摘要:
The polymer degassing apparatus includes a barrel-shaped horizontal container 41 having a supply port 42 for supplying a reactant, a discharge port 43 for discharging a reactant, a stirring means 45 for stirring a reactant, and a degassing means for drawing a gas via a degassing port 44 of the horizontal container. The supply port is positioned below the molten liquid level of the reactant. A recovery container 37 that is connected to the degassing port for recovering a volatile substance in the gas and a vacuum pump 36 are provided. The stirring means includes a plurality of stirring rods 46 oriented along the same direction as the axis in the horizontal container and coupling members 47 for coupling the stirring rods along the same direction as the axis, provided that the coupling members are placed at a distance from the virtual rotation center of the stirring means.
摘要:
The object is to provide a method and apparatus for producing a polyhydroxy carboxylic acid according to which an annular diner can be efficiently obtained in the production of polyhydroxy carboxylic acid which is small in distribution breadth of molecular weight in depolymerization and opening ring polymerization steps. There are provided a depolymerization device 11 which depolymerizes hydroxy carboxylic acid or a polycondensate thereof into an annular dimer, a upper distillation column 13 which condenses the annular dimer vaporized in the depolymerization device 11, and lower distillation column 12 which refluxes the annular dimer and is provided between the depolymerization device 11 and the upper distillation column 13, said depolymerization device 11 having a polycondensate feed opening 54 and an annular dimer discharge opening 55 which are provided at a casing 50, a liquid film being formed inside the casing 50 and heated by a heating part.
摘要:
An object of the present invention is to provide a method and a system by which hydroxycarboxylic acid cyclic dimers are efficiently generated, allowing high yields of high-quality polyhydroxycarboxylic acid to be obtained. The method for synthesizing polyhydroxycarboxylic acid comprises a depolymerization step for depolymerizing hydroxycarboxylic acid oligomers to produce hydroxycarboxylic acid cyclic dimers, wherein, in the depolymerization step, a reaction solution is heated via heat transfer from a heat medium passage under reduced pressure while the reaction solution is being flowing through a horizontally provided reaction solution passage.
摘要:
A manufacturing process of purified lactic acid includes a fermentation process where a pH adjusting agent containing calcium and a microorganism are added to a sugar-containing solution to produce lactic acid in the form of calcium lactate, and a purification process where sulfuric acid is added to a solution containing calcium lactate to separate calcium ions in the form of calcium sulfate. Prior to the step of adding sulfuric acid, a reverse osmosis membrane concentration step removes water; a crystallization step crystallizes and removes calcium lactate; and a reverse osmosis membrane concentration step where the solution from which calcium lactate has been removed is heated and allowed to pass through the reverse osmosis membrane removes water, the crystallization step and the subsequent reverse osmosis membrane concentration step being repeated one or more times.
摘要:
This invention provides an equipment and a method for producing polyhydroxycarboxylic acid whereby the yield of a starting material in the process can be improved.An equipment for producing polyhydroxycarboxylic acid, comprising a ring-opening polymerization apparatus, a liquid phase devolatilizing apparatus, and a drying apparatus, wherein: an indirect heat exchanger is connected to a vent gas discharge path of the liquid phase devolatilizing apparatus; the indirect heat exchanger captures a dispersed in-process substance containing hydroxycarboxylic acid cyclic dimers and transfers the substance to the ring-opening polymerization apparatus; a wet condenser and a hot well are connected to a vent gas discharge path of the indirect heat exchanger and that of the drying apparatus, respectively; the wet condenser captures a dispersed in process substance containing the cyclic dimers with the use of a refrigerant containing hydroxycarboxylic acid corresponding to the cyclic dimers and transfers the substance to the hot well; the hot well causes hydrolysis of the cyclic dimers for generation of hydroxycarboxylic acid; the generated hydroxycarboxylic acid is mixed with a refrigerant and the mixture is circulated to the wet condenser; and hydroxycarboxylic acid is highly concentrated via circulation between the wet condenser and the hot well and then discharged, is provided.
摘要:
When obtaining a target substance by gradually cooling the reaction liquid by cooling in a plurality of stages divided in series, and then distilling the cooled reaction liquid by distillation in a plurality of stages divided in series, this method and this apparatus include: circulating a heating medium to be used for cooling in the plurality of the stages by way of; sequentially passing the heating medium toward the most upstream cooling stage from the most downstream cooling stage of the reaction liquid; cooling the heating medium which has been discharged from the most upstream cooling stage by using the heating medium for keeping or raising the temperature of the liquid which has been discharged from the distillation in the plurality of the stages; and returning the cooled heating medium back to the most downstream cooling stage of the reaction liquid.