Abstract: A problem is to provide an industrially advantageous method in which in purifying a furfural composition, the formation of a solid matter which have been unable to be controlled so far is stably reduced, and furfural is purified with high efficiency wherein the problem has been solved by a method for producing furfural including distilling a composition containing furfural by a distillation column to obtain furfural, wherein a concentration of a furfural dimer in a column bottom liquid of the distillation column is controlled to 20 ppm by mass to 5,000 ppm by mass.

Abstract: The present invention aims to provide a method for producing polybutylene terephthalate (PBT) with an excellent color using biomass-derived 1,4-butanediol (BG). The invention relates to a method for producing PBT comprising a step of subjecting a diol component containing raw material 1,4-BG having a nitrogen content of 0.01 to 50 ppm by mass and a dicarboxylic acid component to esterification or ester-exchange reaction, and a polycondensation reaction step for obtaining PBT from the reactant, wherein the content of gamma butyrolactone in the raw material 1,4-BG is 1 to 100 ppm by mass.

Abstract: The present invention relates to a method for producing a hydride having a carbon number of 4, comprising contacting, in liquid phase, an unsaturated compound having a carbon number of 4 as a raw material with a solid catalyst obtained by loading a metal element belonging to Groups 9 to 11 of the long periodic table on a support, thereby performing hydrogenation to produce a corresponding hydride having a carbon number of 4, wherein hydrogenation is performed in the presence of, as a solvent, a 1,4-butanediol having a nitrogen component concentration of 1 ppm by weight to 1 wt % in terms of nitrogen atom.

Abstract: An object of the present invention is to provide high-purity gamma-butyrolactone (GBL) capable of preventing occurrence of reaction other than the object at the time of use, which reaction is caused due to a high acidity of GBL, and the present invention relates to a gamma-butyrolactone composition containing gamma-butyrolactone and a nitrogen-containing compound, wherein a content of the gamma-butyrolactone is 99.0% by mass or more, and a total content of the nitrogen-containing compound is 0.1 ppm by mass to 1,000 ppm by mass as converted to a nitrogen atom.

Abstract: The present invention relates to a method for producing a hydride having a carbon number of 4, comprising contacting, in liquid phase, an unsaturated compound having a carbon number of 4 as a raw material with a solid catalyst obtained by loading a metal element belonging to Groups 9 to 11 of the long periodic table on a support, thereby performing hydrogenation to produce a corresponding hydride having a carbon number of 4, wherein hydrogenation is performed in the presence of, as a solvent, a 1,4-butanediol having a nitrogen component concentration of 1 ppm by weight to 1 wt % in terms of nitrogen atom.

Abstract: A 1,4-butanediol-containing composition having high thermal stability as compared with conventional 1,4BG, and a 1,4-butanediol-containing composition having a concentration of 1,4-butanediol of 99.00% by weight or more and not more than 99.99% by weight and containing an amide compound in a concentration, as converted into a nitrogen atom, of from 1.0 to 25 ppm by weight.

Abstract: A 1,4-butanediol (1,4BG)-containing composition having high thermal stability, and having a concentration of 1,4-butanediol of 99.00% by weight or more and not more than 99.99% by weight and 2-pyrrolidone or N-methylpyrrolidone in a concentration, as converted into a nitrogen atom, of from 1.0 to 25 ppm by weight.

Abstract: The present invention relates to a method for producing tetrahydrofuran comprising: feeding raw material 1,4-butanediol containing gamma butyrolactone to a reaction tank, and performing a dehydration cyclization reaction in the presence of a homogeneous acid catalyst having a pKa of 4 or less and being dissolvable in 1,4-butanediol to produce tetrahydrofuran, wherein a gas containing tetrahydrofuran, gamma butyrolactone and water in the reaction tank is introduced into a heat exchanger and when obtaining a condensate from the outlet of the heat exchanger, the ratio of the concentration of gamma butyrolactone in the condensate based on the concentration of gamma butyrolactone in the raw material 1,4-butanediol is from 20 to 100%.

Abstract: An object of the present invention is to provide high-quality 1,4BG capable of working out to a raw material of PBT with good color tone, by efficiently removing and refining impurities mixed when producing a biomass-derived 1,4BG on an industrial scale and the present invention relates to a production method of refined 1,4BG, where a crude 1,4BG-containing solution is obtained from refined raw material 1,4BG obtained by removing bacterial cells, salt contents and water from the fermentation culture medium, through a step of removing high-boiling-point components and/or low-boiling-point components by distillation and/or a step of converting an unsaturated compound to a hydride and the target product is obtained as a side stream in a further distillation step.

Abstract: At the time of producing a polyester by using a dicarboxylic acid component and a biomass-resource-derived diol as raw materials, a polyester is efficiently produced with good color tone, as the raw material diol derived from biomass resources, a diol in which the content of a cyclic carbonyl compound having a carbon atom number of 5 or 6 is from 0.01 to 12 ppm by mass, is used, and by controlling the content of a cyclic carbonyl compound having a carbon atom number of 5 or 6 in the raw material diol to fall in a prescribed range, the color tone of the polyester is improved.

Abstract: The present invention aims to provide a method for producing polybutylene terephthalate (PBT) with an excellent color using biomass-derived 1,4-butanediol (BG). The invention relates to a method for producing PBT comprising a step of subjecting a diol component containing raw material 1,4-BG having a nitrogen content of 0.01 to 50 ppm by mass and a dicarboxylic acid component to esterification or ester-exchange reaction, and a polycondensation reaction step for obtaining PBT from the reactant, wherein the content of gamma butyrolactone in the raw material 1,4-BG is 1 to 100 ppm by mass.

Abstract: The present invention is aimed to provide a 1,4-butanediol-containing composition having high thermal stability as compared with conventional 1,4BG, and the present invention is concerned with a 1,4-butanediol-containing composition having a concentration of 1,4-butanediol of 99.00% by weight or more and not more than 99.99% by weight and containing an amide compound in a concentration, as converted into a nitrogen atom, of from 1.0 to 50 ppm by weight.

Abstract: The present invention is concerned with a method for producing tetrahydrofuran including carrying out a dehydration cyclization reaction of 1,4-butanediol in the presence of an acid catalyst having a pKa value of not more than 4 within a reactor, wherein a raw material liquid containing 1,4-butanediol to be provided for the reaction contains from 0.01 to 0.35% by weight of 2-(4-hydroxybutoxy)-tetrahydrofuran and 1 ppm by weight or more and not more than 1,000 ppm by weight of at least one of an amine and an amide in terms of a concentration as converted into a nitrogen atom.

Abstract: The present invention relates to a method for producing a hydride having a carbon number of 4, comprising contacting, in liquid phase, an unsaturated compound having a carbon number of 4 as a raw material with a solid catalyst obtained by loading a metal element belonging to Groups 9 to 11 of the long periodic table on a support, thereby performing hydrogenation to produce a corresponding hydride having a carbon number of 4, wherein hydrogenation is performed in the presence of, as a solvent, a 1,4-butanediol having a nitrogen component concentration of 1 ppm by weight to 1 wt % in terms of nitrogen atom.

Abstract: An object of the present invention is to provide an industrially advantageous production method of 1,4BG, ensuring that generation of THF in the crude 1,4BG can be also suppressed and at the same time, the concentration of 2-(4-hydroxybutoxy)-tetrahydrofuran can be reduced. The present invention relates to a method for producing 1,4-butanediol, comprising heating crude 1,4-butanediol containing from 0.01 to 0.5 wt % of 2-(4-hydroxybutoxy)-tetrahydrofuran and from 1 to 25 wt % of water at 80° C. or more in the presence of an amine to obtain purified 1,4-butanediol.

Abstract: The present invention relates to a method for producing tetrahydrofuran comprising: feeding raw material 1,4-butanediol containing gamma butyrolactone to a reaction tank, and performing a dehydration cyclization reaction in the presence of a homogeneous acid catalyst having a pKa of 4 or less and being dissolvable in 1,4-butanediol to produce tetrahydrofuran, wherein a gas containing tetrahydrofuran, gamma butyrolactone and water in the reaction tank is introduced into a heat exchanger and when obtaining a condensate from the outlet of the heat exchanger, the ratio of the concentration of gamma butyrolactone in the condensate based on the concentration of gamma butyrolactone in the raw material 1,4-butanediol is from 20 to 100%.