Upgrading lignin from lignin-containing residues through reactive extraction

Abstract

Disclosed are methods of functionalizing lignin using reactive extraction. The invention also generally relates to functionalized lignin. An exemplary method for producing functionalized lignin is disclosed, which comprises: providing a residue comprising lignin and cellulose; subjecting the residue to a liquid comprising an organic compound, thereby forming a first mixture; wherein the subjecting is performed at a first temperature of about 100° C. or less; and wherein the first mixture comprises: a first liquid fraction comprising solubilized functionalized lignin, wherein the solubilized functionalized lignin is functionalized with the organic compound; and a first solid fraction comprising cellulose.

1 - 32 . (canceled) 
     
     
         33 . A functionalized lignin comprising:
 (a) an ethoxyl content of about 1 to about 45 per 100 Ar; and   (b) at least one of:
 (i) a phenolic OH content of less than about 70; and 
 (ii) a β-O-4 content of at least about 10. 
   
     
     
         34 . The functionalized lignin of  claim 33 , wherein the functionalized lignin further comprises an acyl content of about 1 to about 45 per 100 Ar. 
     
     
         35 . The functionalized lignin of  claim 33 , wherein the functionalized lignin is produced by
 providing a residue comprising lignin and cellulose;   subjecting the residue to a liquid comprising an organic compound selected from an alcohol and an organic acid, thereby forming a first mixture;   wherein the subject is performed at a first temperature of about 100° C. or less and for a time of less than about 225 minutes; and   wherein the first mixture comprises:   a first liquid fraction comprising a solubilized functionalized lignin functionalized with the organic compound; and   a first solid fraction comprising cellulose.   
     
     
         36 . The functionalized lignin of  claim 35 , wherein the residue comprises less than about 20 wt. % hemicellulose, based on the dry weight of the residue. 
     
     
         37 . The functionalized lignin of  claim 35 , wherein the residue is produced by
 exposing a biomass to a first fluid comprising water, thereby forming a second mixture comprising:
 a second liquid fraction; and 
 a second solid fraction comprising the residue; 
   wherein the second fluid has a second temperature of at least about 350° C. and a first pressure of at least about 180 bar.   
     
     
         38 . The functionalized lignin of  claim 37 , wherein the second fluid comprises supercritical water. 
     
     
         39 . The functionalized lignin of  claim 37 , wherein the biomass is a lignocellulosic biomass. 
     
     
         40 . The functionalized lignin of  claim 37 , wherein the biomass is a treated lignocellulosic biomass obtained by a process comprising extracting at least a portion of hemicellulose from a lignocellulosic biomass using a second fluid comprising water, thereby forming a third mixture comprising:
 a third liquid fraction comprising hemicellulose; and   a third solid fraction comprising the treated lignocellulosic biomass,   wherein the second fluid has a third temperature of at least about 110° C. and a second pressure of at least about 10 bar.   
     
     
         41 . A thermoplastic blend comprising a thermoplastic polymer and the functionalized lignin of  claim 33 . 
     
     
         42 . The thermoplastic blend of  claim 41 , wherein the thermoplastic polymer is a polyolefin. 
     
     
         43 . The thermoplastic blend of  claim 41 , further comprising an additional thermoplastic polymer. 
     
     
         44 . A functionalized lignin comprising:
 (c) an acyl content of about 1 to about 45 per 100 Ar;   (d) at least one of:
 (i) a phenolic OH content of less than about 70; and 
 (ii) a β-O-4 content of at least about 10. 
   
     
     
         45 . The functionalized lignin of  claim 44 , wherein the functionalized lignin is produced by
 providing a residue comprising lignin and cellulose;   subjecting the residue to a liquid comprising an organic compound selected from an alcohol and an organic acid, thereby forming a first mixture;   wherein the subject is performed at a first temperature of about 100° C. or less and for a time of less than about 225 minutes; and   wherein the first mixture comprises:
 a first liquid fraction comprising a solubilized functionalized lignin functionalized with the organic compound; and 
 a first solid fraction comprising cellulose. 
   
     
     
         46 . The functionalized lignin of  claim 45 , wherein the residue comprises less than about 20 wt. % hemicellulose, based on the dry weight of the residue. 
     
     
         47 . The functionalized lignin of  claim 45 , wherein the residue is produced by
 exposing a biomass to a first fluid comprising water, thereby forming a second mixture comprising:
 a second liquid fraction; and 
 a second solid fraction comprising the residue; 
   wherein the second fluid has a second temperature of at least about 350° C. and a first pressure of at least about 180 bar.   
     
     
         48 . The functionalized lignin of  claim 47 , wherein the second fluid comprises supercritical water. 
     
     
         49 . The functionalized lignin of  claim 47 , wherein the biomass is a lignocellulosic biomass. 
     
     
         50 . The functionalized lignin of  claim 47 , wherein the biomass is a treated lignocellulosic biomass obtained by a process comprising extracting at least a portion of hemicellulose from a lignocellulosic biomass using a second fluid comprising water, thereby forming a third mixture comprising:
 a third liquid fraction comprising hemicellulose; and   a third solid fraction comprising the treated lignocellulosic biomass,   wherein the second fluid has a third temperature of at least about 110° C. and a second pressure of at least about 10 bar.   
     
     
         51 . A thermoplastic blend comprising a thermoplastic polymer and the functionalized lignin of  claim 44 . 
     
     
         52 . The thermoplastic blend of  claim 51 , wherein the thermoplastic polymer is a polyolefin.