Biomass Pretreatment Process

Abstract

A process is described for pretreating lignocellulosic biomass. The process comprises swelling the lignocellulosic biomass with an aqueous liquid. The pretreated lignocellulosic biomass may be used as a feedstock for the enzymatic conversion to ethanol, or in a thermal conversion. process to produce bio-oil. The pretreatment results in a greater yield and, in the case of a thermal conversion process, a better quality of the bio-oil. The pretreatment process may be used to adjust the composition and amount of inorganic material present in the lignocellulosic biomass material.

1 - 29 . (canceled) 
     
     
         30 . A process for converting a solid lignocellulosic biomass material to a bio-oil, the process comprising:
 a. pretreating a solid lignocellulosic biomass material to produce a solid modified lignocellulosic biomass material having an increased bulk porosity; and   b. subjecting the solid modified lignocellulosic biomass material to enzymatic hydrolysis, thermoconversion, or any combination thereof   
     
     
         31 . The process of  claim 30  wherein step (a) comprises contacting the solid lignocellulosic biomass material with a swelling agent. 
     
     
         32 . The process of  claim 31  wherein the swelling agent is a solvent. 
     
     
         33 . The process of  claim 31  wherein the swelling agent is an aqueous liquid. 
     
     
         34 . The process of  claim 31  wherein the solid lignocellulosic biomass material is contacted with a swelling agent at a temperature between 35° C. and 100° C. 
     
     
         35 . The process of  claim 31  wherein the solid lignocellulosic biomass material is contacted with a swelling agent at a temperature greater than 100° C. 
     
     
         36 . The process of  claim 31  wherein step (a) further comprises removing the swelling agent from the solid lignocellulosic biomass material. 
     
     
         37 . The process of  claim 36  wherein the swelling agent is removed by applying mechanical action to the solid lignocellulosic biomass material. 
     
     
         38 . The process of  claim 37  wherein the mechanical action results in a particle size reduction of the solid lignocellulosic biomass material. 
     
     
         39 . The process of  claim 30  wherein the ash content of the solid lignocellulosic biomass material is reduced to less than 5 wt %, based on dry weight. 
     
     
         40 . The process of  claim 30  wherein the ash content of the solid lignocellulosic biomass material is reduced to less than 3 wt %, based on dry weight. 
     
     
         41 . The process of  claim 30  wherein the Fe content of the solid lignocellulosic biomass material is reduced to less than 2,000 mg/kg, based on dry weight. 
     
     
         42 . The process of  claim 30  wherein the Fe content of the solid lignocellulosic biomass material is reduced to less than 1,600 mg/kg, based on dry weight. 
     
     
         43 . The process of  claim 32  wherein the solvent comprises an inorganic acid or an inorganic base. 
     
     
         44 . The process of  claim 30  further comprising adding an inorganic catalytic material before step (b). 
     
     
         45 . The process of  claim 44  wherein the inorganic catalytic material is dissolved in a solvent. 
     
     
         46 . The process of  claim 45  wherein the solvent is an aqueous liquid. 
     
     
         47 . The process of  claim 44  wherein the catalytic material is in a particulate form. 
     
     
         48 . The process of  claim 44  wherein the catalytic material comprises an inorganic salt. 
     
     
         49 . The process of  claim 44  wherein the catalytic material comprises a cation selected from the group consisting of K, NH 4 , Na, Ba, Mn, Mg, Ca, Li, Zn, and mixtures thereof. 
     
     
         50 . The process of  claim 44  wherein the catalytic material comprises an anion selected from the group consisting of OH, CO 3 , SO 4 , PO 4 , Cl, NO 3 , and mixtures thereof 
     
     
         51 . The process of  claim 44  wherein the catalytic material comprises an insoluble inorganic material, in a colloidal or nanoparticular form. 
     
     
         52 . The process of  claim 38  wherein the insoluble inorganic material is selected from the group of refractory oxides, zeolites, cationic clays, anionic clays, layered hydroxide materials, hydrotalcites, and any mixture thereof. 
     
     
         53 . The process of  claim 30  wherein thermoconversion comprises a process selected from the group consisting of pyrolysis, catalytic cracking, gasification, steam gasification, hydrotreatment, and any combination thereof. 
     
     
         54 . The process of  claim 30  further comprising the step of subjecting the solid modified lignocellulosic biomass material to drying, milling, comminuting or any combination thereof before step (b).