Hitachi, Ltd.

Hitachi Plant Technologies, Ltd.

Yasunari Sase

Toshiaki Matsuo

Takeyuki Kondo

Masayuki Kamikawa

Masashi Tanto

Kenichiro Oka

Hiroyuki Ito

Michio Suzuki

Susumu Harada

Hidekazu Nakamoto

Chikao Oda

Naruyasu Okamoto

Tsutomu Kawamura

Tomofumi Shiraishi

Provided are a device and a method for efficiently producing a polyester by using 1,4-butanediol as a starting material. The device for producing a polyester includes: a preparation tank () for starting material slurry; a storage tank () for starting material slurry; an esterification reactor (); an initial polycondensation reactor (); a middle polycondensation reactor (); and a final polycondensation reactor (). An exhaust system for each of the initial, middle, and final polycondensation reactors includes a wet condenser (, or) using a liquid containing 1,4-butanediol as a coolant; and a hot well (, or) connected to the corresponding wet condenser. Herein, process scattered substances scattering with exhaust are collected, and hydrolyzed in the hot well, so as to be returned to the esterification step. This allows the polyester to be efficiently produced.

Device and method for producing polyester

This invention provides a cost-effective method for removing impurities from waste glycerin generated in the process of biodiesel production, so as to prevent a supercritical water reaction tube from clogging, when synthesizing acrolein by allowing supercritical water and acid to react with glycerin. The method for purification of glycerin of the invention comprises steps of: heating glycerin containing alkali metal, alcohol, organic fatty acid, and water under reduced pressure, so as to remove alcohol and water; adding sulfuric acid to glycerin from which alcohol and water have been removed, so as to neutralize glycerin; subjecting neutralized glycerin to centrifugation, so as to separate and remove a sulfate of alkali metal and organic fatty acid; adding a sulfate of alkaline earth metal to glycerin collected via centrifugation; and subjecting a mixture of glycerin and a sulfate of alkaline earth metal to centrifugation, so as to separate and remove a sulfate of alkali metal and an alkaline earth metal salt of organic fatty acid.

Glycerin purification method

An object of the present invention is to provide a technology which can suppress the blockage and abrasion of pipes and devices caused by the production of by-products and stably synthesize acrolein at a high yield, under a condition in which energy efficiency is improved by an elevated concentration of glycerol in a reaction liquid, in a process for synthesis of acrolein by reacting supercritical water and an acid with glycerol. An embodiment of the present invention includes: setting a concentration of glycerol in the reaction liquid at 30% by weight or lower; also cooling the reaction liquid to a temperature between a temperature (300&#xb0; C. or lower) at which the reaction stops and a temperature (100&#xb0; C. or higher) at which tar contained in the reaction liquid can keep a state in which its viscosity is sufficiently low; then separating and removing carbon particles from the reaction liquid; subsequently cooling the reaction liquid to a temperature which is a boiling point of water or lower and at which the tar component in the reaction liquid does not adhere to devices; and then decompressing the cooled reaction liquid.

Process for synthesis of acrolein

An object of the present invention is to provide an industrially applicable method for producing acrolein via treatment with supercritical water from glycerin obtained as a by-product during the process of biodiesel fuel production from waste animal/plant fat or oil with the use of an alkali catalyst. The present invention provides a method for producing acrolein, which comprises: a determination step of determining the hydrogen ion concentration in glycerin obtained as a by-product; an acid addition step of adding to the glycerin an acid at an amount calculated based on the results of the determination step so as to make the glycerin acidic; and a supercritical water treatment step of allowing supercritical water to act on the glycerin after the acid addition so as to produce acrolein from the glycerin.

Method and device for synthesizing acrolein

A device and a method for producing high-quality polybutylene succinate are provided. The method for producing polybutylene succinate comprises the steps of: preparing a raw-material slurry by mixing succinic acid or a derivative thereof with 1,4-butanediol in a raw-material slurry preparation tank; storing the raw-material slurry in a raw-material slurry storage tank while maintaining flowability; carrying out an esterification reaction of the raw-material slurry in an esterification reactor; and synthesizing polybutylene succinate with a polycondensation reaction of the ester in a polycondensation reactor, in which the polycondensation reactor is divided, from the upstream side, into at least an initial polycondensation reactor, an intermediate polycondensation reactor, and a final polycondensation reactor, a catalyst is added in an amount from 1000 ppm to 3000 ppm in relation to succinic acid or a derivative thereof, the reaction time in the intermediate polycondensation reactor ranges from 0.25 hours to 0.75 hours, and the reaction temperature in the final polycondensation reactor ranges from 245&#xb0; C. to 255&#xb0; C.

Device and method for producing polybutylene succinate

In order to perform organic synthesis process through action with supercritical water and acid stably while suppressing a trouble caused by a by-product, a method and an apparatus are provided, including the following steps. Water is supplied to high-pressure pumps () and () from water headers () and (), and a pressure-reducing valve () is regulated to increase the pressure to 35 MPa. Temperatures of preheaters () and () and a heater () are increased until the reaction solution is at a temperature of 400&#xb0; C. Acid (sulfuric acid) and an organic compound raw material (glycerin) are supplied from an acid header () and a raw-material header (') for action with the supercritical water to obtain a reaction solution. The obtained reaction solution is cooled to 100 to 200&#xb0; C. by first cooling () and a solid component included in the reaction solution is separated for removal from the reaction solution by a filter (), and then the reaction solution is cooled to a temperature of about 100&#xb0; C. or lower by second cooling () and pressure thereof is reduced (). Further, the reaction solution is cooled by third cooling () and then a synthesized product (acrolein) is captured.

Reaction process utilizing critical water

An object of the present invention is to provide a method for commercially manufacturing acrolein in a large flow rate by making supercritical water and an acid interact with glycerin, wherein by efficiently mixing high-concentration glycerin and supercritical water with each other, the method is made capable of making the synthesis stably proceed with a high yield while the occlusion and abrasion of the pipes and devices due to the generation of by-products are being suppressed. The method for synthesizing acrolein of the present invention is a method for synthesizing acrolein by making supercritical water and an acid interact with glycerin, the method using a reaction apparatus including: a cylindrical mixing flow path for mixing a fluid including glycerin and a fluid including supercritical water with each other; a first inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including glycerin flow into the mixing flow path; and a second inlet flow path, disposed offset from the central axis of the mixing flow path, for making the fluid including supercritical water flow into the mixing flow path, wherein the first inlet flow path and the second inlet flow path are each provided in a plurality of numbers in such a way that the first inlet flow paths and the second inlet flow paths are alternately arranged so as to encircle the central axis of the mixing flow path.

Method for synthesizing acrolein

An apparatus for continuously producing polyester comprises three single reactors, i.e. a single esterification reactor (first reactor), a single initial polymerization reactor (second reactor) and a single final polymerization reactor (third reactor or final polymerizer), where at least one of the first reactor and the second reactor is free from an external stirring power source, or the third reactor is a horizontal, one-shaft-type, low speed rotation type reactor. Necessary number of reactors for the esterification and polycondensation reactions can be a minimum and necessary stirring power consumption for the reaction can be a minimum, and thus polyester polymers of good quality can be efficiently produced at a minimum energy cost in a necessary minimum reactor structure.

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Tokyo, Japan

Yasunari Sase