Hydrogen Sulphide Removal from Biogas: A review of the Upgrading Techniques and Mechanisms Involved

The production of biogas through anaerobic digestion may play an important role in the economy due to the possibility to produce renewable energy from organic waste material. Biogas is considered as a clean form of energy but unfortunately it contains impurities such as hydrogen sulphide (H2S) which makes it ineffective for heating and lighting hence, its removal in biogas upgrading to biomethane is crucial. Due to its corrosive nature and contribution to the greenhouse gas emissions, innovation and efficient strategies for H2S removal are required so that the quality of biogas can be improved for sustainability and economic growth. The removal of H2S is important as far as biogas upgrading is concerned so as to prevent operational hazards and protect the environment, hence the strategies for its removal for effective and eco-friendly use of biogas are the focus of this review. Review papers with both detailed mechanisms and different methods for H2S removal from biogas are lacking. The understanding of the mechanisms that are involved in H2S removal in each method is important hence the review also presents and discusses insightful mechanisms proposed by different researchers. Based on the mechanisms presented in this review, it can be concluded that it is very possible to design and build efficient biogas upgrading plants and also develop cost effective materials with a high removal efficiency.