Nippon Shokubai Co., Ltd.

Nippon Shokubai

Takeshi Nishimura

Yukihiro Matsumoto

Kazuhiko Sakamoto

Sei Nakahara

Osamu Dodo

Harunori Hirao

Tetsuji Mitsumoto

Kenji Sanada

Masakatsu Mori

Hiroo Iwato

Masatoshi Ueoka

Hajime Matsumoto

Yoshitake Ishii

Hidefumi Haramaki

Misao Inada

Yuichi Ijiri

Daisuke Nakamura

Hideki Sogabe

Masatsugu Kitaura

Kazuto Okazaki

Kei Hamamoto

Mamoru Takamura

Michio Tanimoto

Yasuhiro Shingai

Yukihiro Yoneda

Kouji Ueno

Kunihiko Suzuki

Kenji Nakahara

Noriaki Mizutani

Naoto Kasaya

Tatsuaki Yoshimura

Kiyotaka Watanabe

Masahiro Motofuji

Takashi Sera

Hisao Nakama

Motomi Nakamura

A shell-and tube reactor including at least one reaction tube with a measuring means, substantially same solid particles being filled in the reaction tubes with or without the measuring means, a length of the filled solid particle layer, and a pressure drop thereof while passing a gas through the reaction tube, per each reaction tube, being substantially the same, respectively. By measuring the temperature of the catalyst particle layer, such a temperature as a representative can be gasped.

Reactor filled with solid particle and gas-phase catalytic oxidation with the reactor

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

A vertical heat exchanger is described, which allows efficient elimination of the gas generated therein and efficient removal of the sludge accumulated therein. The vertical heat exchanger has at least part of one end of a vent pipe formed of an upper tube sheet part (an upper cover part in the case of a spiral heat exchanger) and the other end thereof connected outside the heat exchanger to an immediately adjacent fluid passing port passing the same fluid as the vent and/or at least part of one end of a drain pipe formed of a lower tube sheet part (a lower cover part in the case of a spiral heat exchanger) and the other end thereof connected outside the heat exchanger to an immediately adjacent fluid passing port passing the same fluid as the drain.

Vertical heat exchanger

A method for the production of acrylic acid comprises (i) a step for introducing a polymerization inhibitor to a stage other than a stage for supplying a raw material and a stage for supplying a reflux of said distilling column or (ii) a step for supplying the acrylic acid recovered by thermally decomposing said oligomer to said stage for dehydration. Thus, the present invention enjoys effective utilization of acrylic acid and exalts the efficiency of production.

Method for production of acrylic acid

A shell-and-tube type heat exchanger of the smallest possible length necessary for heat exchange is disclosed which is capable of obtaining uniform distribution of flow of a shell side fluid and substantially eliminating the structural restriction imposed on the shell side. This shell-and-tube type heat exchanger is provided with one annular conduit furnished with not less than two partitions concurrently serving as an expansion joint for introducing and discharging a shell side fluid and allowing the flow path for said shell side fluid to be separated into an introducing part and a discharging part and which comprises a place having no array of heat-transfer tubes in the flow path for said shell side fluid. It prevents the equipment from necessitating an unnecessary enlargement due to the structural restriction on the shell side and enables the shell side fluid to produce a uniform flow.

Method for production of (meth)acrylic acid by use of a shell-and-tube heat exchanger

It is an object of the present invention to provide a process for producing easily polymerizable substance, which can realize stable operation of a purification system, and can stably maintain a production amount by avoiding production stoppage, upon production of an easily polymerizable substance in plural reactors. The present invention is directed to a process for producing easily polymerizable substance, which comprises mixing easily polymerizable substances obtained in plural reactors in advance, and supplying the mixture to a purification apparatus.

Process for producing easily polymerizable substance

This invention resides in providing a method for the prevention of possible polymerization of the easily polymerizable substance during the purification thereof by a column provided with (a) at least one tray directly fixed to a support ring with a bolt and a nut and/or (b) at least one tray fixed to a support ring with a vertical clamp or a distillation column provided in the lower part thereof with a splash collision plate.

Method for production of easily polymerizable substance and purification apparatus

A method for refining an easily polymerizable matter while preventing an easily polymerizable matter-containing substance from being polymerized and an apparatus for use in the method are disclosed. The method and apparatus for refining and separating the easily polymerizable matter-containing substance by the use of a distillation column provided with a heat exchanger set the linear velocity of a vapor in a connecting line intervening between the distillation column and the heat exchanger at a level of not less than 5 m per second and the retention time of the vapor at a level of not more than 3 seconds.

Method for refining easily polymerizable matter-containing substance and apparatus therefor

This invention is providing a method for efficient treatment of the waste material from a process for production of acrylic acid and an acrylic ester. This is a method for the disposal of waste material, which at least one waste material selected from the group consisting of waste oil, waste water, and waste gas emitted from a process for production of acrylic acid is/are purified with at least one waste material selected from the group consisting of waste oil, waste water, and waste gas emitted from a process for production of an acrylic ester jointly. The efficiency of the treatment is enhanced by simultaneously treating the waste material.

Method for disposal of waste from acrylic acid process and acrylic ester process

Shell-and-tube type heat exchanger and method for production of (meth) acrylic acid by use of the exchange

A method is disclosed which produces acrylic acid in a high yield as maintaining the conditions for purifying acrylic acid in constant ranges and preventing the acrylic acid from polymerization. By using single a single reactor, propylene concentration adjusting in the range of 7&#x2013;15 vol. % and water concentration adjusting in the range of 0&#x2013;10 vol. % are introduced thereinto thereby obtaining an acrylic acid-containing gas. Then the gas is introduced to an acrylic acid absorption column to adjust water concentration in the range of 1&#x2013;45 wt. %, thereby preventing from polymerization.

A method for managing the operation of an apparatus for the reaction of gas phase partial oxidation of an unsaturated hydrocarbon with a molecular oxygen-containing gas for the purpose of omitting wasteful emergency stop of the operation and ensuring execution of necessary emergency measure and a method for producing (meth) acrylic acid by utilizing the method mentioned above are provided. The operation of the apparatus is brought to emergency stop exclusively when thee values of concentrations of various gases obtained by calculation from the flow rates of the gases being introduced at the inlet port of the reactor and the measured values obtained by analysis with gas analyzing instruments both deviate from the ranges of the present values.

Method for managing operation of gas phase reaction apparatus

The object of this invention to provide an improved arrangement that enables to prevent adhesion of polymer on or around the inner wall of a purification apparatus directly equipped on the outer wall thereof with an attachment such as a support by suppressing local temperature lowering inside the apparatus due to the existence of the attachment. The present invention provides a purification apparatus comprising an attachment directly mounted on an outer wall of the apparatus; and a covering material made of a low heat conductive material which partly or entirely covers the outer wall of the apparatus, and which partly or entirely covers the attachment.

Purification apparatus provided with low heat conductive member

An apparatus for the treatment of a waste gas that is capable of recovering the heat generated by the catalytic oxidation of a waste gas to the largest possible extent and allowing the temperature of the treated gas in a first waste gas pre-heater to be adjusted to an arbitrary level incapable of condensing moisture and/or corrosive gas is provided. The apparatus for the treatment of the waste gas includes a molecular oxygen-containing gas supplying device, second to n'th waste gas pre-heaters, a heat-recovering device, and a reactor.

Apparatus for treatment of waste gas

The present invention provides an industrially easy and economical method for purification of acrylic acid which enables to efficiently eliminate impurities from a crude acrylic acid containing aldehydes as the impurities while the formation of acrylic acid polymer is inhibited. The method for purification of acrylic acid includes the step of distilling a crude acrylic acid which is charged with an aldehyde treatment chemical, wherein the concentration ratio of furfural to acrolein by weight in the crude acrylic acid is adjusted so as to satisfy the following equation:(furfural concentration by weight)/(acrolein concentration by weight)&#x2266;100.

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Himeji, Japan

Takeshi Nishimura