Effect of different pretreatments and their parameters on biogas production performance: A review

Energy supply is fundamental to modern society, yet its current reliance on fossil fuels is a major contributor to global warming. A transition to renewable energy is therefore critical, offering both climate mitigation and economic opportunities. Biogas is a particularly effective renewable source, addressing energy needs and waste management simultaneously by converting organic matter into clean fuel. Production occurs through a four-stage anaerobic digestion process, influenced by parameters such as temperature, pH, C/N ratio, retention time, mixing, and moisture. Pretreatment methods can significantly enhance efficiency and yield. For lignocellulosic materials, sodium hydroxide is a common chemical choice, while biological pretreatment offers a low-energy alternative. Among additives, zero-valent iron nanoparticles have shown considerable promise. This article aims to identify optimal conditions to make biogas production more cost-effective. Synthesized studies indicate that maximum biogas yield is achieved by: reducing feedstock particle size, maintaining an inlet concentration near 8%, applying a ratio of 25, ensuring neutral pH, and operating at mesophilic temperatures. A key finding is that pretreatment effectiveness is not universal; it is highly dependent on the specific feedstock and digestion conditions. In conclusion, biogas exemplifies the potential of renewables to create a more sustainable and resilient energy system. By optimizing its production, we can advance toward a greener future that reduces environmental impact while supporting economic growth.