Gradient pretreatment of lignocellulosic biomass
AssigneeE. I. Du Pont de Nemours and Company
InventorsPATRICIA CHEUNG, BRADLEY CURT FOX, MING WOEI LAU, JOSEPH MICHAEL SELBY, GREGORY PAUL SHANKWITZ, STUART M THOMAS, RYAN ERIC WARNER
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Abstract
Lignocellulosic biomass pretreated with ammonia where the concentration of the biomass in the reaction mixture is reduced over time was found to produce more sugars following saccharification, as compared to equivalent biomass pretreated at constant concentration. The concentration of biomass is a solids concentration, which is the percent of dry biomass relative to the total pretreatment reaction mixture on a weight to weight basis.
Claims15
A process for producing fermentable sugars from cellulosic biomass comprising:
- a) providing in a reaction vessel at starting time t0, a reaction mixture comprising:
- i) a solids concentration of cellulosic biomass of between about 40% and about 70%, measured as percent of dry biomass relative to the total mixture on a weight to weight basis;
- and
- ii) ammonia, having a loading concentration of between about 4% and about 24% relative to dry weight of the biomass;
- b) increasing the liquid content of the reaction mixture over time to a final time tn wherein the solids concentration decreases by between about 20% and about 30% producing a pretreated biomass;
- and
- c) contacting the pretreated biomass with a saccharification enzyme consortium under suitable conditions to produce fermentable sugars.
Dependencies are inferred from the claim text.