Fuel by-products of municipal refuse

Abstract

Municipal refuse is treated to produce a particulate mixture consisting essentially of its organic constituents substantially free of inorganic materials, the particles in the mixture being of less than a predetermined maximum particle size, and the mixture also being characterized on a volumetric unit basis by (a) substantial homogeneity of component materials, (b) substantial uniformity from the standpoint of distribution of particle sizes, (c) substantially uniform moisture content, and (d) substantially uniform fuel value. This mixture has many possible uses, including directly as fuel, as raw material for conversion by pyrolysis or hydrogenation, as raw material for the production of hardboard, and as compost or landfill.

What is claimed is: .[. 
     
       1.  As a new product, a particulate mixture consisting essentially of organic consistuents of municipal refuse substantially free of inorganic materials, and prepared by a process comprising the steps of: 1. depositing solid waste materials including relatively frangible and infrangible organic and inorganic solids and a liquid medium in a treatment vessel,   2. subjecting said solids in the presence of said liquid medium in said treatment vessel to forces of sufficient intensity to reduce said relatively frangible organic and inorganic solids to particles of less than a predetermined maximum size forming a mixture with said liquid medium,   3. removing from said treatment vessel in slurry form a portion of said liquid medium and such of said organic and inorganic particles as pass through perforations sized to pass only particles of less than said predetermined maximum size,   4. removing from said treatment vessel separately from said slurry said relatively infrangible solids,   5. removing from said slurry the inorganic constituents thereof, and   6. removing from the resulting slurry of said organic solids and liquid medium a substantial portion of said liquid medium to leave said particulate mixture, the major component material of said mixture being cellulose fibers, the particles in said mixture being of less than predetermined maximum particle size, and said mixture having the following additional characteristics on a volumetric unit basis: a. substantial homogeneity of component materials;   b. substantial uniformity from the standpoint of distribution of particle sizes;   c. substantially uniform moisture content; and   d. substantially uniform fuel value..].     
     
     
       2. The product defined in claim 1 wherein said mixture also includes significant amounts of plastic, food waste, vegetation and textile materials. 
     
     
       3. The product defined in claim 1 wherein all of said particles are sufficiently small to pass through a screen member having circular openings not greater than one inch in diameter. 
     
     
       4. The product defined in claim 1 wherein said uniform moisture content comprises 40-70 percent of said mixture. 
     
     
       5. The product defined in claim 1 wherein all of said particles are sufficiently small to pass through a screen member having circular openings approximately one-eighth inch in diameter. 
     
     
       6. The product defined in claim 3 wherein said maximum size particles are not sufficiently small to pass through a screen member having circular openings approximately one-eighth inch in diameter. 
     
     
       7. The product defined in claim 2 wherein cellulose fibers constitute approximately 80 percent of said mixture. 
     
     
       8. The product defined in claim 2 wherein cellulose fibers constitute approximately 60 percent of said mixture. 
     
     
       9. The product defined in claim 2 wherein cellulose fibers constitute approximately 40-50 percent of said mixture, and said maximum size particles are not sufficiently small to pass through a screen member having circular openings approximately one-eighth inch in diameter. 
     
     
       10. A process for .[.preparing.]. .Iadd.converting .Iaddend.municipal solid waste .Iadd.into fuel .Iaddend.for combustion .Iadd.which has the following characteristics on a volumetric unit basis: i. substantial homogeneity of component materials,   ii. substantial uniformity from the standpoint of distribution of particle sizes,   iii. substantially uniform moisture content, and   iv. substantially uniform fuel value, .Iaddend.comprising the steps of: a. depositing municipal solid waste, including relatively frangible and infrangible organic and inorganic solids, in a treatment vessel together with a liquid medium in sufficient volume to establish a solids content of the order of 4 to 6 percent,   b. subjecting said solids in the presence of said liquid medium in said treatment vessel to mechanical and hydraulic forces of sufficient intensity to reduce said relatively frangible organic and inorganic solids to particles of a predetermined maximum size forming a mixture with said liquid medium,   c. removing from said treatment vessel in slurry form a portion of said liquid medium and such of said organic and inorganic particles as pass through perforations of the order of one inch in diameter,   d. removing said relatively infrangible solids from said treatment vessel separately from said slurry,   e. removing from said slurry the inorganic constituents thereof,   f. accumulating a substantial volume of the resulting slurry to assure the homogeneity thereof, and   g. removing from the resulting slurry of said organic solids and liquid medium a substantial portion of said liquid medium. .Iadd. 11. As a new product, a particulate mixture consisting essentially of organic constituents of municipal refuse substantially free of inorganic materials, and prepared by a process comprising the steps of:     1. depositing solid waste materials including relatively frangible and infrangible organic and inorganic solids and a liquid medium in a treatment vessel,   2. subjecting said solids in the presence of said liquid medium in said treatment vessel to forces of sufficient intensity to reduce said relatively frangible organic and inorganic solids to particles of less than a predetermined maximum size forming a mixture with said liquid medium,   
     
     
       3.  removing from said treatment vessel in slurry form a portion of said liquid medium and such of said organic and inorganic particles as pass through perforations sized to pass only particles of less than said predetermined maximum size, 4. removing said relatively infrangible solids from said treatment vessel separately from said slurry,   5. removing from said slurry the inorganic constituents thereof,   6. accumulating a substantial volume of the resulting slurry of said organic solids and liquid medium to assure the homogeneity thereof, and   7. removing from said accumulated slurry a substantial portion of said liquid medium to leave said particulate mixture, the major component material of said mixture being cellulose fibers, the particles in said mixture being of less than a predetermined maximum particle size, and said mixture having the following additional characteristics on a volumetric unit basis:   a. substantial homogeneity of component materials;   b. substantial uniformity from the standpoint of distribution of particle sizes;   c. substantially uniform moisture content; and   d. substantially uniform fuel value. .Iaddend.