Abstract: Acrolein and/or acrylic acid are prepared from propane and/or propene by a process comprising the following steps: (a) separation of propane and/or propene from a propane- and/or propene-containing gas mixture by absorption in an absorbent, (b) separation of the propane and/or propene from the absorbent to give a gas B and (c) use of the gas B obtained in stage (b) for an oxidation of propane and/or propene to acrolein and/or acrylic acid, no heterogeneously catalyzed dehydrogenation of propane without supply of oxygen being carried out between steps (b) and (c).

Abstract: A method for the production of acrylic acid of high concentration by absorbing acrylic acid with high absorption ratio of acrylic acid is provided. In a method for producing acrylic acid by a procedure comprising a step of catalytic gas phase oxidation reaction and a step of absorbing the acrylic acid-containing gas, while a low boiling substance-containing solution is introduced into the absorption column via a portion different from the top of the column.

Abstract: A process for preparing acrolein or acrylic acid or a mixture thereof as the target product from propane, in which propane is partially dehydrogenated under heterogeneous catalysis in a reaction zone A, molecular hydrogen formed is at least partly combusted to water, any water present in the product gas A formed in reaction zone A is removed therefrom and product gas A is otherwise used to charge a reaction zone B in which propylene formed in reaction zone A is partially oxidized in the presence of remaining propane to give the target product. The target product is removed from the product gas B formed in reaction zone B and propane present in the remaining residual gas is absorbed therefrom into a solvent and, after release from the absorbate, recycled into reaction zone A.

Abstract: The present invention relates to a process for the production of acrylic acid (AA) comprising the steps wherein: a) a 1st gas mixture comprising propylene, oxygen, an inert gas and steam is subjected to a 1st catalytic oxidation reaction stage thereby converting the propylene in the presence of a catalyst mainly into acrolein being contained in a 2nd gas mixture from said 1st catalytic oxidation reaction, b) said 2nd gas mixture from the 1st catalytic oxidation reaction stage is subjected to a 2nd catalytic oxidation reaction stage thereby converting the acrolein in the presence of a catalyst mainly into AA, being contained in a product gas, c) said product gas is subjected to a quench tower, wherein said AA is recovered as an aqueous solution comprising said AA being contained in the process water, wherein a process vent gas is obtained at the top of said quench tower, wherein, said 1st gas mixture has a steam/propylene ratio of >0.

Abstract: An improved catalyst comprising a mixed metal oxide, either promoted or not, is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile.

Abstract: The utilization amount of steam generated by heat recovery tends to decrease in a production process of an organic acid when the concentration of an organic acid solution obtained in a step of collecting an organic acid with a solvent such as water become high. The purpose of the invention is to find an advantageous method for effectively utilizing reaction heat and contribute to global environmental preservation and saving product costs. The present invention provides a production method of an organic acid comprising carrying out a gas-phase catalytic oxidation reaction of raw material gas at the temperature from 250° C. to 450° C.

Abstract: A process for producing a catalyst which has a high mechanical strength and is capable of producing an unsaturated aldehyde and an unsaturated carboxylic acid constantly over a long period of time and in good yield; and, a method for producing an unsaturated aldehyde or carboxylic acid from catalytic oxidation of an olefin, a tertiary butyl alcohol, or a methyl tertiary butyl ether substrate with a gas that contains molecular oxygen and the produced catalyst.

Abstract: Disclosed is an annular distributor having: an annular slit layer that is mounted on an inner circumferential surface of the annular distributor and has at least one slit discharging or introducing a fluid; at least one opening that is formed on an outer circumferential surface of the annular distributor and is connected with any one of a fluid supply duct and a fluid discharge duct; and at least one guide vane selected from three types of guide vanes that are installed in the annular distributor, and splits a flow rate of the fluid supplied from the duct or collects a flow rate of the fluid discharged to the duct. And disclosed are a reactor or heat exchanger has the annular distributor, and a method of producing unsaturated aldehyde or unsaturated acid from olefin by catalytic gas phase oxidation in the reactor.

Abstract: The present invention provides a process of producing unsaturated acids from unsaturated aldehydes by fixed-bed catalytic partial oxidation in a shell-and-tube heat exchanger-type reactor, as well as a shell-and-tube heat exchanger-type reactor for use in the process. In the invention, second-stage reaction zone of mainly producing unsaturated acids by the catalytic vapor phase oxidation of an unsaturated aldehyde-containing gas mixture produced in a first-stage reaction zone with molecular oxygen is divided into two or more shell spaces by at least one partition. Each of the divided shell spaces is filled with a heat transfer medium, and the heat transfer medium in each shell space is maintained at isothermal temperature or a temperature difference of 0-5° C. Also, in order to protect catalyst layers from a highly exothermic reaction, the process is performed at a limited temperature difference between the temperature at a hot spot and the temperature of the heat transfer medium.

Abstract: Acrylic acid is prepared from propene by means of gas-phase oxidation by a process in which a starting gas mixture which contains propene and steam and whose molar propene/steam ratio is ?1 and whose propane content is ?5% is passed at elevated temperatures through a fixed catalyst bed comprising successive catalyst part-beds A and B, the part-bed A passed through first containing, as active material, a mixed oxide containing the elements Mo, Bi and Fe and the part-bed B containing, as active material, a mixed oxide containing the elements Mo and V, in a manner such that at least 96.5 mol % of propene are converted in a single pass through part-bed A.

Abstract: A process for the continuous gas-phase oxidation of C3- and C4-precursors to (meth)acrolein and/or (meth)acrylic acid in the presence of a catalyst in a reactor which has a feed for the reaction mixture at one reactor end and removal of the reaction mixture at the opposite reactor end and which is equipped with means, arranged in the interior of the reactor, for removing the heat of reaction, through which means a heat exchange composition flows and which means are in the form of heat exchanger plates, is proposed.

Abstract: This invention is related to a shell-and-tube type reactor provided with reaction tubes packed with a catalyst and adapted to circulate a heat medium to the fluid outside the tubes and is characterized by a method introducing a gas into the catalyst beds so as to retain the relative humidity of the catalyst in the range of more than 40% while elevating the temperature of the reactor thereby starting up the reactor. This method prevents the catalyst from degradation of activity due to absorption of moisture, exalts the service life of the catalyst, and permits stable production of methacrylic acid.

Abstract: A process for the long-term operation of a heterogeneously catalyzed partial gas phase oxidation of an organic starting compound, in which the reaction gas input mixture is partially oxidized over a fixed catalyst bed which is accommodated in two successive temperature zones A, B whose temperature is changed with increasing operating time such that the initially lower temperature increases and the difference between the two temperatures decreases.

Abstract: A process for heterogeneously catalyzed gas phase partial oxidation of an organic starting compound over a fixed catalyst bed freshly installed into a reaction chamber, in which the reduction in the quality of the fixed catalyst bed is restored with increasing operating time by replacing a portion of the fixed catalyst bed by a replacement fixed catalyst bed part whose volume-specific activity is lower than the volume-specific activity of the replaced fixed catalyst bed part in its freshly installed state.

Abstract: Process for preparing at least one partial oxidation and/or ammoxidation product of propylene, in which the propylene is produced from crude propane by dehydrogenation and is subjected to a heterogeneously catalyzed gas-phase partial oxidation and/or partial gas-phase ammoxidation in the presence of unreacted propane as constituent of a gas mixture 2 containing <1% by volume of 1-butene.

Abstract: The present invention provides a process of producing unsaturated aldehydes and unsaturated acids from olefins by fixed-bed catalytic partial oxidation in a shell-and-tube heat exchanger-type reactor. In this process, the reactor comprises a first-step reaction zone of mainly producing the unsaturated aldehydes, a second-step reaction zone of mainly producing the unsaturated acids, or both the two zones. The first-step reaction zone is divided into two or more zones by a partition. Each of the divided shell spaces is filled with a heat transfer medium, and the heat transfer medium in each shell space is maintained at isothermal temperature or a temperature difference of 0-5° C. The temperatures of the heat transfer media in each of the divided shell spaces are set to increase in the moving direction of reactants. In order to facilitate the removal of heat generation at a location where the partition is placed, a reaction inhibition layer is disposed in the first-step reaction zone.

Abstract: A catalyst for the hydrogenation of C4-dicarboxylic acids and/or their derivatives, preferably maleic anhydride, in the gas phase comprises from 5 to 100% by weight, preferably from 40 to 90% by weight, of copper oxide and from 0 to 95% by weight, preferably from 10 to 60% by weight, of one or more metals or compounds thereof selected from the group consisting of Al, Si, Zn, Pd, La, Ce, the elements of groups III A to VIII A and groups I A and II A as active composition applied in the form of a thin layer to an inert support material.

Abstract: There is provided a process for producing (meth)acrylic acid and (meth)acrylic esters, which can be operated in a continuous and stable manner for a long period of time.

Abstract: In a process for heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, the starting reaction gas mixture is oxidized over a fixed catalyst bed which consists of at least two fixed catalyst bed zones and is accommodated in two successive temperature zones A, B, and the transition from temperature zone A to temperature zone B does not spatially coincide with a transition from one fixed catalyst bed zone to another fixed catalyst bed zone.

Abstract: Process for operating a continuous heterogeneously catalyzed gas phase partial oxidation of at least one organic compound using compressed air as the oxygen source which is filtered before its compression.

Abstract: A method for producing acrylic acid by using an acrylic acid-containing solution of high concentration without azeotropic distillation is provided. This method of producing acrylic acid comprises introducing an acrylic acid-containing gas obtained by catalytic gas phase oxidation reaction into an absorption column and supplying the acrylic acid-containing solution to crystallization step thereby separating the solution into acrylic acid and residual mother liquid, and distilling at least part of the residual mother liquid and circulating the distillate obtained by the distillation to the absorption column.

Abstract: A method for producing acrylic acid from an acrylic acid-containing solution of high concentration without performing azeotropic distillation is provided. This method of producing acrylic acid comprises steps of absorbing acrylic acid-containing gas, distilling the acrylic acid-containing solution without using an azeotropic solvent thereby obtaining crude acrylic acid as a column bottom stream and/or a column side stream, and supplying the crude acrylic acid to a crystallizing step and melt crystallizing the crude acrylic acid thereby obtaining purified acrylic acid.

Abstract: The present invention provides a process for catalytic vapor phase oxidation which prevents runaway reaction or early deterioration of a catalyst, in the production of (meth)acrylic acid or the like from propylene or isobutylene by the catalytic vapor phase oxidation process using a multi-tubular reactor, which can lead to the production thereof constantly in high yield for a long period of time.

Abstract: A chimney tray for a column for thermal treatment of a liquid. The chimney tray includes a total take-off of liquid by a drain connection arranged at an edge of the chimney tray, and having one or more drain channels having a gradient in a direction of the drain connection, and having a gradient in a direction of the one or more drain channels.

Abstract: 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.

Abstract: A multimetal oxide material contains the elements Mo, V and Te and/or Sb and at least one of the elements Nb, Ti, W, Ta and Ce and promoters and has a specific X-ray diffraction pattern. Moreover, such a multimetal oxide material is used as a catalyst for heterogeneously catalyzed gas-phase partial oxidations of hydrocarbons.

Abstract: A continuously operated heterogeneously catalyzed gas-phase partial oxidation of at least one organic compound in an oxidation reactor is operated safely by a process in which an explosion diagram for the feed gas mixture is deposited as the basis of a cut-out mechanism in a computer.

Abstract: An object of the present invention is to provide a method of vapor phase catalytic oxidation which is capable of: efficiently removing heat of reaction; preventing the formation of hot spots; and efficiently providing a desired product. The invention provides a method of vapor phase catalytic oxidation of a substance to be oxidized with a gas containing molecular oxygen by means of a multitubular reactor, wherein the method comprises: performing a reaction of vapor phase catalytic oxidation under such conditions that a heat transfer coefficient of the heat medium is 1,000 W/(m2·K) or higher.

Abstract: The object of the present invention is to provide a process in which, when the unsaturated carboxylic acid is produced, or when the unsaturated aldehyde and/or the unsaturated carboxylic acid are produced by carrying out the catalytic gas phase oxidation reaction by using the fixed-bed multitubular reactor which is packed with the molybdenum-containing catalyst, the reaction can be continued for a long time while a high yield is maintained, regardless of where the hot spot portion occurs and also even if the concentration of the raw gas is high.

Abstract: In an acrylic acid production process which comprises the step of producing acrylic acid by catalytic vapor-phase oxidation of propane, propylene, and/or acrolein; and purifying the acrylic acid produced in the step of producing with distillation in the presence of the polymerization inhibitor for preventing polymerization of the acrylic acid, a viscosity at 20° C. of the bottoms which comprises the polymerization inhibitor, discharged in the step of purifying, is adjusted to 2 Pa·s (2,000 cP) or less and the polymerization inhibitor is extracted using an aqueous medium. According to the method, in an acrylic acid production process, an extraction operation for recovery of the polymerization inhibitor can be continuously conducted in a stable manner.

Abstract: A method for producing polyacrylic acid includes a combined process of an acrylic acid production process and a polyacrylic acid production process. The acrylic acid production process includes the steps of catalytically oxidizing propylene and/or propane in a gaseous phase to generate reaction product, absorbing the reaction product in a solvent, and purifying acrylic acid from an acrylic acid aqueous solution containing the solvent by purification. The polyacrylic acid production process includes the step of utilizing heat medium recovered in the acrylic acid production process to purify polyacrylic acid from the acrylic acid aqueous solution or from acrylic acid.

Abstract: A process for preparing a multimetal oxide material which contains the elements Mo, V and Te and/or Sb and at least one of the elements Nb, Ti, W, Ta and Ce and if desired promoters and has a specific X-ray diffraction pattern, in which process the last process step comprises washing with acidic liquids. In addition, a multimetal oxide material obtainable in such a way is used as a catalyst for heterogeneously catalyzed gas-phase partial oxidations and/or ammoxidation of hydrocarbons.

Abstract: In a process for the preparation of acrylic acid by heterogeneously catalyzed gas-phase oxidation of propene with molecular oxygen in a reaction zone, the catalytically active material is a multimetal oxide which contains the elements Mo, V, Te and/or Sb and has a specific structure.

Abstract: In a process for partially oxidizing propene to acrylic acid in the gas phase under heterogeneous catalysis, a starting reaction gas mixture comprising propene and oxygen and having a specific composition is oxidized in a first reaction stage over a first fixed catalyst bed having a volume-specific activity which is constant or increases in the flow direction and the acrolein-containing product gas mixture of the first reaction stage is subsequently oxidized in a second reaction stage over a second fixed catalyst bed having a volume-specific activity increasing in the flow direction, and the shaped catalyst bodies of both fixed catalyst beds are annular and each have a specific multimetal oxide composition.

Abstract: An oxide catalyst composition for use in producing methacrolein or a mixture of methacrolein and methacrylic acid, wherein the oxide catalyst composition is represented by the formula (Mo+W)l2BiaAbBcFedXeSbfOg, wherein: A is at least one member selected from the group consisting of Y and the elements of the lanthanoid series exclusive of Pm; B is at least one member selected from the group consisting of K, Rb and Cs; X is Co solely, or a mixture of Co and at least one member selected from the group consisting of Mg and Ni; and a, b, c, d, e, f and g are, respectively, the atomic ratios of Bi, A, B, Fe, X, Sb and O, relative to twelve atoms of the total of Mo and W, wherein the atomic ratios (a to f) of the elements and the relationship between the amounts of the elements are chosen so as to satisfy specific requirements.

Abstract: The present invention provides: a production process for a catalyst for synthesis of an unsaturated aldehyde and/or an unsaturated carboxylic acid, which production process is suitable for producing the catalyst with good reproducibility, wherein the catalyst is excellent in activity, selectivity, and physical strength; this catalyst; and a production process for the unsaturated aldehyde and/or the unsaturated carboxylic acid by using this catalyst.

Abstract: In a process for producing a (meth)acrylic acid compound by catalytic vapor phase oxidation, the (meth)acrylic acid compound is produced constantly and efficiently by preventing the change in the composition of the raw material mixed gas, the abnormal temperature increase in the oxidation reactor and the deterioration of the catalytic activity or the useful catalyst life. In the process for producing (meth)acrolein or (meth)acrylic acid by the catalytic vapor phase oxidation reaction of propylene, propane or isobutylene in the oxidation reactor, the temperature of the raw material mixed gas introduced to the oxidation reactor is maintained to be at least the dew point temperature of the raw material mixed gas.

Abstract: A process for the catalytic gas-phase oxidation of propene to acrylic acid, in which the reaction gas starting mixture is oxidized, with a high propene loading, in a first reaction stage, over a first fixed-bed catalyst which is housed in two successive reaction zones A, B, the reaction zone B being kept at a higher temperature than the reaction zone A, and the acrolein-containing product gas mixture of the first reaction stage is then oxidized in a second reaction stage, with a high acrolein loading, over a second fixed-bed catalyst which is housed in two successive reaction zones C, D, the reaction zone D being kept at a higher temperature than the reaction zone C.

Abstract: An orthorhombic phase mixed metal oxide is produced selectively in quantitative yield.

Abstract: Organic compounds are prepared by heterogeneously catalyzed partial gas-phase oxidation of precursor compounds by a process in which a portion of the reaction gas starting mixture is brought from a low initial pressure to a higher final pressure by means of a radial compressor.

Abstract: In a process for preparing acrylic acid, an acrylic acid-containing product gas mixture obtained by catalytic gas phase partial oxidation of a C3 precursor of acrylic acid, after direct cooling with a quench liquid, is fractionally condensed in a separating column provided with internals, rising into itself with sidestream takeoff of crude acrylic acid, and the acrylic acid oligomers which form are dissociated and the resulting dissociation gas is subjected to a countercurrent rectification before it is recycled.

Abstract: A catalyst comprising a mixed metal oxide is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile.

Abstract: Acrylic acid is prepared by heterogeneously catalyzed partial oxidation of propane by a process in which the steam content of the reaction gas starting mixture is reduced in the course of the process.

Abstract: A first and second aspect of the invention relate to a process for producing a (meth)acrylic acid compound and a process for producing a (meth)acrylic ester, respectively. In particular, the second aspect of the invention relates to a process for (meth)acrylic ester production which includes a step in which by-products of a (meth)acrylic ester-yielding reaction are decomposed to recover a (meth)acrylic ester. A third aspect of the invention relates to a method of decomposing by-products of (meth)acrylic ester production in order to recover (meth)acrylic acid, a (meth)acrylic ester, and an alcohol through the decomposition of the by-products of (meth)acrylic ester production. A fourth and fifth aspect of the invention relate to a method of decomposing by-products of (meth)acrylic acid compound production in order to recover (meth)acrylic acid, a (meth)acrylic ester, and an alcohol through the decomposition of by-products of (meth)acrylic acid production and by-products of (meth)acrylic ester production.

Abstract: The invention relates to a process for manufacturing acrylic acid from propane. According to this process, a gas mixture, which is free from molecular oxygen and comprises propane, steam as well as, optionally, an inert gas, is passed over a solid composition of formula (I) Mo1VaTebNbcSidOx  (I) in which: a is between 0.006 and 1, including the end points; b is between 0.006 and 1, including the end points; c is between 0.006 and 1, including the end points; d is between 0 and 3.5, including the end points; and x is the quantity of oxygen bound to the other elements, and depends on their oxidation states, in order to oxidize the propane according to the following redox reaction (1): SOLIDoxidized+PROPANE→SOLIDreduced+ACRYLIC ACID  (1).

Abstract: A method for producing acrylic acid by using an acrylic acid-containing solution of high concentration without azeotropic distillation is provided. This method of producing acrylic acid comprises introducing an acrylic acid-containing gas obtained by catalytic gas phase oxidation reaction into an absorption column and supplying the acrylic acid-containing solution to crystallization step thereby separating the solution into acrylic acid and residual mother liquid, and distilling at least part of the residual mother liquid and circulating the distillate obtained by the distillation to the absorption column.

Abstract: A method for producing acrylic acid by absorbing acrylic acid at a high ratio and obtaining an acrylic acid-containing solution of high concentration is provided. This method comprises a step of circulating part of a discharged gas from an absorption step of acrylic acid to the reactor and discarding the remainder to the out side of system while the gas is cooled before circulation to the reactor. By the method, the acrylic acid-containing solution of high concentration is obtained due to decrease of an acrylic acid loss.

Abstract: A multitube reactor, wherein tubes having smaller tolerance between a nominal size and actual sizes are used as reaction tubes to stably perform a high yield reaction for a long period, a catalyst is filled into the reaction tubes so that the catalyst layer peak temperature portions of the reaction tubes are not overlapped with the connection sites thereof with baffles to effectively prevent hot spots from occurring and stably perform a reaction for a long period without the clogging of the reaction tubes, a heat medium and raw material gas are allowed to flow in the direction of a countercurrent and a specified type of catalyst is filled into the reaction tubes so that activity is increased from the inlet of the raw material gas to the outlet thereof to prevent the autooxidation of products so as to prevent equipment from being damaged due to the reaction, and, at the time of starting, gas with a temperature of 100 to 400° C.

Abstract: A column for the thermal treatment of mixtures which contain one or more polymerizable compounds is proposed, which column has dual-flow trays with openings whose diameter is constant within a dual-flow tray, the dual-flow trays having openings of decreasing diameter with increasing distance from the feed of the mixture to be treated.

Abstract: A method for the production of acrylic acid of high concentration by absorbing acrylic acid with high absorption ratio of acrylic acid is provided. In a method for producing acrylic acid by a procedure comprising a step of catalytic gas phase oxidation reaction and a step of absorbing the acrylic acid-containing gas, while a low boiling substance-containing solution is introduced into the absorption column via a portion different from the top of the column.