Method of Obtaining a High Quality Coke from Low Rank Coal Liquefaction

Abstract

The present disclosure provides methods and systems for coal liquefaction and obtaining a high quality coke from a low rank coal extract. A method of obtaining a high quality coke from a low rank coal extract may include exposing coal to a hydrogenated vegetable oil in the presence of a coal-derived solvent to form a slurry, elevating the temperature of the slurry to facilitate liquefying the coal and liberating a volatile matter, separating the insoluble components from the slurry to obtain a de-ashed coal extract that is quinoline insoluble-free, distilling the coal extract under vacuum to obtain a pitch with a suitable softening point, and coking the pitch to obtain a coke. The coke may be at least one of an anisotropic coke, a metallurgical coke, a graphite coke, an anode coke, and a needle coke.

The invention claimed is 
     
         1 . A method of obtaining a high quality coke from a low rank coal extract, comprising:
 exposing a coal to a hydrogenated vegetable oil in the presence of a coal-derived solvent to form a slurry;   elevating the temperature of the slurry to facilitate liquefying the coal and liberating a volatile matter;   separating the insoluble components from the slurry to obtain a de-ashed coal extract that is quinoline insoluble-free;   distilling the coal extract under vacuum to obtain a pitch with a suitable softening point; and   coking the pitch to obtain a coke.   
     
     
         2 . The method of  claim 1 , wherein the coke is at least one of an anisotropic coke, a metallurgical coke, a graphite coke, an anode coke, and a needle coke. 
     
     
         3 . The method of  claim 1 , further comprising air blowing the pitch to crosslink molecules in the pitch, the air blowing of the pitch used for at least modifying a softening point and increasing coke yield. 
     
     
         4 . The method of  claim 1 , wherein water liberated as a result of the elevated temperature is captured and stored. 
     
     
         5 . The method of  claim 1 , wherein the volatile matter is condensed and recycled. 
     
     
         6 . The method of  claim 1 , wherein separating comprises at least one of centrifugation, filtration, decanting, and float separation. 
     
     
         7 . The method of  claim 1 , wherein the temperature is elevated to between  300  degrees Celsius and 600 degrees Celsius. 
     
     
         8 . The method of  claim 1 , further comprising agitating the slurry to facilitate liquefying the coal. 
     
     
         9 . The method of  claim 1 , wherein the coal is selected from one or more of a sub-bituminous coal, a bituminous coal, a lignite coal, and an anthracite coal. 
     
     
         10 . The method of  claim 1 , further comprising air blowing the pitch to crosslink the heavier molecules in the pitch and modify the softening point to increase the coke yield.