Process for converting food sludges to biomass fuels

A process for producing a biomass fuel that is capable of self-sustained burning in a gasifier-type suspension burner from a feed wastewater produced by a food preparation plant, said wastewater containing fats in an insoluble fraction and protein in a soluble fraction thereof, comprising the following steps:

• A. adding flotation and coagulation chemicals to said feed wastewater in such quantities that all of said insoluble fraction and at least 25% of said soluble fraction are removed in said float sludge to produce partially purified wastewater;
• B. feeding said partially purified wastewater to an aerobic treatment system to produce waste activated sludge;
• C. thickening a selected portion of said waste activated sludge from a solids content of 1-2% to a solids content of 6-7% by weight;
• D. on dry weight basis, admixing 3-4 pounds of an absorptive bulking agent to one pound of sludge solids to obtain a biomass mixture having 6-22% fat, said sludge solids being 0-50% waste activated sludge;
• E. drying said biomass mixture to a moisture content of up to 15%;
• G. regulating the size of particles in said dried biomass mixture to no greater than about 1/8 inch;
• and
• H. conveying said dried and size-regulated biomass mixture to a suspension burner of the gasifier type.