Daicel Chemical Industries, Ltd.

Kuraray Co., Ltd.

Daicel Corporation

Hidetaka Kojima

Yasutaka Tanaka

Hiroshi Koyama

Takaaki Fujiwa

Hiroyuki Miura

Yasuo Tsuji

Masahiro Kagotani

Toyokazu Yagii

Kenji Oka

Takushi Yokoyama

Teruo Itokazu

Shingo Oda

Mitsuo Matsumoto

Masuhiko Tamura

Kunio Koga

Kiyokazu Murata

Takeshi Horikawa

Shigeru Yokota

Yasukazu Murakami

Masaharu Uragami

Kathuyoshi Miwa

Shigeru Yamashita

Koichi Kikuchi

Shinichi Miura

A method produces acetic acid by continuously reacting methanol with carbon monoxide in the presence of a rhodium catalyst, an iodide salt, methyl iodide, methyl acetate, and water; and thereby producing acetic acid at a production rate of 11 mol/L&#xb7;hr or more while keeping the acetaldehyde content of a reaction mixture to 500 ppm or less, in which the reaction is carried out at a carbon monoxide partial pressure in a gaseous phase of a reactor of 1.05 MPa or more and/or at a methyl acetate content of the reaction mixture of 2 percent by weight or more to thereby keep the production rate of acetaldehyde to 1/1500 or less that of acetic acid. This method can reduce production of by-products without reducing the reaction rate of acetic acid even at a low water content and a low hydrogen partial pressure in a reaction system.

Methods for producing acetic acid

A process for producing a purified carboxylic acid having 'n+1' carbon atoms comprises feeding a carboxylic acid stream containing a carboxylic acid having 'n+1' carbon atoms, a hydrogen halide, a lower boiling point (bp) component, a higher bp component, and others to a first distillation column; separating a lower bp fraction containing part of the lower bp component and a higher bp fraction containing part of the higher bp component in the first column; withdrawing a side stream containing at least the carboxylic acid by side cut from the first column; feeding the side stream to a second distillation column; separating a lower bp fraction containing part of the lower bp component and a higher bp fraction containing part of the higher bp component in the second column; and withdrawing a side stream containing the carboxylic acid by side cut from the second column to recover a purified carboxylic acid; and the process further comprises feeding at least one first component (A) selected from the group consisting of an alcohol, corresponding to the carboxylic acid, having &#x201c;n&#x201d; carbon atom(s), and an ester of the alcohol with the carboxylic acid to the first column, and if necessary water. Such a process ensures reduction of the concentration of the hydrogen halide in the purified carboxylic acid.

Process for producing carboxylic acid

A process for producing a carboxylic acid comprises allowing an alcohol having a carbon number of 'n' to continuously react with carbon monoxide in the presence of a carbonylation catalyst system, and a limited amount of water, continuously withdrawing the reaction mixture from the reaction system, introducing the withdrawn reaction mixture into a distillation step (distillation columnsand), and separating a higher-boiling component and a lower-boiling component containing a carboxylic acid having a carbon number of 'n+1', respectively. In the process, the amount of carbon monoxide and/or hydrogen contained in a liquid phase of the reaction system is adjusted to at least one of the following conditions (i) and (ii): (i) the amount of carbon monoxide relative to 1 kilogram of the liquid phase by weight is at least 2 mmol per 1 MPa of carbon monoxide partial pressure of the reaction system, and (ii) the amount of hydrogen relative to 1 kilogram of the liquid phase by weight is at least 50 mmol per 1 MPa of hydrogen partial pressure of the reaction system. Such a process inhibits deactivation of a metal catalyst and deterioration in a reaction rate, and decreases formation of by-products in producing a carboxylic acid under a low water content.

Process for producing acetic acid

An aliphatic diisocyanate compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethane compound; and, within 48 hours after the completion of the preparation of the urethane compound, thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling-point solvent.

Process for preparation of isocyanate compounds

An aliphatic diisocyante compound is prepared in a high yield by reacting dimethyl carbonate with an aliphatic diamine in the presence of an alkali catalyst to produce a corresponding urethene compound; and, within 48 hours after the completion of the preparation of the urethane compound, thermally decomposing the urethane compound under a reduced pressure of 1 to 700 Torr in a high-boiling-point solvent.

Process for preparation of aliphatic diisocyanate compounds

Carboxylic acids are produced in the liquid phase carbonylation reaction from an alcohol or its derivative and carbon monoxide in the presence of a catalyst system containing a rhodium component and an alkyl halide and water, adding an iodide salt to the rhodium/alkyl halide catalyst system so as to maintain the iodine ion concentration in the carbonylation reaction solution at 0.3 mol/l or higher.

Process for producing carboxylic acids

Carboxylic acids are produced in the liquid phase carbonylation reaction from an alcohol or its derivative and carbon monoxide in the presence of a catalyst system containing a rhodium component and an alkyl halide and water, adding an iodide salt to the rhodium/alkyl halide catalyst system so as to maintain the iodine ion concentration in the carbonylation reaction solution at 0.3 mol/.lambda. or higher.

A process for preparing an .alpha.-phenylpropionic acid derivative wherein an .alpha.-phenylethyl alcohol derivative is reacted with carbon monoxide in the presence of a catalyst to give an .alpha.-phenylpropionic acid derivative, which comprises carrying out the reaction in either one of the following manners (I), (II) and (III):

Process for preparing .alpha.-phenylpropionic acid derivative

Disclosed herein is a process for producing a carbonic acid ester by reacting alcohol, carbon monoxide, and oxygen with one another in the presence of a copper compound alone or together with a platinum group metal compound and a reaction accelerator, characterized in that (I) the reaction is carried out in a nitrile compound or amide compound as a solvent, (II) the reaction is carried out in the presence of a reaction accelerator which consists of a quaternary phosphonium halide and a quaternary phosphonium weak acid salt or quaternary phosphonium alkoxide, and/or (III) the reaction is carried out in the presence of a quinoid compound or a compound that changes into a quinoid compound under the reaction conditions.

Process for producing carbonic acid ester

Acetic acid is advantageously prepared from a starting material having a formic acid moiety and a methyl ester moiety by heating said starting material in the presence of (1) carbon monoxide, (2) at least one of (2-a) a metal accelerator selected from beryllium, a metal belonging to the group IIIA, IVB, VB, VIB or IIA of the Periodic Table, a lanthanide metal and an actinide metal and (2-b) an onium compound or a precursor for the onium compound, (3) a rhodium catalyst and (4) an iodine compound.

Process for preparing acetic acid

A process is provided for producing an O-acetyl compound by carbonylating an O-methyl compound with carbon monoxide in the presence of a rhodium catalyst and an iodine compound, comprising

Production of acetyl compound

This invention provides a process for producing an oxy-acetyl compound by carbonylating an oxy-methyl compound with carbon monoxide in the presence of a rhodium catalyst, an iodine compound, and a metallic accelerator, and also in the presence of at least one compound selected from the group consisting of boron compounds, bismuth compounds, and tertiary amide compounds in the reaction system. When at least one of the bismuth or boron compound is present in the reaction system, the carbonylation reaction can proceed without precipitation of any metallic accelerator.

Preparation of an oxy-acetyl compound

An O-acetyl compound, such as acetic anhydride, is prepared by carbonylating the corresponding O-methyl compound, such as methyl acetate, by heating the latter at 130.degree. to 250.degree. C. with carbon monoxide of a partial pressure of 1 to 100 kg/cm.sup.2 G in the presence of a rhodium catalyst and a iodine compound, whereby the reaction is caused to take place in a reaction solution containing a carboxylic acid in the presence of an aluminum accelerator and a rhodium catalyst treated with hydrogen.

Preparation of acetyl compounds

Allyl alcohol is hydroformylated with a gaseous mixture of hydrogen and carbon monoxide, in an aromatic hydrocarbon, in the presence of a rhodium complex and a trisubstituted phosphine, to form hydroxybutyraldehydes which are separated from the reaction mixture within an aqueous medium. The carbon monoxide partial pressure, the rate of consumption of carbon monoxide, the rate at which the carbon monoxide is dissolved in the reaction mixture, reaction temperature and the viscosity of the reaction mixture are selected and controlled in an interrelated way to give a high yield of 4-hydroxybutyraldehyde and reduced catalyst consumption.

Growing community of inventors

Himeji, Japan

Hidetaka Kojima