Upgrading Biogas to Biomethane

Abstract

Biogas provides a flexible clean and efficient form of energy. Enriched biogas may generate large volumes of bioCH4, allowing its usage as an alternative to natural gas via existing natural gas networks or being used directly as fuel by vehicles. There are two broad categories of upgrade techniques where traditional methods focus on ex-situ upgrading, treating processed biogas to methane utilizing catalytic (biological and chemical) conversion, membrane gas-permeation, desulphurization, physical and chemical scrubbing, absorption and adsorption. Significant research has been made to increase performance and boost the economic feasibility of the above technologies, and many industrial plants around the world use ex-situ methods to enrich biogas. In-situ techniques such as CO2 desorption, pressurized reactor, H2 addition and electro-methanogenesis have gained considerable attention recently. This chapter discusses and examines state-of-the-art biogas enriching technologies showcasing in-situ and ex-situ methods.