Biodigesters: social technology for reducing energy insecurity in rural communities of the semi-arid region

Proper waste management is a major worldwide concern; waste is disposed of directly into the environment, affecting water, soil and air quality. The development and production of green energy sources is strongly encouraged in modern society. The aim of this study, in accordance with Sustainable Development Goals (SDGs) 1, 2 and 7 of the 2030 Agenda of the UN, is to combine the correct disposal of animal waste with the generation of energy to mitigate the energy insecurity of families in an extremely vulnerable semi-arid region in the north-east of the country using biodigesters. To this end, a conceptual proposal was drawn up for a low-cost, easy-to-maintain and easy-to-use biodigester. A small-scale prototype was used to assess its operation by evaluating the main factors that affect biogas production (pH, temperature and the biomass properties: total solids, fixed solids, volatile solids, concentration of volatile fatty acids and C/N ratio). Evaluation of the test prototype gave satisfactory results that corroborate other studies and make it possible to propose an economically viable and efficient full-scale biodigester for biogas production.