Method for producing unsaturated aldehyde and/or unsaturated carboxylic acid

Abstract

Provided is a method of subjecting an alkene to partial oxidation by using a fixed bed multitubular reactor, thereby producing an unsaturated aldehyde and/or an unsaturated carboxylic acid each corresponding to the alkene, wherein a plurality of catalyst layers formed by N division (N is N2) with respect to a gas flow direction of a reaction tube are provided, and when a change ( C.) of hot spot temperature per 1 C. change of reaction bath temperature in the catalyst layer is designated as Sn, at least one of the plurality of catalyst layers is regulated to Sn6.

Claims

1. A method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid, which is a method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid each corresponding to an alkene by partially oxidizing the alkene using a fixed bed multitubular reactor, wherein a plurality of catalyst layers formed by N division (N is N3) with respect to a gas flow direction of a reaction tube are provided, and when a change ( C.) of hot spot temperature per 1 C. change of reaction bath temperature in the catalyst layer at the time of 300 hours elapsed after a start of the reaction and varying the reaction bath temperature is designated as Sn, at least one of the plurality of catalyst layers is regulated to Sn6, in which the hot spot means a maximum value of the temperatures within the catalyst layers, and is a hot spot within the catalyst layer arranged nearest to a raw material gas inlet side or in the case where no maximum value of the temperatures is present in the catalyst layer arranged nearest to the raw material gas inlet side, a maximum value of the temperatures as a hot spot within the next or subsequent catalyst layer to the catalyst layer arranged nearest to the raw material gas inlet side, and the reaction bath temperature for determining Sn is set within a range where an alkene conversion is 90% to 99.9%.

2. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 1, wherein at least one of the plurality of catalyst layers is regulated to Sn3.

3. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 1, wherein a concentration of the alkene in a raw material is 7 to 12% by volume.

4. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 1, wherein all of the catalyst layers contain a complex metal oxide having a formulation represented by the following formula (1):
Mo.sub.12Bi.sub.aFe.sub.bCo.sub.cNi.sub.dX.sub.eY.sub.fZ.sub.gO.sub.hFormula (1) X is at least one element selected from the group consisting of magnesium (Mg), calcium (Ca), manganese (Mn), copper (Cu), zinc (Zn), cerium (Ce) and samarium (Sm); Y is at least one element selected from the group consisting of boron (B), phosphorus (P), arsenic (As), antimony (Sb) and tungsten (W); Z is at least one element selected from the group consisting of sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs); a to g represent atomic ratios of the respective components; h is a numerical value determined by degrees of oxidations of the catalyst components; a=0.80 to 2.0, b=1 to 3; c=3 to 7; d=2 to 4; e=0 to 10; f=0 to 10; g=0.01 to 0.10; h is expressed by the numerical value satisfying the oxidation states of other elements; d/a is 1.9 or more and 3.2 or less; d/g is 29 or more and 69 or less; and a/g is 18 or more and 39 or less.

5. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 4, wherein b=1 to 2.5, d=2 to 3.5, and a/g is 18 or more and 35 or less.

6. A method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid, which is a method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid each corresponding to an alkene by partially oxidizing the alkene using a fixed bed multitubular reactor, wherein a plurality of catalyst layers formed by N division (N is N=3) with respect to a gas flow direction of a reaction tube are provided, and when a change ( C.) of hot spot temperature per 1 C. change of reaction bath temperature in the catalyst layer at the time of 300 hours elapsed after a start of the reaction and varying the reaction bath temperature is designated as Sn, at least one of the plurality of catalyst layers is regulated to Sn6, in which the hot spot means a maximum value of the temperatures within the catalyst layers, and is a hot spot within the catalyst layer arranged nearest to a raw material gas inlet side or in the case where no maximum value of the temperatures is present in the catalyst layer arranged nearest to the raw material gas inlet side, a maximum value of the temperature as a hot spot within the next catalyst layer to the catalyst layer arranged nearest to the raw material gas inlet side, and the reaction bath temperature for determining Sn is set within a range where an alkene conversion is 90% to 99.9%.

7. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 6, wherein at least one of the plurality of catalyst layers is regulated to Sn3.

8. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 6, wherein a concentration of the alkene in a raw material is 7 to 12% by volume.

9. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 6, wherein all of the catalyst layers contain a complex metal oxide having a formulation represented by the following formula (1):
Mo.sub.12Bi.sub.aFe.sub.bCo.sub.cNi.sub.dX.sub.eY.sub.fZ.sub.gO.sub.hFormula (1) X is at least one element selected from the group consisting of magnesium (Mg), calcium (Ca), manganese (Mn), copper (Cu), zinc (Zn), cerium (Ce) and samarium (Sm); Y is at least one element selected from the group consisting of boron (B), phosphorus (P), arsenic (As), antimony (Sb) and tungsten (W); Z is at least one element selected from the group consisting of sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs); a to g represent atomic ratios of the respective components; h is a numerical value determined by degrees of oxidations of the catalyst components; a=0.80 to 2.0, b=1 to 3; c=3 to 7; d=2 to 4; e=0 to 10; f=0 to 10; g=0.01 to 0.10; h is expressed by the numerical value satisfying the oxidation states of other elements; d/a is 1.9 or more and 3.2 or less; d/g is 29 or more and 69 or less; and a/g is 18 or more and 39 or less.

10. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 9, wherein b=1 to 2.5, d=2 to 3.5, and a/g is 18 or more and 35 or less.

11. A method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid, which is a method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid each corresponding to an alkene by partially oxidizing the alkene using a fixed bed multitubular reactor, wherein a plurality of catalyst layers formed by N division (N is N=2) with respect to a gas flow direction of a reaction tube are provided, and when a change ( C.) of hot spot temperature per 1 C. change of reaction bath temperature in the catalyst layer at the time of 300 hours elapsed after a start of the reaction and varying the reaction bath temperature is designated as Sn, at least one of the plurality of catalyst layers is regulated to Sn6, in which the hot spot means a maximum value of the temperatures within the catalyst layers, and is a hot spot within the catalyst layer arranged nearest to a raw material gas inlet side, and the reaction bath temperature for determining Sn is set within a range where an alkene conversion is 90% to 99.9%.

12. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 11, wherein at least one of the plurality of catalyst layers is regulated to Sn3.

13. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 11, wherein a concentration of the alkene in a raw material is 7 to 12% by volume.

14. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 11, wherein all of the catalyst layers contain a complex metal oxide having a formulation represented by the following formula (1):
Mo.sub.12Bi.sub.aFe.sub.bCo.sub.cNi.sub.dX.sub.eY.sub.fZ.sub.gO.sub.hFormula (1) X is at least one element selected from the group consisting of magnesium (Mg), calcium (Ca), manganese (Mn), copper (Cu), zinc (Zn), cerium (Ce) and samarium (Sm); Y is at least one element selected from the group consisting of boron (B), phosphorus (P), arsenic (As), antimony (Sb) and tungsten (W); Z is at least one element selected from the group consisting of sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs); a to g represent atomic ratios of the respective components; h is a numerical value determined by degrees of oxidations of the catalyst components; a=0.80 to 2.0, b=1 to 3; c=3 to 7; d=2 to 4; e=0 to 10; f=0 to 10; g=0.01 to 0.10; h is expressed by the numerical value satisfying the oxidation states of other elements; d/a is 1.9 or more and 3.2 or less; d/g is 29 or more and 69 or less; and a/g is 18 or more and 39 or less.

15. The method for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid according to claim 14, wherein b=1 to 2.5, d=2 to 3.5, and a/g is 18 or more and 35 or less.

Description

EXAMPLES

(1) Examples are hereunder described by reference to specific examples, but it should be construed that the present invention is not limited to these Examples so long as the gist of the present invention is not deviated.

(2) It is to be noted that in the following, definitions of acrolein yield, acrylic acid yield, and effective yield are as follows.

(3) $\mathrm{Acrolein}\mathrm{yield}\left(\mathrm{mol}\%\right)=\{\left(\mathrm{Molar}\mathrm{number}\mathrm{of}\mathrm{produced}\mathrm{acrolein}\right)\text{/}\left(\mathrm{Molar}\mathrm{number}\mathrm{of}\mathrm{fed}\mathrm{propylene}\right)\}100\mathrm{Acrylic}\mathrm{acid}\mathrm{yield}\left(\mathrm{mol}\%\right)=\left\{\left(\mathrm{Molar}\mathrm{number}\mathrm{of}\mathrm{produced}\mathrm{acrylic}\mathrm{acid}\right)\text{/}\left(\mathrm{Molar}n\mathrm{umber}\mathrm{of}\mathrm{fed}\mathrm{propylene}\right)\right\}100\mathrm{Effective}\mathrm{yield}\left(\mathrm{mol}\%\right)=\left(\mathrm{Acrolein}\mathrm{yield}\right)+\left(\mathrm{Acrylic}\mathrm{acid}\mathrm{yield}\right)$

(4) Sn as referred to in the present invention refers to a change rate of the hot spot temperature of the catalyst layer relative to the reaction bath. In particular, as for the definition thereof, Sn refers to a change ( C.) of the hot spot temperature of the catalyst relative to the 1 C. change of the reaction bath temperature. This index may also be taken as sensitivity of the hot spot temperature relative to the change of the reaction bath temperature. Thus, the present inventors call this index as the temperature sensitivity, and this can be used as an index for stability of the catalyst in operating the industrial plant using this catalyst.

(5) As described above, Sn can be determined from the hot spot temperatures in the reaction bath temperature at two or more spots selected from arbitrary reaction bath temperatures. The reaction bath temperature for determining Sn is generally 250 C. or higher and 400 C. or lower, preferably 270 C. or higher and 380 C. or lower, and more preferably 290 C. or higher and 360 C. or lower. As a matter of course, these reaction bath temperatures should be a reaction bath temperature at which a suitable conversion of the raw material alkene is attained in the production of an unsaturated aldehyde and/or an unsaturated carboxylic acid. In the case where the raw material is propylene, the reaction bath temperature for determining Sn is set within the range where the propylene conversion is 90% to 99.9%.

(6) As for the reaction bath temperature needed on the occasion of determining Sn, it is preferred to an actual temperature but not a set value. Similarly, an actual value is used for the hot spot temperature, too. In the measurement of the hot spot temperature, a thermocouple is placed in the gas flow direction within a reaction tube, the temperature is measured at intervals of about 5 cm to 10 cm, and a maximum temperature obtained within the catalyst layer is defined as the hot spot temperature. It is preferred that the interval of the temperature measurement is smaller. If the interval is larger than 10 cm, there may be the case where accurate data are not obtained, and hence, such is not preferred.

(7) Production Method 1

(8) (Preparation of Catalyst)

(9) 423.7 parts by weight of ammonium molybdate and 0.73 parts by weight of potassium nitrate were dissolved in 3,000 parts by weight of distilled water while heating and stirring, thereby obtaining an aqueous solution (A1). Separately, 378.4 parts by weight of cobalt nitrate, 139.6 parts by weight of nickel nitrate, and 161.6 parts by weight of ferric nitrate were dissolved in 1,000 parts by weight of distilled water, thereby preparing an aqueous solution (B1); and 97.1 parts by weight of bismuth nitrate was dissolved in 200 parts by weight of distilled water which had been made acidic by the addition of 81 parts by weight of concentrated nitric acid, thereby preparing an aqueous solution (C1). The above-described aqueous solution (A1) was mixed successively with (B1) and (C1) while vigorously stirring, and the produced liquid suspension was dried by using a spray dryer and preliminarily calcined at 440 C. for 6 hours, thereby obtaining a preliminarily calcined powder (D2). At that time, a formulation ratio of the catalytically active component exclusive of oxygen was Mo=12, Bi=1.0, Ni=3.0, Fe=2.0, Co=6.5, and K=0.05 in terms of an atomic ratio.

(10) Thereafter, a powder of 100 parts by weight of the preliminarily calcined powder having 5 parts by weight of crystalline cellulose mixed therewith was added to an inert carrier (spherical substance containing alumina and silica as main components and having a diameter of 4.5 mm), and the carrier weight and the preliminarily calcined powder weight to be used for shaping were adjusted in a proportion such that the supporting rate defined according to the foregoing formula (2) accounted for 50% by weight. The mixture was supported and shaped in a spherical form having a diameter of 5.2 mm by using a 20% by weight glycerin solution as a binder, thereby obtaining a supported catalyst (E2). This supported catalyst (E2) was calcined in an air atmosphere at a calcination temperature of 530 C. for 4 hours, thereby obtaining a catalyst (F2). Similarly, the supported catalyst (E2) was calcined at a calcination temperature of 520 C. for 4 hours, thereby obtaining a catalyst (F3).

(11) Similarly, a preliminarily calcined powder (D1) was obtained by using cesium nitrate in place of the potassium nitrate. A formulation ratio of the catalytically active component exclusive of oxygen of the resulting preliminarily calcined powder (D1) was Mo=12, Bi=1.0, Ni=3.0, Fe=2.0, Co=6.5, and Cs=0.03 in terms of an atomic ratio. This preliminarily calcined powder (D1) was supported and shaped in the same manner as that described above, thereby obtaining a supported catalyst (E1). This supported catalyst (E1) was calcined in an air atmosphere at a calcination temperature of 530 C. for 4 hours, thereby obtaining a catalyst (F1).

Comparative Production Example 1

(12) 423.7 parts by weight of ammonium molybdate and 1.64 parts by weight of potassium nitrate were dissolved in 3,000 parts by weight of distilled water while heating and stirring, thereby obtaining an aqueous solution (A2). Separately, 302.7 parts by weight of cobalt nitrate, 162.9 parts by weight of nickel nitrate, and 145.5 parts by weight of ferric nitrate were dissolved in 1,000 parts by weight of distilled water, thereby preparing an aqueous solution (B2); and 164.9 parts by weight of bismuth nitrate was dissolved in 200 parts by weight of distilled water which had been made acidic by the addition of 42 parts by weight of concentrated nitric acid, thereby preparing an aqueous solution (C2). The above-described aqueous solution (A2) was mixed successively with (B2) and (C2) while vigorously stirring, and the produced liquid suspension was dried by using a spray dryer and preliminarily calcined at 440 C. for 6 hours, thereby obtaining a preliminarily calcined powder (13). At that time, a formulation ratio of the catalytically active component exclusive of oxygen was Mo=12, Bi=1.7, Ni=2.8, Fe=1.8, Co=5.2, and K=0.15 in terms of an atomic ratio.

(13) Thereafter, the preliminarily calcined powder (D3) was supported and shaped in the same manner as that in the preliminarily calcined powder (D2) in Production Example 1, thereby obtaining a supported catalyst (E3).

(14) The supported catalyst (E3) was calcined in an air atmosphere at a calcination temperature of 530 C. for 4 hours, thereby obtaining a catalyst (F4).

(15) In addition, the supported catalyst (E3) obtained in Comparative Production Example 1 was calcined in an air atmosphere at a calcination temperature of 520 C. for 4 hours, thereby obtaining a catalyst (F5).

Example 1

(16) An oxidation reaction of propylene was carried out by using the catalysts (F1) to (F5) as prepared above, respectively. It is to be noted that though in this Example, the catalyst (F1) used on the raw material gas inlet side of the reaction tube and the catalyst (F2) or (F3) used on the raw material gas outlet side of the reaction tube are different in the formulation from each other, the both fall within the formulation range described in the formula (1).

(17) A silica-alumina sphere having a diameter of 5.2 mm was filled in a length of 20 cm from the raw material gas inlet side of a stainless steel-made reactor having an inside diameter of 25 mm, in which a jacket for circulating a molten salt as a heat medium and a thermocouple for measuring the catalyst layer temperature were placed on a tube axis; a dilute catalyst prepared by mixing the catalyst (F1) and a silica-alumina mixture inert spherical carrier in a weight ratio of 85/15 in a length of 80 cm as an oxidation catalyst first layer (on the raw material gas inlet side), the catalyst (F1) in a length of 80 cm as an oxidation catalyst second layer, and the catalyst (F2) in a length of 190 cm as an oxidation catalyst third layer were successively filled, respectively toward the raw material gas outlet, thereby constituting the catalyst layer as a three-layer structure; and the reaction bath temperature was set to 330 C. Feed amounts of propylene, air, water, and nitrogen were set to a raw material molar ratio of propylene:oxygen:water:nitrogen=1:1.7:8.8:1; the gases were circulated such that a space velocity of propylene was 100 h.sup.1; and when the pressure on the reaction tube outlet side at the time of circulating all of the gases was set to 50 kPaG, and 300 hours elapsed after the start of reaction, the reaction bath temperature was varied to carry out the oxidation reaction of propylene. As values at the reaction bath temperature of 318 C. and 328 C., a hot spot temperature of the oxidation catalyst first layer and Sn and an effective yield of the same catalyst layer were obtained. The results are shown in Table 1. It is to be noted that a valued calculated by means of linear approximation was used as for Sn. In addition, as for the hot spot temperature in Table 1, a temperature at a hot spot exhibiting the maximum temperature among the hot spots in each of the catalyst layers was shown.

Example 2

(18) The oxidation reaction of propylene was carried out in the same method as that in Example 1, except that under the oxidation reaction condition of Example 1, the oxidation catalyst (F3) was filled in a length of 190 cm as the oxidation catalyst third layer (on the gas outlet side). As values at the reaction bath temperature of 316 C. and 328 C., a hot spot temperature of the catalyst layer on the raw material gas inlet side and Sn and an effective yield of the same catalyst layer were obtained. The results are shown in Table 1.

Example 3

(19) The oxidation reaction of propylene was carried out in the same method as that in Example 1, except that under the oxidation reaction condition of Example 1, the catalyst (F1) was filled in a length of 120 cm as the oxidation catalyst first layer (on the raw material gas inlet side), and the catalyst (F2) was successively filled in a length of 230 cm as the catalyst second layer (on the gas outlet side) toward the raw material gas outlet, thereby constituting the catalyst layer as a two-layer structure. As values at the reaction bath temperature of 314 C. and 324 C., a hot spot temperature of the catalyst layer on the raw material gas inlet side and Sn and an effective yield of the same catalyst layer were obtained. The results are shown in Table 1.

Example 4

(20) The oxidation reaction of propylene was carried out in the same method as that in Example 1, except that under the oxidation reaction condition of Example 1, the catalyst (F1) was filled in a length of 135 cm as the oxidation catalyst first layer (on the raw material gas inlet side), and the oxidation catalyst (F2) was successively filled in a length of 165 cm as the catalyst second layer (on the gas outlet side) toward the raw material gas outlet, thereby constituting the catalyst layer as a two-layer structure; and that feed amounts of propylene, air, water, and nitrogen were set to a raw material molar ratio of propylene:oxygen:water:nitrogen=1:1.7:2:7.6, the gases were circulated such that a space velocity of propylene was 110 h.sup.1, and when the pressure on the reaction tube outlet side at the time of circulating all of the gases was set to 50 kPaG. As values at the reaction bath temperature of 310 C. and 321 C., a hot spot temperature of the catalyst layer on the raw material gas inlet side and Sn and an effective yield of the same catalyst layer were obtained. The results are shown in Table 1.

Example 5

(21) The oxidation reaction of propylene was carried out in the same method as that in Example 4, except that under the oxidation reaction condition of Example 4, the gases were circulated such that a space velocity of propylene was 150 h.sup.1, and when the pressure on the reaction tube outlet side at the time of circulating all of the gases was set to 80 kPaG. As values at the reaction bath temperature of 314 C. and 326 C., a hot spot temperature of the catalyst layer on the raw material gas inlet side and Sn and an effective yield of the same catalyst layer were obtained. The results are shown in Table 1.

Comparative Example 1

(22) The oxidation reaction of propylene was carried out in the same method as that in Example 1, except that under the oxidation reaction condition of Example 1, a dilute catalyst prepared by mixing the catalyst (F4) and a silica-alumina mixture inert spherical carrier in a weight ratio of 70/30 was filled in a length of 120 cm as the oxidation catalyst first layer (on the raw material gas inlet side), and the catalyst (F5) was successively filled in a length of 230 cm as the oxidation catalyst second layer (on the raw material gas inlet side) toward the raw material gas outlet, thereby constituting the catalyst layer as a two-layer structure; and that the gases were circulated such that a space velocity of propylene was 100 h.sup.1. As values at the reaction bath temperature of 322 C. and 330 C., a hot spot temperature of the catalyst layer on the raw material gas inlet side and Sn and an effective yield of the same catalyst layer were obtained. The results are shown in Table 1.

(23) The results of the foregoing Examples and Comparative Example are summarized. In particular, it was noted that even in the case of largely varying the space velocity of propylene to 110 h.sup.1 to 150 h.sup.1 or the like as in Examples 4 and 5, Sn was kept low according to the method of the present invention.

(24) As shown in Table 1, in comparison of Examples 1, 2 and 3 with Comparative Example 1, it was exhibited that according to the effects of the present invention, not only Sn (temperature sensitivity) can be reduced, but also the hot spot temperature itself relative to the reaction bath temperature can be decreased in combination with the effect of the catalyst species to be used. In addition, an effect for improving the yield could also be obtained at the same time due to a reduction of the hot spot.

(25) TABLE-US-00001 TABLE 1 Space Reaction Maximum velocity of bath Temperature effective propylene temperature of hot spot yield (h.sup.1) ( C.) ( C.) Sn (mol %) Example 1 100 328 401 2.05 91.8 318 380 Example 2 100 328 397 2.21 91.3 316 370 Example 3 100 324 407 1.20 91.5 314 395 Example 4 110 321 394 1.86 91.1 310 376 Example 5 150 326 406 2.02 90.1 314 383 Comparative 100 330 419 7.73 91.1 Example 1 322 353

(26) While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

(27) It is to be noted that the present application is based on a Japanese patent application filed on Jul. 18, 2013 (Japanese Patent Application No. 2013-149333), the entireties of which are incorporated by reference. In addition, all references cited herein are incorporated as a whole.

INDUSTRIAL APPLICABILITY

(28) The present invention is useful for the industrial plant of producing an unsaturated aldehyde or an unsaturated carboxylic acid.