JPS5935897B2 - Method for producing methacrolein and 1,3-butadiene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for the catalytic oxidation of butene mixtures containing isobutene and n-butene with molecular oxygen in the presence of a novel catalyst to obtain methacrolein and 1,3-butadiene.

More specifically, Mo, Bi, Co, Fe, Sb and L
A metal oxide consisting of at least one element selected from the group of Rb, Cs, and Ti is used as a catalyst for i, Na, and a mixed gas of air and a butene mixture containing isobutene and n-butene is applied to the catalyst at high temperature. and a method for obtaining methacrolein and 1,3-part gutadiene. Conventionally, many multicomponent catalysts have been proposed as gas-phase catalytic oxidation catalysts for olefin hydrocarbons (for example, Japanese Patent Publication No.
2324, 47-11733, 47-32043,
47-11964, 48-4762, 46-33
930).

However, all of these methods are still unsatisfactory in terms of conversion period, single-stream yield period, catalyst life, etc. from an industrial practical point of view. As a result of research to eliminate the drawbacks of conventional methods, the present inventors have discovered that Mo, Bi, Co, which does not contain sublimation components,
Fe, Sb, O and Li, Na, Rb, Cs, T
When using a 7-element catalyst consisting of at least one element selected from i, the catalyst is sufficiently active even under conditions of low entrained air ratio and high space velocity, and has high conversion efficiency, selectivity,
It was found that this method is superior in terms of single flow control, catalyst life, etc.

Furthermore, the above catalyst does not require particularly high-purity isobutene and n-butene as raw materials, and the C of cracking naphtha
4 fraction (so-called B-B fraction) or the spent C4 fraction remaining after extracting putadiene from the C4 fraction, that is, a fraction whose main components are a mixture of butene-1, cis-butene-2, trans-butene-2, and isobutene. The strings used are sufficiently effective to methacrolein and are useful chemical intermediate raw materials 1, 3
It is possible to co-produce butadiene.

The present invention was created based on these findings.5
Ru.

That is, the present invention combines a butene mixture containing isobutene and n-butene and molecular oxygen with Mo, Bi, Co, Fe, Sb.
, 0 and at least one element selected from Li, Na, K, Rb, Ca, and Ti in the presence of a gas phase catalytic reaction to produce methacrolein and 1, This is a method for simultaneously producing 3-butadiene.

The catalyst used in the present invention has the general formula MOaBibCOcF
edSbeXfOg (where X is Li, Na, K, Rb
, Cs, and Ti, and A, b, c, d, e, f, and g are MO, Bi, and Ti, respectively.
When the number of atoms of CO, Fe, Sb, X, and O is a-12, b=0. I~10, c=0.1-18d-0.5~
18e=0.01~53)
1Sf=0.001 to 1, g=a value determined by the valence of each element).

That is, the catalyst of the present invention can bring about the above-mentioned good results by adding Sb and the above-mentioned two components X to the five components MO, Bi, CO, Fe, and O. The catalyst may be prepared by any known method such as the evaporation to dryness method or the oxide mixing method, and the catalyst prepared by either method can exhibit sufficient performance.

If a shaped carrier is used to prepare the catalyst, it is preferred to use a carrier with a small surface area, such as fused alumina or silicon carbide. The catalyst obtained by molding or adhering oxide powder to a carrier has a molecular weight of 500 to 750
C., preferably 650 to 700.degree. C., and then subjected to reaction. Calcining at 650 to 700°C provides a long-life catalyst.

The space velocity during the reaction is 1000-5000''1hr (S
TP standard), but preferably 1500 to 4000-
It is 1 hour.

The molar ratio of all butenes to molecular oxygen in the raw material gas introduced into the reaction system is usually 1:(1
It can be used within the range of ~4). In practice, 1:(1.3
~2) It is very effective because the purpose can be sufficiently achieved even if it is used in a nearby low oxygen ratio range. Also, butanes, 1,
3-Butadiene does not have a large effect on the reaction, so
Even if the raw material situation changes, the desired purpose can be achieved by changing the operating conditions.

Furthermore, in this reaction, the reaction gas can be diluted with an inert gas (for example, nitrogen, steam, carbon dioxide, or saturated hydrocarbon) that does not adversely affect the reaction, and the use of steam is particularly preferred. When using steam, the molar ratio of the butene mixture to steam is preferably in the range of 1:(0.3-5). Ultimately, the dilution storage will be determined based on the degree of heat removal control curve of the reactor to be used. Although there is no particular restriction on the reaction pressure, sufficiently favorable results can be obtained by operating under atmospheric pressure.

In addition, since there is no essential difference depending on the particle size of the catalyst,
As the reactor, either a fixed bed type or a fluidized bed type can be used.

The reaction products can be recovered and separated by conventional methods such as condensation, extraction, and distillation.

The present invention will be explained below with reference to examples. In the examples, the conversion mechanism of isobutene and n-butene, the selective storage and storage of methacrolein and methacrylic acid, and 1,3-butadiene are expressed by the following formula. .

Further, the selectivity to carbon monoxide and carbon dioxide is expressed by the following formula.

Example 1 An aqueous solution of 26.59 (21.4 mmol) of ammonium molybdate, 29.19 (100 mmol) of potassium nitrate, and 0.125 f1 of potassium nitrate (
Add an aqueous solution of 1.25 mmol) and stir well,
An aqueous solution of antimony trichloride (2.85 f1 (12.5 mmol)) is added.

Additionally, ferric nitrate 15.14f1 (37.5 mmol)
An aqueous solution of 6.06θ (12.5 mmol) of bismuth nitrate and an aqueous solution of bismuth nitrate were added with continuous stirring and evaporated to dryness. After pyrolyzing this at 300° C. for 4 hours, it is crushed in a mortar.

Granular fused alumina (particle size 3 m) was added to the obtained powder 7.5θ.
m) 30 fl) and 100 cc of distilled water are added and evaporated to dryness while stirring to adhere the catalyst component to the carrier. This is 7
Calcinate at 00°C for 5 hours to obtain a catalyst. The atomic ratio of each metal in the catalyst active component is MO:Bi:CO:Fe:Sb:K
=12:1:8:3:1:0.1. A quartz reaction tube with an inner diameter of 20 mm was filled with 8.3 CC of the obtained catalyst, and 1
-butene 27.7 mol%, cis-2-butene 4.2 mol%.

Trans-2-butene 8.2 mol%, isobutene 47.
10.5 moles of a hydrocarbon mixture containing 5 mol%, butanes 9.9 mol%, 1,3-butadiene 1.0 mol%, C3 hydrocarbons 1.5 mol%, air 67 mol%, water vapor 22
．． Space velocity of 5 mol% raw material gas (0℃, 1 atm standard)
Contact was made for 3000-1 hr. The reaction temperature was 450°C. The results are shown in Table 1. Although the reaction was continued continuously for 2000 hours, there was only a slight decrease in activity.

Comparative Example 1 An experiment was conducted under the same conditions as in Example 1 except that antimony was not included.

As shown in Table 1, the conversion rate was low. Example 2
~6 An experiment was conducted under the same conditions as in Example 1, except that other alkali metals and thallium were used in place of potassium.

As shown in Table 1, the results showed that there was not much difference between each alkali metal and thallium. Comparative Examples 2-6 Example 2
Experiments were conducted under the same conditions as in Example 2 using antimony-free catalysts corresponding to Examples 1 to 6.

As shown in Table 1, the results showed lower convergence than corresponding Examples 2 to 6. Comparative Example 7 An experiment was conducted under the same conditions as in Example 6, except that antimony was not added and silica sol was used instead.

As shown in Table 1, the effect of silica sol was not so great, and it was clear that it was inferior to the effect of antimony. Example 7 An experiment was conducted under exactly the same conditions as in Example 6 except that silicon carbide was used as the carrier.

As shown in Table 1, there was almost no difference between the fused alumina support and the silicon carbide support. Example 8 An experiment was conducted under all the same conditions as Example 2 except that the composition ratios of bismuth, copalt, and iron were changed.

As shown in Table 1, the results showed that the effective carbon content did not change even with a composition with a high iron ratio, which has not been used much in the past. Example 9 After thermally decomposing and pulverizing the catalytic active ingredient, 2% graphite powder was added, and a tablet was made into tablets with a diameter of 5 mm and a thickness of 4 m.
The pellets were processed and molded into pellets of about 1.0 m in diameter.

Claims (1)

[Claims] 1 A butene mixture containing isobutene and n-butene and molecular oxygen are expressed by the general formula MoaBibCocFedSbe
XfOg (where X is Li, Na, K, Rb, Ca, T
Indicates at least one element selected from the group i, a,
b, c, d, e, f, g are respectively Mo, Bi, Co
, the number of atoms of Fe, Sb, X, and O, and when a = 12, b = 0.1 to 10, c = 0.1 to 18, d = 0.5 to 1
8, a metachromatogram characterized by carrying out a gas phase catalytic reaction in the presence of a catalyst represented by e=0.01-5, f=0.001-1, g=a value determined by the valence of each element). Method for simultaneous production of rhein and 1,3-butadiene.