Processes for the oxidation of carbohydrate dehydration products, such as furanics that can be oxidized to the bio-based monomer 2,5-furandicarboxylic acid (FDCA), are disclosed, according to which certain co-feeds, having been discovered to impart a beneficial reaction stabilizing effect, are oxidized together with the carbohydrate dehydration products. This can advantageously counteract, in whole or in part, detrimental effects of humin impurities present in oxidation feed, with such impurities having been generated as byproducts of the upstream dehydrating step. An important co-feed is para-xylene that can be co-oxidized to form the petroleum-based monomer terephthalic acid (TPA), such that co-processing can beneficially yield two valuable monomers, while improving performance, particularly in terms of reaction stability, over comparable processes in which only the first monomer is produced. Related aspects involve opportunities for retrofitting existing monomer production facilities to enable co-processing of carbohydrate dehydration products that can lead to the above-noted advantages.

Processes for the oxidation of carbohydrate dehydration products, such as furanics that can be oxidized to the bio-based monomer 2,5-furandicarboxylic acid (FDCA), are disclosed, according to which certain co-feeds, having been discovered to impart a beneficial reaction stabilizing effect, are oxidized together with the carbohydrate dehydration products. This can advantageously counteract, in whole or in part, detrimental effects of humin impurities present in oxidation feed, with such impurities having been generated as byproducts of the upstream dehydrating step. An important co-feed is para-xylene that can be co-oxidized to form the petroleum-based monomer terephthalic acid (TPA), such that co-processing can beneficially yield two valuable monomers, while improving performance, particularly in terms of reaction stability, over comparable processes in which only the first monomer is produced. Related aspects involve opportunities for retrofitting existing monomer production facilities to enable co-processing of carbohydrate dehydration products that can lead to the above-noted advantages.

Processes for the oxidation of carbohydrate dehydration products, such as furanics that can be oxidized to the bio-based monomer 2,5-furandicarboxylic acid (FDCA), are disclosed, according to which certain co-feeds, having been discovered to impart a beneficial reaction stabilizing effect, are oxidized together with the carbohydrate dehydration products. This can advantageously counteract, in whole or in part, detrimental effects of humin impurities present in oxidation feed, with such impurities having been generated as byproducts of the upstream dehydrating step. An important co-feed is para-xylene that can be co-oxidized to form the petroleum-based monomer terephthalic acid (TPA), such that co-processing can beneficially yield two valuable monomers, while improving performance, particularly in terms of reaction stability, over comparable processes in which only the first monomer is produced. Related aspects involve opportunities for retrofitting existing monomer production facilities to enable co-processing of carbohydrate dehydration products that can lead to the above-noted advantages.

The invention provides a built-in micro-interface oxidation system for preparing terephthalic acid from p-xylene. The oxidation system includes a first reactor, a rectifying tower and a second reactor which are sequentially connected. A first outlet is disposed on a side wall of the first reactor; a first inlet is disposed on a side wall of the second reactor; a material inlet is disposed on a side wall of the rectifying tower; and a material outlet is disposed at a bottom of the rectifying tower. The first outlet is connected with the material inlet of the rectifying tower; the first inlet is connected with the material outlet of the rectifying tower. Micro-interface units are arranged in the first reactor and the second reactor for dispersing and crushing air into bubbles. Through disposing micro-interface units in reactors, problems of high energy consumption, high raw material consumption and low reaction efficiency are solved.

The invention provides a built-in micro-interface oxidation system for preparing terephthalic acid from p-xylene. The oxidation system includes a first reactor, a rectifying tower and a second reactor which are sequentially connected. A first outlet is disposed on a side wall of the first reactor; a first inlet is disposed on a side wall of the second reactor; a material inlet is disposed on a side wall of the rectifying tower; and a material outlet is disposed at a bottom of the rectifying tower. The first outlet is connected with the material inlet of the rectifying tower; the first inlet is connected with the material outlet of the rectifying tower. Micro-interface units are arranged in the first reactor and the second reactor for dispersing and crushing air into bubbles. Through disposing micro-interface units in reactors, problems of high energy consumption, high raw material consumption and low reaction efficiency are solved.

A method of production of malic acid includes treating a first intermediate product to form a second intermediate product. The treating includes substantially removing impurities from the first intermediate product to obtain a treated intermediate product by gas stripping the crude maleic anhydride, or subjecting a mixture of one or more of the crude maleic acid, the crude fumaric acid, and the vent gas scrubber solution obtained from a phthalic anhydride production process or a maleic anhydride production process to crystallization, passing an aqueous solution of the treated intermediate product through a carbon column to substantially remove retained impurities to form the second intermediate product, obtaining a feed that includes the second intermediate product, and causing the feed to undergo hydration reaction in a tubular reactor or a continuous stirred tank reactor to produce malic acid.

A method of production of malic acid includes treating a first intermediate product to form a second intermediate product. The treating includes substantially removing impurities from the first intermediate product to obtain a treated intermediate product by gas stripping the crude maleic anhydride, or subjecting a mixture of one or more of the crude maleic acid, the crude fumaric acid, and the vent gas scrubber solution obtained from a phthalic anhydride production process or a maleic anhydride production process to crystallization, passing an aqueous solution of the treated intermediate product through a carbon column to substantially remove retained impurities to form the second intermediate product, obtaining a feed that includes the second intermediate product, and causing the feed to undergo hydration reaction in a tubular reactor or a continuous stirred tank reactor to produce malic acid.

The present invention provides a process for the production of an aromatic dicarboxylic acid comprising the catalytic oxidation of a hydrocarbon precursor in an organic solvent, comprising the steps of: i) separating a vent gas from an oxidation stage into an organic solvent-rich liquid stream and a water-rich vapour stream in a distillation stage; and ii) separating an aqueous purific ation mother liquor comprising organic compounds from purified aromatic dicarboxylic acid crystals in a separation stage, characterised in that the process further comprises the steps of: iii) transferring the aqueous purification mother liquor from the separation stage to an extraction stage; iv) extracting said organic compounds from the aqueous purification mother liquor by contacting the aqueous purification mother liquor at a temperature of at least 90° C. with an organic liquid in the extraction stage to form an aqueous phase and an organic phase, wherein the concentration of said organic compounds in the aqueous phase is lower than the concentra tion of said organic compounds in the aqueous purification mother liquor; and v) transferring the aqueous phase to said distillation stage. The present invention further provides an apparatus for carrying out the process.

The present invention provides a process for the production of an aromatic dicarboxylic acid comprising the catalytic oxidation of a hydrocarbon precursor in an organic solvent, comprising the steps of: i) separating a vent gas from an oxidation stage into an organic solvent-rich liquid stream and a water-rich vapour stream in a distillation stage; and ii) separating an aqueous purific ation mother liquor comprising organic compounds from purified aromatic dicarboxylic acid crystals in a separation stage, characterised in that the process further comprises the steps of: iii) transferring the aqueous purification mother liquor from the separation stage to an extraction stage; iv) extracting said organic compounds from the aqueous purification mother liquor by contacting the aqueous purification mother liquor at a temperature of at least 90° C. with an organic liquid in the extraction stage to form an aqueous phase and an organic phase, wherein the concentration of said organic compounds in the aqueous phase is lower than the concentra tion of said organic compounds in the aqueous purification mother liquor; and v) transferring the aqueous phase to said distillation stage. The present invention further provides an apparatus for carrying out the process.

The present invention is directed to the intranasal delivery of curcumin adapted so as to target the brain.