Biogas Production and Process Control Improvements

Abstract

Biogas is a sustainable energy produced from biodegradable organic matter through anaerobic digestion. Biogas mainly contains methane (CH4) and carbon dioxide (CO2) and various contaminants, such as water vapor (H2O), ammonia (NH3), hydrogen sulfide (H2S), methyl siloxanes (MSs), nitrogen (N2), oxygen (O2), halogenated volatile organic compounds (VOCs), carbon monoxide (CO) and hydrocarbons whose presence largely depends on the source of biogas. The value of biogas is enhanced further by the production of organic manure as substitutes for chemical fertilizers in crop production. The vast range of applications makes biogas an attractive sustainable energy choice. Bioenergy generation capacity, mainly from biogas globally, has shown promising worth over non-renewable energy options; hence, its production has expanded rapidly during the previous two decades, from 42.38 Exajoules/year in 2000 to about 57.74 Exajoules/year in 2023, an increase of about 36.24%. This study presents the biogas production and potential improvement measures that include factors influencing the process and quality of biogas produces such as C/N (carbon nitrogen ratio, the pH, dilution of feedstock, composition and nutritive value of feedstock, residence period, mixing and stirring, temperature, presence of toxicants, loading time and redox conditions). The main barriers to biogas production and use include lack of technical know-how, lack of subsidies and incentives for biogas production and use. Access to appropriate and affordable biogas technologies, the development of a comprehensive policy on the construction and operation of bio-digesters as well as utilization of biogas and sales of biogas energy products and services are important for an increasing adoption of biogas.