Household Biogas Digesters—A Review

TLDR

Biogas is a value‑added product of anaerobic digestion of organic waste, whose production depends on factors such as pH, temperature, substrate, loading rate, HRT, C/N ratio, and mixing, and household digesters are inexpensive, easy to operate, and reduce organic household waste. This review summarizes the design and operation aspects of small‑scale household biogas digesters. The review examines digester designs (fixed dome, floating drum, plug flow), construction materials, operating parameters (pH, temperature, substrate, loading rate, HRT, C/N ratio, mixing), applications, policies, and social and environmental impacts, noting sizes range from 1 to 150 m³. Biogas and the resulting fertilizer can be used for cooking, lighting, and electricity generation.

Abstract

This review is a summary of different aspects of the design and operation of small-scale, household, biogas digesters. It covers different digester designs and materials used for construction, important operating parameters such as pH, temperature, substrate, and loading rate, applications of the biogas, the government policies concerning the use of household digesters, and the social and environmental effects of the digesters. Biogas is a value-added product of anaerobic digestion of organic compounds. Biogas production depends on different factors including: pH, temperature, substrate, loading rate, hydraulic retention time (HRT), C/N ratio, and mixing. Household digesters are cheap, easy to handle, and reduce the amount of organic household waste. The size of these digesters varies between 1 and 150 m3. The common designs include fixed dome, floating drum, and plug flow type. Biogas and fertilizer obtained at the end of anaerobic digestion could be used for cooking, lighting, and electricity.