Abstract: A method for producing an alkyl nitrite by bringing an aqueous solution containing nitric acid and an alkanol into contact with a gas including nitrogen monoxide and thereby producing an alkyl nitrite, in which the reaction temperature is 60° C. to 100° C., is provided.

Abstract: A carbonate ester purification apparatus including a first distillation column in which an alcohol and a first solution containing a carbonate ester and formaldehyde, or a first solution containing a carbonate ester, formaldehyde and an alcohol is supplied to obtain a distillate containing the formaldehyde and the alcohol from a column top part while obtaining a carbonate ester solution with a lower content of formaldehyde than in the first solution from a column bottom part, a reactor having a catalyst for producing an acetal and/or a hemiacetal by reacting the formaldehyde to the alcohol and a reflux part refluxing a fluid containing the acetal and/or the hemiacetal to the first distillation column.

Abstract: Provided is a carbonate ester purification apparatus including a treatment part for mixing a first solution containing a carbonate ester and an acidic substance with an alcohol solution of a metal alcoholate to obtain a mixed solution containing a reaction product of the acidic substance and the metal alcoholate, a separation part for removing a metal salt contained in the reaction product from the mixed solution to obtain a second solution, and a distillation part for removing a component from the second solution, the component different in boiling point from the carbonate ester to obtain a carbonate ester solution, wherein a content of the metal alcoholate in the alcohol solution is 5 to 18 mass %.

Abstract: A carbonate ester purification apparatus including a first distillation column in which an alcohol and a first solution containing a carbonate ester and formaldehyde, or a first solution containing a carbonate ester, formaldehyde and an alcohol is supplied to obtain a distillate containing the formaldehyde and the alcohol from a column top part while obtaining a carbonate ester solution with a lower content of formaldehyde than in the first solution from a column bottom part, a reactor having a catalyst for producing an acetal and/or a hemiacetal by reacting the formaldehyde to the alcohol and a reflux part refluxing a fluid containing the acetal and/or the hemiacetal to the first distillation column.

Abstract: The infrared gas analysis device includes: a measurement cell to allow a sample gas containing a component to be measured to flow therethrough; a comparison cell including a reference gas; a pair of light sources provided in one end side of the measurement cell and the comparison cell, the cells being irradiated with an infrared ray from one and the other of the light sources, respectively; and a detection unit provided in another end side of the measurement cell and the comparison cell to detect the component to be measured by using infrared rays output from the measurement cell and the comparison cell. A gas for detection made of a component different from the component to be measured and having an infrared absorption band at at least a part of wavenumbers in infrared absorption bands of the component to be measured is encapsulated in the detection unit.

Abstract: Provided is a production device including: a first reactor to form a second gas containing an ester and nitric oxide from a first gas containing carbon monoxide, a nitrite, and nitric oxide; an absorption column to separate the second gas and an absorbing solution into a condensate containing the ester and a noncondensable gas; a second reactor to introduce an alcohol, the noncondensable gas, and oxygen gas thereinto to form a third gas containing nitric oxide and a nitrite; a third reactor to form a fourth gas containing a nitrite from the noncondensable gas and a bottom liquid from the second reactor and to feed the fourth gas to the second reactor; a first measurement unit to measure the concentration of a nitrite in the first gas; and a first flow rate-adjusting unit to adjust the amount of the noncondensable gas to the third reactor based on the concentration.

Abstract: A method manufactures diethyl carbonate by reaction distillation where transesterification and distillation are simultaneously performed in a multistage reaction distillation column provided with a catalyst introduction port and a raw material introduction port located below the catalyst introduction port, wherein: (a) the reaction is performed in a countercurrent flow format in which contact is brought about between a transesterification catalyst, dimethyl carbonate, and ethanol; (e) 1 to 250 mmol of catalyst is used per mole of dimethyl carbonate; (f) the ratio of the volume of air in the catalyst introduction port and the raw material introduction port regarding the volume of air in the reaction distillation part is 0.1 to 0.9; (g) the recirculation ratio in the reaction distillation column is 0.5 to 10; and (h) the temperature of the top part of the column and the reaction distillation part is 60 to 100° C.

Abstract: Disclosed is a process for preparing a diaryl oxalate which comprises the step of transesterifying a dialkyl oxalate or/and an alkylaryl oxalate with an aryl alcohol in the presence of a tetra(aryloxy)titanium as a catalyst, wherein the tetra(aryloxy)titanium is fed into a reaction system of the transesterification as an aryl alcohol solution of the tetra(aryloxy)titanium which is prepared by reacting a tetraalkoxy titanium and an excess amount of the aryl alcohol and removing a by-producing alkyl alcohol.

Abstract: A method manufactures diethyl carbonate by reaction distillation where transesterification and distillation are simultaneously performed in a multistage reaction distillation column provided with a catalyst introduction port and a raw material introduction port located below the catalyst introduction port, wherein: (a) the reaction is performed in a countercurrent flow format in which contact is brought about between a transesterification catalyst, dimethyl carbonate, and ethanol; (e) 1 to 250 mmol of catalyst is used per mole of dimethyl carbonate; (f) the ratio of the volume of air in the catalyst introduction port and the raw material introduction port regarding the volume of air in the reaction distillation part is 0.1 to 0.9; (g) the recirculation ratio in the reaction distillation column is 0.5 to 10; and (h) the temperature of the top part of the column and the reaction distillation part is 60 to 100° C.

Abstract: A method for producing nitrous acid ester in which nitric oxide, oxygen, and an alcohol are reacted, thereby generating nitrous acid ester includes a step of generating nitrous acid ester by supplying a bottom liquid from a bottom part of the reaction column, and nitric oxide and/or carbon monoxide, a step of supplying nitrous acid ester to the reaction column; a step of supplying a reaction liquid containing water, nitric acid, and the alcohol to a nitric acid condensing column from the reactor; and a step of separating a low-boiling point component by distillation from the reaction liquid under control of a concentration of the alcohol in a condensed liquid being generated at a bottom part of the nitric acid condensing column to be less than 4.0% by weight so as to introduce the condensed liquid into the reactor from the nitric acid condensing column.

Abstract: A method is provided for producing highly pure 1,6-hexanediol in which the contents of impurities such as 1,4-cyclohexanediol, 1,5-hexanediol, 1,2-cyclohexanediol, 1,7-pentanediol, 1,5-pentanediol and high boiling point components are significantly reduced.

Abstract: There is provided a process for preparing 1,6-hexanediol by esterifying a carboxylic acid mixture resulted from oxidation of cyclohexane with oxygen, and then hydrogenating the esters, which substantially does not contain a compound leading to a high ester value.

Abstract: An objective is to provide a process for preparing 1,5-pentanediol and/or 1,6-hexanediol comprising esterifying, with an alcohol such as methanol, ethanol, butanol or 1,6-hexanediol, a mixture of carboxylic acids such as glutaric acid, adipic acid and 6-hydroxycaproic acid which are a by-product in preparation of cyclohexanone by oxidation of cyclohexane with oxygen or an oxygen-containing gas; and hydrogenating the resulting esterified product in the presence of a copper-containing catalyst, which process is an industrially suitable process for preparing 1,5-pentanediol and/or 1,6-hexanediol in a high yield while controlling deterioration of the catalyst. The above objective is achieved by hydrogenating the esterified product with a catalyst obtained by prereducing a copper-containing catalyst in an alcohol having an acid value (AV) of 0.5 mg KOH/g or less or an ester having an acid value (AV) of 0.5 mg KOH/g or less.

Abstract: An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.

Abstract: A method is provided for obtaining highly pure 1,6-hexanediol in which the contents of impurities such as 1,4-cyclohexanediol, 1,5-hexanediol, 1,2-cyclohexanediol, 1,7-pentanediol, 1,5-pentanediol and high boiling point components are significantly reduced.

Abstract: An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.

Abstract: An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.

Abstract: An alkyl nitrite is produced with high efficiency by bringing a nitrogen monoxide gas into contact with an aqueous solution of an alkyl alcohol and nitric acid in a reactor 2, which aqueous solution may be a liquid fraction generated in an alkyl nitrite-production process in which an alkyl alcohol is reacted with nitrogen monoxide and oxygen in a reaction column 1.

Abstract: A composition consisting essentially of a diaryl carbonate and contains a furan ring-containing compound in an amount of not more than 1 ppm is favorably employable for producing less colored polycarbonate.

Abstract: A composition consisting essentially of a diaryl carbonate and contains a furan ring-containing compound in an amount of not more than 1 ppm is favorably employable for producing less colored polycarbonate