Method for the production of fermentable sugars and cellulose from lignocellulosic material
AssigneeAmerican Process, Inc.
InventorsTheodora Retsina, Vesa Pylkkanen
Life of this patent
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Abstract
A method for the production of fermentable sugars and high viscosity cellulose from lignocellulosic material in a batch or continuous process is provided. Lignocellulosic material is fractionated in a fashion that cellulose is removed as pulp, cooking chemicals can be reused, lignin is separated for the production of process energy, and hemicelluloses are converted into fermentable sugars, while fermentation inhibitors are removed. High yield production of alcohols or organic acids can be obtained from this method using the final reaction step.
Claims20
A process for producing fermentable hemicellulose sugars from a lignocellulosic material, said process comprising:
- (a) contacting a lignocellulosic material with a first solution of an aliphatic alcohol, water, and a first amount of sulfur dioxide in a first stage to produce a first mixture comprising cellulose, hemicellulose oligomers, lignin, and lignosulfonates, wherein said first amount of sulfur dioxide is in a moisture-adjusted concentration of from 12 wt % to 30 wt % in said first solution within said first stage;
- (b) removing and recovering cellulose pulp from said first mixture, to produce a second mixture comprising hemicellulose oligomers, lignin, and lignosulfonates;
- (c) contacting said second mixture with a second amount of sulfur dioxide in a second stage, in the presence of heat, to further hydrolyze said hemicellulose oligomers into fermentable hemicellulose sugars, wherein said second amount of sulfur dioxide is in a concentration of from 0.05 wt % to 9 wt % in a second solution within said second stage;
- (d) removing at least a portion of said aliphatic alcohol from said second mixture, thereby producing a third mixture comprising fermentable hemicellulose sugars;
- and
- (e) recovering said fermentable hemicellulose sugars.
A process for producing fermentable hemicellulose sugars from a lignocellulosic material, said process comprising:
- (a) contacting a lignocellulosic material with a first solution of an aliphatic alcohol, water, and sulfur dioxide in a first stage to produce a first mixture comprising cellulose, hemicellulose oligomers, lignin, and lignosulfonates, wherein said first amount of sulfur dioxide is in a moisture-adjusted concentration of from 12 wt % to 30 wt % in said first solution within said first stage;
- (b) removing and recovering cellulose pulp from said first mixture, to produce a second mixture comprising hemicellulose oligomers, lignin, and lignosulfonates;
- (c) contacting said second mixture with a sulfur-containing compound in a second stage, in the presence of heat, to further hydrolyze said hemicellulose oligomers into fermentable hemicellulose sugars, wherein said sulfur-containing compound is selected from the group consisting of sulfur dioxide, sulfurous acid, sulfuric acid, a lignosulfonate, and any combinations thereof, and wherein said sulfur-containing compound is in a concentration of from 0.05 wt % to 9 wt % in a second solution within said second stage;
- (d) removing at least a portion of said aliphatic alcohol from said second mixture, thereby producing a third mixture comprising fermentable hemicellulose sugars;
- and
- (e) recovering said fermentable hemicellulose sugars.
A process for producing fermentable hemicellulose sugars from a lignocellulosic material, said process comprising:
- (a) contacting a lignocellulosic material with a first solution of an aliphatic alcohol, water, and sulfur dioxide in a first stage to produce a first mixture comprising cellulose, hemicellulose oligomers, and lignin, wherein said first amount of sulfur dioxide is in a moisture-adjusted concentration of from 12 wt % to 30 wt % in said first solution within said first stage;
- (b) sulfonating, in the presence of said sulfur dioxide, at least some of said lignin into lignosulfonates and lignosulfonic acids in said first stage, wherein said concentration of sulfur dioxide is selected to control the extent of lignin sulfonation;
- (c) removing and recovering cellulose pulp from said first mixture, to produce a second mixture comprising hemicellulose oligomers, lignin, lignosulfonates, and lignosulfonic acids;
- (d) introducing said second mixture into a second stage in the presence of heat, wherein said lignosulfonic acids catalyze hydrolysis of said hemicellulose oligomers into fermentable hemicellulose sugars;
- (e) removing at least a portion of said aliphatic alcohol from said second mixture, thereby producing a third mixture comprising fermentable hemicellulose sugars;
- and
- (f) recovering said fermentable hemicellulose sugars.
Dependencies are inferred from the claim text.