Synthetic coal and methods of producing synthetic coal from fermentation residue

Abstract

Synthetic coal, methods of producing synthetic coal, produced from fermentation residue, such as the residue from ethanol production, by subjecting the fermentation residue to hydrothermal carbonization in an aqueous solution at a temperature and a pressure sufficient to form a synthetic coal solid and a liquid component. The solid synthetic coal component has a low ash content and may be used as a carbon source for energy production, such as for combustive thermal energy generation, or for gassification for the production of synthesis gas.

1 . A method of producing a synthetic coal from fermentation residues, the method comprising the steps of:
 a) obtaining a fermentation residue;   b) subjecting said fermentation residue to hydrothermal carbonization in an aqueous medium at a temperature and a pressure sufficient to form a synthetic coal solid.   
     
     
         2 . The method of  claim 1  further comprising separating synthetic coal solid from the aqueous medium. 
     
     
         3 . The method of  claim 1  wherein the temperature is between about 170° C. and about 225° C. 
     
     
         4 . The method of  claim 1  wherein the pressure is between about 0.8 and about 2.41 MPa. 
     
     
         5 . The method of  claim 1  further comprising combining the fermentation residue with an acidic buffer. 
     
     
         6 . The method of  claim 1  wherein the fermentation residue is produced from corn based ethanol production. 
     
     
         7 . A method of producing a synthetic coal from fermentation residues, the method comprising the steps of:
 a) obtaining an fermentation residue;   b) subjecting said fermentation residue to hydrothermal carbonization in an aqueous solution at a temperature of between about 170° C. and about 225° C. and a pressure of between about 0.8 and about 2.41 MPa; and   c) separating a synthetic coal solid from a liquid component. \   
     
     
         8 . The method of  claim 7  further comprising combining the fermentation residue with an acidic buffer. 
     
     
         9 . The method of  claim 1  wherein the fermentation residue is a byproduct of corn based ethanol production. 
     
     
         10 . The method of  claim 7  further comprising employing the synthetic coal as a carbon source within a combustive thermal energy generation system. 
     
     
         11 . The method of  claim 7  further comprising gasifying the synthetic coal. 
     
     
         12 . The method of  claim 12  wherein gasifying the synthetic coal produces a synthesis gas. 
     
     
         13 . The method of  claim 7  further comprising providing the synthetic coal as a source of coke for the manufacture of steel. 
     
     
         14 . A synthetic coal produced by the process comprising the steps of:
 a) obtaining an fermentation residue;   b) subjecting said fermentation residue to hydrothermal carbonization in an aqueous solution at a temperature and a pressure sufficient to form a synthetic coal solid and a liquid component.   
     
     
         15 . The synthetic coal of  claim 14  wherein the process further comprises separating the synthetic coal solid from the liquid component. 
     
     
         16 . The synthetic coal of  claim 14  wherein the temperature is between about 170° C. and about 225° C. 
     
     
         17 . The synthetic coal of  claim 14  wherein the pressure is between about 0.8 and about 2.41 MPa. 
     
     
         18 . The synthetic coal of  claim 14  wherein the process further comprises combining the fermentation residue with an acidic buffer. 
     
     
         19 . The synthetic coal of  claim 14  wherein the fermentation residue is produced from corn based ethanol production. 
     
     
         20 . The synthetic coal of  claim 14  wherein the synthetic coal has an ash content of <1% by weight.