초록 ▼

Comminuted cellulosic materials which may or may not contain lignin are partially or totally hydrolyzed or saccharified by an improved organosolv process using an aqueous acetone solvent mixture containing a small amount of an acidic compound and containing at least about 70 percent by volume of ace

Comminuted cellulosic materials which may or may not contain lignin are partially or totally hydrolyzed or saccharified by an improved organosolv process using an aqueous acetone solvent mixture containing a small amount of an acidic compound and containing at least about 70 percent by volume of acetone and up to virtually anhydrous acetone. The process is performed at elevated reaction temperatures, preferably at 145°C. to 230°C., for a limited period of time and then with cooling such that the resultant dissolved sugars from the hydrolysis are not degraded into non-sugars. In particular the reaction is conducted such that the cellulosic material is dissolved and such that at least ninety percent or more of available sugars in the cellulosic material are recovered. Unexpectedly it has been found that acetone at high concentration forms stable complexes with the sugars which prevents their degradation and also facilitates separation of the sugars. Lignin and sugars derived are commercially useful chemical compounds.

대표청구항 ▼

In a process for the production of carbohydrate hydrolysates as sugars from a comminuted cellulosic material which can contain lignin by treating the material in a pressure vessel with a solvent mixture of acetone and water containing a small amount of an acidic compound at elevated temperatures to

In a process for the production of carbohydrate hydrolysates as sugars from a comminuted cellulosic material which can contain lignin by treating the material in a pressure vessel with a solvent mixture of acetone and water containing a small amount of an acidic compound at elevated temperatures to form reducing sugars in a liquor, the improvement which comprises: (a) providing mixtures of acetone and water containing greater than 70 volume percent acetone and the catalytic acidic compound as the solvent mixture in the pressure vessel at the elevated temperatures with the cellulosic material; (b) repeatedly treating the cellulosic material in the solvent mixture for a limited period of time at the elevated temperatures until the cellulosic material is at least partially dissolved and such that at least 90 percent of the solubilized sugars from the cellulosic material are recovered without degradation to non-sugars in the liquor; and (c) rapidly cooling the liquor as it is removed from the pressure vessel after each treatment, wherein the cellulosic material is treated on a batch or continuous basis in the pressure vessel using successive amounts of the solvent mixture thereby defining successive stages of treatment at the elevated temperatures, wherein less than 50 percent by weight of the cellulosic material is dissolved in each stage of treatment and wherein in each stage the cellulosic material is treated for a limited period of time in the pressure vessel and then the withdrawn liquor is rapidly cooled when removed from the pressure vessel so as to achieve the sugar recovery.