Nippon Shokubai Co., Ltd.

Osamu Dodo

Takeshi Nishimura

Yukihiro Matsumoto

Kazuhiko Sakamoto

Sei Nakahara

Masakatsu Mori

Tetsuji Mitsumoto

Kazuto Okazaki

Michio Tanimoto

Daisuke Nakamura

Hidefumi Haramaki

Hiroo Iwato

Hideki Sogabe

Masatsugu Kitaura

Mamoru Takamura

Harunori Hirao

Kei Hamamoto

Yuichi Ijiri

Takehiro Takashima

Kazukiyo Arakawa

Masatsuga Kitaura

Yousuke Ogata

Chilled coolant is prepared by liquid coolant utilizing the latent heat generated by a gasification of liquefied propylene, for example, and this chilled coolant is used in heat exchangers which are used in a process for production of acrylic acid or acrolein. This method allows effective utilization of the latent heat which used to be discarded and permits a reduction of energy consumption of cooling required separately in the step for production. By recovering the chilled coolant with the liquid coolant, it makes possible to stabilize the gasification of propylene, etc. and consequently stabilize the production of acrylic acid. This invention consists of providing the method for the production of acrylic acid, etc. and the apparatus which make effective use of the latent heat generated in the steps of production.

Method for production of acrylic acid and apparatus for production of acrylic acid

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 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

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

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

In a shell-and-tube type reactor, the leakage between the upper and lower chambers is substantially decreased by tightly fitting the reaction tubes to the shield. The present invention provides a reactor for use in catalytic gas phase oxidation characterized by expanding reaction tubes to at least one groove formed in the reaction tube-fixing part of an intermediate tube sheet to form a shield, thereby forming plural of chambers with the intermediate tube sheet, and forming an expansion joint around the periphery of each of the chambers.

Reactor for catalytic gas phase oxidation

Provided are a packed column arranged so as to be capable of effectively preventing polymerization of a polymerizable compound such as a (meth)acrylic acid in treating the compound, and a method for treating a polymerizable compound using the packed column. The packed column, which is provided with a packing support plate and is filled with a packing on the packing support plate, is arranged so as to include a packing layer (B) having a greater percentage of voids than that of a packing layer (A), between the packing support plate and the packing layer (A).

Packed column and polymerizable compound treating method using the same

In an apparatus provided with a plate type heat exchanger as a heater and/or a cooler and operated to treat a gas containing an easily blocking substance, a method for preventing the plate type heat exchanger from being blocked is disclosed which is characterized by i) setting the width of a flow path on a plate of the plate type heat exchanger in the apparatus in a range of 6-25 mm and ii) setting the average flow rate of the gas passing the plate type heat exchanger in the apparatus per unit cross-sectional area of the flow path on the plate in the range of 3-15 m/s. In the exchange of heat of an easily blocking substance by the use of a plate type heat exchanger, a method for preventing the plate type heat exchanger from blockage is disclosed which has the plate type heat exchanger provided in the port for introducing a gas containing an easily blocking substance with a gas dispersion plate. This invention, in the heat exchange of an effluent gas emanating from a process for the production of (meth)acrylic acid or an ester thereof or the disposal of the gas, significantly allays blockage of the interior of the plate type heat exchanger.

Method for preventing plate type heat exchanger from blockage

The temperature distribution of a heating medium in the reactor is allayed and the occurrence of hot spots is repressed. In a shell-and-tube type reactor provided with donut type and disc type baffle plates, reaction tubes are disposed even in the holes formed in the donut type baffle plates and an empty space devoid of a configuration of the reaction tubes is formed at the center of the shell. According to this invention, (meth)acrylic acid and/or (meth)acrolein can be produced at a low energy by catalytic gas phase oxidation of propylene- or isobutylene-containing gas.

In the reaction of catalytic gas phase oxidation by means of a shell-and-tube type reactor adapted to circulate a heating medium to the shell of the reactor through the medium of a circulation device connecting an annular conduit connected thereto, a method for the catalytic gas phase oxidation characterized by subjecting a part of the heating medium extracted from the shell of the reactor to heat exchange, introducing the heating medium resulting from the heat exchange into the proximity of a heating medium circulation inlet on the inlet side of the circulation device or the annular conduit on the outlet side of the reactor. The flow rate of the heating medium after the heat exchange is preferred to be in the range of 2-40 vol. % based on the flow rate of the heating medium within the shell of the reactor and the temperature difference of the heating medium at the inlet and the outlet to be in the range of 15-150&deg; C. According to this invention, it is made possible to reduce evenly the hot spots in the reaction tubes, improve the yield of the product aimed at, and implement a reaction of catalytic gas phase oxidation of propylene or isobutylene.

Method for catalytic gas phase oxidation

A shell-and-tube reactor has a plurality of reaction tubes incorporated therein, a circulation path for the heating medium formed outside the reaction tubes, a heating medium introducing section provided on the upper part of the shell in the reactor and a heating medium discharge section provided on the lower part of the shell in the reactor, a back pressure applying means for the heating medium is further provided in the heating medium discharge section.

Shell-and-tube reactor

According to the present invention, a tank for storing an easily polymerizable compound, the tank fitted with a liquid inlet pipe , a liquid draw-off pipe and a liquid recirculating pipe , is characterized in that, assuming terminal ends of the individual pipes are located at the same height, the apex angle formed by a line joining the central points of the end openings of the pipe and the pipe at the central point of a horizontal cross section of the tank, or the apex angle formed by a line joining the central points of the pipe and the pipe at the central point of the horizontal cross section of the tank, is equal to or larger than 90&deg;. A method of storing an easily polymerizable compound of the invention utilizes the aforementioned tank for storing the polymerizable compound.

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Hyogo, Japan

Osamu Dodo