Strategies for Biomethane Purification: A Critical Review and New Approaches

The global shift towards clean energy emphasizes waste valorization as a key to achieving sustainable development goals. Biomethane production from organic waste not only converts waste to energy but also reduces greenhouse gas emissions. The growth trajectory of sustainability and environmental protection highlights the significance of energy valorization in anaerobic digestion to produce biomethane and digestate. A 2019 UN report noted that 17% of global food production, equating to 1.0 billion tons, became waste, with major contributions from food waste (61%), households (26%), and food services (13%). The value derived from biomethane, carbon dioxide, nitrogen, ammonia, and manure underscores the need for economically sustainable valorization pathways to attract investment and ensure market viability. Research into purifying biogas for diverse applications has advanced, with technologies such as membranes, genetic manipulation, and metabolic engineering showing potential for improving biogas conversion. Enhanced membrane technologies promise improved biogas quality and efficiency. This review focuses on developing a microscale biogas purification plant and examining processes such as amine scrubbing, absorption, adsorption, and membrane separation as promising methods.