Advances in biogas cleaning, enrichment, and utilization technologies: a way forward

The biogas generated by anaerobic digestion consists of CH4, CO2, and traces of other gases like H2S and water vapour. Biogas utilization has numerous environmental and economic benefits. Before being used as fuel for industrial or vehicular applications, it is necessary to enrich it. Methane enriched biogas can be regarded as a substitute for fossil natural gas. The available various biogas cleaning and enrichment techniques differ in terms of working, gas quality, energy requirement, separation efficiency, and operational problems. This paper reviews the various technologies for biogas cleaning and enrichment with gas purity and impurities, CH4 recovery and loss, energy requirement, enrichment efficiency, and costs. Among the various alternatives, water scrubbing and membrane separation are the most cost-effective techniques while chemical scrubbing offers relatively high biomethane purities with less CH4 losses. The possible utilization of the biogas and the criteria for gas quality are also reviewed.

Automated summary

The paper reviews various technologies for biogas cleaning and enrichment, comparing them in terms of gas purity, CH4 recovery and loss, energy requirement, enrichment efficiency, and costs.