Comparative techno-economic analysis on a biogas reforming plant: Case study on partial upgrading with a pressure swing water absorption

Abstract

The state-of-the-art biogas valorisation process is the combustion. However, the low margin for this operation fosters interest in alternative biogas valorization options. Biogas conversion into bio-syngas and the consecutive synthesis of biofuels is a promising possibility. A biogas-to-biomethanol process is analysed, using a pressure-swing water absorption unit. Three case studies are evaluated for a 1MWe biogas plant, testing the CO₂ removal layout for methanol production. The better performance, methanol yield of 112% and internal rate of return of 15.29%, requires a CO${}_2$ removal upstream from the reformer unit, and only for the reacting stream. Results indicate a levelized cost of methanol of 1000 €/ton. Furthermore, the synthesis operating pressure impacts the key performance parameters, allowing for a 35% net present value increase. This paper shows that biogas reforming combined with PSWA is an ideal option to produce cheap raw material for chemical synthesis, ideal for many fuel synthesis processes.