Process and System For Manufacturing Improved Heat Value Solid Fuel From Solid Waste

Abstract

A method for manufacturing solid fuel, including estimating a heat value for at least a portion of a combustible waste stream. At least one type of combustible polymer is added to the combustible waste stream as needed to raise the estimated heat value of the portion of combustible waste stream to a desired heat value. The combustible waste stream is heated and mixed with the at least one type of combustible polymer to increase the structural integrity of a solid fuel formed from the mixed combustible waste stream and to increase the hydrophobic properties of the solid fuel. The heated and mixed combustible waste stream is pressed into objects of solid fuel, such as briquettes, which are substantially hydrophobic.

What is claimed is: 
     
         1 . A method for manufacturing solid fuel, comprising:
 removing non-combustible and hazardous materials from a waste stream of substantially solid materials to produce a substantially combustible waste stream;   estimating a heat value for at least a portion of the combustible waste stream;   adding at least one type of combustible polymer to the combustible waste stream as needed to raise the estimated heat value of the portion of combustible waste stream to a desired heat value;   heating and mixing the combustible waste stream with the at least one type of combustible polymer to increase the structural integrity of a solid fuel formed from the mixed combustible waste stream and to increase the hydrophobic properties of the solid fuel; and   pressing the heated and mixed combustible waste stream into objects of solid fuel which are substantially hydrophobic.   
     
     
         2 . The method of  claim 1  wherein the at least one type of combustible polymer includes recycled resins. 
     
     
         3 . The method of  claim 1  wherein at least two types of combustible polymers are selectively added to the combustible waste stream. 
     
     
         4 . The method of  claim 1  wherein the combustible polymer is heated to a temperature between 200 degrees F. to about 350 degrees F. at least during mixing with the combustible waste stream. 
     
     
         5 . The method of  claim 1  wherein the waste stream of substantially solid materials is obtained from at least one of residential solid waste, commercial solid waste, and municipal solid waste. 
     
     
         6 . The method of  claim 1  wherein the desired heat value is between 10,000 BTU to 13,000 BTU. 
     
     
         7 . Briquettes formed as solid fuel objects according to the method of  claim 1 . 
     
     
         8 . A method for manufacturing solid fuel, comprising:
 removing non-combustible and hazardous materials from a waste stream obtained from at least one of residential solid waste, commercial solid waste, and municipal solid waste to produce a substantially combustible waste stream;   estimating a heat value for at least a portion of the combustible waste stream;   adding at least one type of combustible polymer to the combustible waste stream as needed to raise the estimated heat value of the portion of combustible waste stream to a desired heat value;   heating and mixing the combustible waste stream with the at least one type of combustible polymer to increase the structural integrity and to increase the hydrophobic properties of solid fuel objects formed from the mixed combustible waste stream; and   pressing the heated and mixed combustible waste stream into objects of solid fuel which are substantially hydrophobic.   
     
     
         9 . The method of  claim 8  wherein the at least one type of combustible polymer includes recycled resins. 
     
     
         10 . The method of  claim 8  wherein the desired heat value is between 10,000 BTU to 13,000 BTU. 
     
     
         11 . The method of  claim 8  wherein the at least one combustible polymer is heated to a temperature between 200 degrees F. to slightly below a temperature at which the combustible polymer begins to char, at least during mixing with the combustible waste stream. 
     
     
         12 . The method of  claim 8  wherein at least two types of combustible polymers are selectively added to the combustible waste stream. 
     
     
         13 . The method of  claim 12  wherein at least one of the combustible polymers is a type of polystyrene. 
     
     
         14 . Briquettes formed as solid fuel objects according to the method of  claim 8 . 
     
     
         15 . A method for manufacturing solid fuel, comprising:
 removing non-combustible and hazardous materials from a waste stream obtained from at least one of residential solid waste, commercial solid waste, and municipal solid waste to produce a substantially combustible waste stream;   estimating a heat value for at least a portion of the combustible waste stream;   selectively adding at least one type of polystyrene as a combustible polymer from a first receptacle and at least one different type of combustible polymer from a second receptacle to the combustible waste stream as needed to raise the estimated heat value of the portion of combustible waste stream to a desired heat value;   heating and mixing the combustible waste stream with the at least two types of combustible polymers to between 300 degrees F. to about 350 degrees F. to increase the structural integrity and to increase the hydrophobic properties of solid fuel objects formed from the mixed combustible waste stream; and   pressing the heated and mixed combustible waste stream into objects of solid fuel which are substantially hydrophobic.   
     
     
         16 . The method of  claim 15  wherein about 3 weight percent to about 7 weight percent of the polystyrene is added. 
     
     
         17 . The method of  claim 16  wherein about 30 weight percent to about 40 weight percent of the at least one different type of combustible polymer is added. 
     
     
         18 . The method of  claim 15  wherein about 4 weight percent to about 6 weight percent of the polystyrene is added and about 32 weight percent to about 38 weight percent of the at least one different type of combustible polymer is added, and the mixture is heated to slightly below a temperature at which the combustible polymers begin to char. 
     
     
         19 . The method of  claim 18  further including increasing pressure on the heated and mixed combustible waste stream as it is fed into a product forming machine for forming the solid fuel objects. 
     
     
         20 . Briquettes formed as solid fuel objects according to the method of  claim 19 .