Locally-regulated pressurized pretreatment of lignocellulosic biomass
AssigneesPurdue Research Foundation, Bowen Engineering Corporation
InventorsMichael R. Ladisch, Brian Stater, Bradley Spindler
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Abstract
Described are methods for pretreating lignocellulosic biomass that comprise passing a hot aqueous biomass slurry through a heat exchange passage from an inlet to an outlet and locally regulating pressure in the passage by feed of a pressurized liquid medium to one or more intermediate locations of the passage. Also described are methods for producing ethanol from the pretreated biomass.
Claims20
A method for processing lignocellulosic biomass, comprising:
- passing an aqueous slurry including the lignocellulosic biomass through a first passage of a heating device from an inlet opening to an outlet opening, said aqueous slurry having a temperature above 100° C. and being at a first pressure substantially at or above the saturation vapor pressure of water at said temperature;
- and
- feeding a liquid aqueous medium under a second pressure into said first passage through at least one additional opening at a location intermediate said inlet opening and said outlet opening so as to locally regulate pressure within the first passage.
A method for pretreating lignocellulosic biomass to increase its susceptibility to enzymatic hydrolysis, comprising:
- providing particulate lignocellulosic biomass;
- mixing the particulate lignocellulosic biomass with an aqueous medium to prepare an aqueous biomass slurry;
- passing the aqueous biomass slurry through a first passage of a heat exchanger from an inlet opening to an outlet opening, said aqueous biomass slurry having a temperature above 100° C. and being at a first pressure substantially at or above the saturation vapor pressure of water at said temperature;
- passing a heated exchange medium through a second passage of the heat exchanger, said second passage in heat exchange relationship with said first passage;
- and
- feeding a liquid aqueous medium at a second pressure into the first passage through at least one additional opening at a location intermediate said inlet opening and said outlet opening so as to locally regulate pressure within the first passage.
A method for producing ethanol from lignocellulosic biomass, comprising:
- (a) pretreating lignocellulosic biomass to increase its susceptibility to hydrolysis by a cellulase enzyme, said pretreating comprising:
- providing particulate lignocellulosic plant biomass;
- mixing the particulate lignocellulosic plant biomass with an aqueous medium to prepare an aqueous plant biomass slurry;
- passing the aqueous plant biomass slurry through a first passage of a heat exchanger from an inlet opening to an outlet opening, said aqueous plant biomass slurry having a temperature above 100° C. and being at a first pressure substantially at or above the saturation vapor pressure of water at said temperature;
- passing a heated fluid medium through a second passage of the heat exchanger, said second passage in heat exchange relationship with said first passage;
- feeding a liquid aqueous medium at a second pressure into said first passage through at least one additional opening at a location intermediate said inlet opening and said outlet opening so as to locally regulate pressure in said first passage;
- (b) hydrolyzing lignocellulosic biomass subjected to step (a) with a cellulase enzyme so as to produce glucose from cellulose of the biomass;
- (c) fermenting a medium including said glucose to produce ethanol;
- and
- (d) purifying the ethanol.
Dependencies are inferred from the claim text.