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.
