SBIR-STTR Award

This Small Business Innovation Research Phase I project is a feasibility study for economically producing and utilizing marketable fuels from sewage sludge. According to U.S. EPA s National Sewage Sludge Survey, approximately 7.8 million tons of sewage sludge (dry basis) are generated each year in the U.S. as a byproduct of municipal waste water treatment. Management of sewage sludge is a growing concern due to the increase in generated volumes of sludge, demand for lower pollutant discharges, and rise in disposal costs. The proposal develops the novel technology for sewage sludge carbonization and utilization. The carbonization process converts sewage sludge into a quality and pumpable slurry fuel at costs lower than traditional disposal processes. The carbonized slurry fuel can be utilized for co-firing or reburning in coal-fired utility boilers, with greatly reduced emissions compared to sludge incinerators. Objectives of this project include I) to convert a dilute sewage sludge to a uniform and pumpable slurry fuel with a heating value far greater than the original sludge, 2) to determine fuel characteristics of the carbonized sewage sludge versus process conditions, 3) to define emissions and ash characteristics from combustion of the carbonized sewage sludge, and 4) to evaluate cofiring and reburning as potential applications of the carbonized sewage sludge. It is anticipated that Phase I and II research will establish the combustion of carbonized sewage sludge as an economically and environmentally desirable method of disposal and utilization Research plans have been structured to compile the necessary data to construct an integrated demonstration facility in Phase III. The U S market size for carbonized sewage sludge is estimated to be approximately $2.3 billion per year. Preliminary economic estimates demonstrate that the technology will be extremely competitive in most geographic regions of the US.

This Small Business Innovation Research Phase II project will demonstrate the technical and economic feasibility of the Slurry Carbonization process in generating an improved fuel product from low grade Municipal Sewage Sludge (MSS). Approximately 7.8 million dry tons of MSS are generated each year in the U.S. as a byproduct of municipal waste water treatment. MSS management is a growing concern due to the increase in generated volumes of sludge, demand for lower pollutant discharges, and rise in disposal costs. Slurry Carbonization is a moderate temperature and pressure treatment, which removes oxygen functional groups from the MSS and produces a homogeneous, carbon-hydrogen enriched char product for co-combustion or reburning in suspension-fired coal boilers. The overall objective of Phase II research is to develop the scientific and engineering data necessary to design, build and operate a demonstration facility in Phase III scale-up. Phase II research will focus on bench-scale optimization using EnerTech's 2.2 gal/hr PDU and pilot-scale engineering studies using HTI's 510 lb/hr PDU. Pilot-scale combustion and reburning experiments then will be conducted in EER's 1.0 MM Btu/hr BSF. It is anticipated that Phase II research will establish Slurry Carbonization as an economically and environmentally desirable method of MSS utilization. In addition to treatment of MSS, other applications of EnerTech's Slurry Carbonization process technology include clean coal combustion and the production of homogeneous slurry fuels from industrial sludge, pulp and paper mill wastes, Kraft mill black liquor, MSW, RDF, wood wastes and other sources of renewable biomass.