Partial oxidation of sewage sludge

A process for the partial oxidation of sewage sludge comprising:

• (1) heating a concentrated aqueous slurry of sewage sludge comprising combustible and non-combustible materials and having a solids content in the range of at least 3 wt. % in the absence of air at a temperature in the range of about 200.degree. to 600.degree. F. and at a pressure at or above the vapor pressure of water at said elevated temperature until a large portion of the organic matter in said sewage is agglomerated;
• (2) dewatering the heated pumpable aqueous slurry of sewage sludge from (1) to a solids content in the range of about 25 to 50 wt. %;
• (3) mixing the pumpable aqueous slurry of sewage sludge produced in (2) having a higher heating value (HHV) of at least 3,000 Btu/lb (dry basis) with a supplemental fuel comprising a liquid hydrocarbon or a liquid hydrocarbonaceous fuel having a higher heating value (HHV) of at least about 10,000 Btu/lb to produce a pumpable feed slurry having a solids content in the range of about 30 to 65 wt. %, and having a higher heating value (HHV) of at least about 6,000 Btu/lb (dry basis);
• and
• (4) reacting said pumpable feed slurry from (3) in the reaction zone of a partial oxidation gas generator at a temperature in the range of about 1800.degree. F. to 2800.degree. F. and a pressure in the range of about 1-35 atmospheres, and in the presence of a free-oxygen containing gas, thereby producing a hot raw effluent stream of synthesis gas, reducing gas or fuel gas.

A process for the partial oxidation of sewage sludge comprising:

• (1) heating a concentrated aqueous slurry of sewage sludge obtained from sewage and comprising combustible and non-combustible materials and having a solids content of at least 3 wt. % in the absence of air at a temperature in the range of about 200.degree. to 600.degree. F. and at a pressure at or above the vapor pressure of water at said elevated temperature until a large portion of the organic matter in said sewage is agglomerated;
• (2) dewatering the heated aqueous pumpable slurry of sewage sludge from (1) to a solids content in the range of about 25 to 50 wt. %;
• (3) mixing the pumpable slurry of sewage sludge produced in (2) having a higher heating value (HHV) of at least 3,000 Btu/lb (dry basis) with a supplemental fuel comprising a gaseous fuel having a higher heating value (HHV) of at least about 75 BTU per Standard Cubic Foot (SCF) to produce a dispersion of sewage sludge in gaseous fuel, wherein said dispersion has a higher heating value (HHV) of at least 300 BTU/SCF;
• and
• (4) reacting said atomized dispersion from (3) in the reaction zone of a partial oxidation gas generator at a temperature in the range of about 1800.degree. F. to 2800.degree. F. and a pressure in the range of about 1-35 atmospheres, and in the presence of a free-oxygen containing gas, thereby producing a hot raw effluent stream of synthesis gas, reducing gas or fuel gas.