Abstract: The disclosed invention is a method for manufacturing an oxidized organic compound which includes a step of forming an oxidized organic compound, in use of a fixed-bed reactor having a reaction tube packed with an oxide catalyst, by supplying at least one type of organic compound as a reaction feedstock gas and using a molecular oxygen-containing gas to carry out a catalytic gas-phase oxidation reaction; and a step of stopping the catalytic gas-phase oxidation reaction. In the manufacturing method, when stopping the catalytic gas-phase oxidation reaction, the supply of the reaction feedstock gas is stopped, after which an inert gas is supplied to the reactor, then a molecular oxygen-containing gas is supplied, subsequent to which the supply of the molecular oxygen-containing gas to the reactor is stopped.

Abstract: A fixed-bed reactor containing a first catalyst layer filled with a first catalyst for producing acrolein from propylene; a second catalyst layer filled with a second catalyst for producing acrylic acid from acrolein; and an inert substance layer provided between the first catalyst layer and the second catalyst layer, and filled with an inert substance of a cylindrical shape having a surrounding wall in which an opening is formed. A process for producing acrylic acid containing the step of producing acrylic acid from propylene by using the aforementioned fixed-bed reactor.

Abstract: An object of the present invention is to provide: a catalyst for production of acrylic acid which is a catalyst usable for production of acrylic acid and is excellent in the catalytic performances such as catalytic activity and in the physical properties such as physical strength of the catalyst itself; and a process for production of acrylic acid using this catalyst. As a means of achieving this object, a catalyst for production of acrylic acid according to the present invention is a catalyst obtained by drying a mixed liquid of starting materials including molybdenum and vanadium as essential components to give a dried material, molding the dried material with a liquid binder, and calcining the resultant molding, with the catalyst being characterized in that an ignition loss ratio of the dried material is from 5 to 40% by mass.

Abstract: In industrial scale production of acrolen and/or acrylic acid by catalytic gas-phase oxidation of propylene or a propylene-containing gas with molecular oxygen or a molecular oxygen-containing gas or in industrial scale production of acrylic acid by catalytic gas-phase oxidation of acrolein or an acrolein-containing gas with molecular oxygen or a molecular oxygen-containing gas, this invention provides a process characterized in that the initial stage operation is carried out under advancedly elevated reaction temperature and thereafter the reaction temperature is lowered to carry out the steady state operation. According to this process, acrolein and/or acrylic acid can be produced in high yield stably over prolonged period.

Abstract: The invention offers an improvement in a process for start-up in the occasion of producing acrolein and acrylic acid by catalytically oxidizing propylene at vapor phase under high load conditions, the start-up meaning the step of increasing the propylene supply rate (loading) from the non-reacting condition to the prescribed reaction conditions. This process is characterized in that the propylene supply rate is increased in the start-up stage of the reaction until the prescribed composition of starting reactant gas and the flow rate of the starting reactant gas are obtained, while adjusting at least one of the reaction temperature, the composition of the starting reactant gas and flow rate of the starting reactant gas, so as to maintain the propylene conversion at not lower than 90 mol %, the maximum peak temperature of the catalyst layer in each reaction zone at no higher than 450° C.

Abstract: The invention offers an improvement in a process for start-up in the occasion of producing acrylic acid by catalytically oxidizing acrolein at vapor phase under high load conditions, the start-up meaning the step of increasing the acrolein supply rate (loading) from the non-reacting condition to the prescribed reaction conditions. This process is characterized in that the acrolein supply rate is increased in the start-up stage of the reaction until the prescribed composition of starting reactant gas and the flow rate of the starting reactant gas are obtained, while adjusting at least one of the reaction temperature, the composition of the starting reactant gas and the flow rate of the starting reactant gas, so as to maintain the acrolein conversion at not lower than 90 mol %, the maximum peak temperature of the catalyst layer in each reaction zone at no higher than 400° C.

Abstract: The object of the present invention is to provide, in the production of a useful oxidized organic compound by a catalytic gas-phase oxidation reaction on an industrial scale, a manufacturing method which, even when operation has been temporarily interrupted for periodic inspection or emergency shutdown, fully avoids the danger of an explosion due to reaction feedstock gases and the like remaining inside the reaction apparatus, and which, when operation is restarted, is able to shorten, relative to the prior art, the period required for the reaction to return to a stable steady state, and moreover which, after operation has restarted, does not undergo a decrease in yield, and allows a high yield to be stably maintained over a long period, whereby the production efficiency can be greatly increased.

Abstract: The fixed-bed reactor of the present invention which solves the above problems is a fixed-bed reactor comprising: a first catalyst layer filled with a first catalyst for producing acrolein from propylene; a second catalyst layer filled with a second catalyst for producing acrylic acid from acrolein; and an inert substance layer provided between the first catalyst layer and the second catalyst layer, and filled with an inert substance of a cylindrical shape having a surrounding wall in which an opening is formed. The process for producing acrylic acid of the present invention is a process for producing acrylic acid comprising the step of producing acrylic acid from propylene by using the fixed-bed reactor of the present invention.

Abstract: A catalyst for producing acrylic acid from propane and/or acrolein by gas-phase catalytic oxidation with molecular oxygen-containing gas, comprising a catalytic active component containing molybdenum and vanadium as essential elements, and having a crystallinity T of 5% or more and 20% or less in the 20 range of 5° to 90°, measured by an X-ray diffraction analysis with Cu-K? radiation; and a process for producing acrylic acid by gas-phase catalytic oxidation of propane and/or acrolein with molecular oxygen, comprising the step of conducting the gas-phase catalytic oxidation in the presence of the catalyst. According to the catalyst and the process for producing acrylic acid of the present invention, it is possible to stably produce acrylic acid at a high yield for a long period.

Abstract: A catalyst for producing acrolein and/or acrylic acid from propylene by gas-phase catalytic oxidation with molecular oxygen-containing gas, comprising a catalytic active component containing molybdenum, bismuth and cobalt as essential elements, and having a crystallinity T of 4% or more and 18% or less in the 2? range of 5° to 90°, measured by an X-ray diffraction analysis with Cu—K? radiation; and a process for producing acrolein and/or acrylic acid by gas-phase catalytic oxidation of propylene with molecular oxygen, comprising the step of conducting the gas-phase catalytic oxidation in the presence of the catalyst. According to the catalyst and the process for producing acrolein and/or acrylic acid of the present invention, it is possible to stably produce acrolein and/or acrylic acid at a high yield for a long period.

Abstract: Conventional gas-phase catalytic oxidation reaction apparatus comprising two reactors for production of acrylic acid is subject to problems of high equipment costs for the reactors and piping, necessity for wide installation area and easy accumulation of carbides generated by autoxidation of acrolein. On the other hand, conventional reaction apparatus comprising a single reactor has the drawbacks that the composition of gas in the first stage reaction and in the second stage reaction cannot be optimized independently of each other, and that the allowable concentration of starting propylene is limited because of the risk of explosion.

Abstract: The invention provides a method of gas-phase catalytic oxidation, in particular, a production method of (meth)acrylic acid, which enables stable continuous operation of gas-phase catalytic oxidation over a long term, maintaining high yield and suppressing increase in pressure loss. In the method a fixed bed reactor is used, in which a treating agent for removing organic substance and/or carbides, preferably a treating agent having an adsorption capacity of at least 0.05% by mass, as measured by crotonaldehyde as an indicator of organic substance, is disposed on the upstream side of the gas-phase oxidation catalyst layer in respect of the direction of the gas flow. It is desirable that at least a part of the treating agent is exchanged at a frequency of at least once a year.

Abstract: A method of loading solid particles into reaction tubes of a fixed-bed multitubular reactor, comprising the step of loading two or more kinds of solid particles into each of the reaction tubes so that the respective kinds of the solid particles are stacked in layers in a direction of an axis of the tube, wherein a gaseous fluid is introduced into the reaction tubes at least once every time the each kind of the solid particles is loaded in the layer.

Abstract: In industrial scale production of acrolen and/or acrylic acid by catalytic gas-phase oxidation of propylene or a propylene-containing gas with molecular oxygen or a molecular oxygen-containing gas or in industrial scale production of acrylic acid by catalytic gas-phase oxidation of acrolein or an acrolein-containing gas with molecular oxygen or a molecular oxygen-containing gas, this invention provides a process characterized in that the initial stage operation is carried out under advancedly elevated reaction temperature and thereafter the reaction temperature is lowered to carry out the steady state operation. According to this process, acrolein and/or acrylic acid can be produced in high yield stably over prolonged period.

Abstract: The present invention provides: a fixed-bed shell-and-tube reactor, which can stably produce an aimed product for a long period when a solid particulate material such as a catalyst is packed and used for each substance; and its usage. The fixed-bed shell-and-tube reactor comprises a plurality of reaction tubes that are packed with a solid particulate material and arranged in parallel, wherein the solid particulate material is weighed so as to be uniform volume, and is packed in each reaction tube in a packing time of not shorter than 30 seconds per liter.

Abstract: The invention offers an improvement in a process for start-up in the occasion of producing acrolein and acrylic acid by catalytically oxidizing propylene at vapor phase under high load conditions, the start-up meaning the step of increasing the propylene supply rate (loading) from the non-reacting condition to the prescribed reaction conditions. This process is characterized in that the propylene supply rate is increased in the start-up stage of the reaction until the prescribed composition of starting reactant gas and the flow rate of the starting reactant gas are obtained, while adjusting at least one of the reaction temperature, the composition of the starting reactant gas and flow rate of the starting reactant gas, so as to maintain the propylene conversion at not lower than 90 mol %, the maximum peak temperature of the catalyst layer in each reaction zone at no higher than 450° C.

Abstract: The invention offers an improvement in a process for start-up in the occasion of producing acrylic acid by catalytically oxidizing acrolein at vapor phase under high load conditions, the start-up meaning the step of increasing the acrolein supply rate (loading) from the non-reacting condition to the prescribed reaction conditions. This process is characterized in that the acrolein supply rate is increased in the start-up stage of the reaction until the prescribed composition of starting reactant gas and the flow rate of the starting reactant gas are obtained, while adjusting at least one of the reaction temperature, the composition of the starting reactant gas and the flow rate of the starting reactant gas, so as to maintain the acrolein conversion at not lower than 90 mol %, the maximum peak temperature of the catalyst layer in each reaction zone at no higher than 400° C.

Abstract: As an improvement in the production method of acrylic acid by two-stage catalytic vapor-phase oxidation of propylene comprising catalytic vapor-phase oxidation of a propylene-containing gas at a first reactor to produce an acrolein-containing gas, and successive catalytic vapor-phase oxidation of the obtained product gas to produce acrylic acid, a process which enables acrylic acid production on an industrial scale for a long period, with stability at high yield is offered. This process is characterized in that a filler formed of a solid inert material is disposed at a cooling part which is provided on the downstream side to the direction of gas flow through the catalyst layer in the first reactor and/or on the gas outlet side of the first reactor, in such a way that the voidage in the filler becomes 45-99%.

Abstract: An object of the present invention is to provide: a catalyst for production of acrylic acid which is a catalyst usable for production of acrylic acid and is excellent in the catalytic performances such as catalytic activity and in the physical properties such as physical strength of the catalyst itself; and a process for production of acrylic acid using this catalyst. As a means of achieving this object, a catalyst for production of acrylic acid according to the present invention is a catalyst obtained by drying a mixed liquid of starting materials including molybdenum and vanadium as essential components to give a dried material, molding the dried material with a liquid binder, and calcining the resultant molding, with the catalyst being characterized in that an ignition loss ratio of the dried material is from 5 to 40% by mass.

Abstract: An object of the present invention is to provide: a catalyst for production of acrylic acid which catalyst is so high active as to give a still higher selectivity of acrylic acid (which is the objective product) or a long-catalytic-life-time catalyst for production of acrylic acid which catalyst is so high active as to be able to give a high acrylic acid yield while suppressing the temperature rise of the oxidation reaction to a low one; and processes for production of acrylic acid using these catalysts.