Showa Denko K.k.

Toshitaka Hiro

Takanori Aoki

Tatsuharu Arai

Makoto Saito

Koichi Nishimura

Toshio Ohi

Kenji Usui

Takami Ohe

Haruki Ishikami

Tsunekichi Kuriyama

Yasuaki Toyomasu

Kazuhiro Sakurai

Shoichi Oishi

Yoshiharu Mizuno

It is the objective to provide a method of stabilizing hydroxylamine at a high temperature and a high concentration or in a case that metal impurities such as Fe got mixed therewith, and a stabilized hydroxylamine solution. A method for stabilizing hydroxylamine related to the present invention is characterized by adding ethylenediamine-N,N'-di(o-hydroxyphenylacetic acid) as a preservation stabilizer.

Stabilizer and method for stabilizing hydroxylamine, and stabilized hydroxylamine solution

It is an object of the present invention to provide a process for producing a hydroxylamine by reacting a salt of hydroxylamine with an alkali compound, where the yield reduction due to formation of a complex between the produced hydroxylamine and a salt produced as a by-product or adsorption of the hydroxylamine to the by-product salt is decreased, and a high-concentration and high-purity hydroxylamine is safely produced at a high yield. The process for producing a hydroxylamine of the present invention comprises a reaction step of reacting a salt of hydroxylamine with an alkali compound to obtain a hydroxylamine while keeping the reaction solution at a pH of 7 or more, a purification step of purifying the hydroxylamine by ion exchange, and a concentration step of concentrating the hydroxylamine by distillation at the column bottom.

Process for producing hydroxylamine

Denitrated combustion exhaust gas is desulfurized with ammonia, the waste water obtained from washing the desulfurization waste water or dust ash is filtered using calcium carbonate, the pH of the filtrate is adjusted, carbon dioxide and/or aqueous carbonic acid is added and then a flocculating agent is added, and ammonia is recovered from the supernatant after precipitation and separation of the solid portion. The recovered ammonia is added to the denitrated gas for treatment of the combustion exhaust gas.

Combustion exhaust gas treatment process and treatment apparatus

Methods for continuously producing 2,3-dichloro-1-propanol (2,3-DCH) and epichlorohydrin in high yields and in a stabel manner for a long time are disclosed. In a method where allyl alcohol is chorinated in a hyrochloric acid solution and the reaction solution is introduced into a degassing tower to release hydrogen chloride and 2,3-DCH is obtained from the remaining solution, the concentraton of chlorine in the reaction mixture to be introduced into the degassing tower is maintaining to 0.015 g/ml or less and/or the partial pressure of chlorine gas in the reactor immediately before the degassing tower to 0.08 MPa or less, by monitoring and/or the partial pressure of chlorine gas in the reactor immediately before the degassing tower to 0.08 MPa or less, by monitoring and/or controlling the chlorine concentration of a solution at the outlet of the reactor immediately before the degassing tower and/or the partial pressure of chlorine gas present in the gas phase section of the reactor and the flow rate of chlorine gas immediately before the degassing tower.

Method for producing 2,3-dichloro-1-propanol and epichlorohyrin

Processes are provided for producing propargyl alcohol in an industrially advantageous manner. One of the processes comprises reaction of 1,2,3-trichloropropane with 3 equivalents or more of an alkali compound to produce propargyl alcohol. The other process comprises (1) a first step of reaction of 2,3-dichloro-1-propanol with an amine to produce chloroallyl alcohol, and (2) a second step of reaction of the chloroallyl alcohol obtained in the above step (1) with an alkali compound to produce propargyl alcohol.

Production process and use for propargyl alcohol and its intermediate

In a process for production of allyl chloride whereby allyl alcohol and hydrogen chloride are reacted in the presence of a catalyst and the resulting allyl chloride is distilled off from the reaction system, the by-production of diallyl ether is suppressed by lowering the molar concentration ratio of hydrogen chloride with respect to allyl alcohol in the reaction solution (&lsqb;AAL&rsqb; /&lsqb;HCL&rsqb;).

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Kawasaki, Japan

Toshitaka Hiro