Method of carrying out heterogenous catalitic partial oxidation in gas phase of acrolein into acrylic acid

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

 

The text descriptions are given in facsimile form.

1. The method of carrying out heterogeneous catalytic partial oxidation in the gas phase of acrolein in acrylic acid, in which the source of the reaction gas mixture containing acrolein, molecular oxygen and at least one inert gas diluent is passed through at a high temperature catalyst fixed bed, the catalyst which is made so that their active mass contains at least one oxide multimetall, which contains the elements Mo and V, and which over time increases the temperature of the fixed catalyst layer, while partial oxidation in the gas phase is interrupted, at least one and when the temperature of the fixed catalyst layer is from 200 to 450°C over him miss free from acrolein containing molecular oxygen, inert gas and, if necessary, water vapor, and, if necessary, CO, gas mixture G oxidizing action, characterized in that at least one interrupt carried out before the improving temperature of the fixed catalyst layer is 2°C, or 4°C or 8°C or 10°C, and long-term temperature increase of 2°C or 4°C or 8°C, or 10°C. there is then, when applying the actual flow temperature of the fixed catalyst layer at a time passes through the measurement point equalization curve developed by Legendre and Gauss's method of least sum of squared errors achieved temperature increase of 2°C or 4°C or 8°C, or 10°C.

2. The method according to claim 1, characterized in that the time during which the gas mixture G is passed through a fixed catalyst layer 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 layer contains at least 2 vol.% the oxygen.

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

5. The method according to claim 1, characterized in that the gas mixture G, which is passed through a fixed catalyst layer contains from 1 to 8% vol. oxygen, from 0 to 3% vol. WITH from 0 to 5% vol. CO2from 0 to 25% vol. H2O and at least 55% vol. N2.

6. The method according to claim 1, characterized in that the active mass of the catalyst is at least one oxide multimetallic General formula I,

in which the variables have the following meanings:
X1= mean W, Nb, TA, Cr and/or CE,
X2= mean of Cu, Ni, Co, Fe, Mn and/or Zn,
X3= means Sb and/or Bi,
X4= means one or more alkali metals,
X5= means one or more alkaline earth metals,
X6= denotes Si, Al, Ti and/or Zr,
a = 1 to 6
b = is equal to 0.2 to 4,
with = equal to 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 of which is determined by the valence and amount of non-oxygen elements in the formula I.

7. The method according to claim 1, characterized in that it is carried out in shell-and-tube reactor.

8. The method according to claim 1, characterized in that the temperature increase fixed catalyst layer during the time carried out in such a way that the content of acrolein in the gas mixture the product does not exceed 1500 weight. mlnc

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

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

11. The method according to claim 1, characterized in that the CO content in the gas mixture G for time tGduring which the gas mixture passed through the catalyst fixed bed, reduce different from 0 on the real values.

12. The method according to one of claims 1 to 11, characterized in that the gas mixture G is >0 to ≤20 weight. mlnc gas containing Mo connection.

13. The method according to one of claims 1 to 11, characterized in that the oxygen content of the gas mixture G for time tGduring which the gas mixture G is passed through a fixed catalyst layer increases from a low initial value to a higher end value.

14. The method according to item 12, characterized in that the oxygen content of the gas mixture G for time tGduring which the gas mixture G is passed through a fixed catalyst layer increases from a low initial value to a higher end value.

15. The method according to one of claims 1 to 11 and 14, characterized in that the temperature increase fixed catalyst layer during the time they spend in such a way that the conversion of acrolein in a single pass of the reaction gas mixture through the fixed catalyst layer is not lower than 94 mol.%.

16. The method according to item 12, characterized in that the temperature increase fixed catalyst layer during the time they spend in such a way that the conversion of acrolein in a single pass of the reaction gas mixture through the fixed catalyst layer is not lower than 94 mol.%.

17. The method according to item 13, wherein policemilitary fixed catalyst layer during the time they spend so that conversion acrolein in a single pass of the reaction gas mixture through the fixed catalyst layer is not lower than 94 mol.%.

18. The method according to one of claims 1 to 11, 14, 16 and 17, characterized in that the starting reaction gas mixture contains from 6 to 15 vol.% acrolein.

19. The method according to item 12, characterized in that the starting reaction gas mixture contains from 6 to 15 vol.% acrolein.

20. The method according to item 13, characterized in that the starting reaction gas mixture contains from 6 to 15 vol.% acrolein.

21. The method according to item 15, characterized in that the starting reaction gas mixture contains from 6 to 15 vol.% acrolein.



 

Same patents:

FIELD: chemistry.

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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.

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FIELD: chemistry.

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7 cl, 1 tbl, 5 ex

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39 cl, 11 ex

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

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30 cl, 3 ex, 1 tbl, 2 dwg

FIELD: chemistry.

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6 cl, 1 ex

FIELD: chemistry.

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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.

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EFFECT: method improvement.

32 cl, 1 tbl, 1 ex, 3 dwg

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