Enhancement of methane potential in fractionated biogas stream through composite-hybrid biochemical pathway processes: a review

Biomass (substrates) is a sustainable organic material that, when degraded anaerobically, yields methane. Anaerobic degradation of organic waste is a century old technique which was engineered and brought into commercial application for energy utilization purpose. In the recent past years, extensive research has been carried out all around the world to enhance the percentage of methane composition in biogas and to increase the yield of biogas from anaerobic degradation. This paper mainly depicts detailed review of the four phases of anaerobic degradation and how bacteria itself plays a rate-limiting role of anaerobic degradation system. It also reviews about the key parameters of anaerobic degradation system and its impacts in the system. To overcome the disadvantage of conventional anaerobic degradation process, many process modifications, pretreatments, and co-digestions are followed. The current study deciphers comprehensive review about the pretreatment methods available for various substrates and compares the efficiency of methane enhancement of various pretreatment methods adopted and its recent advancements; co-digestion of substrates and their methane production efficiencies were studied.