Mitsubishi Rayon Company, Limited

Yoshiyuki Taniguchi

Yasuhiro Kabu

Motomu Oh-Kita

Yoshimasa Ando

Miezi Sugiyama

Masao Kobayashi

Toru Kuroda

Junichi Doi

Masaaki Kato

Hideyasu Takezawa

Masanori Tokuda

Michiyuki Kouno

Tomohiko Mawatari

Yoshihiko Satou

Nobuo Momodomi

A method for supplying reaction gases in which at least a material to be oxidized and a gas containing molecular oxygen are mixed and the resultant mixture is supplied to a catalytic gas-phase oxidation reactor, characterized in that, a feed rate of the material to be oxidized and a feed rate of the gas containing molecular oxygen are adjusted so that when a composition of a gas at the inlet of the catalytic gas-phase oxidation reactor is changed from a composition A point [the concentration of the material to be oxidized: R(a), and the concentration of oxygen: O(a)] represented by plotting a concentration of the material to be oxidized and a concentration of oxygen in the gas at said inlet to a composition B point [R(b) and O(b)] [the composition A point and the composition B point are compositions outside an explosion range, and R(a)&#x2260;R(b) and O(a)&#x2260;O(b)], compositions on the way of the change from the composition A point to the composition B point fall outside the explosion range.

Method for supplying reaction gases in catalytic vapor phase oxidation process

The present invention aims to provide a transfer method and a transfer facility for an easily polymerizable substance that limits standing retention of the easily polymerizable substance in the feed pump, etc., and the generation and adherence of solid matter such as polymer or precipitate that accompanies such retention, in a facility in which respective feed pumps are disposed at the plurality of passages that branch off at the easily polymerizable substance inflow side and converge at the easily polymerizable substance outflow side. In this easily polymerizable substance transfer method, in the case where one feed pumpoperates and the other feed pumpis stopped, a portion of the easily polymerizable substance is fed to feed pumpand second passagein a direction that is opposite to the direction of flow of the easily polymerizable substance when feed pumpis activated. In this easily polymerizable substance transfer facility, a check valveprovided downstream to feed pumphas a hole in the valve plug that permits passage of the easily polymerizable substance.

Transporting method and transporting facility for easily polimerizable material

A fixed-bed multitubular reactor, comprising a plurality of reaction tubes () filled with a catalyst and catalyst temperature measurers () measuring the temperatures of the reaction tubes near the radical center parts thereof. The catalyst temperature measurer () is installed in each of a part of the plurality of reaction tubes (), and the measurement positions thereof are differentiated from each other in the longitudinal direction of the reaction tubes ().

Fixed bed multitube reactor

A method of removing a sticky substance or a waste liquid containing a sticky substance which comprises, mixing a solid substance having inflammability and liquid-absorptivity into the sticky substance or the waste liquid containing the sticky substance wherein these are mixed to allow a liquid component of the sticky substance or the waste liquid containing the sticky substance to be absorbed into the solid substance and to allow the sticky substance to be entangled with the solid substance, and then removing the sticky substance together with the solid substance.

Method of removing tacky substance or waste liquid containing tacky substance

The method for preserving a catalyst of the present invention is characterized in that, in a process for continuously producing an objective product by a vapor phase oxidation reaction using a phosphorus-molybdenum-vanadium catalyst containing phosphorus, molybdenum and vanadium, the phosphorus-molybdenum-vanadium catalyst retained in a reactor is maintained under a condition of a water content of 30 mg or less per 1 g of catalyst dry weight, before the start of the reaction or during the stop of the reaction. By this, deterioration of the catalyst retained in the reactor can be simply prevented.

Method for preserving catalyst

A method of producing a methacrylic acid ester which comprises carrying out an ester-exchange reaction between methyl methacrylate and an alcohol or a phenol while removing by-product methanol as an azeotropic mixture with methyl methacrylate from the reaction system under reflux conditions, by the use of a reaction apparatus equipped with a distillation column. A methacrylic acid ester is produced with a good productivity by controlling the reflux ratio.

Process for producing methacrylic ester

A method for preparing a multicomponent catalyst including molybdenum, bismuth, iron and cesium or thallium for producing methacrolein and methacrylic acid by the gas-phase catalytic oxidation of isobutylene or tert-butanol with molecular oxygen, wherein an aqueous nitric acid solution containing 0.01 to 0.36 mole of nitric acid per mole of ammonium molybdate, which is a material for the molybdenum component of the catalyst, and at least one material for the bismuth, iron, cesium and thallium components of the catalyst is added to an aqueous solution containing ammonium molybdate and materials for the remaining catalyst components, if any, to obtain a slurry which is then dried and calcined, provided that the nitric acid excludes nitric acid radicals contained in the materials containing the catalyst components. The amount of nitric acid used is controlled in a particular range, so that a highly active catalyst for gas-phase catalytic oxidation is obtained.

Preparation of catalysts for producing methacrolein and methacrylic acid

The present invention provides a process for the production of methacrolein and methacrylic acid by the gas phase catalytic oxidation of isobutylene or t-butanol at high temperature using molecular oxygen in the presence of catalyst consisting of molybdenum, tungsten, bismuth, iron, nickel, antimony, and an alkali metal, to which zinc or lead is added, and further phosphorus sulfur, silicon, selenium, germanium or boron, and magnesium, cobalt, manganese or tin are added.

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Hiroshima, Japan

Yoshiyuki Taniguchi