Biogas Production using Different Wastes: A Review

Abstract

Biogas as a renewable energy source has recently been receiving attention due to its numerous advantages, specifically in energy production and waste treatment. Several challenges, including the amount of gas produced, the nature of substrates, and factors affecting production, remain a problem. Hence, this review is aimed at investigating different wastes used in biogas production (nature of substrates), the amount of gas produced, and factors that made a remarkable impact on the outcome of the production. In this review, stages of biogas production, purification of biogas, biomass (substrate) pretreatment, classes of wastes used in biogas and their various outcomes, setting the anaerobic digester, factors influencing the rate of biogas production, and the biogas industry have been extensively reviewed. It was discovered that different substrates produced different amounts of biogas. A substrate with less polysaccharide, e.g., cellulose, and a higher microbial population produces more gas than substrates with high polysaccharide and less microbial population. This is clearly due to the fact that biogas is a by-product of microbial activities; a higher number of microbes will increase gas production. Substrates with high polysaccharide have a slower digestion rate than those with less polysaccharide. Hence, these and other factors should be considered before making the choice of substrate to be used.