Process for conversion of a cellulosic material

Abstract

Methods to convert a cellulosic material into a bio-oil. In one embodiment, the method comprises (a) contacting the cellulosic material with a liquid solvent in an inert atmosphere at a reaction temperature in the range from equal to or more than about 260° C. to equal to or less than about 400° C. to produce a product mixture; (b) separating a middle fraction from the product mixture to produce a product mixture middle fraction. A first portion of the product mixture middle fraction can be recycled as part of the liquid solvent in step a). At least part of the product mixture is hydrotreated before at least a portion of a middle fraction of the treated product mixture is recycled as part of the liquid solvent in step a).

What is claimed is: 
     
         1 . A process for the conversion of a cellulosic material into a bio-oil, comprising the steps of:
 (a) contacting the cellulosic material with a liquid solvent in an inert atmosphere at a reaction temperature in the range from equal to or more than about 260° C. to equal to or less than about 400° C. to produce a product mixture;   (b) separating a middle fraction from the product mixture to produce a product mixture middle fraction;   (c) recycling a first portion of the product mixture middle fraction by using said first portion as part of the liquid solvent;   (d) hydrotreating at least part of said first portion of the product mixture before the recycling step (c); and   (e) using a second portion of the product mixture middle fraction to produce a bio-oil.   
     
     
         2 . The process of  claim 1  wherein the hydrotreating step (d) is performed before the separating step (b). 
     
     
         3 . The process of  claim 1  wherein the hydrotreating step (d) is performed after the separating step (b). 
     
     
         4 . The process of  claim 1 , wherein the hydrotreating step comprises contacting the at least part of said first portion with a hydrogenation catalyst in the presence of hydrogen. 
     
     
         5 . The process of  claim 4 , wherein the hydrogenation catalyst comprises at least one metal in groups 8-11. 
     
     
         6 . The process of  claim 5 , wherein the hydrogenation catalyst further comprises a carbon carrier. 
     
     
         7 . The process of  claim 4 , wherein the hydrogenation catalyst comprises at least one metal in group 6. 
     
     
         8 . The process of  claim 1 , wherein the hydrotreating step is carried out at a temperature in a range of about 80 degrees C. to about 350 degrees C. 
     
     
         9 . The process of  claim 8 , wherein the hydrotreating step is carried out at a temperature in a range of about 100 degrees C. to about 250 degrees C. 
     
     
         10 . The process of  claim 9 , wherein the hydrotreating step is carried out at a temperature in a range of about 150 degrees C. to about 200 degrees C. 
     
     
         11 . The process of  claim 1 , wherein the hydrotreating step is carried out under a pressure in a range of about 0.1 MPa to about 25 MPa. 
     
     
         12 . The process of  claim 11 , wherein the hydrotreating step is carried out under a pressure in a range of about 1 MPa to about 15 MPa. 
     
     
         13 . The process of  claim 12 , wherein the hydrotreating step is carried out under a pressure in a range of about 5 MPa to about 10 MPa. 
     
     
         14 . The process of  claim 1 , wherein the hydrotreating step comprises a hydrogen to liquid ratio of 10 to 10,000 mL/L. 
     
     
         15 . The process of  claim 14 , wherein the hydrotreating step comprises a hydrogen to liquid ratio of 50 to 1000 mL/L. 
     
     
         16 . The process of  claim 15 , wherein the hydrotreating step comprises a hydrogen to liquid ratio of 100 to 500 mL/L. 
     
     
         17 . The process of  claim 1 , wherein the hydrotreating step comprises a liquid hourly space velocity in a range of about 0.1 L/L/h to about 10 L/L/h. 
     
     
         18 . The process of  claim 17 , wherein the hydrotreating step comprises a liquid hourly space velocity in a range of about 0.3 L/L/h to about 3 L/L/h. 
     
     
         19 . The process of  claim 18 , wherein the hydrotreating step comprises a liquid hourly space velocity in a range of about 0.5 L/L/h to about 2 L/L/h.