Nippon Shokubai Co., Ltd.

Nippon Shokubai Kagaku Kogyo Co., Ltd.

Hideki Sogabe

Yukihiro Matsumoto

Takeshi Nishimura

Kazuhiko Sakamoto

Osamu Dodo

Hiroshi Yoshida

Akira Inoue

Kunio Sano

Kiichiro Mitsui

Takahiro Takeda

Tooru Ishii

Atsushi Okubo

Sumio Nakashima

Hiroshi Uchida

Teruaki Yabuuchi

A method for quickly starting up a reactor and a reactor system therefor are provided. A shell-and-tube reactor in the system is adapted to circulate a heat medium having a solid point in the range of 50-250&#xb0; C. to the outside of the reaction tubes and characterized by initiating temperature elevation of the reactor by introducing a gas of a temperature in the range of 100-400&#xb0; C. to the reaction tubes' side and then circulating the heat medium in a heated state to the outside of the reaction tubes. By introducing a gas of an elevated temperature preparatorily to the reaction tubes, it is made possible to prevent the heat medium after circulation from being solidified again and enable the reactor to be quickly started up.

Method for starting up reactor and reactor system

Crystal of sublimable material is recovered by introducing a reaction gas containing sublimable material into a vertical recovery chamber kept at a temperature near a depositing temperature of the sublimable material to form a crystal deposit of the sublimable material on a surface of a wall of the chamber, and cooling the wall formed with the crystal deposit to a temperature below the previous temperature to cause a contraction difference between the crystal deposit and the wall formed with the crystal deposit, and break away the deposited crystal from the wall.

Method for recovering sublimable material

The present invention provides a process for producing a carboxylic acid ester by reacting a carboxylic acid with an alcohol in a suspension of a strongly acidic cation exchange resin which is a catalyst, which process comprises introducing a reaction mixture slurry containing said ion exchange resin, from a reactor for the above reaction to a resin-separating vessel, separating, in said resin-separating vessel, said reaction mixture slurry into a clear solution and a slurry-like high-concentration mixture, and discharging the clear solution from the upper section of the resin-separating vessel and the slurry-like high-concentration mixture from near the bottom of the resin-separating vessel to circulate it into the reactor. Preferably, the resin-separating vessel is operated under such conditions that the ascending speed of the clear solution becomes 0.003 m/sec or less. The process allows efficient separation/recovery of ion exchange resin from reaction mixture and reuse of recovered resin in the reaction.

Process for production of carboxylic acid ester and resin-separating

A method for the purification of waste water by the use of a heat-exchanger type reaction vessel composed of a plurality of inner tubes and a shell defining jointly with the outer peripheries of the inner tubes a passage for the flow of a heat transfer medium, which method comprises passing said waste water through said inner tubes and, at the same time, feeding a molecular oxygen-containing gas to the flow of said waste water thereby establishing contact between said waste water and said feed gas and consequently effecting wet oxidation of the impurities present in said waste water.

Method for purification of waste water

Method for production of unsaturated carboxylic acid esters

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Himeji, Japan

Hideki Sogabe