Gaseous Biofuels from Waste: Low Environmental and Toxicological Impact with Maximum Benefit on the Greenhouse Effect

This paper on using gaseous biofuels from waste is from the proceedings of 14th international Conference on Urban Transport and the Environment in the 21st Century, which was held in Malta in 2008. The authors note that biomethane, which can be used in existing natural gas engines, supports vehicles with low environmental and toxicological impact, would be particularly suitable for urban area operation (fleets of cars, buses and trucks), and can satisfy the more stringent regulation limits that are being put in place worldwide. They maintain that on-site biomethane production, through anaerobic digestion or future gasification-methanization plants, will allow the problem of gas distribution to be overcome when a natural gas grid is not widely diffused. The capture and use of biomethane derived from the organic waste matter decomposition process allows a significant reduction of greenhouse gas emissions into the atmosphere. The authors also consider the problems of land use competition, the efficiency of biomass utilization, second generation technologies that leave edible fractions of plants for food use, improvements in hydrogen production by dark fermentation, the direct production of methane/hydrogen mixtures, and the development of gas engines with higher efficiency and further reduced emissions.