Sustainable Production of Biogas from Renewable Sources: Global Overview, Scale Up Opportunities and Potential Market Trends

Abstract

Anaerobic Digestion (AD), which is the most prominent bioenergy technology worldwide, is a profitable alternative that provides a sustainable solution to treat organic wastes and reduce greenhouse gases emission, while producing energy in the form of methane, improving fertilizer potency and reducing pollution. The most common substrates used in AD process include animal manure and slurry, agricultural residues and their by-products, organic waste from food industries, organic fraction of municipal waste, sewage sludge, and energy crops. However, the feedstocks have different methane yield and they influence the biodigester operational behavior. Thus, many anaerobic biodigesters designs have been implemented, such as anaerobic sequencing batch reactor, continuous stirred tank reactor, anaerobic plug-flow reactor, anaerobic contact reactor, among others. Biogas produced by different sources is mainly composed by CH4, CO2, H2S, NH3 and water vapour, which have different impacts on biogas utilization. To reduce those impacts, methods of removal of undesirable components in biogas have been applied, such as condensation and absorption. Technologies for the conversion of renewable energy sources in electricity, heat and steam have undergone substantial progress over the past two decades. The total amount of electricity produced from biogas is 63.3 TWh and is estimated that the global power generation capacity will increased more than double in biogas production over the next decade, from 14.5 GW in 2012 to 29.5 GW in 2022.