showing the most favorable economics with \gt97\% purity CH4 production cost at \$4.31 per kg of CH4 and energy consumption of 9.35 kWh per kg of CH4. This study demonstrates that the integrated molecular-process optimization framework can effectively guide the search for adsorbent materials for biogas upgrading.