Design and optimization of multilayer composite membrane for biomethane enrichment: Process simulations and economics

Abstract

The depletion of fossil fuels has led to the development of various biogas upgrading techniques that can be a reliable and sustainable energy source. At present, membrane-based gas separation and enrichment have received more acceptance to contend with the traditional biogas upgrading processes. Remarkably, multilayered composite membranes (MCM) fabricated from selective polymers and fillers have achieved high consideration in the field of CO2separation. In this regard, the present study focuses on fabricating and optimizing the porous layer of MCM using Polyether sulfone (PES) and Torlon polymers and their morphological influences on overall membrane performance. The MCM membranes fabricated from the PES porous substrate exhibited 3–4 fold higher permeation than the Torlon. Besides, the effect of zeolite type and % loading on the selective layer performance in CO2gas permeation was examined. From the gas permeation experiments, a 6 % loaded 3A zeolite sample exhibited maximum permeation flux for CO2, which is 1.7 folds compared to the neat Polyether block amide (PEBAX)/PES membrane and 5.8 fold to the neat PEBAX/Torlon without compromising the selectivity. Furthermore, process simulation using Aspen Hysys reveals the economic feasibility of membrane-based biomethane enrichment. Overall, the study results are compared with Robeson’s plot, which reveal the substantial potential of MCM-based membrane technology as a biogas upgrading process and offers assistance in developing an appropriate porous support for MCM.