Abstract: The invention generally relates to the manufacture of acrolein. In particular, the invention generally relates to a process for the continuous production of acrolein via the catalytic oxidation of propylene.

Abstract: A hollow cylindrical shaped catalyst body for gas phase oxidation of an alkene to an ?,?-unsaturated aldehyde and/or an ?,?-unsaturated carboxylic acid comprises a compacted multimetal oxide having an external diameter ED, an internal diameter ID and a height H, wherein ED is in the range from 3.5 to 4.5 mm; the ratio q=ID/ED is in the range from 0.4 to 0.55; and the ratio p=H/ED is in the range from 0.5 to 1. The shaped catalyst body is mechanically stable and catalyzes the partial oxidation of an alkene to the products of value with high selectivity. It provides a sufficiently high catalyst mass density of the catalyst bed and good long-term stability with acceptable pressure drop.

Abstract: There is provided a process for producing a shaped catalyst for a fixed bed oxidation reaction or a fixed bed oxidative dehydrogenation reaction, the catalyst having both of sufficient mechanical strength and catalyst performance, and the catalyst is produced by supporting a catalyst powder containing a complex metal oxide having molybdenum as an essential ingredient on an inert support by a tumbling granulation method at a relative centrifugal force of 1 to 35G.

Abstract: A method for separating and recovering an aromatic aldehyde from a mixture thereof that also contains tar and light and heavy impurities, includes feeding the liquid flow containing this mixture into an evaporator, vaporizing the mixture in order to separate, on the one hand, a gaseous flow containing the aromatic aldehyde, the light impurities, the heavy impurities that can be vaporized at the selected evaporation temperature and pressure and, on the other hand, a liquid flow essentially containing the tar, and recovering the aromatic aldehyde from the separated gaseous flow.

Abstract: A catalyst and a catalyst packing schedule are designed so that a relation between the raw material conversion rate at which the yield of the objective product becomes maximum and the raw material conversion rate at which a high and low correlation between maximum temperature of the catalyst layer present closest to a reaction gas inlet side Zin and maximum temperature of the catalyst layer present closest to a reaction gas outlet side Zout is reversed satisfies a specific condition of 0.5?Cmax?Ccrs?5, in which Cmax: a raw material conversion rate at which yield of the objective products becomes maximum; and Ccrs: a raw material conversion rate at which, when maximum temperature of the catalyst layer Zin is regarded as Tin, maximum temperature of the catalyst layer Zout is regarded as Tout, and the raw material conversion rate is changed, a high and low correlation between Tin and Tout is reversed.

Abstract: This invention provides a method for producing acrolein and/or acrylic acid by catalytic gas-phase oxidation, which method makes it possible to carry out a continuous operation steadily for a long period of time while a high yield is maintained. This method is characterized by comprising filling each of reaction tubes of a fixed-bed multitubular reactor with at least two species of catalysts each of which essentially comprises, as catalytically active components, oxide of molybdenum, oxide of bismuth and oxide of iron and/or composite oxide of at least two of said elements, said at least two species of catalysts being different in the ratio of D1/D2, D1 denoting the proportion of the total pore volume of pores whose pore diameter falls within the range of at least 0.03 ?m and less than 0.3 ?m to the total pore volume of the whole pores, and D2 denoting the proportion of the total pore volume of pores whose pore diameter falls within the range of at least 0.

Abstract: A process for preparation of catalysts for the production of acrylonitrile, acetonitrile and hydrogen cyanide comprising contacting at an elevated temperature, propylene, ammonia and oxygen in the vapor phase in the presence of a catalyst, said catalyst comprising a complex of metal oxides wherein a heat-decomposable nitrogen containing compound is added during the process for the preparation of the catalyst.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d90A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7·(d90A2)1.5·(a)?1?820. A shaped catalyst body obtained by the process. A catalyst obtained by grinding the shaped catalyst body. A process for heterogeneously catalyzing the partial gas phase oxidation of an alkane, alkanol, alkanal and/or an alkenal of 3 to 6 carbon atoms using the catalyst.

Abstract: A process for preparation of catalysts for the production of acrylonitrile, acetonitrile and hydrogen cyanide comprising contacting at an elevated temperature, propylene, ammonia and oxygen in the vapor phase in the presence of a catalyst, said catalyst comprising a complex of metal oxides wherein a heat-decomposable nitrogen containing compound is added during the process for the preparation of the catalyst.

Abstract: A process for preparation of catalysts for the production of acrylonitrile, acetonitrile and hydrogen cyanide comprising contacting at an elevated temperature, propylene, ammonia and oxygen in the vapor phase in the presence of a catalyst, said catalyst comprising a complex of metal oxides wherein a heat-decomposable nitrogen containing compound is added during the process for the preparation of the catalyst.

Abstract: A process for charging a longitudinal section of a catalyst tube with a homogeneous fixed catalyst bed section whose active composition is at least one multielement oxide or comprises elemental silver on an oxidic support body and whose geometric shaped catalyst bodies and shaped inert bodies have a specific inhomogeneity of their longest dimensions.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5hOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d90A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7·(d90A2)1.5·(a)?1?820. A shaped catalyst body obtained by the process. A catalyst obtained by grinding the shaped catalyst body. A process for heterogeneously catalyzing the partial gas phase oxidation of an alkane, alkanol, alkanal and/or an alkenal of 3 to 6 carbon atoms using the catalyst.

Abstract: A process for long-term operation of a heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, in which the propene present in the reaction gas input mixture is partially oxidized as this gas mixture passes through the fixed catalyst bed which is accommodated in two spatially successive temperature zones A, B, and, in long-term operation, as a measure to counteract the reduction in the quality of the fixed catalyst bed, the temperature of at least one of the two temperature zones is increased such that the difference TB?TA becomes increasingly greater, where TB is the temperature of temperature zone B, and TA the temperature of temperature zone A.

Abstract: A catalyst for use in the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid, the catalyst comparing (or, preferably, being composed of) a mixed oxide containing molybdenum, bismuth and iron, which has improved methanical strength, is produced by a method including the steps of (1) drying an aqueous solution or an aqueous slurry containing raw materials of the catalyst and then firstly calcining a dried product in a molecular oxygen-containing gas atmosphere to obtain a calcined product; (2) heating the calcined product obtained in Step (1) in the presence of a reducing material to obtain a reduced product having a mass loss of 0.05 to 6%; and (3) secondly calcining the reduced product obtained in Step (2) in a molecular oxygen-containing gas atmosphere.

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: A process for preparing (meth)acrolein by heterogeneously catalyzed gas phase partial oxidation of a precursor compound, in which the reaction gas mixture which comprises at least 3% by volume of precursor compound is passed through a fresh fixed catalyst bed whose active material is a multielement oxide which comprises the elements Mo, Fe and Bi and at least one of the elements Ni and Co, and the fixed catalyst bed is loaded with at least 40 l (STP)/l·h of precursor compound, and the precursor compound is converted to an extent of at least 90 mol %, wherein, over the first 8000 operating hours, during X=10 to 500 operating hours, the highest temperature of the reaction gas mixture in the fixed catalyst bed is 400 to 450° C. and, during the remaining 8000?X operating hours, is 300 to <400° C., and the loading of the fixed catalyst bed with organic precursor compound, averaged over the time, for the X=10 to 500 operating hours is greater than for the 8000?X operating hours.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide which comprises the element Mo, the elements Bi and/or V and one or more of the elements Co, Ni, Fe, Cu and alkali metals, in which sources of the different elements are used to obtain a finely divided mixture which is coarsened to a powder by press agglomeration, the coarsened powder is used to form, by press agglomeration, shaped bodies V which are separated into undamaged shaped bodies V+ and into damaged shaped bodies V?, the undamaged shaped bodies V+ are converted by thermal treatment to the shaped catalyst bodies K, and the damaged shaped bodies V? are comminuted and recycled into the obtaining of the finely divided mixture.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [BiaZ1bOx]p[BicMo12FedZ2eZ3fZ4gZ5hZ6iOy]1, in which a finely divided oxide BiaZ1bOx and, formed from element sources, a finely divided mixture of stoichiometry BicMo12FedZ2eZ3fZ4gZ5hZ6i are mixed in a ratio of p:1, this mixture is used to form shaped bodies and these are treated thermally, where 0<c?0.8.

Abstract: A catalyst for use in the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid, the catalyst comparing (or, preferably, being composed of) a mixed oxide containing molybdenum, bismuth and iron, which has improved methanical strength, is produced by a method including the steps of (1) drying an aqueous solution or an aqueous slurry containing raw materials of the catalyst and then firstly calcining a dried product in a molecular oxygen-containing gas atmosphere to obtain a calcined product; (2) heating the calcined product obtained in Step (1) in the presence of a reducing material to obtain a reduced product having a mass loss of 0.05 to 6%; and (3) secondly calcining the reduced product obtained in Step (2) in a molecular oxygen-containing gas atmosphere.

Abstract: A method of preparing a catalyst for producing acrolein by oxidation of propylene at high space velocity, said catalyst is a Mo—Bi—Fe—Co based composite metal oxide. Producing unsaturated aldehyde via partial oxidation of lower unsaturated olefin at high space velocity using said catalyst is suitable for process with or without off-gas recirculating. Said catalyst is prepared by co-precipitation, the reaction conditions for using said catalyst to produce unsaturated aldehyde are, the space velocity of unsaturated lower olefin relative to catalyst being 120˜200 h-1(STP), reaction temperature being 300˜420° C. and absolute pressure being 0.1˜0.5 MPa; a single-stage unsaturated lower olefin conversion ratio of greater than 98.0% and carbon oxide yield of less than 3.3% with an overall yield of unsaturated lower aldehyde and acid of greater than 94.0% are obtained. The process to prepare the said catalyst is simple, easy to be repeated, and capable of industrial scale-up.

Abstract: A process for preparing (meth)acrolein by heterogeneously catalyzed gas phase partial oxidation of a precursor compound, in which the reaction gas mixture which comprises at least 3% by volume of precursor compound is passed through a fresh fixed catalyst bed whose active material is a multielement oxide which comprises the elements Mo, Fe and Bi and at least one of the elements Ni and Co, and the fixed catalyst bed is loaded with at least 40 l (STP)/l·h of precursor compound, and the precursor compound is converted to an extent of at least 90 mol %, wherein, over the first 8000 operating hours, during X=10 to 500 operating hours, the highest temperature of the reaction gas mixture in the fixed catalyst bed is 400 to 450° C. and, during the remaining 8000?X operating hours, is 300 to <400° C., and the loading of the fixed catalyst bed with organic precursor compound, averaged over the time, for the X=10 to 500 operating hours is greater than for the 8000?X operating hours.

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: A catalyst composition for use in manufacturing methacrolein by reacting with one of isobutene and t-butanol, the catalyst composition being represented by the formula of: x (Mo12BiaFebCocAdBeOf)/y Z. Mo12BiaFebCocAdBeOf is an oxide compound. Z is a catalyst carrier is one of graphite, boron, silicon, germanium powder, and a mixture thereof. Mo, Bi, Fe, Co, and O are chemical symbols of molybdenum, bismuth, iron, cobalt, and oxygen respectively. A is one of W, V, Ti, Zr, Nb, Ni, and Re. B is one of K, Rb, Cs, Sr, and Ba. The catalyst is adapted to not only enhance the production of methacrolein with high activeness and high selectivity but also effectively control the heat point of the catalyst during the methacrolein manufacturing process to prolong the catalyst life.

Abstract: A catalyst, its method of preparation and its use for producing at least one of methacrolein and methacrylic acid, for example, by subjecting isobutane or isobutylene or a mixture thereof to a vapor phase catalytic oxidation in the presence of air or oxygen. In the case where isobutane alone is subjected to a vapor phase catalytic oxidation in the presence of air or oxygen, the product is at least one of isobutylene, methacrolein and methacrylic acid.

Abstract: An object of the present invention is to provide a molding and a method for producing the same; a catalyst for the production of an unsaturated aldehyde and an unsaturated carboxylic acid, and a method for producing the same; and a catalyst for the production of methacrylic acid, and a method for producing the same. The molding of the present invention shows a shape including a plurality of columnar portions disposed with a predetermined gap; and bridge portions which are provided at both ends in longitudinal directions of two adjacent columnar portions and join adjacent columnar portions each other; and including through holes surrounded by a plurality of columnar portions in the longitudinal directions of the columnar portions, and openings formed on a peripheral surface by a gap between the plurality of adjacent columnar portions.

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 present invention relates to a catalyst system, an oxidation reactor comprising the same, and a method for producing an acrolein and an acrylic acid by using the same. By using the catalyst system according to the present invention, when acrolein and acrylic acid are produced, since heat accumulation in a catalyst layer may be effectively prevented, catalyst deterioration may be prevented, and the catalyst may be stably used for a long period of time. In addition, an acrolein and an acrylic acid may be produced at high selectivity and high yield.

Abstract: Disclosed is a shell-and-tube reactor that may be used for fixed-bed catalytic partial oxidation, the reactor being characterized by including at least one reaction zone of a first-step reaction zone for mainly producing unsaturated aldehydes and a second-step reaction zone for mainly producing unsaturated acids, wherein at least one reaction zone of the above reaction zones comprises two or more catalytic layers; each of the catalytic layers is packed with a formed product of catalyst that is different in pore density and/or pore size in a catalytically active component; and the pore density and/or pore size is controlled in such a manner that specific surface area of the catalytically active component increases from the inlet of the reactor to the outlet of the reactor. A method for producing unsaturated aldehydes and/or unsaturated fatty acids from olefins using the same reactor is also disclosed.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide which comprises the element Mo, the elements Bi and/or V and one or more of the elements Co, Ni, Fe, Cu and alkali metals, in which sources of the different elements are used to obtain a finely divided mixture which is coarsened to a powder by press agglomeration, the coarsened powder is used to form, by press agglomeration, shaped bodies V which are separated into undamaged shaped bodies V+ and into damaged shaped bodies V?, the undamaged shaped bodies V+ are converted by thermal treatment to the shaped catalyst bodies K, and the damaged shaped bodies V? are comminuted and recycled into the obtaining of the finely divided mixture.

Abstract: A fixed bed reactor for gas-phase catalytic oxidation, the fixed bed reactor, comprising a reaction tube filled with a gas-phase oxidation catalyst, wherein a solid acid is placed in an end portion(s) of the reaction tube or between catalyst layers of the catalyst, or mixed in the catalyst; the solid acid is an oxide or a complex oxide containing at least one kind of element selected from the group consisting of aluminum (Al), silicon (Si), titanium (Ti) and zirconium (Zr), and has a shape of sphere, cylindrical column, cylindrical tube, star, ring, tablet or pellet; the catalyst is a complex oxide containing molybdenum (Mo) and bismuth (Bi) or a complex oxide containing molybdenum (Mo) and vanadium (V); and acid strength(H0) of the solid acid meets an inequality: ?5.6?H0?1.5.

Abstract: A process for preparing at least one target product by partial oxidation and/or ammoxidation of propylene, in which the propylene source used is a propane dehydrogenation, the propane used therein being obtained by a rectificative prepurification of crude propane.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [BiaZ1bOx]p[BicMo12FedZ2eZ3fZ4gZ5hZ6iOy]1, in which a finely divided oxide BiaZ1bOx and, formed from element sources, a finely divided mixture of stoichiometry BicMo12FedZ2eZ3fZ4gZ5hZ6i are mixed in a ratio of p:1, this mixture is used to form shaped bodies and these are treated thermally, where 0<c?0.8.

Abstract: A process for producing geometric shaped catalyst bodies K whose active material is a multielement oxide of stoichiometry [Bi1WbOx]a[Mo12Z1cZ2dFeeZ3fZ4gZ5nOy]1, in which a finely divided oxide Bi1WbOx with the particle size d50A1 and, formed from element sources, a finely divided intimate mixture of stoichiometry Mo12Z1cZ2dFeeZ3fZ4gZ5h with the particle size d50A2 are mixed in a ratio of a:1, this mixture is used to form shaped bodies and these are treated thermally, where (d50A1)0.7•(d90A1)1.5•(a)?1?820.

Abstract: A catalyst for use in the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid, the catalyst comparing (or, preferably, being composed of) a mixed oxide containing molybdenum, bismuth and iron, which has improved mechanical strength, is produced by a method including the steps of (1) drying an aqueous solution or an aqueous slurry containing raw materials of the catalyst and then firstly calcining a dried product in a molecular oxygen-containing gas atmosphere to obtain a calcined product; (2) heating the calcined product obtained in Step (1) in the presence of a reducing material to obtain a reduced product having a mass loss of 0.05 to 6%; and (3) secondly calcining the reduced product obtained in Step (2) in a molecular oxygen-containing gas atmosphere.

Abstract: A process for preparing acrolein or acrylic acid or a mixture thereof by heterogeneously catalyzed partial gas oxidation of propylene, in which the starting reaction gas mixture has the following contents: from 6 to 9% by volume of propylene, from 8 to 18% by volume of molecular oxygen, from 6 to 30% by volume of propane and from 32 to 72% by volume of molecular nitrogen.

Abstract: A catalyst composition for use in manufacturing methacrolein by reacting with one of isobutene and t-butanol, the catalyst composition being represented by the formula of: x (Mo12Bi8FebCocAdBeOf)/y Z. Mo12BiaFebCocAdBeOf is an oxide compound. Z is a catalyst carrier is one of graphite, boron, silicon, germanium powder, and a mixture thereof Mo, Bi, Fe, Co, and O are chemical symbols of molybdenum, bismuth, iron, cobalt, and oxygen respectively. A is one of W, V, Ti, Zr, Nb, Ni, and Re. B is one of K, Rb, Cs, Sr, and Ba. The catalyst is adapted to not only enhance the production of methacrolein with high activeness and high selectivity but also effectively control the heat point of the catalyst during the methacrolein manufacturing process to prolong the catalyst life.

Abstract: The invention provides a process which enables, in preparation of acrolein by catalytic gas-phase oxidation of propylene in the presence of molecular oxygen or a molecular oxygen-containing gas or in preparation of acrylic acid by catalytic gas-phase oxidation of acrolein in the presence of molecular oxygen or a molecular oxygen-containing gas, using single kind of atalyst, to suppress occurrence of localized extraordinarily high temperature spots (hot spots) in the catalyst layer and can stably maintain high acrolein or acrylic acid yield for a long time. The process is characterized by use of an oxide catalyst containing molybdenum as an essential component and having relative standard deviation of its particle size in a range of 0.02 to 0.20.

Abstract: A method for producing (meth)acrylic acid or (meth)acrolein, comprising a catalytic gas phase oxidation process for producing (meth)acrylic acid or (meth)acrolein by supplying propylene, propane, or isobutylene and a gas containing molecular oxygen to a reactor which contains a catalyst filled therein, wherein a gas containing molecular oxygen is supplied to the reactor having the catalyst filled therein during shutdown of the catalytic gas phase oxidation process does not lower the reaction activity of the catalyst and the selectivity of target products when re-starting the running after shutdown of the catalytic gas phase oxidation process.

Abstract: A catalyst for production of unsaturated aldehydes, such as methacrolein, by gas phase catalytic oxidation of olefins, such as isobutylene, contains oxides of molybdenum, bismuth, iron, cesium and, optionally, other metals. The catalyst has a certain relative amount ratio of cesium to bismuth, a certain relative amount ratio of iron to bismuth and a certain relative amount ratio of bismuth, iron, cesium and certain other metals to molybdenum and, optionally, tungsten. For a catalyst of the formula: Mo12BiaWbFecCodNieSbfCsgMghZniPjOx wherein a is 0.1 to 1.5, b is 0 to 4, c is 0.2 to 5.0, d is 0 to 9, e is 0 to 9, f is 0 to 2.0, g is from 0.4 to 1.5, h is 0 to 1.5, i is 0 to 2.0, j is 0 to 0.5 and x is determined by the valences of the other components, c:g=3.3-5.0, c:a=2.0-6.0 and (3a+3c+2d+2e+g+2h+2i)/(2×12+2b)=0.95-1.10.

Abstract: A process for regenerating a catalyst consisting of a mixed oxide having molybdenum, bismuth and iron used for preparing an unsaturated aldehyde and/or an unsaturated carboxylic acid by catalytically oxidizing propylene, isobutylene and/or tert.-butanol with molecular oxygen in a gas phase, in which the catalyst is regenerated by thermally treating the deteriorated catalyst in an atmosphere of a gas containing molecular oxygen at a temperature of 200 to 500° C., and then thermally treating the catalyst in the presence of a reducing compound at a temperature of 200 to 500° C.

Abstract: Disclosed is a method for producing unsaturated aldehydes or unsaturated fatty acids from at least one compound selected from the group consisting of propylene, propane, (meth)acrolein, isobutylene, t-butyl alcohol, methyl-t-butyl ether and o-xylene by means of fixed-bed catalytic partial oxidation in a shell-and-tube reactor, characterized in that the reactor includes a reaction zone for producing unsaturated aldehydes as a main product, the reaction zone having an inactive material layer inserted into a position where a hot spot is to be generated in a reaction tube. A fixed-bed shell-and-tube reactor for use in the above method is also disclosed. According to the present invention, at least one layer of inactive material is packed at the point of a hot spot to control the hot spot temperature efficiently, thereby increasing the lifetime of a catalyst and producing unsaturated aldehydes and unsaturated fatty acids with high yield.

Abstract: Acrolein is prepared by a process of heterogeneous catalyzed partial gas phase oxidation, by passing a starting reaction gas mixture which comprises propene, molecular oxygen and at least one inert gas, in which the molecular oxygen to propene (O2:C3H6) mole ratio is ?1, and carbon dioxide and saturated hydrocarbons together in a total amount of at most 15 mol %, at elevated temperature and at an hourly space velocity on the fixed catalyst bed of propene present in the starting reaction gas mixture of ?120 l (STP)/l·h through a fixed catalyst bed whose catalysts are comprised of annular unsupported catalysts whose active component is at least one multimetal oxide of formula I, Mo12WaCobFecBidSieKfOn??(I) wherein a ranges from ?1 to ?3, b ranges from ?3 to ?8, c ranges from ?1 to ?4, d ranges from ?0.5 to ?1.5, e ranges from ?0 to ?10, and f ranges from ?0 to ?0.

Abstract: A process prepares methacrolein from isobutane by subjecting isobutane to a partial catalytic dehydrogenation in the gas phase and using the isobutenic product gas mixture to charge an oxidation zone in which the isobutene is oxidized to methacrolein in the gas phase with heterogeneous catalysis using molecular oxygen accompanied by molecular nitrogen as the oxygen source.

Abstract: An object of the present invention is to provide a catalytic gas phase oxidation reaction in which: even under reaction conditions of a higher gas pressure, a higher concentration of the raw material gas and a larger space velocity of a reaction gas, the thermal accumulation at the hot spot portion can be sufficiently suppressed with ease and at low costs, so that the reaction can be continued for a long time while a high yield is maintained.

Abstract: A process for the long-term operation of a heterogeneously catalyzed gas phase partial oxidation of propene to acrolein, in which the temperature of the fixed catalyst bed is increased over the time and the gas phase partial oxidation is interrupted at least once per calendar year and the gas mixture G consisting of molecular oxygen, inert gas and optionally steam is conducted through the fixed catalyst bed at a temperature of the fixed catalyst bed of from 250 to 550° C.

Abstract: Coated catalysts which are suitable for the gas-phase catalytic oxidation of propene to acrolein are prepared by a process in which rings are used as supports and water is used as a binder.

Abstract: In the process for producing (meth)acrolein or (meth)acrylic acid, which comprises feeding a raw material of the (meth)acrolein or (meth)acrylic acid, and a molecular oxygen-containing gas mixed with a diluting gas and compressed by a compressor, to an oxidation reactor to conduct a catalytic gas-phase oxidation reaction therebetween; feeding the obtained reaction gas to an absorption column to contact with water; recovering an aqueous solution of the (meth)acrolein or (meth)acrylic acid from a bottom of the absorption column and an exhaust gas from a top of the absorption column; and recycling a part or whole of the thus recovered exhaust gas to use as the diluting gas, the temperature of the mixed gas at a suction inlet of the compressor is controlled to a temperature higher than a dew point thereof. According to the process of the present invention, the compressor is prevented from suffering from clogging or damage thereto.

Abstract: In a process for heterogeneously catalyzed partial gas phase oxidation of propene to acrolein, the starting reaction gas mixture is oxidized at a propene loading of <160 l (STP) of propene/l of fixed catalyst bed·h over a fixed catalyst bed which is accommodated in two successive reaction zones A, B, the highest temperature of the reaction gas mixture within reaction zone A being above the temperature of the reaction gas mixture within reaction zone B.

Abstract: A process for preparing (meth)acrolein and/or (meth)acrylic acid by heterogeneously catalyzed gas phase partial oxidation of an organic precursor compound over a fresh fixed catalyst bed, in which the process is started up at a reduced hourly space velocity of charging gas mixture on the fixed catalyst bed.

Abstract: A catalyst useful for catalytic vapor-phase oxidation of isobutylene, t-butanol or propylene to produce respectively corresponding unsaturated aldehyde and unsaturated carboxylic acid is provided. The catalyst consists of ring-formed shaped bodies composed of (i) a catalyst composition containing at least molybdenum and bismuth as the active ingredients and (ii) inorganic fibers. The catalyst excels in mechanical strength, can give the object products at high yield and shows little activity degradation with time.