Method for prolonged heterogeneously catalysed partial oxidation of propene to acrylic acid in gaseous phase

FIELD: chemistry.

SUBSTANCE: invention relates to a method for prolonged heterogeneously catalysed partial oxidation of propene to acrylic acid in gaseous phase, in which the initial gaseous reaction mixture 1, containing propene, molecular oxygen and at least one inert gas, where molecular oxygen and propene are in molar ratio O2:C3H6≥1, is first passed through a fixed catalyst bed 1 at high temperature at the first stage of the reaction, where the active mass of the catalysts is at least one multimetal oxide, containing molybdenum and/or tungsten, as well as at least one element from a group consisting of bismuth, tellurium, antimony, tin and copper, so that, conversion of propene in a single passage is ≥93 mol % and associated selectivity of formation of acrolein, as well as formation of acrylic acid by-product together is ≥90 mol %, temperature of the product gaseous mixture 1 leaving the first reaction stage is reduced if necessary through direct and/or indirect cooling, and if necessary, molecular oxygen and/or inert gas is added to the product gaseous mixture 1, and after that, the product gaseous mixture 1, acting as initial reaction mixture 2, which contains acrolein, molecular oxygen and at least one inert gas, where molecular oxygen and acrolein are in molar ratio O2:C3H4O≥0.5, is passed through a second fixed catalyst bed 2 at high temperature at the second reaction stage, where the active mass of the catalysts is at least one multimetal oxide, containing molybdenum and vanadium so that, conversion of acrolein in a single passage is ≥90 mol % and selectivity of the resultant formation of acrylic acid at both stages is ≥80 mol % in terms of converted propene, and temperature of each fixed catalyst bed is increased independently of each other. Partial oxidation in gaseous phase is interrupted at least once and at temperature of fixed catalyst bed 1 ranging from 250 to 550°C and temperature of fixed catalyst bed 2 ranging from 200 to 450°C, gaseous mixture G, which consists of molecular oxygen, inert gas and water vapour if necessary, is first passed through fixed catalyst bed 1, and then, if necessary, through an intermediate cooler and then finally through fixed catalyst bed 2, in which at least a single interruption takes place before temperature of the fixed catalyst bed 2 increases by 8°C or 10°C, wherein prolonged increase of temperature by 8°C or 10°C, is possible when virtual passage of temperature of the fixed catalyst bed in the period of time on the leveling curve running through the measuring point using the Legendre-Gauss method of the least sum of squares of errors, temperature increase of 7°C or 10°C is achieved.

EFFECT: method increases service life of catalyst.

24 cl, 1 ex, 3 dwg

 

The text descriptions are given in facsimile form.

1. How long carrying out heterogeneously catalyzed partial oxidation in the gas phase of propene to acrylic acid, which contains propene, molecular oxygen and at least one inert gas source of the reaction gas mixture is 1, containing molecular oxygen and the propene in a molar ratio of O2:C3H6≥1, first, in the first stage reaction is passed at elevated temperature through the first fixed catalyst layer 1, the catalysts which are designed so that their active mass represents at least one oxide multimetallic containing molybdenum and/or tungsten, and at least one of the elements of the group comprising bismuth, tellurium, antimony, tin and copper, in such a way that the conversion of propene in a single pass is ≥93 mol.% and the associated selectivity of the formation of acrolein and formation of by-product acrylic acid together is ≥90 mol.%, the temperature leaving the first reaction stage product gas mixture 1 through direct and/or indirect cooling, if necessary, reduce to a product gas mixture 1, if necessary, add molecular oxygen and/or inert gas, and then the product gas mixture 1 as containing acrolein, molecular oxygen and at least one inert gas source reaction mixture 2, which contains the molecular oxygen and the acrolein in a molar ratio of About2:C3H4O≥0.5, and the second reaction stage at elevated temperatures miss h is the cut of the second fixed catalyst layer 2, the catalysts which are made so that their active mass represents at least one oxide multimetallic containing the elements molybdenum and vanadium, so that the conversion acrolein in a single pass is ≥90 mol.% and selectivity resultimage at both stages of education acrylic acid, calculated on converted propene is ≥80 mol.% and when in the course of time increases the temperature of each fixed catalyst layer independently from each other, while partial oxidation in the gas phase, at least once interrupted and when the temperature of the fixed catalyst layer 1 from 250 to 550°C and the temperature of the fixed catalyst layer 2 from 200 to 450°C consisting of molecular oxygen, inert gas and, if necessary, water vapor gas mixture G is passed first through the fixed catalyst layer 1, and then, if necessary, through an intermediate cooler and finally through the fixed catalyst layer 2, characterized in that at least one interrupt exercise before increasing the temperature of the fixed catalyst layer 2 is 8 or 10°C, and long-term temperature rise of 8 or 10°C, there is then, when applying the actual flow temperature kata is estomago fixed layer within time passes through the measurement point equalization curve developed by Legendre and Gauss's method of least sum of squared errors achieved by increasing the temperature 8 or 10°C.

2. The method according to claim 1, characterized in that the time during which the gas mixture G is passed through the fixed catalyst layers is from 2 to 120 hours

3. The method according to claim 1, characterized in that the gas mixture G, which is passed through a fixed catalyst layers contains at least 4% vol. the oxygen.

4. The method according to claim 1, characterized in that the active mass of the catalysts of the fixed catalyst layer 1 represents at least one oxide multimetallic General formula I,

in which the variables have the following meanings:
X1= Nickel and/or cobalt,
X2= thallium, an alkali metal and/or alkaline earth metal,
X3= zinc, phosphorus, arsenic, boron, antimony, tin, cerium, lead and/or tungsten,
X4= silicon, aluminum, titanium and/or zirconium,
a=0.5 to 5,
b=0.01 to 5, preferably 2 to 4,
C=0 to 10, preferably 3 to 10,
d=0 to 2, preferably 0.02 to 2,
e=0 to 8, preferably 0 to 5,
f=0 to 10 and
n = indicates the number of which is determined by the valence and amount of non-oxygen elements in the formula I.

5. The method according to claim 1, characterized in that the active mass of the catalysts of the fixed catalyst layer 2 represents at least one oxide multimetallic General formula IV,
br/> in which the variables have the following meanings:
X1=W, Nb, TA, Cr and/or CE,
X2=Cu, Ni, Co, Fe, Mn and/or Zn,
X3=Sb and/or Bi,
X4= one or more alkali metals,
X5= one or more alkaline earth metals,
X6=Si, Al, Ti and/or Zr,
a=1 to 6
b=0.2 to 4,
with=0.5 to 18,
d=0 to 40,
e=0 to 2
f=0 to 4,
g=0 to 40 and
n = indicates the number determined by the valence and amount of non-oxygen elements in the IV.

6. The method according to claim 1, characterized in that the load-propene catalyst fixed layer 1 is ≥90 nl/l·h

7. The method according to claim 1, characterized in that the load-propene catalyst fixed layer 1 is ≥130 nl/l·h

8. The method according to claim 1, characterized in that the content of propene in the reaction of the source gas mixture 1 is from 7 to 15%vol.

9. The method according to claim 1, characterized in that the content of propene in the reaction of the source gas mixture 1 is from 8 to 12%vol.

10. The method according to claim 1, characterized in that the content of acrolein source in the reaction gas mixture 2 is from 6 to 15 vol.%.

11. The method according to one of claims 1 to 10, characterized in that the temperature increase of the catalyst fixed layer 1 during the time carried out in such a way that the content of propene in the product gas mixture 1 in the first reaction stage does not exceed 10000 weight. mlnc

13. The method according to one of claims 1 to 10, characterized in that the temperature increase of the catalyst fixed layer 2 during the time carried out in such a way that the content of acrolein in the product gas mixture of the second reaction stage does not exceed 1500 weight. mlnc

14. The method according to claim 11, characterized in that the temperature increase of the catalyst fixed layer 2 during the time carried out in such a way that the content of acrolein in the product gas mixture of the second reaction stage does not exceed 1500 weight. mlnc

15. The method according to item 12, characterized in that the temperature increase of the catalyst fixed layer 2 to perform such a way that the content of acrolein in the product gas mixture of the second reaction stage does not exceed 1500 weight. mlnc

16. The method according to one of claims 1 to 10, 14 and 15, characterized in that the temperature increase of the catalyst fixed layer 2 during the time carried out in such a way that the conversion of acrolein in a single pass of the reaction gas mixture across the catalyst fixed layer 2 is not reduced below 92 mol.%.

17. The method according to claim 11, characterized in that the temperature increase of the catalyst fixed layer 2 during the time carried out in such a way that the conversion of acrolein in a single pass of the reaction gas mixture through the fixed catalyst layer 2 is not reduced below 92 mol.%.

18. The method according to item 12, characterized in that the temperature increase of the catalyst fixed layer 2 during the time carried out in such a way that the conversion of acrolein in a single pass of the reaction gas mixture through the fixed catalyst layer 2 is not reduced below 92 mol.%.

19. The method according to item 13, wherein increasing the temperature of the fixed catalyst layer 2 to perform such a way that the conversion of acrolein in a single pass of the reaction gas mixture through the fixed catalyst layer 2 is not reduced below 92 mol.%.

20. The method according to one of claims 1 to 10, 14, 15 and 17-19, characterized in that both the reaction stage is carried out in a single shell-and-tube reactor.

21. The method according to claim 11, characterized in that both the reaction stage is carried out in a single shell-and-tube reactor.

22. The method according to item 12, characterized in that both the reaction stage is carried out in a single shell-and-tube reactor.

23. The method according to item 13, wherein both reaction stage is carried out in one couchot the service the reactor.

24. The method according to item 16, characterized in that both the reaction stage is carried out in a single shell-and-tube reactor.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to improvement of the method of producing (meth)acrylic acid or (meth)acrolein through gas-phase catalytic oxidation of at least one oxidisable substance, chosen from propylene, propane, isobutylene and (meth)acrolein, molecular oxygen or a gas, which contains molecular oxygen, using a multitubular reactor, with such a structure that, there are several reaction tubes, with one (or several) catalytic layer (catalytic layers) in the direction of the axis of the tube, and a coolant can flow outside the said reaction tubes so as to regulate temperature of reaction, in which temperature of the said reaction of gas-phase catalytic oxidation is increased by varying temperature of the coolant at the inlet for regulating temperature of the reaction, while (1) temperature of coolant at the inlet for regulating temperature of the reaction is varied by not more than 2°C for each variation as such, and (2) when variation is done continuously, the time interval from the variation operation, directly preceding the present, is not more than 10 minutes, and, in addition, the difference between the maximum value of peak temperature of reaction of the catalyst layer of the reaction tube and temperature of the coolant at the inlet for regulating temperature of reaction is not less than 20°C.

EFFECT: method in which sharp increase of temperature is suppressed even after changing reaction conditions with aim of increasing temperature for improving efficiency, thus preventing catalyst deactivation, and achieving stable output.

3 cl, 5 dwg, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of carrying out heterogenous catalytic partial oxidation in gas phase of acrolein into acrylic acid, during which reaction gas mixture, containing acrolein, molecular oxygen and at least one inert gas-thinner, is passed through having higher temperature catalytic still layer, whose catalysts are made in such way that their active mass contains at least one oxide of multimetal, containing elements Mo and V, and in which during time, temperature of catalytic still layer is increased, partial oxidation in gas phase being interrupted at least once and at temperature of catalytic still layer from 200 to 450°C acrolein-free, containing molecular oxygen, inert gas and, if necessary, water vapour, as well as, if necessary, CO, gas mixture of G oxidative action is passed through it, at least one interruption being performed before increase of catalytic still layer temperature constitutes 2°C or 4°C or 8°C or 10°C during a long period of time, temperature increase constituting 2°C or 4°C or 8°C or 10°C over a long period of time occurring when in plotting factual course of temperature of catalytic still layer during time on laid through measurement points equation curve according to elaborated by Legendre and Gauss method of the least sum of error squares 2°C or 4°C or 8°C or 10°C temperature increase is achieved.

EFFECT: ensuring spread of hot point with time which is less than in previous methods.

21 cl, 3 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing (met)acrolein and/or (met)acrylic acid through heterogeneous catalytic partial oxidation in gaseous phase, in which a fresh fixed-bed catalyst at 100-600°C in a reactor is loaded with a mixture of loading gas, which along with at least, one C3/C4 organic precursor compound subject to partial oxidation and oxidation with molecular oxygen, contains at least one gas-diluent. The process is carried out after establishing content of the mixture of loading gas at constant conversion of organic precursor compound and at constant content of the mixture of loading gas initially in the input period for 3-10 days with load of 40-80% of higher final load, and then at higher filling load of the catalyst with a mixture of loading gas. In the input period, maximum deviation of conversion of organic precursor compound from arithmetic time-averaged and maximum deviation of the volume ratio of one component of the mixture loading gas, oxidising agent, organic precursor compound and gas-diluent, from the arithmetic time-averaged volume ratio of the corresponding component of the mixture of loading gas should not exceed ±10% of the corresponding arithmetic mean value.

EFFECT: method allows for eliminating shortcomings of previous technical level.

3 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention concerns aggregate for (met)acrylic acid obtainment, including: reactor for (met)acrylic acid obtainment by catalytic gas phase oxidation reaction of one, two or more source compounds including propane, propylene, isobutylene and (met)acrolein, in gas mix of source substances including one, two or more source compounds including propane, propylene, isobutylene and (met)acrolein, and oxygen; heat exchanger connected to reactor and intended for cooling of reaction gas mix including obtained (met)acrylic acid; and absorption column connected to heat exchanger and intended for contact absorbing fluid with reaction gas mix for (met)acrylic acid absorption, so that (met)acrylic acid is absorbed from reaction gas mix by absorbing fluid. Additionally the aggregate includes: bypass pipe connecting reactor and absorption column without the use of intermediary heat exchanger; and device for flow rate adjustment in reaction gas flow passing through bypass pipe in order to maintain almost constant flow rate of gas mix feed of source materials to reactor or almost constant pressure of gas mix of source materials at the reactor inlet. Also invention concerns improved method of (met)acrylic acid obtainment by extraction of (met)acrylic acid absorbed by absorbing fluid.

EFFECT: heat power tapping from reaction gas mix, stable and continuous process even in case of heat exchanger intended for heat power extraction is blocked.

2 cl, 3 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: 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.

EFFECT: method allows for stable output of the target product, with high output for a long period of time, without reduction of catalyst activity.

3 dwg, 2 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: 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: AaBbCcCadFeeBifMo12Ox 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.

EFFECT: improved preparing method.

7 cl, 1 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of carrying out heterogenous catalytic partial oxidation in gas phase of acrolein into acrylic acid, during which reaction gas mixture, containing acrolein, molecular oxygen and at least one inert gas-thinner, is passed through having higher temperature catalytic still layer, whose catalysts are made in such way that their active mass contains at least one oxide of multimetal, containing elements Mo and V, and in which during time, temperature of catalytic still layer is increased, partial oxidation in gas phase being interrupted at least once and at temperature of catalytic still layer from 200 to 450°C acrolein-free, containing molecular oxygen, inert gas and, if necessary, water vapour, as well as, if necessary, CO, gas mixture of G oxidative action is passed through it, at least one interruption being performed before increase of catalytic still layer temperature constitutes 2°C or 4°C or 8°C or 10°C during a long period of time, temperature increase constituting 2°C or 4°C or 8°C or 10°C over a long period of time occurring when in plotting factual course of temperature of catalytic still layer during time on laid through measurement points equation curve according to elaborated by Legendre and Gauss method of the least sum of error squares 2°C or 4°C or 8°C or 10°C temperature increase is achieved.

EFFECT: ensuring spread of hot point with time which is less than in previous methods.

21 cl, 3 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: 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.

EFFECT: high-precision temperature adjustment ensuring stable process of gas phase catalytic oxidation.

5 cl, 5 dwg, 2 ex

FIELD: organic chemistry, chemical technology.

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EFFECT: improved method of synthesis.

39 cl, 11 ex

FIELD: industrial production of methacrylic acids at reduced amount of industrial wastes.

SUBSTANCE: proposed method is performed by catalytic oxidation of propane, propylene or isobutylene in vapor phase at separation of final product and forming of high-boiling mixture as by-product which contains (according to Michaels addition) water, alcohol or methacrylic acid added to methacrylic group. By-product is decomposed in thermal decomposition reactor at simultaneous distillation of decomposition products in distilling column from which methacrylic acid is taken in form of distillate. Flow of liquid decomposition residue is forced for peripheral direction by means of mixing blades before withdrawal from reactor. Peripheral direction is obtained with the aid of liquid fed from the outside of decomposition reactor; to this end use is made of initial high-boiling material or flow of liquid discharged from decomposition reactor. If necessary, etherification stage is performed through interaction with alcohol for obtaining methecrylic ester. Decomposition of by-product formed at obtaining methacrylic acid by oxidation of propylene or isobutylene or at obtaining methacrylic acid by interaction of acid with alcohol by alcohol through introduction of by-product into thermal decomposition reactor provided with distilling column which has plates made in form of disks and toroids for simultaneous decomposition and distillation. Plant proposed for realization of this method includes thermal decomposition reactor and distilling column, level meters and lines for discharge of liquid containing easily polymerized compounds. Level indicator mounted at area of accumulation of liquid shows pressure differential. Line for detecting the side of high pressure of this level meter is connected with accumulated liquid discharge line.

EFFECT: updated technology; increased yield of target products.

38 cl, 14 dwg, 2 tbl, ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: 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.

EFFECT: improved method of synthesis.

12 cl, 7 dwg, 1 ex

The invention relates to an improved method for the removal of formaldehyde or its adducts of organic liquid mixtures obtained in the production of methyl methacrylate containing at least a carboxylic acid or an ester of carboxylic acid and formaldehyde or its adducts, which forms a two-phase mixture of water, comprising at least one extraction liquid organic mixture in the system liquid-liquid using water as the extractant with getting the flow of the organic phase and flow of the aqueous phase, and the flow of the organic phase contains significantly reduced the concentration of formaldehyde or its adducts compared with the liquid organic mixture

The invention relates to an improved process for the preparation of methyl methacrylate, comprising the stages of (i) interaction propionic acid or its ester with formaldehyde or its predecessor in the condensation reaction with the formation of the stream of gaseous products containing methyl methacrylate, residual reactants, methanol and by-products, (ii) processing at least one portion of the stream of gaseous products with the formation of a stream of liquid products containing almost all of the methyl methacrylate and at least one impurity, which melts at a temperature above the melting temperature of pure methyl methacrylate, run over the flow of the liquid product at least one operation fractional crystallization, which contains the stage (iii) cooling the specified flow of liquid product to a temperature between about -45oAnd about -95oSo that the flow of liquid product forms solid crystals of methyl methacrylate and uterine fluid, and these crystals have a higher content of methyl methacrylate than the specified stream of liquid products or uterine fluid, (iv) the separation of these crystals of solid methyl methacrylate from the specified match Azania impurity in a lower concentration, than the specified stream of liquid products

The invention relates to the production of Ethylenediamine acids or their esters

The invention relates to a method for producing high-purity acrylic acid (options) with a residual content of aldehydes less than 10 parts/million

FIELD: chemistry.

SUBSTANCE: invention relates to a thermal separation method using fractional condensation of a product-gas mixture, obtained through heterogeneous catalysed partial oxidation of propene and/or propane in gaseous phase to acrylic acid, for separating at least one mass flow, concentrated with acrylic acid, from a product-gas mixture containing acrylic acid, which involves continuous static operation of at least one device for thermal separation, containing at least one effective separation chamber with a fractionation column which has mass-transfer trays as built-in separating elements, in which the product-gas mixture is loaded, containing acrylic acid as at least one mass flow, and from which at least one mass flow containing acrylic acid is unloaded under the condition that, the overall mass flow loaded into the effective separation chamber and obtained from combining separate mass flows loaded into the separating chamber, contains X wt % components distinct from acrylic acid, the mass flow which is unloaded from the effective separation chamber with the largest content of acrylic acid, contains Y wt % components distinct from acrylic acid, ratio X:Y is ≥5, effective separation chamber, except the loading and unloading place, is bordered by a solid phase and contains, besides the mass-exchange trays as built-in separating elements in the fractionation column, at least one circulating heat exchanger, and total volume of the chamber, filled with liquid phase, is ≥1 m3, wherein temperature of the liquid phase is at least partially ≥80°C, when the effective separation chamber is divided into n separate volume elements, wherein the highest and lowest temperature of liquid phase in a separate volume element differ by not more than 2°C, and the volume element in the effective separation chamber is solid, total dwell time ttotal.

≤20 h, where A = (Ti-To)/10°C, To= 100°C, Ti = arithmetic mean value of the highest and lowest temperature of the ith volume element in the liquid phase in °C, msi = total mass of acrylic acid in the volume of the liquid phase of the ith volume element, mi = total liquid phase mass unloaded from the ith volume element, and is the sum of all volume elements i, under the condition that, volume elements i with liquid phase mass mi and as volume elements with a dead zone are also not included in the sum of all volume elements i, as well as volume elements i, which do not contain liquid phase, and total amount of liquid phase contained in volume elements with a dead zone is not more than 5 wt % of the total amount of liquid phase contained in the effective separation chamber.

EFFECT: separation of mass flow concentrated with acrylic acid.

10 cl, 12 dwg, 2 ex, 2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to improvement of the method of producing (meth)acrylic acid or (meth)acrolein through gas-phase catalytic oxidation of at least one oxidisable substance, chosen from propylene, propane, isobutylene and (meth)acrolein, molecular oxygen or a gas, which contains molecular oxygen, using a multitubular reactor, with such a structure that, there are several reaction tubes, with one (or several) catalytic layer (catalytic layers) in the direction of the axis of the tube, and a coolant can flow outside the said reaction tubes so as to regulate temperature of reaction, in which temperature of the said reaction of gas-phase catalytic oxidation is increased by varying temperature of the coolant at the inlet for regulating temperature of the reaction, while (1) temperature of coolant at the inlet for regulating temperature of the reaction is varied by not more than 2°C for each variation as such, and (2) when variation is done continuously, the time interval from the variation operation, directly preceding the present, is not more than 10 minutes, and, in addition, the difference between the maximum value of peak temperature of reaction of the catalyst layer of the reaction tube and temperature of the coolant at the inlet for regulating temperature of reaction is not less than 20°C.

EFFECT: method in which sharp increase of temperature is suppressed even after changing reaction conditions with aim of increasing temperature for improving efficiency, thus preventing catalyst deactivation, and achieving stable output.

3 cl, 5 dwg, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of carrying out heterogenous catalytic partial oxidation in gas phase of acrolein into acrylic acid, during which reaction gas mixture, containing acrolein, molecular oxygen and at least one inert gas-thinner, is passed through having higher temperature catalytic still layer, whose catalysts are made in such way that their active mass contains at least one oxide of multimetal, containing elements Mo and V, and in which during time, temperature of catalytic still layer is increased, partial oxidation in gas phase being interrupted at least once and at temperature of catalytic still layer from 200 to 450°C acrolein-free, containing molecular oxygen, inert gas and, if necessary, water vapour, as well as, if necessary, CO, gas mixture of G oxidative action is passed through it, at least one interruption being performed before increase of catalytic still layer temperature constitutes 2°C or 4°C or 8°C or 10°C during a long period of time, temperature increase constituting 2°C or 4°C or 8°C or 10°C over a long period of time occurring when in plotting factual course of temperature of catalytic still layer during time on laid through measurement points equation curve according to elaborated by Legendre and Gauss method of the least sum of error squares 2°C or 4°C or 8°C or 10°C temperature increase is achieved.

EFFECT: ensuring spread of hot point with time which is less than in previous methods.

21 cl, 3 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention refers to the catalyst composition; to the method of its preparation and to the method of ethane and/or ethylene selective oxidation to acetic acid. The catalyst composition for ethane and/or ethylene selective oxidation to acetic acid on the carrier includes the following elements: molybdenum, vanadium, niobium and titanium in combination with oxygen corresponding to the empiric formula MoaTicVdNbeOx, where a, c, d, e are such gram-atomic element ratio whereat 0<a≤1; 0.05<c≤2; 0<d≤2; 0<e≤1 and x is element valency in the said composition. The described above catalyst composition includes the following stages: (a) preparation of the mixture containing molybdenum, vanadium, niobium and titanium in the solution; (b) drying of the obtained solid material and (c) calcination of the dried solid material with obtaining of the catalyst composition. The method of acetic acid selective preparation from the gaseous mixture containing ethane and/or ethylene includes contacting of the gaseous mixture with oxygen-containing gas at increased temperature in the presence of the described above catalyst composition.

EFFECT: increase of catalyst composition selectivity in relation to acetic acid.

22 cl, 3 tbl, 5 ex

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