Biomass Liquefaction to Produce Refinery-Ready Bio-Oil

Abstract

A bio-oil product is produced from biomass material by subjecting the biomass material to a first stage liquefaction process, where the first stage liquefaction process includes combining the biomass material with a co-solvent including methanol and water to form a first slurry mixture, providing the slurry mixture within a first liquefaction reactor and maintaining the first slurry mixture at a sufficient temperature and pressure so as to convert a portion of the biomass material into a first liquefied bio-oil product as well as form a first aqueous product and a first solid product, and separating the first liquefied bio-oil product from the aqueous and solid products. The solid product obtained from the first stage liquefaction process is subjected to a second stage liquefaction process, where the second stage liquefaction process includes combining the first solid product with methane to form a second slurry mixture, and providing the second slurry mixture within a second liquefaction reactor and maintaining the second slurry mixture at a sufficient temperature and pressure so as to convert a portion of the first solid product to a second liquefied bio-oil product as well as form a second aqueous product and a second solid product.

What is claimed: 
     
         1 . A method of producing a bio-oil product with a total acid number (TAN) less than 5 from biomass material, the method comprising:
 subjecting the biomass material to a first stage liquefaction process, the first stage liquefaction process comprising:
 combining the biomass material with a co-solvent comprising methanol and water to form a first slurry mixture; and 
 providing the slurry mixture within a first liquefaction reactor and maintaining the first slurry mixture at a temperature between 200° C. and 310° C. and a pressure between 1000 psig (6.9 MPa) and 2000 psig (17.2 MPa) so as to convert a portion of the biomass material into a first liquefied bio-oil product as well as form a first aqueous product and a first solid product; 
   separating the first liquefied bio-oil product from the aqueous and solid products; and   subjecting the solid product obtained from the first stage liquefaction process to a second stage liquefaction process, the second stage liquefaction process comprising:
 combining the first solid product with methanol to form a second slurry mixture; and 
 providing the second slurry mixture within a second liquefaction reactor and maintaining the second slurry mixture at a temperature between 200° C. and 310° C. and a pressure between 1000 psig (6.9 MPa) and 2000 psig (17.2 MPa) so as to convert a portion of the first solid product to a second liquefied bio-oil product as well as form a second aqueous product and a second solid product. 
   
     
     
         2 . The method of  claim 1 , wherein the biomass material comprises pulverized wood. 
     
     
         3 . The method of  claim 2 , wherein the mass ratio of biomass material to co-solvent is at least about 1:5. 
     
     
         4 . The method of  claim 1 , wherein the co-solvent comprises each of methanol and water in a range of 40% to 60% of the co-solvent. 
     
     
         5 . The method of  claim 1 , wherein at least 80% by weight of the biomass material is converted to the first liquefied bio-oil product within the first liquefaction reactor. 
     
     
         6 . The method of  claim 1 , wherein one or both of the first and second liquefaction reactors is free of any catalyst. 
     
     
         7 . The method of  claim 1 , where each of the first and second liquefied bio-oil products has a total acid number (TAN) no greater than 3. 
     
     
         8 . The method of  claim 1 , wherein each of the first and second liquefied bio-oil products has an oxygen content of no greater than about 25% by weight of the liquefied bio-oil product. 
     
     
         9 . The method of  claim 8 , wherein the oxygen content is no greater than about 20% by weight of the liquefied bio-oil product. 
     
     
         10 . The method of  claim 1 , wherein each of the first and second liquefied bio-oil products has a water content of no greater than about 10% by weight of the liquefied bio-oil product. 
     
     
         11 . The method of  claim 1 , further comprising:
 separating water and/or methanol from one or more of the products obtained from the first liquefaction reactor and/or the second liquefaction reactor; and   recycling the separated water and/or methanol for use as at least a portion of the co-solvent combined with the biomass material that forms the first slurry mixture.   
     
     
         12 . The method of  claim 1 , further comprising:
 combining the first liquefied bio-oil product with the second liquefied bio-oil product to form a combined liquefied bio-oil product.   
     
     
         13 . The method of  claim 12 , further comprising:
 combining the combined liquefied bio-oil product with hydrogen in a hydrodeoxygenation reactor at a temperature between 200° C. and 300° C. and a pressure between 1000 psig (6.9 MPa) and 2000 psig (17.2 MPa) so as to remove oxygen from carbon-based compounds within the combined liquefied bio-oil product to form a final bio-oil product.   
     
     
         14 . The method of  claim 13 , wherein the final bio-oil product has a total acid number (TAN) less than 1. 
     
     
         15 . The method of  claim 13 , wherein the final bio-oil product has an oxygen content of no greater than about 10% by weight of the final bio-oil product. 
     
     
         16 . The method of  claim 13 , wherein the final bio-oil product has a water content of no greater than about 5% by weight of the final bio-oil product. 
     
     
         17 . The method of  claim 13 , wherein the final bio-oil product includes hydrocarbons ranging from C 10  to C 24 . 
     
     
         18 . A liquefied bio-oil product formed according to the method of  claim 12 . 
     
     
         19 . A liquefied bio-oil product derived from a biomass material comprising pulverized wood, wherein the liquefied bio-oil product has a total acid number (TAN) that is less than 5, and further has an oxygen content no greater than 25% by weight of the liquefied bio-oil product. 
     
     
         20 . The liquefied bio-oil product of  claim 20 , wherein the oxygen content is no greater than 10% by weight of the liquefied bio-oil product, and the bio-oil product further includes a plurality of carbon-containing compounds having carbon chains in the range of C 10  to C 24 .