Nanolignocellulose compositions and processes to produce these compositions

Abstract

Some variations provide a new nanolignocellulose composition comprising, on a bone-dry, ash-free, and acetyl-free basis, from 35 wt % to 80 wt % cellulose nanofibrils, cellulose microfibrils, or a combination thereof, from 15 wt % to 45 wt % lignin, and from 5 wt % to 20 wt % hemicelluloses. The hemicelluloses may contain xylan or mannan as the major component. Novel properties arise from the hemicellulose content that is intermediate between high hemicellulose content of raw biomass and low hemicellulose content of conventional nanocellulose. The nanolignocellulose composition is hydrophobic due to the presence of lignin. Processes for making and using the nanolignocellulose compositions are also described.

What is claimed is: 
     
         1 . A nanolignocellulose composition comprising, on a bone-dry, ash-free, and acetyl-free basis, from about 35 wt % to about 80 wt % cellulose nanofibrils, cellulose microfibrils, or a combination thereof, from about 15 wt % to about 45 wt % lignin, and from about 5 wt % to about 20 wt % hemicelluloses. 
     
     
         2 . The nanolignocellulose composition of  claim 1 , wherein said composition comprises from about 40 wt % to about 70 wt % cellulose nanofibrils, cellulose microfibrils, or a combination thereof on a bone-dry, ash-free, and acetyl-free basis. 
     
     
         3 . The nanolignocellulose composition of  claim 1 , wherein said composition comprises from about 45 wt % to about 60 wt % cellulose nanofibrils, cellulose microfibrils, or a combination thereof on a bone-dry, ash-free, and acetyl-free basis. 
     
     
         4 . The nanolignocellulose composition of  claim 1 , wherein said composition comprises from about 20 wt % to about 40 wt % lignin on a bone-dry, ash-free, and acetyl-free basis. 
     
     
         5 . The nanolignocellulose composition of  claim 1 , wherein said composition comprises from about 25 wt % to about 35 wt % lignin on a bone-dry, ash-free, and acetyl-free basis. 
     
     
         6 . The nanolignocellulose composition of  claim 1 , wherein said composition comprises from about 7 wt % to about 15 wt % hemicelluloses on a bone-dry, ash-free, and acetyl-free basis. 
     
     
         7 . The nanolignocellulose composition of  claim 1 , wherein said composition comprises from about 8 wt % to about 14 wt % hemicelluloses on a bone-dry, ash-free, and acetyl-free basis. 
     
     
         8 . The nanolignocellulose composition of  claim 1 , wherein said hemicelluloses contain xylan as the major component. 
     
     
         9 . The nanolignocellulose composition of  claim 1 , wherein said hemicelluloses contain mannan as the major component. 
     
     
         10 . The nanolignocellulose composition of  claim 1 , wherein said nanolignocellulose composition is characterized by at least 99% filtration completion in less than 100 minutes. 
     
     
         11 . A pulp product or a paper product containing the nanolignocellulose composition of  claim 1 . 
     
     
         12 . A process for producing a nanolignocellulose composition, said process comprising:
 (a) providing a lignocellulosic biomass feedstock;   (b) digesting said feedstock with a reaction solution including steam and/or hot water in a digestor under effective reaction conditions to produce a digested stream containing cellulose-rich solids, hemicellulose oligomers, and lignin;   (c) optionally washing said cellulose-rich solids to remove at least a portion of said hemicellulose oligomers and/or at least a portion of said lignin from said cellulose-rich solids;   (d) mechanically treating said cellulose-rich solids to form a nanolignocellulose composition containing cellulose nanofibrils and/or cellulose nanocrystals, hemicelluloses, and lignin; and   (e) recovering said nanolignocellulose composition.   
     
     
         13 . The process of  claim 12 , wherein said nanolignocellulose composition comprises, on a bone-dry, ash-free, and acetyl-free basis, from about 35 wt % to about 80 wt % cellulose nanofibrils, cellulose microfibrils, or a combination thereof, from about 15 wt % to about 45 wt % lignin, and from about 5 wt % to about 20 wt % hemicelluloses. 
     
     
         14 . The process of  claim 12 , wherein said nanolignocellulose composition is characterized by at least 99% filtration completion in less than 100 minutes. 
     
     
         15 . The process of  claim 12 , said process further comprising forming a pulp product or a paper product containing said nanolignocellulose composition.