Compositions and methods for composite fuels

Abstract

A solid composite fuel for the mitigation of emissions from a coal-fired power plant includes a solid monothilic fuel material formed from the pyrolysis of a coal material and at least one solid renewable fuel material.

1 .- 19 . (canceled) 
     
     
         20 . A method of making a solid composite fuel, the method comprising: preparing a coal material and at least one solid renewable fuel material; blending the coal material and the at least one solid renewable fuel material into a mixture; drying the mixture; pyrolyzing the mixture in at least one pyrolyzer; and cooling resulting solid chars to form a solid composite fuel. 
     
     
         21 . The method according to  claim 20  wherein preparing the coal material and the at least one solid renewable fuel material comprises at least one of sizing, analyzing and quantifying the coal material and the at least one solid renewable fuel material. 
     
     
         22 . The method according to  claim 20  further comprising a step of forming the resulting solid chars into at least one of pellets, rods and briquettes. 
     
     
         23 . The method according to  claim 20  further comprising recovering at least one of mercury, a tar oil product, and a liquid condensate from evolved pyrolysis gases from the at least one pyrolyzer. 
     
     
         24 . The method according to  claim 23  further comprising at least one of utilizing the recovered tar oil as fuel and processing the recovered tar oil. 
     
     
         25 . The method according to  claim 20  further comprising adding at least one binder material to the coal material and the at least one solid renewable fuel material in one of prior to, during and after the blending of the coal component and the at least one solid renewable fuel material. 
     
     
         26 . The method according to  claim 25  further comprising preparing at least one liquid renewable fuel material and blending the at least one liquid renewable fuel material with the at least one binder material. 
     
     
         27 . The method according to  claim 20  further comprising selecting the coal material from the class of lignite, sub-bituminous or bituminous coal; and selecting the solid renewable material from at least one of: (a) terrestrial plant biomass such as forest or cane plants or grasses; (b) petroleum coke; (c) aquatic plant biomass such as algae, micro algae and diatoms; (d) waste synthetic solid materials containing less than 1% halogen; and (e) combinations thereof. 
     
     
         28 . The method according to  claim 20  wherein the preparing step further comprises sizing the coal material and the solid renewable material to like-sized particles; and analyzing at least one of the moisture content and the carbon content of each of the coal material and the solid renewable material. 
     
     
         29 . The method according to  claim 28  wherein the blending step further comprises separately metering the coal material and the solid renewable material in response to the analyzed moisture content or the analyzed carbon content, or both of the coal material and the solid renewable material. 
     
     
         30 . The method according to  claim 20  wherein the mixture has a dry weight fraction of coal material of greater than 50%. 
     
     
         31 . The method according to  claim 20  wherein the drying step further comprises drying the mixture at a temperature of between 212 degrees Fahrenheit and 300 degrees Fahrenheit for a time sufficient to achieve a moisture content of less than 2% moisture prior to introduction into the at least one pyrolyzer. 
     
     
         32 . The method according to  claim 20  wherein the pyrolyzing step further comprises pyrolyzing at a temperature between 800 degrees Fahrenheit and 1,200 degrees Fahrenheit. 
     
     
         33 . The method according to  claim 20  wherein the pyrolyzing step further comprises at least two sequential pyrolyzing steps. 
     
     
         34 . The method according to  claim 25  wherein the binder includes at least one of: a blend of sugar syrup and starch; unsaturated or oxygenated or cyclic hydrocarbons such as phenolic resins; and a portion of tar oil product condensed from pyrolysis gases and having an atmospheric boiling point above 500 degrees Fahrenheit. 
     
     
         35 . The method according to  claim 34  wherein the tar oil portion of the binder material is the residue resulting from the solvent extraction of the condensed pyrolysis liquids having an atmospheric boiling point of greater than 500 degrees Fahrenheit, where the extraction is carried out against an alkane solvent of less than 10 carbons, against cyclo-pentane or against cyclo-hexane or a mixture thereof at a temperature of less than 250 degrees Fahrenheit. 
     
     
         36 . The method according to  claim 35  wherein of the binder material is the residue resulting from the solvent extraction of the condensed pyrolysis liquids having an atmospheric boiling point of greater than 600 degrees Fahrenheit. 
     
     
         37 . The method according to  claim 22  wherein the pyrolyzing step occurs prior to the forming step. 
     
     
         38 . The method according to  claim 21  further comprising a step of forming the mixture into at least one of pellets, rods and briquettes step, and wherein the forming step occurs prior to the pyrolyzing step. 
     
     
         39 . The method according to  claim 38  further comprising adding at least one binder material to the coal material and the at least one solid renewable fuel material prior to the pyrolyzing step, the binder material including a portion of tar oil product condensed from pyrolysis gases and having an atmospheric boiling point above 500 degrees Fahrenheit. 
     
     
         40 . The method according to  claim 39  further comprising metering a liquid renewable fuel material into the mixture in addition to the coal material and the at least one solid renewable fuel material. 
     
     
         41 . The method according to  claim 40  wherein a portion of the liquid renewable fuel material comprises a tar oil product recovered from a pyrolysis step. 
     
     
         42 . A product for use as a metallurgical coal product made by the method of  claim 20  and having the following properties: a GCV in excess of 12,500 BTU per pound; an equilibrium moisture of less than 5% by weight; and a volatile matter content of less than 15% by weight. 
     
     
         43 . A product for use as a CO 2  mitigating power plant fuel product made by the method of  claim 20  and having the following properties: a GCV in excess of 12,500 BTU per pound; an equilibrium moisture of less than 5% by weight; and a volatile matter content of less than 25% by weight.