Method for producing ethanol and co-products from cellulosic biomass
AssigneeAbengoa Bioenergy New Technologies, Inc.
InventorQuang A. Nguyen
Life of this patent
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Abstract
The present invention generally relates to processes for production of ethanol from cellulosic biomass. The present invention also relates to production of various co-products of preparation of ethanol from cellulosic biomass. The present invention further relates to improvements in one or more aspects of preparation of ethanol from cellulosic biomass including, for example, improved methods for cleaning biomass feedstocks, improved acid impregnation, and improved steam treatment, or “steam explosion.”
Claims48
A method for pretreatment of cellulosic biomass feedstock comprising cellulose, hemicellulose, and lignin, the method comprising:
- contacting the cellulosic biomass feedstock with an acidic liquid medium to form an acid-impregnated biomass feedstock;
- contacting the acid-impregnated cellulosic biomass feedstock with H2O at elevated temperature and pressure within a contact zone under conditions effective for solubilizing hemicellulose and producing a steam treated feedstock, wherein the pressure in the contact zone is at least about 55 psig;
- subjecting the steam treated feedstock within a depressurization zone to conditions and for at time effective for solubilizing hemicellulose and producing a volatilized fraction of the steam treated feedstock;
- and
- releasing at least a portion of the volatilized fraction from the depressurization zone for control of temperature and pressure within the depressurization zone, wherein the pressure within the depressurization zone is controlled to from about 5 to about 50 psig.
A method for pretreatment of cellulosic biomass feedstock comprising cellulose, hemicellulose, and lignin, the method comprising:
- contacting the cellulosic biomass feedstock with an acidic liquid medium to form an acid-impregnated cellulosic biomass feedstock;
- in a first pretreatment stage, contacting the acid-impregnated cellulosic biomass feedstock with H2O at elevated temperature within a contact zone containing a vapor phase wherein the partial pressure of water vapor is at least about 55 psig to solubilize hemicellulose and produce a volatilized fraction of the acid-impregnated feedstock;
- and
- in a second pretreatment stage, releasing at least a portion of the volatilized fraction from the contact zone at a rate effective to control the pressure of in the contact zone, wherein the pressure in the second pretreatment stage is reduced by at least about 30 psig as compared to the first pretreatment stage pressure, the pressure in the second pretreatment stage is controlled above atmospheric pressure, and the acid-impregnated feedstock is held in the second pretreatment stage for a time effective for solubilizing hemicellulose and producing a volatilized fraction of the steam treated feedstock.
A method for pretreatment of cellulosic biomass feedstock comprising cellulose, hemicellulose, and lignin, the method comprising:
- introducing said feedstock into a steam contact zone, said contact zone having an inlet for steam and an outlet for pretreated feedstock;
- introducing steam into said contact zone at said inlet to contact steam and said feedstock and form a steam treated feedstock, wherein the pressure in the contact zone is at least about 51) psig;
- and
- removing pretreated feedstock from said contact zone through said outlet and into a receiving zone, wherein the pressure in the receiving zone does not differ from the pressure in the contact zone by more than about 200 psig, the pressure in the receiving zone is controlled above atmospheric pressure, and the pretreated feedstock is held in the receiving zone for a time effective for solubilizing hemicellulose and producing a volatilized fraction of the steam treated feedstock.
A method for pretreatment of cellulosic biomass feedstock comprising cellulose, hemicellulose, and lignin, the method comprising:
- introducing said feedstock into a steam contact zone;
- introducing steam into said contact zone to contact said feedstock and form a steam-treated feedstock, wherein the pressure in the contact zone is at least about 51) psig;
- and
- passing said steam-treated feedstock from said steam contact zone through a flow restriction and into a receiving zone, the pressure drop across said flow restriction being less than about 150 psi, the pressure in the receiving zone is controlled above atmospheric pressure, and the steam-treated feedstock is held in the receiving zone for a time effective for solubilizing hemicellulose and producing a volatilized fraction of the steam treated feedstock.
A method for pretreatment of cellulosic biomass feedstock comprising cellulose, hemicellulose, and lignin, the method comprising:
- in a first pretreatment stage, contacting the cellulosic biomass feedstock with H20 within a contact zone containing a vapor phase wherein the partial pressure of water vapor is at least about 55 psig, said H20 being distributed within said zone so that the biomass is brought to a target temperature, and the average temperature of any region of the biomass that contains more than 15% by weight of the biomass does not differ by more than 5° C. from said target temperature, and
- in a second pretreatment stage, reducing the pressure by at least 31) psig as compared to the first pretreatment stage pressure, the pressure in the second pretreatment stage is controlled above atmospheric pressure, and the feedstock-is held in the second pretreatment stage for a time effective for solubilizing hemicellulose and producing a volatilized fraction of the steam treated feedstock.
Dependencies are inferred from the claim text.