A comprehensive review on methane enrichment in biogas through the purification process using biomass-based adsorbents

Abstract

Biogas, a promising biofuel source, is impeded in direct application due to significant impurities such as CO₂ and H₂S. As a result, enhancing biogas purity has become a substantial area of research. Recent efforts have aimed to improve biogas quality, explicitly focusing on mitigating global warming effects linked to excessive CO₂ emissions. Notably, most existing biogas purification methods are costly, and there is limited research on using sustainable materials for this purpose. This review delves into the documented developments in utilizing natural materials as affordable adsorbents for biogas purification. While water scrubbing remains the prevailing method globally, adopted by over 40% of countries, the article explores alternative technologies, including various scrubbing methods, swing adsorption, cryogenic separation, and biological upgradation. Hybrid biological processes play a crucial role in methane upgrading systems, aiming to boost pure CH₄ production while minimizing energy and chemical requirements. Additionally, the article summarizes various numerical models frequently employed to predict biomass upgradation. The conclusion addresses key process bottlenecks and proposes scientific directives for effectively translating bench-scale studies into large-scale implementation. Overall, this article serves as a valuable resource, offering readers comprehensive technical insights into the upgradation of biogas derived from biomass anaerobic digestion. In biomass anaerobic digestion, organic materials undergo decomposition by microorganisms without oxygen, yielding methane-rich biogas. By exploring this process, the article advances sustainable energy production from renewable biomass sources.