Treatment of coal

Abstract

Process for treating coal to enhance its rank, wherein the temperature of the material is gradually increased in a controlled set of atmospheres, to allow for the reduction of surface and inherent moisture and the controlled reduction of volatile matter while maintaining the coal's natural structural integrity. The process reduces the time, capitalization, and production costs required to produce coal of enhanced rank, thus substantially increasing the cost effectiveness and production rate over prior processes.

What is claimed is:  
     
         1 . A process for treating biomass to increase its rank, comprising heating the biomass to remove moisture and volatiles to form treated biomass in which a majority of its natural structural integrity is maintained, and collecting the treated biomass.  
     
     
         2 . A process for treating coal to increase its rank, comprising heating the coal in a non-oxidizing atmosphere to remove substantially all moisture and a pre determined amount (from 5 to 95%) of volatile matter from the raw feedstock while maintaining a majority of the coal's natural structural form and integrity.  
     
     
         3 . A process according to  claim 2  wherein said pre determined amount is from 5 to 95% of volatile matter..  
     
     
         4 . A process according to  claim 2 . wherein said coal is selected from peat, lignite, sub-bituminous coal, bituminous coal and anthracite coal.  
     
     
         5 . A process according to  claim 2 , wherein the treated coal has a BTU content of 12.500 BTU/lb. or higher.  
     
     
         6 . A process according to  claim 2 , wherein the moisture content of the coal is reduced to about 2% by weight of the treated coal.  
     
     
         7 . A process according to  claim 2 . wherein the volatile content of the treated coal is reduced to a predetermined volatile content percentage such as between 5 and 30% by weight.  
     
     
         8 . A process according to  claim 2 , wherein prior to heating the coal is subject to crushing to reduce the average size of the coal to 1-2 inches.  
     
     
         9 . A process according to  claim 8 , wherein the coal prior to crushing is subjected to a preliminary drying step to reduce the surface moisture content.  
     
     
         10 . A process according to  claim 9 , wherein the surface moisture content is reduced to about 2-4% by weight.  
     
     
         11 . A process according to  claim 8 , wherein the crushed coal is subjected to a drying step by heating to a temperature in the range of 200-250F. for a period of about 5 minutes in order to remove the surface moisture.  
     
     
         12 . A process according to  claim 11 , wherein the surface moisture content is reduced to about 1-2% by weight.  
     
     
         13 . A process according to  claim 11 , wherein the temperature of the coal obtained after the drying step is raised to 400-750 F. for about 2-4 minutes to substantially reduce the inherent moisture content and to initiate the volatile reduction process.  
     
     
         14 . A process according to  claim 13 , wherein the temperature of the coal is elevated to about 900-1100° F. for a period of about 1-4 minutes to produce coal with an inherent moisture content of less than 5% and a mass content loss of up to 50% by weight.  
     
     
         15 . A process according to  claim 14 , wherein the temperature of the coal is raised to 1300-1550° F. and retained at that temperature for about 2-4 minutes to produce coal with a moisture content of 1-2% and a volatile content of 15-25%.  
     
     
         16 . A process according to  claim 15 , wherein the temperature of the coal is raised to 2000-2400° F. to produce coal with a moisture content of 0-2% and a volatiles content of 5-15%.  
     
     
         17 . A process according to  claim 16 , wherein the coal is cooled by exposing the coal to a dry cooling gas.  
     
     
         18 . A process according to  claim 17 , wherein the cooling gas is substantially free of oxygen.  
     
     
         19 . A process according to  claim 18 , wherein the cooling gas has a moisture content of less than 1% by weight.  
     
     
         20 . A process according to  claim 2 , wherein steam and volatiles removed during heating of the coal are recycled to provide a non-oxidizing atmosphere and to prevent ignition of the coal during heating.  
     
     
         21 . A process for treating coal in an inert atmosphere to increase its rank, comprising the steps of: 
 (a) Heating coal at 200-250° F. to produce coal virtually free of surface moisture.    (b) Heating the coal produced in step (a) to a temperature of 400-750° F. for about 2-4 minutes to produce coal having inert moisture content of between 2-5%.    (c) Heating the coal produced in step (b) to a temperature of about 900-1100° F. for up to about 5 minutes to produce coal having an inherent moisture content of 1-2% and mass reduction of up to 50%    (d) Heating the coal produced in step (c) to a temperature of 1300-1550° F. for about 2-4 minutes, to produce coal having a moisture content of less than 2% and volatiles content of less than 25%.    (e) Heating the coal produced in step (d) to a temperature of about 2000-2400° F. for 2-4 minutes, to produce coal having a moisture content of less than 2% by weight and a volatile content of 15% or less by weight;    (f) Cooling the coal produced in step (e) by exposing to a cooling gas which is substantially free of oxygen and moisture to form treated coal; and    (g) Collecting the treated coal.    
     
     
         22 . A process according to  claim 21 , wherein prior to step (b), coal produced in step (a) is crushed to produce coal having a top size of about 2 inches.  
     
     
         23 . A process according to  claim 22 , wherein the ¼″ and less treated coal that is collected is formed into briquettes and provided with a waterproof binder/igniter/coating.  
     
     
         24 . Biomass of increased rank produced according to the process of  claim 1 .  
     
     
         25 . Biomass of increased rank according to  claim 24 , provided with a waterproof binder/igniter/coating.  
     
     
         26 . Treated coal produced according to the process of  claim 2 .  
     
     
         27 . Treated coal according to  claim 26 , provided with a water-proof binder/igniter/coating.  
     
     
         28 . Treated coal according to  claim 26  in the form of briquettes.  
     
     
         29 . Briquettes according to  claim 28  provided with a water-proof binder/igniter/coating.