Method of prolonged heterogeneous catalysed partial oxidation of propene to acrolein in gaseous phase

Present invention pertains to improvement of the method of producing (met)acrylic acid or (met)acrolein using a multi-pipe reactor with a fixed bed. The reactor has several pipes, with at least one catalyst bed in the direction of the axis of the pipe. A heat carrier can regulate temperature outside the flow of the reaction pipe. In the reaction pipes, there is gas-phase catalytic oxidation of at least one type of oxidisable substance, propylene, propane, isobutylene and (met)acrolein by molecular oxygen or a gas, containing molecular oxygen. At the beginning of the process, the difference between the coolant temperature and the peak temperature of the catalyst is set in the interval 20-80°C, and during the process, peak temperature T(°C) of the catalyst in the direction of the axis of the pipe satisfies equation 1, given below: (equation 1), where L, T₀, X and X₀ stand for length of the reaction pipe, peak temperature of the catalyst in the direction of the axis of the pipe at the beginning of the process, the length up to the position which gives the peak temperature T at the input of the reaction pipe, and the length to the position which gives the peak temperature T₀ at the input of the reaction pipe, respectively.

Present invention pertains to perfection of the method of obtaining at least, one product of partial oxidation and/or ammoxidising of propylene, chosen from a group, comprising propylene oxide, acrolein, acrylic acid and acrylonitrile. The starting material is raw propane. a) At the first stage, raw propane, in the presence and/or absence of oxygen, is subjected to homogenous and/or heterogeneous catalysed dehydrogenation and/or oxydehydrogenation. Gas mixture 1, containing propane and propylene is obtained. b) If necessary, a certain quantity of the other components in gas mixture 1, obtained in the first stage, besides propane and propylene, such as hydrogen and carbon monoxide is separated and/or converted to other compounds, such as water and carbon dioxide. From gas mixture 1, gas mixture 1' is obtained, containing propane and propylene, as well as other compounds, besides oxygen, propane and propylene. c) At the third stage, gas mixture 1 and/or gas mixture 1' as a component, containing molecular oxygen, of gas mixture 2, is subjected to heterogeneous catalysed partial gas-phase oxidation and/or propylene, contained in gas mixture 1 and/or gas mixture 1', undergoes partial gas-phase ammoxidising. Content of butane-1 in gas mixture 2 is ≤1 vol.%. The method increases output of desired products and efficiency of the process.

Method of (meth)acrolein or (meth)acrylic acid production is implemented by of catalytic phase oxidation reaction of propane, propylene, isobutylene or (meth)acrolein with oxygen-containing gas. Non-organic salt is used as heat carrier for reaction temperature adjustment. Pipeline for heat carrier feeding has adjustment valve adjusting heat carrier feed and circulation rate and rotating freedom of rotation axis. Rotation axis adjoins case with capability of sliding against each other. Gasket filling material sealing the case of adjustment valve is based on mica.

Invention relates to method of simultaneous production of acetophenone and α-phenylpropionic aldehide, which are aromatic substances. Method lies in oxidation of α-methylstyrole with air in presence of highly-silicious zeolite catalyst of pentasyl type with molar ratio SiO₂/Al₂O₃=120 in H-form, in amount of 2-6 weight %, at the rate of air supply of 20-40 l/h, reaction temperature of 80-100°C during 3-5 hours. The method allows for obtaining acetophenone with selectivity of 41.6-58.9% and α-phenylpropionic aldehide with selectivity of 37.9-54.7%, with α-methylstyrole conversion of 54.1-73.0 weight %.

Invention concerns improved method of catalytic oxidation in vapour phase which supplies effective removing of reactionary heat, excludes hot spot formation, and supplies effective receipt of base product. Method of catalytic oxidation is disclosed in the vapour phase (a) of propylene, propane or isobutene by the instrumentality of molecular oxygen for receiving (meth)acrolein, and/or oxidation (b) of (meth)acrolein by molecular oxygen for receiving (meth)acryl acid, by the instrumentality of multiple-tubular reactor, contained: cylindrical reactor vessel, outfitted by initial material supply inlet hole and discharge hole for product, variety of reactor coolant pipes, located around the cylindrical reactor vessel and used for insertion the heat carrier into cylindrical reactor vessel or for removing the heat carrier from it, circulator for connection of variety loop pipeline to each other, variety of reaction tube, mounted by the instrumentality of tube reactor lattices, with catalyst. Also multiple-tubular reactor contains: variety of partitions, located lengthways of reaction tubes and used for changing heat carrier direction, inserted into reactor vessel. According to this heat carrier coolant flow is analysed and there are defined zones in reactor which have heat-transfer coefficient of heat carrier less than 1000 W/(m²·K); also reaction of catalytic oxidation is averted in the vapour phase in mentioned zones of reactor and reaction of catalytic oxidation is implemented in the vapour phase in reactor.

Proposed method consists in continuous cleaning of acrolein. Aqueous solution of acrolein free from difficult-to-condense gas is fed to distilling column equipped with at least one evaporator mounted in its base and at least one condenser mounted in its upper part. Mixture mainly containing water is discharged from distilling column base. Mixture mainly containing acrolein and water is discharged from upper part of distilling column. Mixture discharged from upper part of distilling column is cooled in condenser to temperature at which aqueous condensate may be obtained in addition to considerable amount of acrolein-rich gaseous mixture.

Invention relates to an improved method for synthesis of acrolein or acrylic acid or their mixture. Method involves at step (A) propane is subjected for partial heterogenous catalyzed dehydrogenation in gaseous phase to form a gaseous mixture A of product comprising molecular hydrogen, propylene, unconverted propane and components distinct from propane and propene, and then from a gaseous mixture of product from step (A) distinct from propane and propylene at least partial amount of molecular hydrogen is isolated and a mixture obtained after this isolation is used as a gaseous mixture A' at the second step (B) for loading at least into one oxidation reactor and in at least one oxidation reaction propylene is subjected for selective heterogenous catalyzed gas-phase partial oxidation with molecular oxygen to yield as the end product of gaseous mixture B containing acrolein or acrylic acid, or their mixture, and the third (C) wherein in limits of partial oxidation of propylene at step (B) of gaseous mixture B acrolein or acrylic acid or their mixtures as the end product are separated and at least unconverted propane containing in gaseous mixture at step (B) is recovered to the dehydrogenation step (A) wherein in limits of partial oxidation of propylene at step (B) molecular nitrogen is used as additional diluting gas. Method provides significant decreasing of by-side products.

Invention relates to a process of catalytic oxidation in vapor phase, which prevents emergence of non-controllable reaction and premature poisoning of catalyst in (meth)acrylic acid synthesis. Vapor-phase catalytic oxidation process, wherein feed gas is supplied for oxidation to reaction tubes of multi-tubular reactor provided with multiple, disposed in reactor shell, reaction tubes filled with catalyst and multiple deflectors serving to modify direction of heat-carrier stream introduced into reactor shell. Temperature is measured in catalyst, which is placed in a reaction tube and is not connected with at least one deflector, as well as temperature in catalyst, which is placed in a reaction tube and is connected with all deflectors.

Invention relates to a method for synthesis of acrolein and/or acrylic acid from propane and/or propene. Method involves the following steps: (a) isolating propane and/or propene from gaseous mixture A containing propane and/or propene by their absorption with adsorbent; (b) isolating propane and/or propene from adsorbent to form gas B containing propane and/or propene, and (c) using gas B obtained in stage (b) for oxidation of propane and/or propene to acrolein and/or acrylic acid wherein the heterogeneous catalytic dehydrogenation of propane without feeding oxygen is not carried out. Method shows economy and maximal exploitation period of used catalyst without its regeneration.

Claimed method includes feeding of raw gas mixture through pipeline from raw material mixer into oxidation reactor and catalytic oxidation of raw mixture in vapor phase to produce (meth)acrolein or (meth)acrylic acid. Said pipeline is heated and/or maintained in heated state and temperature of gas mixture fed into oxidation reactor is by 5-25⁰C higher then condensation temperature of raw gas mixture.

Present invention pertains to improvement of the method of producing (met)acrylic acid or (met)acrolein using a multi-pipe reactor with a fixed bed. The reactor has several pipes, with at least one catalyst bed in the direction of the axis of the pipe. A heat carrier can regulate temperature outside the flow of the reaction pipe. In the reaction pipes, there is gas-phase catalytic oxidation of at least one type of oxidisable substance, propylene, propane, isobutylene and (met)acrolein by molecular oxygen or a gas, containing molecular oxygen. At the beginning of the process, the difference between the coolant temperature and the peak temperature of the catalyst is set in the interval 20-80°C, and during the process, peak temperature T(°C) of the catalyst in the direction of the axis of the pipe satisfies equation 1, given below: (equation 1), where L, T₀, X and X₀ stand for length of the reaction pipe, peak temperature of the catalyst in the direction of the axis of the pipe at the beginning of the process, the length up to the position which gives the peak temperature T at the input of the reaction pipe, and the length to the position which gives the peak temperature T₀ at the input of the reaction pipe, respectively.

Present invention pertains to perfection of the method of obtaining at least, one product of partial oxidation and/or ammoxidising of propylene, chosen from a group, comprising propylene oxide, acrolein, acrylic acid and acrylonitrile. The starting material is raw propane. a) At the first stage, raw propane, in the presence and/or absence of oxygen, is subjected to homogenous and/or heterogeneous catalysed dehydrogenation and/or oxydehydrogenation. Gas mixture 1, containing propane and propylene is obtained. b) If necessary, a certain quantity of the other components in gas mixture 1, obtained in the first stage, besides propane and propylene, such as hydrogen and carbon monoxide is separated and/or converted to other compounds, such as water and carbon dioxide. From gas mixture 1, gas mixture 1' is obtained, containing propane and propylene, as well as other compounds, besides oxygen, propane and propylene. c) At the third stage, gas mixture 1 and/or gas mixture 1' as a component, containing molecular oxygen, of gas mixture 2, is subjected to heterogeneous catalysed partial gas-phase oxidation and/or propylene, contained in gas mixture 1 and/or gas mixture 1', undergoes partial gas-phase ammoxidising. Content of butane-1 in gas mixture 2 is ≤1 vol.%. The method increases output of desired products and efficiency of the process.

Invention concerns improved method of obtaining at least one product of partial propylene oxidation and/or ammoxidation, propylene selected out of group including propyleneoxide, acrolein, acrylic acid and acrylnitryl, where source substance is propane. Method involves a) at the first stage, homogeneous and/or heterogeneous catalysed dehydration and/or oxydehydration of raw propane in the presence and/or in the absence of oxygen, to obtain gas mix containing propane and propylene; and b) if required, separation of part gas mix 1 obtained at the first stage and its components other than propane and propylene, such as hydrogen, carbon monoxide, or transformation of this part in the other compounds, such as water, carbon dioxide, so that gas mix 1' containing propane and propylene and compounds other than oxygen, propane and propylene is obtained from gas mix 1; and at least one more stage c) heterogeneous catalysed ammoxidation and/or partial gas phase ammoxidation of propylene containing in gas mix 1 and/or gas mix 1' in gas mix 1 or gas mix 1' containing molecular oxygen of gas mix 2, where total C₄-hydrocarbon content in gas mix 2 is < 3 volume %.

Invention concerns improved method of catalytic oxidation in vapour phase which supplies effective removing of reactionary heat, excludes hot spot formation, and supplies effective receipt of base product. Method of catalytic oxidation is disclosed in the vapour phase (a) of propylene, propane or isobutene by the instrumentality of molecular oxygen for receiving (meth)acrolein, and/or oxidation (b) of (meth)acrolein by molecular oxygen for receiving (meth)acryl acid, by the instrumentality of multiple-tubular reactor, contained: cylindrical reactor vessel, outfitted by initial material supply inlet hole and discharge hole for product, variety of reactor coolant pipes, located around the cylindrical reactor vessel and used for insertion the heat carrier into cylindrical reactor vessel or for removing the heat carrier from it, circulator for connection of variety loop pipeline to each other, variety of reaction tube, mounted by the instrumentality of tube reactor lattices, with catalyst. Also multiple-tubular reactor contains: variety of partitions, located lengthways of reaction tubes and used for changing heat carrier direction, inserted into reactor vessel. According to this heat carrier coolant flow is analysed and there are defined zones in reactor which have heat-transfer coefficient of heat carrier less than 1000 W/(m²·K); also reaction of catalytic oxidation is averted in the vapour phase in mentioned zones of reactor and reaction of catalytic oxidation is implemented in the vapour phase in reactor.

Invention relates to an improved method for synthesis of acrolein or acrylic acid or their mixture. Method involves at step (A) propane is subjected for partial heterogenous catalyzed dehydrogenation in gaseous phase to form a gaseous mixture A of product comprising molecular hydrogen, propylene, unconverted propane and components distinct from propane and propene, and then from a gaseous mixture of product from step (A) distinct from propane and propylene at least partial amount of molecular hydrogen is isolated and a mixture obtained after this isolation is used as a gaseous mixture A' at the second step (B) for loading at least into one oxidation reactor and in at least one oxidation reaction propylene is subjected for selective heterogenous catalyzed gas-phase partial oxidation with molecular oxygen to yield as the end product of gaseous mixture B containing acrolein or acrylic acid, or their mixture, and the third (C) wherein in limits of partial oxidation of propylene at step (B) of gaseous mixture B acrolein or acrylic acid or their mixtures as the end product are separated and at least unconverted propane containing in gaseous mixture at step (B) is recovered to the dehydrogenation step (A) wherein in limits of partial oxidation of propylene at step (B) molecular nitrogen is used as additional diluting gas. Method provides significant decreasing of by-side products.

Invention relates to catalytic oxidation of organic substances in vapor phase in reaction tubes of multitube reactor of heat-exchange type with an immobile catalyst layer, and to a method for synthesis of (meth)acrolein or (meth)acrylic acid in these reactors. Method for catalytic oxidation in vapor phase for preparing the reaction product is carried out in multitube reactor with a great number of reaction tubes by feeding the parent gaseous raw and oxygen-containing gas into reaction tubes filled with a solid catalyst. Method involves measurement and regulation of pressure loss in reaction tubes after filing a catalyst by such manner that pressure loss in corresponding tubes will be in limits ±20% of average pressure loss value of reaction tubes. If necessary, inert substance is filled into inlet part of reaction tubes or removal of filled catalyst and repeated filling catalyst for reaction tube showing pressure loss value less an average pressure loss for reaction tube or a reaction tube showing pressure loss value above an average pressure loss value. Method for synthesis of (meth)acrolein or (meth)acrylic acid is carried out in indicated multitube reactor by feeding propane, propylene or isobutylene and molecular oxygen into reaction tubes filled with a catalyst with regulation pressure loss values as said above. For regulation of filling an inert substance is used. Also, method involves prediction of reaction states into reaction tubes by measurement of temperature of catalytic layer of reaction tubes or by imitation analysis of liquid state of a heat-carrier circulating on the outside of reaction tubes with heat of material into reaction tubes. Then method involves assay of conditions in filling catalyst into tubes in correspondence with prognosis results and heterogeneity of reaction states among reaction tubes is removed. Invention provides enhancing yield of the end product and increasing the catalyst life work based on retaining its mechanical strength by prevention its grinding during charge and removal of decomposed catalyst from reaction tubes.

The invention provides, that the multitubular reactor consists of the set of the reaction tubes containing the placed in them catalyst, and the housing supplied with the reaction tubes located inside it, in which the heat-carrier passing in the inter-tubular space is introduced. The reaction tubes are selected from the tubes having the equal nominal outer diameter and the wall thickness. The tolerance of the outer diameter is selected from ±0.62 % and the tolerance of the wall thickness - from ±19 % up to -0 %. The tolerance of the outer diameter - from ±0,56 % and the tolerance of the wall thickness - from ±17 % up to -0 %. The method of the catalytic oxidation in the vapor-phase consists in the usage of the multitubular reactor, circulation of the heat carrier in the reaction tubes inter-tube space and feeding of the source gas into the reaction tubes filled with the catalyst, for production of the gaseous product of the reaction, including the determination of the performance specification on the catalyst packing into the reactionary tubes. The multitubular reactor additionally includes the deflectors connected with the reaction tubes through the positions of the joints, for the change of the directions of the passage of the heat-carrier medium introduced into the housing. It is possible to use the heat-exchange reactor with the immovable layer of the catalytic agent additionally containing the set of the reaction tubes, in the inter-tube space of which the heat carrier is passing. The specification is determined by means of provision in one of the reaction tube of at least two catalytic layers with the different specifications of packaging of the catalyst and the change of the lengths of the reaction zones of the reaction tube for relocation of the places of the maximal temperatures of the catalytic layer along the reaction tube or formation of the layer containing the thinning agent in the reaction tube disposed in the places of the joints for determination of the specification on the catalyst packaging to provide the control of the reaction temperature in the places of joints. The version of realization the method of the catalytic oxidation use oxidation of propylene, propane or isobutylene and-or (metha) acrolein by the catalytic oxidation in the vapor phase with the help of the gas containing the molecular oxygen, for production of the (metha)acrolein and-or the(metha)acrylic acid including the packaging of the Mo-Bi catalyst and-or Sb-Mo catalyst in the reaction tubes so, that activity is increasing from the inlet of the process gas into the reaction tubes up to the outlet of the process gas from the reaction tubes and ensures the possibility for the heat-transfer medium and the process gas to pass through as the counter current. The multitubular reactor used in the method contains: the cylindrical housing, the set of the annular tubes, the circulation device, the set of the reaction tubes limited by the set of the of tube plates of the reactor and containing the catalyst, and the set of the deflectors. According to the method of the start-up of the shell-and-tube reactor having the circulating system of the heat-exchange medium, which is the solid substance at the room temperature, the heating of reaction tubes takes place by introduction of the gas with the temperature from 100 up to 400°С into the inter-tube space of the reaction tubes and circulation of the heated heat carrier. The shell-and-tube reactor has the reaction tubes and the inlet and the outlet for the liquid passing in the inter-tube space of the reaction tubes for withdrawal of the heat formed inside the reaction tubes. Due to the method of the catalytic oxidation the invention ensures prevention of formation of the local overheating and the clogging of the reaction tubes, the increased outlet of the gaseous product of the reaction and the increased service life of the catalyst and also the stable operation of the multi-tube reactor for the long time.

Invention relates to a method for synthesis of acrolein and/or acrylic acid from propane and/or propene. Method involves the following steps: (a) isolating propane and/or propene from gaseous mixture A containing propane and/or propene by their absorption with adsorbent; (b) isolating propane and/or propene from adsorbent to form gas B containing propane and/or propene, and (c) using gas B obtained in stage (b) for oxidation of propane and/or propene to acrolein and/or acrylic acid wherein the heterogeneous catalytic dehydrogenation of propane without feeding oxygen is not carried out. Method shows economy and maximal exploitation period of used catalyst without its regeneration.

Claimed method includes feeding of raw gas mixture through pipeline from raw material mixer into oxidation reactor and catalytic oxidation of raw mixture in vapor phase to produce (meth)acrolein or (meth)acrylic acid. Said pipeline is heated and/or maintained in heated state and temperature of gas mixture fed into oxidation reactor is by 5-25⁰C higher then condensation temperature of raw gas mixture.

Invention relates to the improved method for preparing acrylic acid and selective oxidation of propylene to acrolein. Method involves carrying out reaction of propylene with oxygen in the first zone reaction with the first catalyst corresponding to the following formula: A_aB_bC_cCa_dFe_eBi_fMo₁₂O_x wherein A means Li, Na, K, Rb and Cs and their mixtures also; B means Mg, Sr, Mn, Ni, Co and Zn and their mixtures also; C means Ce, Cr, Al, Sb, P, Ge, Sn, Cu, V and W and their mixtures also wherein a = 0.01-1.0; b and e = 1.0-10; c = 0-5.0 but preferably 0.05-5.0; d and f = 0.05-5.0; x represents a number determined by valence of other presenting elements. Reaction is carried out at enhanced temperature providing preparing acrylic acid and acrolein and the following addition of acrolein from the first reaction zone to the second reaction zone containing the second catalyst used for conversion of acrolein to acrylic acid. Method provides high conversion of propylene to acrylic acid and acrolein.

Invention relates to a process and apparatus for thermal removal of coke from loose mass of granulated selective zeolite catalyst based on pentasil-type crystalline aluminosilicates for production of olefins having 2 and 3 carbon atoms from mixture of olefins having 4-8 carbon atoms or methanol or dimethyl ether. Process is carried out in reactor (1) wherein catalyst is used in the form of loose mass. In preliminary stage, reactor (1) is flushed by heated nitrogen stream at entry temperature 460-500°C in order to replace hydrocarbons out of catalyst. Then, reactor is cooled by heated nitrogen stream at entry temperature from 420 to less than 460°C. In the main stage, nitrogen/air mix slowly heated to entry temperature 460-500°C is passed through reactor and, in additional stage, reactor is flushed by nitrogen stream heated to entry temperature 460-500°C in order to wash out air out of zeolite catalyst. Apparatus for implementation of described process comprises heater (6) designed to heat nitrogen and nitrogen/air streams, in series connected reactor (1), in series connected air cooler (12), and in series connected pressure gun (14).