A Net Energy Comparison of Anaerobic Digestion vs. Ultra-High Temperature Gasification to Achieve Zero Energy

Ultra-high temperature gasification (“UHTG”) offers a new and highly efficient method of extracting usable energy from wastewater treatment plant (“WWTP”) solids. By using electric heating elements in a high temperature alloy reactor operated in a reducing environment, virtually all of the organic matter can be reformed to a clean, chemical grade syngas comprised of hydrogen and carbon monoxide. By comparison, anaerobic digestion (“AD”) of WWTP solids fails to convert a good portion of the available carbon into usable energy products–carbon is lost in the form of carbon dioxide gas, un-reacted volatile suspended solids, un-reacted fixed carbon, and fuel required for digester heating. Consequently, UHTG systems are shown to have a net electrical energy output of nearly two to one compared to AD systems.