JPH07112988B2 - Solid oxygen carrier, process for its production and method of using solid oxygen carrier - Google Patents

Description

Detailed Description of the Invention a. The present invention relates to a solid oxygen carrier used for producing butadiene by contacting butene with oxidative dehydrogenation in the absence of molecular oxygen to produce butadiene, a method for producing the same, and a method for producing butadiene. It relates to a method of using the solid oxygen carrier.

As a method of producing butadiene from butene, a method of dehydrogenating butene by contacting butene with a catalyst in the absence of oxygen,
A method is known in which butene is brought into contact with a catalyst in the presence of molecular oxygen to carry out oxidative dehydrogenation. However, the former often produces free carbon, so that steam must be added as a countermeasure, and catalyst regeneration must be performed more frequently. In addition, the latter has a drawback that the refining process is complicated because various oxygen-containing hydrocarbon compounds are by-produced.

As another method of oxidative dehydrogenation, JP-A-59-161324 discloses that butane and / or butene are brought into contact with a metal oxide and butadiene is produced by oxidative dehydrogenation by the bound oxygen, and at the same time, a metal produced And / or a method for producing butadiene has been proposed, which comprises oxidizing a lower oxide thereof with an oxygen-containing gas to regenerate a regenerated metal oxide, and then contacting the metal oxide with butane and / or butene for oxidative dehydrogenation. As described above, the method of producing butadiene by oxidative dehydrogenation of butane and / or butene with the bound oxygen by using the metal oxide as the oxygen carrier has a mild reaction and is superior to the oxidative dehydrogenation by molecular oxygen. There is an advantage that there are few by-products of various oxygen-containing hydrocarbon compounds. Examples of metal oxides include C ₀ O, Bi ₂ O ₃ , CdO, Fe ₂ O ₃ , MnO ₂ , SnO, and T.
An example using eO ₂ is shown, and it is said that the butadiene yield reaches 90% when Bi ₂ O ₃ / γ-alumina is used. Since a side reaction due to oxygen occurs, a step of removing the adhering molecular oxygen by treatment with steam or a steam-containing gas is required after the metal oxide is regenerated. Is also observed.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The present invention relates to a solid oxygen carrier which solves the above-mentioned drawbacks, a process for producing the same, and a process for using the solid oxygen carrier for producing butadiene.

B. Means for Solving the Problems The solid oxygen carrier for producing butadiene according to the present invention contains an oxide of Bi and an oxide of Mo in an atomic ratio of Mo / Bi of 0.28 to 0.49. Characteristically, it is used to contact butene with oxidative dehydrogenation in the absence of molecular oxygen.

The solid oxygen carrier of the present invention comprises Bi oxide and Mo / B
It contains an oxide of Mo in the atomic ratio of i of 0.28 to 0.49, and more preferably 0.33 to Mo / Bi of the atomic ratio.
It contains an oxide of Mo in the range of 0.46.

Butadiene can be produced in high yield by contacting this solid oxygen carrier with butene in the absence of molecular oxygen, but it is more preferable if the solid oxygen carrier contains phosphorus. Bi containing no phosphorus
In the solid oxygen carrier composed of the oxide of Mo and the oxide of Mo, the combustion reaction tends to occur at the initial stage of the reaction and the butadiene yield tends to be low, but when phosphorus is contained, the combustion reaction can be suppressed and It is expected that the yield will be improved.

Since the butadiene yield does not improve so much even if the phosphorus content is too high, the P / Bi atomic ratio is usually 0.8 or less, preferably 0.3 or less, and more preferably 0.1 or less.

The solid oxygen carrier containing the oxide of Bi and the oxide of Mo, or further containing phosphorus can be sufficiently used as it is, but sintering is suppressed when SiO ₂ is added as a carrier. Oxidative regeneration reaction becomes easy. Further, addition of an appropriate amount of SiO ₂ also has the effect of improving the butadiene yield.

An appropriate amount of SiO ₂ added is less than 30% by weight based on the total weight of the solid oxygen carrier. Above this Si
Since the active ingredient is diluted with O _{2, the} butadiene yield tends to decrease, which is not preferable.

The shape of the solid oxygen carrier may be selected according to the method of use, and for example, powder, granule, or the like can be used.

The method for producing the solid oxygen carrier in the present invention includes:
Molybdic acid and basic bismuth nitrate were added to water at a ratio of Mo / Bi atomic ratio of 0.28 to 0.49, and the mixture was heated at 80 to 120 ° C for 10
Heat and stir for ~ 20 hours to form an aqueous suspension, which is washed with water
A method comprising drying and calcining a solid obtained by filtration is suitable.

When producing oxides containing Bi as a solid oxygen carrier, oxides of Mo and phosphorus, molybdic acid and basic bismuth nitrate are used, and the atomic ratio of Mo / Bi is 0.28 to 0.4.
It is added to water at a ratio of 9 and heated and stirred at 80 to 120 ° C. for 10 to 20 hours to give an aqueous suspension, which is washed with water and filtered to give a solid product having a P / Bi atomic ratio of 0.8. Phosphoric acid may be added to the following phosphorus to form an aqueous mixture, and the aqueous mixture may be dehydrated, dried, and calcined. When phosphoric acid is added to form an aqueous mixture, water may be added appropriately.

When SiO ₂ is used as a carrier, molybdic acid and basic bismuth nitrate are added to water at a ratio of Mo / Bi atomic ratio of 0.28 to 0.49 and heated at 80 to 120 ° C. for 10 to 20 hours.
The mixture is stirred to form an aqueous suspension, which is washed with water and filtered, and silica sol is added to the obtained solid to form an aqueous mixture. The aqueous mixture is dehydrated, dried, and calcined. Water may be added if necessary when the silica sol is added to form an aqueous mixture.

Further, when containing SiO ₂ as a carrier containing phosphorus, molybdic acid and basic bismuth nitrate are added to water at a ratio that the atomic ratio of Mo / Bi is 0.28 to 0.49, and 80 to 120 ° C.
Heat and stir for ~ 20 hours to form an aqueous suspension, which is washed with water
Phosphoric acid and silica sol are added to the solid product obtained by filtration so that the P / Bi atomic ratio becomes 0.8 or less to form an aqueous mixture, and the aqueous mixture is dehydrated, dried, and calcined. When phosphoric acid and silica sol are added to form an aqueous mixture, water may be added if necessary.

The firing temperature may be any temperature in the range of the reaction temperature or higher and lower than the temperature at which sintering is allowed by high temperature firing, and preferably 600 to 7
It is in the range of 50 ° C.

As a method for producing a Si-Mo-Bi-based or Si-P-Mo-Bi-based composite oxide, a production method using bismuth nitrate and ammonium molybdate as raw materials is used in the presence of molecular oxygen. As a method for producing a catalyst for use, for example, JP-B-37-85
As known from No. 68, when the composite oxide produced by this method is used as a solid oxygen carrier, the butadiene yield is higher than that obtained by the production method using basic bismuth nitrate and molybdic acid as starting materials. Since the rate is low and the activity decreases rapidly, it is necessary to frequently perform oxidative regeneration.

On the other hand, the production method using basic bismuth nitrate and molybdic acid as starting materials is preferable because a sufficiently high butadiene yield can be expected and the activity duration is long.

To use the solid oxygen carrier of the present invention to produce butadiene, the solid oxygen carrier is contacted with butene in the absence of molecular oxygen to oxidatively dehydrogenate the butene with the bound oxygen of the solid oxygen carrier. The solid oxygen carrier whose bound oxygen has been reduced by contact with is contacted with the molecular oxygen-containing gas to increase the bound oxygen of the solid oxygen carrier, and then contacted with butene again.

As a raw material for producing butadiene, 1-butene, 2-butene single gas, a mixed gas thereof, or a gas containing them is used.

The reaction temperature for the production of butadiene by oxidative dehydrogenation of butene is about 450 to 575 ° C, preferably 475 to 550 ° C, and more preferably
The reaction pressure is 500 to 525 ° C, and the reaction pressure is about atmospheric pressure.

A solid oxygen carrier whose bound oxygen is reduced by contact with butene is contacted with a molecular oxygen-containing gas to increase the bound oxygen of the solid oxygen carrier and then contacted with butene again to carry out an oxidative dehydrogenation reaction. By repeating the oxidative regeneration and the oxidative dehydrogenation reaction in the same manner, butadiene can be effectively produced.

In the regeneration reaction, in order to oxidize and regenerate the solid oxygen carrier with oxygen gas or oxygen-containing gas (air, etc.), it is better to carry out the regeneration heat at the same temperature as the butadiene formation reaction or at a slightly higher temperature. It is preferable because it can be effectively used in the process, and when the carrier (SiO ₂ ) is used, it is usually 400-600 ℃
Done in.

In the absence of carrier, to suppress sintering,
It is necessary to control the generation of heat of oxidation that causes sintering. For example, oxidation regeneration is performed by gradually or stepwise increasing the temperature from a low temperature to a high temperature side using a gas having a constant oxygen concentration. For example, the temperature is raised from about 150 ° C to about the reaction temperature in the end.

In addition, the diluted oxygen gas is used to carry out oxidative regeneration at a constant temperature, for example, at a temperature about the same as the reaction temperature, or at a constant temperature, or from a low temperature to a gradual or stepwise temperature increase. Oxidative regeneration may be performed by gradually or stepwise changing the concentration.

When the solid oxygen carrier of the present invention is used to produce butadiene, it can be carried out in either a fluidized bed (moving bed) reaction or a fixed bed reaction.

If the oxidative dehydrogenation reaction and regeneration reaction of butene are carried out in a fluidized bed (moving bed) and the metal or its oxide is circulated between them, the production of butadiene by butene oxidative dehydrogenation can be carried out completely continuously. . In the case of a fixed bed, two or more reaction towers are installed side by side, and if they are alternately applied to butene for oxidative dehydrogenation reaction and regeneration reaction, butadiene can be produced substantially continuously. it can.

Mo-Bi does not have to be completely converted to its highest valence oxide during oxidative regeneration, and it is not necessary to convert it to its lowest valence oxide after the butadiene formation reaction.
In short, it can be used in a state where the amount of bound oxygen increases and decreases before and after the reaction. What kind of conditions should be used depends on factors such as the reaction rate of butene, the selectivity of butadiene, the equipment volume and the required energy. It may be decided based on the judgment.

Example 1 Basic bismuth nitrate 11 having a Bi ₂ O ₃ concentration of 80% by weight was added to 1.6 l of water.
8.73 g and 30.09 g of molybdic acid having a MoO ₃ concentration of 80% by weight were added, and the mixture was heated and stirred under reflux at 100 ° C. for 16 hours to obtain an aqueous suspension. Next, this mixture was subjected to suction filtration, followed by washing with 4.0 l of water and filtration, and then 2.05 g of 85% phosphoric acid was added to the obtained solid matter, followed by rapid stirring with a homogenizer, and the resulting mixture was gradually evaporated to dryness. And then in a dryer maintained at 120 ° C for 1
It was dried for 6 hours. Finally, the dried product is placed in an electric furnace at 700
Calcination for 3 hours at an atomic ratio of Bi: Mo: P = 1.00: 0.41:
A solid oxygen carrier with a composition of 0.03 was obtained.

Example 2 A solid oxygen carrier having an atomic ratio of Bi: Mo: P = 1.00: 0.44: 0.03 was prepared in the same manner as in Example 1 except that the addition amount of molybdic acid was changed.

Comparative Example 1 A solid oxygen carrier having an atomic ratio of Bi: Mo: P = 1.00: 0.10: 0.03 was prepared in the same manner as in Example 1 except that the addition amount of molybdic acid was changed.

Comparative Example 2 A solid oxygen carrier having an atomic ratio of Bi: Mo: P = 1.00: 0.27: 0.03 was prepared in the same manner as in Example 1 except that the addition amount of molybdic acid was changed.

Comparative Example 3 A solid oxygen carrier having an atomic ratio of Bi: Mo: P = 1.00: 0.54: 0.03 was prepared in the same manner as in Example 1 except that the addition amount of molybdic acid was changed.

[Performance Test 1] The solid oxygen carrier obtained in each Example and Comparative Example was used as 16
Pulverized into ~ 32 mesh, 0.5g of each was packed in a pulse reactor, and 1-butene gas of 99.9% purity containing no molecular oxygen was supplied to the reaction tube kept at 500 ° C with a pulse supply rate of 1cc.
It was supplied every 0 minutes.

The average values of the reaction results for 10 pulses from the start of the reaction are shown in Table 1 and FIG.

In FIG. 1, the horizontal axis represents the Mo / Bi atomic ratio in the solid oxygen carrier shown in Table 1, and the vertical axis represents the butadiene yield when each solid oxygen carrier is used.

From FIG. 1, it can be seen that a butadiene yield of 40% or more can be obtained in the Mo / Bi atomic ratio range of 0.28 to 0.49.

Further, in the Mo / Bi atomic ratio range of 0.33 to 0.46, a butadiene yield of 50% or more is obtained, which is more preferable.

Next, the influence of the P content will be described.

[Examples 3 to 7] Bi: Mo: P = 1.00: 0.41: 0 (Example 3), 1.0 by atomic ratio in the same manner as in Example 1 except that the addition amount of phosphoric acid was changed.
0: 0.41: 0.02 (Example 4), 1.00: 0.41: 0.04 (Example 5), 1.00: 0.41: 0.31 (Example 6), 1.00: 0.41: 0.76
A solid oxygen carrier having the composition of (Example 7) was prepared.

[Performance Test 2] In the same manner as in Performance Test 1, the average value of the reaction results for 10 pulses from the start of the reaction is shown in Table 2.

Table 3 shows the reaction results of the first pulse immediately after the start of the reaction.

It can be seen from Table 2 that when the Mo / Bi atomic ratio is 0.41, the butadiene yield of 60% or more is maintained at 10 pulse averages in the P / Bi atomic ratio of 0 to 0.76. From the above, it is understood that the butadiene yield of the first pulse when P = 0 is 41%, and therefore it is preferable to contain a trace amount or more of phosphorus.

[Example 8] In the same manner as in Example 1, when a solid oxygen carrier having a composition of Bi: Mo: P = 1.00: 0.41: 0.03 was prepared, a predetermined amount of 20% silica sol was added simultaneously with phosphoric acid. A solid oxygen carrier containing 0.7% by weight, 17.0% by weight, 26.0% by weight, 30.0% by weight, 35.0% by weight, 35.0% by weight and 45.0% by weight of SiO ₂ was prepared.

[Performance Test 3] The average value of the reaction results for 10 pulses from the start of the reaction is shown in Table 4 in the same manner as in Performance Test 1 using the solid oxygen carrier of Example 8.

From the results shown in Table 4, including less than 30% by weight of SiO ₂ not only reduces the amount of expensive metal components used, but also has the effect of improving the butadiene yield by adding an appropriate amount. I understand.

[Performance Test 4] Bi: Mo: P = 1.00: 0.41: 0.03, SiO ₂ 2 prepared in Example 8
In the same manner as in the performance test 1, a reaction test of continuous 60 pulses was conducted using 6.0% by weight of the solid oxygen carrier. Table 5 shows the reaction results as an average value for every 10 pulses.

The butadiene yield drops sharply from 21 to 30 pulses, which indicates that this reaction is not a catalytic reaction but an oxidation reaction of Mo—Bi with bound oxygen.

In contrast, using the solid oxygen carrier of Example 1,
Table 6 shows the reaction results of each 10-pulse average when the regeneration reaction was performed every 10 pulses.

The regeneration reaction was carried out by contacting the solid oxygen carrier with air at 200 ° C. for 1 hour, then raising the temperature and contacting with air at 500 ° C. for 0.5 hour.

That is, it has been shown that the solid oxygen carrier maintains a high level of butadiene yield by repeating regeneration.

[Performance Test 5] Bi: Mo: P = 1.00: 0.41: 0.03, SiO ₂ 2 prepared in Example 8
15 g of 6.0 wt% solid oxygen carrier (16-32 mesh)
Was charged in a small flow reactor and 10 mol% of 1-butene gas (50
(ml / min) was supplied at a space velocity of 200 Hr ⁻¹ to conduct a reaction test. After 1 hour and 30 minutes from the start of the reaction, the starting butene gas was switched to an oxygen-containing gas (20% oxygen gas diluted with nitrogen), and oxidation regeneration was carried out at 500 ° C. for 1 hour. Next, Table 7 shows the reaction results when the raw material butene gas was changed to carry out the oxidative dehydrogenation reaction, and then the oxidative regeneration and the oxidative dehydrogenation reaction were similarly carried out.

It can be seen that even in the flow-type reaction, butadiene can be satisfactorily produced by repeating the regeneration of the solid oxygen carrier.

[Performance Test 6] Bi: Mo: P = 1.00: 0.41: 0.03, SiO ₂ 2 prepared in Example 8
15 g of 6.0 wt% solid oxygen carrier (16-32 mesh)
Was charged into a small flow reactor and the reactor was diluted with nitrogen.
Space velocity 200H with 10 mol% 1-butene gas (50 ml / min)
was fed at r ^-1, 450 ° C. The reaction temperature respectively, 475 ° C., 500
Reaction tests were conducted at temperatures of ℃, 525 ℃ and 550 ℃. The reaction results are shown in Table 8.

The reaction temperature is preferably about 475 ° C to 550 ° C, more preferably 500 ° C to 525 ° C.

[Performance Test 7] A reaction test was conducted in the same manner as in Performance Test 1 except that the solid oxygen carrier prepared in Example 1 was used and C-2-butene and t-2-butene were used as raw material butenes. . Table 9 shows the average values of the reaction results for 10 pulses from the start of the reaction.

It can be seen that good results are obtained also when 2-butene is used as the raw material.

Example 9 To a 5% ammonium hydroxide solution of ammonium molybdate, a 3N nitric acid solution of bismuth nitrate was gradually added,
Then, the mixture was heated and stirred for 20 hours. Next, phosphoric acid was added to the obtained aqueous suspension, which was further heated and stirred, and finally heated and concentrated to 12
It was dried at 0 ° C for 16 hours. The obtained solid was pulverized to 16 to 32 mesh and calcined at 600 ° C. for 3 hours to obtain a solid oxygen carrier. It had a composition of Bi: Mo: P = 1.00: 0.41: 0.04.

When a pulse reaction test was conducted using 0.5 g of this solid oxygen carrier, the average reaction results of the initial 10 pulses were 1-
The butene conversion was 57.6%, the butadiene selectivity was 75.3%, and the butadiene yield was 43.3%.

When a solid oxygen carrier having a similar composition produced by using a basic bismuth nitrate and molybdic acid as raw materials was used, the butadiene selectivity was almost the same as in Example 1, but the 1-butene conversion rate was higher. Butadiene yield was low due to the low

C. Effect of the Invention Since molecular oxygen and flammable gases such as butene and butadiene do not coexist in the reaction system, there is no danger of explosion and the operating conditions are not limited.

A solid oxygen carrier that has an excellent butadiene yield and can be used industrially stably is obtained. By using it, the yield of butene is 40% or more and the amount of side reaction products is small. , Butadiene can be produced.

[Brief description of drawings]

Figure 1 shows the effect of Mo / Bi atomic ratio in solid oxygen carrier on the butadiene yield.
The atomic ratio of Mo / Bi in the solid oxygen carriers shown in the table, the vertical axis represents the butadiene yield when each solid oxygen carrier was used.

Claims (15)

[Claims] 1. An oxide of Bi and an atomic ratio of Mo / Bi of 0.28 to.
Solid oxygen carrier for the production of butadiene by the oxidative dehydrogenation of butene in the absence of molecular oxygen, characterized by containing an oxide of Mo in the range of 0.49. 2. A solid oxygen carrier according to claim 1, which contains an oxide of Mo in the atomic ratio Mo / Bi in the range of 0.33 to 0.46. 3. The solid oxygen carrier according to claim 1 or 2, which contains phosphorus in an atomic ratio of P / Bi of 0.8 or less. 4. A solid oxygen carrier according to claim 1, 2 or 3 containing less than 30% by weight of total SiO ₂ . 5. Molybdic acid and basic bismuth nitrate,
Add Mo / Bi atomic ratio of 0.28 to 0.49 to water,
Heat and stir at 0-120 ° C for 10-20 hours to give an aqueous suspension,
A method for producing a solid oxygen carrier for butadiene production by oxidative dehydrogenation of butene in the absence of molecular oxygen, which comprises drying and calcining a solid obtained by washing and filtering this with water. 6. Molybdic acid and basic bismuth nitrate,
Add Mo / Bi atomic ratio of 0.28 to 0.49 to water,
Heat and stir at 0-120 ° C for 10-20 hours to give an aqueous suspension,
This is washed with water and filtered to give a solid product with an atomic ratio of P / Bi.
6. The method for producing a solid oxygen carrier according to claim 5, wherein phosphoric acid is added so as to obtain phosphorus of 0.8 or less to form an aqueous mixture, and the aqueous mixture is dehydrated, dried and calcined. 7. Molybdic acid and basic bismuth nitrate,
Add Mo / Bi atomic ratio of 0.28 to 0.49 to water,
Heat and stir at 0-120 ° C for 10-20 hours to give an aqueous suspension,
The method for producing a solid oxygen carrier according to claim 5, wherein silica sol is added to a solid obtained by washing and filtering this with water to form an aqueous mixture, and the aqueous mixture is dehydrated, dried and calcined. 8. Molybdic acid and basic bismuth nitrate,
Add Mo / Bi atomic ratio of 0.28 to 0.49 to water,
Heat and stir at 0-120 ° C for 10-20 hours to give an aqueous suspension,
This is washed with water and filtered to give a solid product with an atomic ratio of P / Bi.
The method for producing a solid oxygen carrier according to claim 5, wherein phosphoric acid and silica sol are added so as to obtain phosphorus of 0.8 or less to form an aqueous mixture, and the aqueous mixture is dehydrated, dried and calcined. 9. Molybdic acid and basic bismuth nitrate,
The method for producing a solid oxygen carrier according to claim 5, 6, 7 or 8, wherein the Mo / Bi atomic ratio is added to water at a ratio of 0.33 to 0.46. 10. The method for producing a solid oxygen carrier according to claim 7 or 8, wherein the silica sol is added so that SiO ₂ is less than 30% by weight of the whole. 11. A solid oxygen carrier containing oxides of Bi and oxides of Mo in the Mo / Bi atomic ratio ranging from 0.28 to 0.49 in the absence of molecular oxygen for the production of butadiene with butene. Contacting to oxidatively dehydrogenate butene with bound oxygen of solid oxygen carrier and contact with butene to reduce bound oxygen solid oxygen carrier to contact with molecular oxygen-containing gas to increase bound oxygen of solid oxygen carrier A method of using a solid oxygen carrier, which is then contacted with butene again. 12. The solid oxygen carrier has a Mo / Bi atomic ratio.
The use of a solid oxygen carrier according to claim 11, which contains an oxide of Mo in the range of 0.33 to 0.46. 13. The solid oxygen carrier has a P / Bi atomic ratio of 0.
Claim 11 containing phosphorus of 8 or less
Item 10. Use of the solid oxygen carrier according to item 12 or 12. 14. A method according to claim 11 wherein the solid oxygen carrier contains less than 30% by weight of total SiO ₂ .
Use of the solid oxygen carrier according to claim 12 or 13. 15. A method of using the solid oxygen carrier according to claim 11, 12, 13 or 14 for oxidative dehydrogenation of butene at a temperature of 450 to 575 ° C. and a normal pressure.