초록 ▼

A process for recovering cellulose using sulfuric acid and utilizing the recovered cellulose by hydrolysis to yield glucose. Cellulosic raw materials are hydrolyzed by dilute sulfuric acid to remove hemicellulose, after which the solid residue is separated and is treated with concentrated sulfuric a

A process for recovering cellulose using sulfuric acid and utilizing the recovered cellulose by hydrolysis to yield glucose. Cellulosic raw materials are hydrolyzed by dilute sulfuric acid to remove hemicellulose, after which the solid residue is separated and is treated with concentrated sulfuric acid to dissolve cellulose contained therein. After blending and mixing of the residue in the concentrated sulfuric acid under mild reaction conditions, cellulose is reprecipitated by addition of water or an organic solvent such as methanol. The recovered cellulose can then be hydrolyzed by cellulose enzymes and/or dilute acids to provide a high yield of glucose. High level recovery and reconcentration of the sulfuric acid is also disclosed.

대표청구항 ▼

A process for recovering cellulose from a cellulosic material which contains hemicellulose, cellulose and lignin, which comprises the steps of: contacting the cellulosic material with dilute acid under mild conditions to hydrolyze only the hemicellulose portion thereof; removing the hydrolyzed hemic

A process for recovering cellulose from a cellulosic material which contains hemicellulose, cellulose and lignin, which comprises the steps of: contacting the cellulosic material with dilute acid under mild conditions to hydrolyze only the hemicellulose portion thereof; removing the hydrolyzed hemicellulose portion from the remainder of the cellulosic material residue, said residue being in solid form; blending and mixing said residue with concentrated sulfuric acid under mild conditions to dissolve and partially hydrolyze the cellulose portion of said residue, the lignin portion being substantially unaffected by the mild reaction conditions and remaining as a solid; and reprecipitating the dissolved and partially hydrolyzed cellulose by adding a reprecipitating agent to the reaction mass resulting from said blending and mixing step, said reprecipitating agent being a member selected from the group consisting of water, water soluble organic solvents and mixtures thereof. The process of claim 1 wherein said reprecipitated cellulose has a lowered DP and has its internal structure and lignin seal disrupted whereby said cellulose may be readily substantially completely hydrolyzed to yield glucose. The process of claim 11 further comprising the step of hydrolyzing said reprecipitated cellulose to glucose by means of cellulase enzymes or a dilute acid or a mixture of a dilute acid and enzymes.