Biomass Pretreatment Process
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).