Process for converting polysaccharides in an inorganic molten salt hydrate

Abstract

A process is disclosed for converting polysaccharides to platform chemicals. The process comprises dissolving the polysaccharides in a inorganic molten salt hydrate, converting the polysaccharides to monosaccharides, and converting the monosaccharides to platform chemicals that are easily separable from the inorganic molten salt hydrate. Preferably the polysaccharides are provided in the form of a biomass, more preferably a ligno-cellulosic biomass.

1 .- 28 . (canceled) 
     
     
         29 . A process for converting ligno-cellulosic biomass to platform chemicals, said process comprising the steps of:
 a) dissolving ligno-cellulosic biomass in an inorganic molten salt hydrate;   b) converting the dissolved ligno-cellulosic biomass to monosaccharides;   c) converting the monosaccharides to platform chemicals that are easily separable from the inorganic molten salt hydrate;   d) separating the platform chemicals from the inorganic molten salt hydrate.   
     
     
         30 . The process of  claim 29 , further comprising: pre-treating the lignocellulosic biomass through comminution, or subjecting the ligno-cellulosic biomass to comminution during step a). 
     
     
         31 . The process of  claim 29 , wherein the molten salt hydrate comprises a composition, the composition comprising at least Zn, Ca or Li halides, or mixtures thereof, with a content of 40 to 80 wt % of salt in said composition. 
     
     
         32 . The process of  claim 29 , wherein in step b), the acid is an inorganic soluble acid. 
     
     
         33 . The process of  claim 29 , wherein lignin is separated out after step b). 
     
     
         34 . The process of  claim 29 , wherein acid is removed prior to step c). 
     
     
         35 . The process of  claim 29 , wherein step c) takes place in a fixed bed catalyst, slurry reactor, expanded bed catalyst, moving bed catalyst, or trickle bed catalyst. 
     
     
         36 . The process of  claim 29 , wherein the hydrogenation catalyst is selected from a noble metal of the series of Ru, Rh, Pd and Pt, or a transition metal of the series Cu, Cr, Co, Ni and Fe. 
     
     
         37 . The process of  claim 29 , wherein the hydrogenation catalyst comprises a support selected from: activated carbon; aluminum oxide; hydrotalcites; silicates; titanates; zirconates; other metallic oxides comprising SnO 2 , Bi 2 O 5 , Sb 2 O 5 , MoO 3 , WO 3 ; mixed oxides comprising SiO 2 —Al 2 O 3 , SiO 2 —TiO 2 , Al 2 O 3 —ZnO, SiO 2 —ZrO 2 , SiO 2 —SnO 2 , SiO 2 —MoO 3 , SiO 2 —WO 3 ; metallic salts comprising AlPO 4 , FePO 4 , Zn 3 (PO 4 ) 2 , Mg 3 (PO4) 2 , Ti 3 (PO 4 ) 4 , Zr 3 (PO 4 ); and basic oxides comprising MgO, BeO, La 2 O 3 , CeO 2 , Pr 2 O 3 , Nd 2 O 3 , SmO 2 , ZrO 2 . 
     
     
         38 . The process of  claim 29 , wherein steps (b) and (c) are performed in a one-pot combination. 
     
     
         39 . The process of  claim 29 , wherein at least one transition metal is present during step (c) in the inorganic molten salt solution in the molar ratio of transition metal to polyol from 0.01 to 5; and wherein the transition metal salt anion is a halide selected from the group consisting of Cu, Ni, Co, Fe, V, and mixtures thereof. 
     
     
         40 . The process of  claim 29 , wherein water is continuously removed during steps (c)-(d). 
     
     
         41 . A process for the conversion of ligno-cellulosic biomass comprising hemicellulose to platform chemicals, comprising the steps of:
 a) contacting the ligno-cellulosic biomass comprising hemicellulose with an inorganic molten salt hydrate to form a mixture;   b) hydrolyzing the mixture of step a) with acid to form monosaccharides comprising xylose;   c) hydrogenating the mixture obtained in step b) with a hydrogenation catalyst and hydrogen to convert monosaccharides comprising xylose in the mixture to polyols comprising xylitol;   d) separating the platform chemicals comprising xylitol from the inorganic molten salt hydrate.   
     
     
         42 . The process of  claim 41 , wherein in step b), the acid is an inorganic soluble acid. 
     
     
         43 . The process of  claim 41 , wherein acid is removed prior to step c). 
     
     
         44 . The process of  claim 41 , wherein water is continuously removed during steps (c)-(d). 
     
     
         45 . A process for the conversion of ligno-cellulosic biomass comprising cellulose to platform chemicals, comprising the steps of:
 a) contacting the ligno-cellulosic biomass comprising cellulose with an inorganic molten salt hydrate to from a mixture;   b) hydrolyzing the mixture of step a) with acid;   c) hydrogenating the mixture obtained in step b) with a hydrogenation catalyst and hydrogen to convert monosaccharides comprising glucose in the mixture to polyols comprising sorbitol;   d) heating the mixture obtained from step c) to effect dehydration of polyols comprising sorbitol to dehydration products comprising isosorbide;   e) separating dehydration products and excess water from the hydrated inorganic molten salt, the hydrated inorganic molten salt after recovery being directed to step a).   
     
     
         46 . The process of  claim 45 , wherein the molten salt hydrate wherein the inorganic molten salt hydrate comprises 60-85 wt % ZnCl 2 hydrate 
     
     
         47 . The process of  claim 45 , wherein in step b), the acid is an inorganic soluble acid. 
     
     
         48 . The process of  claim 45 , wherein lignin is separated out after step b). 
     
     
         49 . The process of  claim 45 , wherein steps b) and c) are performed in a one-pot combination. 
     
     
         50 . The process of  claim 45 , wherein water is continuously removed during steps (c)-(d).