This invention relates to a process for preparing succinic acid and succinate ester from a succinic acid salt in fermentation broth. In the first stage of this invention, renewable carbon resources are utilized to produce succinic acid through biological fermentation. The succinic acid salt in the fermentation process is subjected to double displacement reaction with a strong acid leading to release of succinic acid. Succinic acid is recovered by fractional crystallization integrated with simulated moving bed chromatography to produce succinic acid and succinate ester.

This invention relates to a process for preparing succinic acid and succinate ester from a succinic acid salt in fermentation broth. In the first stage of this invention, renewable carbon resources are utilized to produce succinic acid through biological fermentation. The succinic acid salt in the fermentation process is subjected to double displacement reaction with a strong acid leading to release of succinic acid. Succinic acid is recovered by fractional crystallization integrated with simulated moving bed chromatography to produce succinic acid and succinate ester.

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.

Disclosed is an ester plasticizer composition, as a plasticizer composition, which comprises a hybrid alkyl-substituted terephthalate compound and a non-hybrid alkyl-substituted terephthalate compound as active ingredients, improves workability due to high absorption speed for the resins and short melting time, and thus may imparts a uniform foaming property upon being applied to wallpaper formulation.

Disclosed is an ester plasticizer composition, as a plasticizer composition, which comprises a hybrid alkyl-substituted terephthalate compound and a non-hybrid alkyl-substituted terephthalate compound as active ingredients, improves workability due to high absorption speed for the resins and short melting time, and thus may imparts a uniform foaming property upon being applied to wallpaper formulation.

The present invention relates to a process for preparing a terephthalic diester by reacting terephthalic acid with at least one alcohol, wherein terephthalic acid is suspended in the alcohol in a dispersing tank, the preliminary suspension is passed from the dispersing tank into a reactor and converted in the presence of an esterification catalyst, and water of reaction is distilled off together with the vapor as alcohol-water azeotrope, the vapor is at least partly condensed, the condensate is separated into an aqueous phase and an organic phase, the organic phase is dewatered and the dewatered organic phase is passed at least partly into the dispersing tank.

The present invention relates to a process for preparing a terephthalic diester by reacting terephthalic acid with at least one alcohol, wherein terephthalic acid is suspended in the alcohol in a dispersing tank, the preliminary suspension is passed from the dispersing tank into a reactor and converted in the presence of an esterification catalyst, and water of reaction is distilled off together with the vapor as alcohol-water azeotrope, the vapor is at least partly condensed, the condensate is separated into an aqueous phase and an organic phase, the organic phase is dewatered and the dewatered organic phase is passed at least partly into the dispersing tank.

The present invention relates to a process for preparing a terephthalic diester by reacting terephthalic acid with at least one alcohol, wherein terephthalic acid is suspended in the alcohol in a dispersing tank, the preliminary suspension is passed from the dispersing tank into a reactor and converted in the presence of an esterification catalyst, and water of reaction is distilled off together with the vapor as alcohol-water azeotrope, the vapor is at least partly condensed, the condensate is separated into an aqueous phase and an organic phase, the organic phase is dewatered and the dewatered organic phase is passed at least partly into the dispersing tank.

The present invention relates to a process for preparing a terephthalic diester by reacting terephthalic acid with at least one alcohol, wherein terephthalic acid is suspended in the alcohol in a dispersing tank, the preliminary suspension is passed from the dispersing tank into a reactor and converted in the presence of an esterification catalyst, a reaction suspension is drawn off from a region between the upper region and the lower region of the reactor, a first stream of the reaction suspension is recycled into the upper region of the reactor and a second stream of the reaction suspension is introduced into the lower region of the reactor, and the reaction suspension is thus mixed, wherein the stream drawn off and/or the first stream is passed through a heat exchanger outside the reactor and heated; and water of reaction is distilled off together with the vapor as alcohol-water azeotrope, the vapor is at least partly condensed, the condensate is separated into an aqueous phase and an organic phase and the organic phase is at least partly recycled into the reaction system.