Abstract:
A process is described for improving the performance of certain multiphase reaction systems including a solid catalyst, one or more reactants in the gas phase and one or more reactants in the liquid phase, wherein a targeted maximum concentration of a reactant in the liquid phase is identified for providing improved value in terms of byproduct formation, catalyst deactivation and yields of desired products, and this targeted concentration is closely approached and preferably achieved, but not substantially exceeded, downstream in a continuous process or later in time from the initiation of a batch in a semibatch mode of operation of such processes.
Abstract:
Disclosed herein are methods for synthesizing 1,2,5,6-hexanetetrol (HTO), 1,6 hexanediol (HDO) and other reduced polyols from C5 and C6 sugar alcohols or R glycosides. The methods include contacting the sugar alcohol or R-glycoside with a copper catalyst, most desirably a Raney copper catalyst with hydrogen for a time, temperature and pressure sufficient to form reduced polyols having 2 to 3 fewer hydoxy groups than the starting material. When the starting compound is a C6 sugar alcohol such as sorbitol or R-glycoside of a C6 sugar such as methyl glucoside, the predominant product is HTO. The same catalyst can be used to further reduce the HTO to HDO.
Abstract:
Disclosed herein are methods for synthesizing 1,2,5,6-hexanetetrol (HTO), 1,6 hexanediol (HDO) and other reduced polyols from C5 and C6 sugar alcohols or R glycosides. The methods include contacting the sugar alcohol or R-glycoside with a copper catalyst, most desirably a Raney copper catalyst with hydrogen for a time, temperature and pressure sufficient to form reduced polyols having 2 to 3 fewer hydoxy groups than the starting material. When the starting compound is a C6 sugar alcohol such as sorbitol or R-glycoside of a C6 sugar such as methyl glucoside, the predominant product is HTO. The same catalyst can be used to further reduce the HTO to HDO.
Abstract:
Disclosed herein are methods of synthesizing shorter chain polyols. Methods of hydrolyzing polysaccharides are further disclosed. The present invention is also directed towards methods of selectively synthesizing sorbitol.
Abstract:
A method for reducing contaminants in the production of a bio-derived glycol product of polyol hydrogenolysis is described. The method involves subjecting an aqueous, polyol product mixture (from the hydrogenolysis conversion of biologically-derived carbohydrate feedstock) to ion-exclusion chromatography to separate and reduce impurities from an eluant fraction containing a desired product, and distilling the eluant fraction to yield the desired product (e.g., propylene glycol or ethylene glycol). The reaction product mixture can be introduced into a continuous ion-exclusion chromatography system to reduce the impurities and produce in a high-throughput manner a finished otherwise commercially acceptable glycol product.
Abstract:
A method for reducing contaminants in the production of a bio-derived glycol product of polyol hydro-genolysis is described. The method involves subjecting an aqueous, polyol product mixture (from the hydrogenolysis conversion of biologically-derived carbohydrate feedstock) to ion-exclusion chromatography to separate and reduce impurities from an eluant fraction containing a desired product, and distilling the eluant fraction to yield the desired product (e.g., propylene glycol or ethylene glycol). The reaction product mixture can be introduced into a continuous ion-exclusion chromatography system to reduce the impurities and produce in a high-throughput manner a finished otherwise commercially acceptable glycol product.