Environmental Aspects and Perspectives of the Brazilian Market for Biogas and Biomethane from Anaerobic Digestion: a Review

In addition to agriculture, Brazil stands out as one of the main meat exporters. In beef production, the waste from the slaughter of a 400-kg bovine produces about 26 kg of waste. In pig farming, the waste generated in the slaughter of a 90-kg pig corresponds to 2.7 kg. Both residues are potential substrates for the production of bioenergy through anaerobic digestion and co-digestion. Likewise, the biogas plants in operation in the country annually generate 1.83 BNm 3 of biogas, and the sector is expanding since the national production capacity is 42.7 Bm 3 /year. This biogas generated through the biological process is an energy source that stands out due to the growing demand for technologies that offer clean energy. Renewable energy sources can ensure greater diversity in the world’s energy matrix, in addition to reducing greenhouse gases emissions and dependence on fossil fuels. Therefore, this review addresses the fundamentals of anaerobic digestion and co-digestion, the environmental impacts of biogas and biomethane, and Brazil’s energy potential for biogas production. In addition, we discussed the biogas purification technologies, the applications of biomethane, and the current scenario and perspectives of Brazilian biogas involving government initiative policies, technical regulation, international panorama, and economic, environmental, and legislative aspects.