Method of separating lignocellulosic material into lignin, cellulose and dissolved sugars
AssigneeMidwest Research Institute
InventorsStuart K. Black, Bonnie R. Hames, Michele D. Myers
Life of this patent
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Abstract
A method for separating lignocellulosic material into (a) lignin, (b) cellulose, and (c) hemicellulose and dissolved sugars. Wood or herbaceous biomass is digested at elevated temperature in a single-phase mixture of alcohol, water and a water-immiscible organic solvent (e.g., a ketone). After digestion, the amount of water or organic solvent is adjusted so that there is phase separation. The lignin is present in the organic solvent, the cellulose is present in a solid pulp phase, and the aqueous phase includes hemicellulose and any dissolved sugars.
Claims8
A method for separating lignocellulosic material into lignin, cellulose, and dissolved sugars composed mostly of hemicellulose and sugars, the method comprising:
- the steps of:
- (a) digesting the solid lignocellulosic material in a single phase mixture of an alcohol, water and a water-immiscible ketone having at least 4 carbon atoms to solubilize lignin and hemicellulose and leave a cellulosic solid phase;
- said water being present in said single phase mixture in an amount of about 10 to 65 percent by weight, and said water-immiscible ketone being present in an amount of about 7 to about 65% by weight;
- (b) adjusting the amount of water in said single liquid phase mixture to cause phase separation into two liquid phases of a lignin water-immiscible ketone stream and a stream of dissolved sugars composed mostly of hemicellulose;
- and
- (c) separating said mixture into first, second and third phases;
- wherein said first phase is a liquid and comprises high purity lignin by evaporating water-immiscible ketone;
- said second phase comprises high purity cellulose in a solid phase;
- and said third phase is aqueous and comprises hemicellulose and dissolved sugars.
A method for separating lignocellulosic material into lignin, cellulose, and dissolved sugars composed mostly of hemicellulose and sugars, the method comprising:
- the steps of:
- (a) digesting lignocellulosic material in a single phase mixture of an alcohol, water and a water-immiscible ketone having at least 4 carbon atoms to solubilize lignin and hemicellulose and leave a cellulose solid phase;
- said water being present in said single phase mixture in an amount of about 10 to 65 percent by weight, and said water-immisible ketone being present in an amount of about 7 to about 65% by weight;
- (b) adjusting the amount of said ketone in said single liquid phase mixture to cause phase separation into two liquid phases of a lignin water-immiscible ketone stream and a stream of dissolved sugars composed mostly of hemicellulose;
- and
- (c) separating said mixture into first, second and third phases;
- wherein said first phase is liquid and comprises high purity lignin by evaporating water immiscible ketone said second phase comprises high purity cellulose in a solid phase;
- and said third phase is an aqueous alcohol mixture and comprises hemicellulose and dissolved sugars.
Dependencies are inferred from the claim text.