Low-capital-cost fuel-gas production from combined organic residues — the global potential

An international project on energy recovery from biomass is described for organic wastes, such as agriculture residues and crops grown for energy recovery. The bioconversion to fuel gas of all these is based on “controlled landfilling”, a low-capital-cost batch digestion method associated with the managed recovery of methane from sanitary landfills. An engineering analysis predicts the digester size for small-scale biogas production. The digestibility of seven municipal and agricultural wastes in laboratory batch systems was experimentally determined by eight investigators on five continents. The reported bioconversion ranged from 0.1 to 0.4 m³ biogass per kg substrate. The relative consistency of the results offers encouragement to evaluate the fuel-gas generation potential in developing countries. An appendix presents a mathematical model of a landfill bioreactor.