Abstract: Disclosed is a novel integrated process for production of cyclic esters which includes recovery of starting materials, such as lactic acid from a dilute aqueous lactic acid-containing solution, by solvent extraction. The starting materials are then formed into cyclic esters by removal of water wherein the concentration of higher molecular weight oligomers is maintained below about 20 wt % of the reaction composition. The process further includes providing a recovery solvent for the reaction composition and separating the cyclic esters from the starting materials and higher molecular weight oligomers by liquid-liquid equilibrium separation. The present invention is further directed toward independent novel unit operations of the overall process. The present invention provides for the efficient production and recovery of cyclic esters due to integration of the various unit operations by use of appropriate solvents and recycle streams.

Abstract: Disclosed is a novel integrated process for production of cyclic esters which includes recovery of starting materials, such as lactic acid from a dilute aqueous lactic acid-containing solution, by solvent extraction. The starting materials are then formed into cyclic esters by removal of water wherein the concentration of higher molecular weight oligomers is maintained below about 20 wt % of the reaction composition. The process further includes providing a recovery solvent for the reaction composition and separating the cyclic esters from the starting materials and higher molecular weight oligomers by liquid-liquid equilibrium separation. The present invention is further directed toward independent novel unit operations of the overall process. The present invention provides for the efficient production and recovery of cyclic esters due to integration of the various unit operations by use of appropriate solvents and recycle streams.

Abstract: Disclosed is a method for producing cyclic esters by the conversion of hydroxy carboxylic acids and their derivatives to their respective cyclic esters. Such cyclic esters, including lactide or glycolide, are particularly useful for producing polymers which can be used to make biodegradable materials, such as biodegradable packaging material. Various methods of cyclic ester production are disclosed, including liquid phase and vapor phase reactions. Also disclosed are various methods for recovering cyclic esters from product-containing streams.

Abstract: Disclosed is a method for thermochemically converting a carbohydrate material into ethanol wherein the carbohydrate material and a metal salt are reacted at elevated temperature to form an intermediate carbohydrate complex salt and/or a lactate metal salt which then is pyrolyzed in the presence of water into ethanol. Preferred carbohydrate materials for the process are various sugars and the metal salt preferably is a metal oxide, hydroxide, or carbonate. The intermediate complex and/or lactate salt may be separated from its aqueous reaction mixture prior to its pyrolysis to reduce the ultimate separation of ethanol from water. Alternatively, the metal of the metal salt may be one whose carbonate decomposes to metal oxide and carbon dioxide during the pyrolysis step of the process to generate said metal salt in situ.

Abstract: Disclosed is a process for converting a carbohydrate or lactic acid feedstock into an ethanol product in the presence of a metal salt at a reaction temperature ranging from about 250.degree. to about 400.degree. C. The improvement comprises establishing a reaction mixture of said feedstock, said metal salt, water, and an organic solvent. The organic solvent has a boiling point above about 150.degree. C., is stable at the reaction temperature, and solvates said feedstock. The solvent is selected from the group consisting of an alcohol, an ether, a tertiary amine, an amine oxide, a quaternary ammonium hydroxide, and a sulfoxide.

Abstract: A method is provided to manufacture a mixture of 1,4-dicarboalkoxy-1-cyclohexene and 1,3-dicarboalkoxy-1-cyclohexene which can be cyclized and rearranged to isophthalic acid and terephthalic acid.