JPH0840969A - Production of acrolein and catalyst - Google Patents

Abstract

PURPOSE:To obtain a catalyst for producing acrolein by vapor phase catalytic oxidation of propylene using molecular oxygen. CONSTITUTION:This method for producing a catalyst is to mix a composition (1) of the general formula (Mo)a(Bi)b(Fe)c(X)d(Z)f(O)g. [X is Ni or Co and Z i s W, Be, Mg, S, Ca, Sr, Ba, Te, Se, Ce, Ge, Mn, Zn, Cr, Ag, Sb, Pb, As, B, P, Nb, Cu, Cd, Sn, Al, Zr or Ti; (a), (b), (c, (d), (f) or (g) represents atom ratio of each element and (b) is 0.1-10, (c) is 0 20, (d) is 0-20 and (f) is 0-4 when (a) is 12 and (g) is a number of atom necessary for satisfying a valency of each componentl with a composition (2) of the general formula, (A)m(Mo)n(O)p [A is K, Rb, Cs or Tl and (m), (n) and (p) are each an atomic ratio of each element and (n) is 1-9 and (p) is 3n+1 when (m) is 2] under heating, evaporate and bake the mixed composition. This method for producing acrolein is to use the catalyst.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improved process for the vapor phase catalytic oxidation of propylene with molecular oxygen to produce acrolein and a process for the production of an improved catalyst for this catalytic oxidation reaction.

[0002]

2. Description of the Related Art Many proposals have hitherto been made regarding catalysts used for producing acrolein by subjecting propylene to vapor-phase catalytic oxidation with molecular oxygen. Among them, in addition to containing Mo, Bi and Fe as essential components, at least one element selected from the group consisting of Co and Ni, and one selected from the group consisting of K, Rb, Cs and Tl Many proposals have been made regarding catalysts containing the above elements. However, these conventionally proposed catalysts are still insufficient in catalytic performance such as catalytic activity, selectivity to acrolein, stability of the catalyst, and catalyst life, and improvement thereof has been desired.

[0003]

The object of the present invention is to provide Mo,
Propylene in the presence of a catalyst which is a mixture of Bi and preferably a composition containing one or more elements selected from the group consisting of Fe, Ni and Co and a composition containing an alkali metal salt of molybdic acid. It is an object of the present invention to provide an improved method for producing acrolein in good yield by subjecting benzene to vapor phase catalytic oxidation with molecular oxygen.

The object of the present invention is to provide a composition containing Mo, Bi and, preferably, one or more elements selected from the group consisting of Fe, Ni and Co, and a composition containing an alkali metal salt of molybdic acid. It is intended to provide a method for producing the above-mentioned catalyst for producing acrolein, which is improved in catalytic activity, selectivity to acrolein, and stability by mixing, heating and mixing, evaporating and drying, and calcining.

[0005]

According to the present invention, the general formula (1) (Mo) a (Bi) b (Fe) c (X) d (Z) is used.
f (O) g (1) [In the formula, X represents one or more elements selected from the group consisting of Ni and Co, and Z represents W, Be, and M.
g, S, Ca, Sr, Ba, Te, Se, Ce, Ge,
Mn, Zn, Cr, Ag, Sb, Pb, As, B, P,
Represents one or more elements selected from the group consisting of Nb, Cu, Cd, Sn, Al, Zr and Ti, and includes a, b, c,
d, f and g represent the atomic ratio of each element, and when a = 12 with a as a reference, b = 0.1-10, c = 0-
20, d = 0 to 20, f = 0 to 4, and g is the number of atoms required to satisfy the valence of each component. ] The composition (1) represented by the general formula (2) (A) m (M
o) n (o) p (2) [In the formula, A represents one or more elements selected from the group consisting of K, Rb, and Cs, and m, n, and p represent the atomic ratio of each element, Based on m, m =
When n is 2, n = 1 to 9 and p = 3n + 1. ] In the presence of a catalyst which is a mixture with the composition (2) represented by the above, there is provided a method for producing acrolein, which comprises catalytically oxidizing propylene with molecular oxygen in a gas phase.
Further, there is provided a method for producing a catalyst used in the above-mentioned method for producing acrolein, which comprises heating and mixing the composition (1) and the composition (2), evaporating and drying the mixture, and calcining the mixture.

In order to obtain the effects of the present invention, it is important to prepare the composition (1) and the composition (2) separately first. The catalyst in the present invention is obtained by mixing the composition (1) and the composition (2), and the composition of the entire composition is a composition known in the art. Despite having the same overall composition, the catalyst of the present invention obtained by first preparing the composition (1) and the composition (2) separately and then mixing them has higher performance than the catalyst of the prior art. Although it is not clear why the composition (1) and the composition (2) respectively provide a plurality of preferable active sites necessary for the subject reaction of the present invention, and their high concerted effects provide high selectivity. Is considered to have occurred. On the other hand, in the catalyst of the prior art, the alkali metal element or thallium of the composition (2) is not preferable for the target reaction of the present invention, or the alkali metal element or thallium of the composition (2) together with the group of elements constituting the composition (1) in the precipitation process of catalyst preparation It is considered that the selectivity does not exceed a certain level in order to form an unnecessary phase.

In order to obtain the effects of the present invention, the mixing ratio of the composition (1) and the composition (2) has a preferable range. That is, the atomic ratio A / Bi of A of the composition (2), that is, K, Rb or Cs and Bi of the composition (1) is 0.0.
It is mixed so as to be in the range of 2 to 1.0, and more preferably in the range of 0.05 to 0.5. K, R of composition (2)
When the atomic ratio of b, Cs, or Tl to Bi of the composition (1) is less than 0.02 or exceeds 1.0, the concerted effect of the composition (1) and the composition (2) is unsatisfactory. It becomes sufficient, and the selectivity and the oxidation activity become insufficient.

The composition (1) and the composition (2) used in the method of the present invention can be prepared by a method usually used in this field, for example, the following method: the composition (1) is , A suitable molybdate, for example, ammonium molybdate, is heated and dissolved in pure water, an aqueous solution of a Bi compound is added thereto, and if necessary, an aqueous solution of a compound of one or more elements selected from Fe, Co and Ni. And, if necessary, W, Be, Mg, S, Ca, Sr, B
a, Te, Se, Ce, Ge, Mn, Zn, Cr, A
g, Sb, Pb, As, B, P, Nb, Cu, Cd, S
A compound of one or more elements selected from the group consisting of n, Al, Zr, and Ti is added, and if necessary, SiO2
And the like, and the resulting mud-like suspension is dried, calcined and calcined in the temperature range of 200 ° C. to 650 ° C .; composition (2) is a suitable molybdate,
For example, ammonium molybdate is heated and dissolved in pure water, and a compound of one or more elements selected from K, Rb, Cs, and Tl, such as cesium nitrate, is added to the Cs: Mo atomic ratio of 2: 1 to 9. And then neutralize with nitric acid,
It is adjusted by evaporation to dryness, calcination, and firing in the temperature range of 200 to 500 ° C.

In the present invention, the catalyst is prepared as follows. That is, the composition (1) and the composition (2) described above.
The atomic ratio of K, Rb or Cs of the composition (2) to Bi of the composition (1) is in the range of 0.01 to 1.0, preferably 0.02 to 0.5. To mix. When mixing, it is more preferable to add water in order to enhance the catalyst performance. Mixing is performed in the temperature range of 30 ° C to 300 ° C. The resulting mixture is evaporated to dryness at a temperature of 300 ° C. or lower and calcined in the temperature range of 300 ° C. to 650 ° C. There is no particular limitation on the amount of water added when water is added during mixing,
It is preferable that the slurry state is such that the mixing can be sufficiently performed. When water is added, heating and mixing can be performed in an autoclave under self-generated pressure. The catalyst is used as a granular or shaped body in a fixed bed, but can also be used in a moving bed or a fluidized bed. In the present invention, the raw material of the catalyst is preferably a compound that can be decomposed into an oxide form in the catalyst preparation process. Examples of such compounds include nitrates, ammonium salts, organic acid salts, oxides, metal acids, ammonium metal acid salts and the like. As a raw material of silica, silica sol, silica gel, silicate ester, silicate or the like is used.

In the gas-phase catalytic oxidation reaction according to the present invention, a mixed gas consisting of 1 to 10% by volume of propylene, 3 to 20% by volume of molecular oxygen and 70 to 96% by volume of a diluent gas is used as the source gas composition. A space velocity of 300 on the catalyst under a temperature range of 250 to 450 ° C. and a pressure of atmospheric pressure to 10 atmospheres
It is implemented by introducing at ~ 5000 / hr.

Air is usually used as the molecular oxygen source, but pure oxygen may be used. The diluent gas used is an inert gas such as nitrogen or carbon dioxide. A part of the non-condensable gas contained in the reaction gas may be circulated and used as a diluent gas. It is preferable to use water vapor together as a diluent gas in order to enhance activity and selectivity. In that case, steam is usually added to the source gas in an amount of up to 60% by volume.

The present invention will be explained in more detail with reference to Examples and Comparative Examples: [Example 1] 127.2 gr of ammonium paramolybdate was dissolved while heating and stirring 1200 ml of water to obtain a liquid A. Cobalt nitrate 139.6 gr and ferric nitrate 72.2 gr were dissolved in 180 ml of water to prepare a liquid B. 28.6 gr of bismuth nitrate was dissolved in a nitric acid aqueous solution consisting of 15 ml of 60% nitric acid and 150 ml of water to prepare a C liquid.

Liquid B and liquid C were sequentially added dropwise to liquid A, and the resulting slurry solution was spray-dried, calcined and calcined at 300 ° C., and the Mo / Bi / Fe / Co atomic ratio was 12 /. 1 /
A composition (1) of 3/8 was obtained; while stirring 200 ml of water with heating, 19.6 gr of ammonium molybdate was dissolved, 39.0 gr of cesium nitrate was added, and the mixture was neutralized with nitric acid and then evaporated. Drying, calcination, and baking at 400 ° C. gave a composition (2) having a Cs / Mo atomic ratio of 2/1; a composition (1) having a Cs / Bi atomic ratio of 0.05. ) And the composition (2) at a ratio of 232/1, water was added so as to be 80 wt%, sufficiently heated and mixed at 100 ° C., evaporated to dryness at 120 ° C., and baked at 400 ° C. A catalyst was prepared; 1 ml of the obtained catalyst was charged into a normal flow reactor, and 6% by volume of propylene, 8% by volume of oxygen,
The reaction was performed under the conditions of a source gas composition of 25% by volume of steam and a nitrogen content of 61% by volume, a reaction temperature of 340 ° C., and a space velocity of 1000 / hr to evaluate the performance of the catalyst. Table 1 shows the results.

[Examples 2 to 11] The composition (1) prepared in the same manner as in Example 1 and the composition (2) shown in Table 1 had the A / Bi atomic ratio shown in Table 1. A catalyst was prepared in the same manner as in Example 1. The performance of the obtained catalyst was evaluated in the same manner as in Example 1.

The results are shown in Table 1.

Example 12 A catalyst was prepared in the same manner as in Example 1 except that 69.6 gr of nickel nitrate was used in place of the cobalt nitrate of Example 1. The performance of the obtained catalyst was evaluated in the same manner as in Example 1. Table 1 shows the results.

[Examples 13 and 14] Composition (1) prepared in the same manner as in Example 10 and composition (2) shown in Table 1
A catalyst was prepared in the same manner as in Example 10 so that the atomic ratios shown in Table 1 were obtained. The performance of the obtained catalyst was evaluated in the same manner as in Example 1. Table 1 shows the results.
Example 15 The composition (1) prepared in the same manner as in Example 1 and the composition (2) shown in Table 1 were treated in the same manner as in Example 1 so that the A / Bi atomic ratio was 1.2. The catalyst was prepared by the method. The performance of the obtained catalyst was evaluated in the same manner as in Example 1. Table 1 shows the results. [Comparative Example 1] Only the composition (1) prepared in the same manner as in Example 1 was used as a catalyst, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2] Evaluation was carried out in the same manner as in Example 1 using only the composition (2) having a Cs / Mo ratio of 2/7 prepared in the same manner as in Example 1 as a catalyst. Table 1 shows the results. [Comparative Example 3] Ammon paramolybdate 127.7 gr and cesium nitrate 0.59 gr were dissolved while heating and stirring 1200 ml of water to prepare a solution A. Cobalt nitrate 139.6 gr and ferric nitrate 72.2 gr were dissolved in 180 ml of water to prepare a liquid B. 60% nitric acid 15ml and water 150m
28.6 gr of bismuth nitrate was dissolved in a nitric acid aqueous solution containing 1 to prepare a C liquid. Liquid B and liquid C were sequentially added dropwise to liquid A, and the resulting slurry solution was spray-dried and calcined.
A catalyst having a Mo / Bi / Fe / Co / Cs atomic ratio of 12.05 / 1/3/8 / 0.05, that is, a catalyst having the same composition as in Example 1 was prepared by firing at 0 ° C. The performance of the obtained catalyst was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 4] The amounts of ammonium paramolybdate and cesium nitrate in Comparative Example 3 were 128.3 g each.
In the same manner as in Comparative Example 3 except that r and 0.94 gr were used, the Mo / Bi / Fe / Co / Cs atomic ratio was 12.1.
A catalyst of ⅓ / 3/8 / 0.08, that is, a catalyst having the same composition as in Example 2 was prepared. The performance of the obtained catalyst was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[Comparative Example 5] The amounts of ammonium paramolybdate and cesium nitrate in Comparative Example 3 were 129.9 g each.
In the same manner as in Comparative Example 3 except that r and 1.17 gr were used, the Mo / Bi / Fe / Co / Cs atomic ratio was 12.2.
A catalyst of 5/1/3/8 / 0.1, that is, a catalyst having the same composition as in Example 3 was prepared. The performance of the obtained catalyst was evaluated in the same manner as in Example 1. The results are shown in Table 2.
(Margins) Table 1 Example Composition (2) A * / Bi atom Reaction temperature Conversion rate Selectivity Yield ratio Example 1 Cs2 Mo04 0.05 340 ° C 96.0% 88.8% 85.2% 2 〃 0.08 340 96.6 88.7 85.7 3 〃 0.1 360 97,2 87.4 84.9 4 Cs2 Mo3 010 0.05 340 95.5 88.1 84.1 5 Cs2 Mo7 022 0.05 340 94.7 88.5 83.8 6 Rb2 Mo04 0.05 340 96.9 88.8 86.0 7 Rb2 Mo6 016 0.05 360 97.6 88.5 86.4 8 K2 Mo04 0.05 340 95.0 89.6 8 K2 Mo4 013 0.05 360 96.8 87.8 85.0 10 Tl2 MoO4 0.05 340 97.1 88.8 86.2 11 Tl2 MoO13 0.05 360 97.8 88.5 86.5 12 Cs2 Mo04 0.05 340 96.6 87.6 85.5 13 〃 0.08 340 96.9 88.6 85.9 14 〃 0.1 360 96.8 88.5 85.7 15 Cs2 Mo04 1.2 400 97.5 70.4 68.6 Comparative Example 1-0,0 360 57.2 56.5 32.3 2 Cs2 Mo7 2022-360 18.5 23.8 4.4 * A represents K, Rb, Cs or Tl.

The conversions in the table are propylene conversions,
The selectivity and yield mean the selectivity and yield for acrolein, respectively. (The following margins) Table 2 Reaction temperature Conversion rate Selectivity Yield comparison example 3 340 ° C 98.4% 83.9% 82.6% 4 340 98.2 84.6 83.1 5 360 98.8 84.0 83.0 The conversion rate in the table is the propylene conversion rate, and the selectivity and The yield means the selectivity to acrolein and the yield, respectively.

[0022]

INDUSTRIAL APPLICABILITY Acrolein can be effectively produced by using a novel catalyst having excellent activity, selectivity to acrolein, and stability. (Below margin)

Claims (8)

[Claims] 1. The general formula (1) (Mo) a (Bi) b (F
e) c (X) d (Z) f (O) g (1) [where X is N
i represents one or more elements selected from the group consisting of i and Co, and Z represents W, Be, Mg, S, Ca, Sr, Ba, T
e, Se, Ce, Ge, Mn, Zn, Cr, Ag, S
b, Pb, As, B, P, Nb, Cu, Cd, Sn, A
represents one or more elements selected from the group consisting of 1, Zr and Ti, a, b, c, d, f and g represent atomic ratios of the respective elements, and a = 12 based on a. Sometimes b =
0.1-10, c = 0-20, d = 0-20, f = 0
4 and g is the number of atoms required to satisfy the valence of each component. ] The composition (1) represented by the general formula (2) (A) m (Mo) n (o) p (2) [wherein
A represents one or more elements selected from the group consisting of K, Rb, Cs, and Tl, m, n, and p represent the atomic ratio of each element, and when m = 2 when m is a reference. , N = 1
˜9, p = 3n + 1. ] The composition (2) shown by
A process for producing acrolein, which comprises subjecting propylene to gas phase contact with molecular oxygen in the presence of a catalyst which is a mixture with. 2. The production method according to claim 1, wherein the mixing ratio of the composition (1) and the composition (2) is 0.02 to 1.0 expressed by the atomic ratio of A / Bi. 3. Composition 3 (1) and composition (2) at 30 ° C.
3. The production method according to claim 1 or 2, wherein a catalyst obtained by heating and mixing in a temperature range from 300 to 300 ° C or less and calcining in a temperature range from 300 to 650 ° C is used. 4. A catalyst obtained by carrying out heating and mixing of the composition (1) and the composition (2) in the presence of water.
The manufacturing method described. 5. The general formula (1) (Mo) a (Bi) b (F
e) c (X) d (Z) f (O) g (1) [where X is N
i represents one or more elements selected from the group consisting of i and Co, and Z represents W, Be, Mg, S, Ca, Sr, Ba, T
e, Se, Ce, Ge, Mn, Zn, Cr, Ag, S
b, Pb, As, B, P, Nb, Cu, Cd, Sn, A
represents one or more elements selected from the group consisting of 1, Zr and Ti, a, b, c, d, f and g represent atomic ratios of the respective elements, and a = 12 based on a. Sometimes b =
0.1-10, c = 0-20, d = 0-20, f = 0
4 and g is the number of atoms required to satisfy the valence of each component. ] The composition (1) represented by the general formula (2) (A) m (Mo) n (o) p (2) [wherein
A is 1 selected from the group consisting of K, Rb, Cs or Tl
Represents more than one kind of element, m, n and p represent atomic ratios of each element, and when m = 2 based on m, n = 1 to 1
9, p = 3n + 1. ] It heat-mixes with the composition (2) shown by these, it evaporates to dryness, and it heats, The manufacturing method of the catalyst used for the manufacturing method of acrolein characterized by the above-mentioned. 6. The method for producing a catalyst according to claim 5, wherein the mixing ratio of the composition (1) and the composition (2) is 0.02 to 1.0 expressed as an atomic ratio of A / Bi. 7. A composition (1) and a composition (2) are heated and mixed in a temperature range of 30 ° C. to 300 ° C., evaporated to dryness at a temperature of 300 ° C. or lower, and in a temperature range of 300 ° C. to 650 ° C. The method for producing a catalyst according to claim 5 or 6, which comprises calcination. 8. The method for producing a catalyst according to claim 7, wherein the composition (1) and the composition (2) are heated and mixed in the presence of water.