Modified sulfuric acid and uses thereof

Abstract

An aqueous composition comprising: sulfuric acid; a substituted aromatic compound; and a peroxide. Said composition being capable of delignifying biomass under milder conditions than conditions under which kraft pulping takes place.

1 . An aqueous acidic composition comprising:
 sulfuric acid;   a substituted aromatic compound; and   a peroxide.   
     
     
         2 . The composition according to  claim 1  where said a substituted aromatic compound is a disubstituted aromatic compound comprising an amine group and a sulfonic acid group. 
     
     
         3 . The composition according to  claim 1 , wherein sulfuric acid, said substituted aromatic compound are present in a molar ratio ranging from 28:1 to 2:1. 
     
     
         4 . The composition according to  claim 1 , where said substituted aromatic compound has a molecular weight below 300 g/mol. 
     
     
         5 . The composition according to  claim 1 , where said substituted aromatic compound is a secondary amine. 
     
     
         6 . The composition according to  claim 1 , where said substituted aromatic compound is selected from the group consisting of: sulfanilic acid; metanilic acid; orthanilic acid; and combinations thereof. 
     
     
         7 . An aqueous composition for use in the processing and depolymerisation of cellulose from a plant source, wherein said composition comprises:
 sulfuric acid present in an amount ranging from 20-80 wt % of the total weight of the composition;   a substituted aromatic compound; and   a peroxide;   
       wherein the sulfuric acid and the substituted aromatic compound are present in a mole ratio ranging from 2:1 to 28:1. 
     
     
         8 . The composition according to  claim 7 , where the peroxide is hydrogen peroxide. 
     
     
         9 . The composition according to  claim 7 , where said substituted aromatic compound comprises an aromatic compound having a sulfonamide substituent. 
     
     
         10 . The composition according to  claim 7 , where said substituted aromatic compound comprises an aromatic compound having a sulfonamide substituent is selected from the group consisting of:
 benzene sulfonamides; toluene sulfonamides; substituted benzene sulfonamides; and substituted toluene sulfonamides.   
     
     
         11 . A one-pot process to separate lignin from a lignocellulosic feedstock, said process comprising the steps of:
 providing a vessel;   providing said lignocellulosic feedstock;   providing a composition comprising;
 an acid; 
 a modifying agent comprising a substituted aromatic compound; and 
 a peroxide; 
   exposing said lignocellulosic feedstock to said composition in said vessel for a period of time sufficient to remove at least 80% of the lignin present said lignocellulosic feedstock;   optionally, separating and removing a liquid phase comprising dissolved lignin fragments from a solid phase comprising cellulose fibres.   
     
     
         12 . The process according to  claim 11 , wherein said acid is sulfuric acid. 
     
     
         13 . The process according to  claim 11  wherein said peroxide is hydrogen peroxide. 
     
     
         14 . The process according to  claim 11 , wherein the period of time is sufficient to remove at least 90% of the lignin present on said plant material. 
     
     
         15 . The process according to  claim 11 , wherein the period of time is sufficient to remove at least 95% of the lignin present on said plant material. 
     
     
         16 . The process according to  claim 11 , wherein the temperature of the composition prior to the step of exposing it to the lignocellulosic feedstock is below 50° C. 
     
     
         17 . The process according to  claim 11 , wherein the temperature of the composition prior to the step of exposing it to the lignocellulosic feedstock is below 40° C. 
     
     
         18 . The process according to  claim 11 , wherein the temperature of the composition prior to the step of exposing it to the lignocellulosic feedstock is below 30° C. 
     
     
         19 . The process according to  claim 11 , wherein the temperature of the composition prior to the step of exposing it to the lignocellulosic feedstock is below 25° C. 
     
     
         20 . The process according to  claim 11 , wherein said method is carried out at ambient temperature. 
     
     
         21 . The process according to  claim 11 , wherein said method is carried out at ambient pressure.