Temperature-Optimized Conversion of Lignocellulosic Biomass

Abstract

A process is disclosed for converting lignocellulosic material to liquid fuels. In the process the cellulose is dissolved in an Ionic Liquid. The conversion process may comprise pyrolysis, thermal cracking, hydrocracking, catalytic cracking, hydrotreatment, or a combination thereof. Undissolved lignin is removed from the Ionic Liquid medium, and is converted in a separate conversion process. The Ionic Liquid preferably is an inorganic molten salt hydrate.

1 . A process for converting lignocellulosic biomass material to a liquid fuel, said process comprising the steps of:
 (i) contacting the lignocellulosic biomass material with an Ionic Liquid to form a solution of at least part of the cellulose component of the biomass material;   (ii) separating undissolved lignin from the cellulose solution;   (iii) converting the dissolved cellulose material to a liquid fuel at a first temperature T 1 ; and   (iv) converting the undissolved lignin to a liquid fuel at a second temperature T 2 ;   
       wherein T 1 <T 2 . 
     
     
         2 . The process of  claim 1  wherein T 2 −T 1  is at least 50° C., at least 100° C., or at least 200° C. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . The process of  claim 1  wherein T 1  is less than 200° C. 
     
     
         6 . The process of  claim 1  wherein T 2  is 200° C. or above. 
     
     
         7 . The process of  claim 1  wherein step (iii) is carried out in the presence of a catalyst, or wherein step (iv) is carried out in the presence of a catalyst or wherein steps (iii) and (iv) are carried out in the presence of a catalyst. 
     
     
         8 . (canceled) 
     
     
         9 . The process of  claim 7  wherein step (iv) is carried out in a cyclone reactor, a fixed fluidized bed reactor, or a transported fluidized bed reactor. 
     
     
         10 . The process of  claim 7  the catalyst in step (iv) acts as a heat transfer medium. 
     
     
         11 . The process of  claim 7  wherein the catalyst in step (iv) comprises a solid acid. 
     
     
         12 . The process of  claim 11  wherein the catalyst comprises a zeolite. 
     
     
         13 . The process of  claim 12  wherein the zeolite comprises zeolite Y, ZSM-5, or a combination thereof. 
     
     
         14 . The process of  claim 7  wherein the catalyst of step (iv) comprises a solid base, hydrotalcite, a hydrotalcite-like material, a mixed metal oxide, a layered hydroxy salt, a clay, or a calcination product thereof. 
     
     
         15 . (canceled) 
     
     
         16 . The process of  claim 7  wherein the catalyst in step (iv) comprises alumina. 
     
     
         17 . The process of  claim 7  wherein the catalyst in step (iv) is mixed with a particulate inert heat transfer medium. 
     
     
         18 . The process of  claim 7  wherein step (iv) is carried out at a temperature in the range of from 300° C. to 600° C. 
     
     
         19 . The process of  claim 1  wherein the liquid fuel produced in step (iii) is insoluble in the Ionic Liquid. 
     
     
         20 . The process of  claim 1  wherein the Ionic Liquid comprises an organic cation or molten salt hydrate. 
     
     
         21 . (canceled) 
     
     
         22 . The process of  claim 21  wherein the molten sat hydrate comprises a halogen anion. 
     
     
         23 . (canceled) 
     
     
         24 . The process of  claim 20  wherein the molten salt hydrate comprises a cation selected from the group consisting of Zn, Ba, Ca, Li, Al, Cu, Fe, Cu(NH 3 ) x  and Cr. 
     
     
         25 . The process of  claim 20  wherein the Ionic Liquid is a molten salt hydrate comprising ZnCl 2 , CaCl 2 , LiCl, or a mixture thereof. 
     
     
         26 . The process of  claim 1  comprising the further step of upgrading the liquid fuel obtained in step (iii) and/or (iv).