Sustainable energy from biomass: A review of optimization strategies in biogas processes

Biomass to energy conversion has evolved into an essential route for mitigating greenhouse gas emissions and fossil fuel dependence. Anaerobic digestion (AD), among other biomass conversion technologies, has received considerable interest because it can generate biogas—a clean and renewable energy carrier. Nevertheless, difficulties surrounding substrate heterogeneity, process inefficiency, and scaling have limited the mass implementation of improved biogas systems. To this end, this review comprehensively investigates novel optimization methods for enhancing biogas yield, conversion efficiency, and process sustainability. The review thoroughly analyzes important aspects like substrate selection, process parameter optimization, reactor design, and microbial community management. Agricultural residues, food waste, and organic sludge are presented as major substrates, whose biochemical characteristics determine biogas productivity. It is discovered that microbial activity and biogas kinetics are significantly impacted by parameter tuning, including hydraulic retention duration, temperature, pH, and organic loading rate. The function of reactor design, such as continuous stirred tank and plug‐flow systems, is examined in terms of mixing strategy and scalability. Microbial engineering developments, co‐digestion strategy, and digestate management are also discussed to enhance process efficiency. The findings emphasize not only the technical progress but also the challenges in the availability of substrates, scale‐up of reactors, and techno‐economy viability. With solutions to these, the review emphasizes the crucial role of optimized AD processes in the attaining of sustainable energy solutions. This paper offers insights for researchers, policymakers, and stakeholders in the industry towards a more circular and more resilient future energy.