Biochemical methane potential of livestock and agri-food waste streams in the Castilla y León Region (Spain)

•An inventory of agri-food waste streams was carried out in Castilla y León (Spain).•The potential for methane production from 23 wastes and their mixtures was evaluated.•5% of the energy demand in the evaluated area could be covered by the analyzed wastes.•Livestock and agro-food wastes could cover up to 24% of regional total energy demand.•Logistical aspects are critical in regions with dispersion of population and industry.

An inventory of agri-food industry organic waste streams with potential for biogas production was carried out in a logistically viable area of Castilla y León (Spain). The potential for methane production from 23 wastes and their mixtures was evaluated theoretically and in laboratory batch assays. Obtained methane yields ranged from 290-725 mL CH4 g VS− 1waste, and the methane content in biogas ranged from 46-72% for raw wastes. The estimation of the regional fluxes of waste and methane potentials suggests anaerobic digestion in a centralized plant as a sustainable solution for the valorization of the organic wastes generated in this area, where up to 5% of the primary energy demand can be covered by the calculated total biogas energy potential. Sector-specific waste streams (livestock and agri-food industry) could cover up to 24% of regional total energy demand. Logistical aspects are critical in Castilla y León due to the high dispersion of the population and the industrial facilities.