An Analytical Design Model of a Vacuum Pressure Swing Adsorption Process for Biogas Upgrading

Abstract

An analytical plant design model was developed to describe the quasi-stationary state of vacuum pressure swing adsorption(VPSA) process for upgrading biogas (CO2 and CH 4 ) to biomethane (CH 4 ). A reduced VPSA cycle comprising the steps adsorption,depressurization, and evacuation was considered, using a model biogas with 50% CO 2 in 50% CH4 . The mass balance for the gasphase was formulated using a simplified advection-reaction approach and for the solid phase using the Linear Driving Force (LDF)model. The steady-state model serves as a basis for process design and optimization, allowing the determination of the requiredbed height as a function of the target product purity.