A process for disposing of sewage sludge comprising the steps of, (1) dewatering the sewage sludge to produce an aqueous slurry of sewage sludge having a solids content of about 10 to 30 wt. %; (2) simultaneously heating and shearing said dewatered sewage sludge at about 150.degree. F. to 210.degree. F. in the absence of air for 0.5 seconds to 60 minutes while being continuously passed through a tubular-shaped processing means containing a plurality of rotating agitators, thereby producing a pumpable slurry having a viscosity of less than about 2000 centipoise; (3) dewatering the sewage sludge if necessary; (4) mixing at a temperature in the range of about ambient to 180.degree. F. in a ribbon or in-line static mixer the slurry of sewage sludge from (2) and/or (3) with a supplemental solid carbonaceous fuel e.g. coal and/or petroleum-coke to produce a pumpable aqueous slurry of sewage sludge and supplemental fuel having a solids content in the range of about 50 to 60 wt. %; (5) mixing the slurry of sewage sludge and supplemental fuel from (4) in a steam jacketed continuous rotary disc mixer at about 180.degree. F. to 250.degree. F. while removing steam to produce a pumpable slurry of dewatered sewage sludge and solid fuel having a solids content of 50 to 65 wt. % and a HHV of 6,000 to 18,000 BTU/LB; and (6) burning said pumpable slurry from (5) in a partial oxidation gasifier, furnace, boiler, or incinerator to produce an effluent gas stream. In a preferred embodiment, the effluent gas stream is cleaned and purified and non-contaminating ash and slag are separated. By this process, noxious sewage sludge may be disposed of without contaminating the environment. By-product synthesis gas, reducing gas, or fuel gas may be produced.