JP3328340B2 - Process for producing acrolein or acrylic acid, and catalyst used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing acrolein and / or acrylic acid from propane.

[0002]

2. Description of the Related Art In recent years, demand for acrylic acid has been increasing as a raw material for water absorbent resins, paper processing agents, fiber processing agents, flocculants and the like. Currently, acrylic acid or its intermediate acrolein is produced using propylene as a raw material,
Further, a method for producing from propane, which is an inexpensive raw material, is being studied. There have been several reports on the production of acrolein or acrylic acid from propane.

[0003] M. Ai, Chem. Commun. 786 (1986)
It is shown that acrylic acid is produced in one step from propane on a vanadyl phosphate-based catalyst modified with e. Regarding the vanadyl phosphate system, the present inventors disclose a catalyst modified with gold and / or silver in Japanese Patent Application No. 3-344667. JP-A-2-83348 discloses a Bi-V-Mo-Ag catalyst, and JP-A-2-67236 discloses a BP catalyst. Further, Y. Takita, Chem. Lett. 1733 (1989) reports that the reaction from propane to acrolein proceeds on various phosphate catalysts. However,
According to the findings of the present inventors, these catalysts have many points to be improved industrially as catalysts for producing acrolein or acrylic acid from propane in terms of activity, selectivity, durability, etc. Is desired.

[0004]

SUMMARY OF THE INVENTION The present invention provides a catalyst having excellent activity and selectivity for producing acrolein and / or acrylic acid by reacting propane with molecular oxygen.

[0005]

SUMMARY OF THE INVENTION The present invention is a catalyst for producing acrolein and / or acrylic acid from propane comprising a heteropolyacid containing phosphorus and molybdenum as essential components or a salt thereof. Further, the present invention provides a method for producing acrolein and / or acrylic acid by reacting propane and molecular oxygen, and using a catalyst comprising a heteropolyacid containing phosphorus and molybdenum as essential components or a salt thereof. A process for producing acrolein and / or acrylic acid, which is a feature.

According to the present invention, acrolein and / or acrylic acid can be produced from propane in high yield. The catalyst of the present invention is a heteropolyacid or a salt thereof containing phosphorus and molybdenum as essential components, and further added with other components as necessary. Preferred catalysts are those of the general formula Pa Mob Vc Ad Xe Ox. Here, P is phosphorus, Mo is molybdenum, V is vanadium, A is arsenic and / or antimony, X is tin, lead, cerium, cobalt, iron, zirconium, thorium, tungsten, germanium, nickel, rhenium, bismuth, chromium, Boron, magnesium, calcium, barium, strontium, selenium,
O represents at least one element selected from the group consisting of tellurium, silver, aluminum, zinc, copper, titanium, potassium, rubidium, cesium and thallium, O represents oxygen, and when b = 12, a = 0.5 to 3 , C = 0.01-3, d
= 0 to 3, e = 0 to 3, and x represents a number determined by the oxidation state of each constituent element. The basic structure of the catalyst of the present invention is phosphomolybdic acid or a salt thereof, and it is considered that in the preferred catalyst of the present invention, part of phosphorus and / or molybdenum in the crystals of the basic structure is replaced by another element.

A known method for producing a heteropolyacid can be applied to the preparation of the catalyst of the present invention. For example, it is possible to prepare a solution of a heteropolyacid or a soluble heteropolyacid salt by adding a predetermined amount of a metal oxide, a nitrate or the like to a phosphoric acid aqueous solution and heating and dissolving the same, followed by drying, baking, molding, and other steps to produce the solution. it can. Alternatively, a solution of a heteropolyacid is prepared, and a counter cation is added to the solution to form an insoluble heteropolyacid salt to form a precipitate, and the solution is separated by filtration or, without separation, dried, calcined, and molded. And the like.

[0008] As the drying method, a known method such as a method of evaporating and drying the solution in a box-type dryer or a spray drying method can be used. The drying temperature is usually 50 to 200C. The catalyst intermediate having undergone the drying step is calcined after or without molding. Final firing temperature is 200-50
0 ° C, preferably 250-400 ° C. As the firing atmosphere, an inert gas such as nitrogen, helium, or argon,
Oxygen-containing gas such as air, oxygen and oxygen-enriched air, reducing gas such as hydrogen and hydrocarbon, steam, and a mixed gas thereof can be used. Further, the drying step and the firing step can be performed continuously or integrally.

The catalyst can be molded by a known method such as extrusion molding, compression molding, spray drying granulation (fluidized bed catalyst), and tumbling granulation. The shape of the catalyst is not particularly limited, such as a sphere, a cylinder, a ring, and a fine particle (a fluidized bed catalyst). Also, pre-formed alumina, silica alumina, silica, titania, silicon carbide, cordierite, mullite, those carrying the catalyst composition of the present invention on a carrier such as diatomaceous earth,
It is included in the scope of the present invention.

In the method of the present invention, acrolein and / or acrylic acid are produced by reacting an oxygen-containing gas with propane in the presence of a catalyst. As the oxygen-containing gas, it is desirable to use air for economic reasons. However, pure oxygen or, conversely, air diluted with nitrogen or the like can also be used. Particularly, in a process in which unreacted propane needs to be recycled, it is preferable to use pure oxygen from the viewpoint of preventing accumulation of inert gas. The use of steam or carbon dioxide as the diluting gas is also included in the scope of the present invention.

[0011] The reaction temperature is from 250 to 500 ° C, preferably from 300 to 450 ° C. At 250 ° C. or lower, the reaction is slow, and at 500 ° C. or higher, the heteropolyacid is decomposed, so that acrolein or acrylic acid cannot be obtained. The reaction pressure may be any of reduced pressure, normal pressure, and pressurized. Preferably 1
５5 kg / cm ² abs. The space velocity of the reaction is 100-1
000 [1 / hr], preferably 500 to 5,000
The range is [1 / hr]. The molar ratio of oxygen to propane is between 0.1 and 10. The reaction can be carried out on either the oxygen excess side or the propane excess side with respect to the stoichiometric ratio, but it is desirable to set the reaction conditions so as to avoid the explosion range for safety reasons.

[0012]

The present invention will be described below with reference to examples. The composition (atomic ratio) of the prepared catalyst is summarized in Table 1. Example 1 While stirring and heating 600 ml of water, 9.4 g of 85% phosphoric acid was added.
Molybdenum trioxide 100 g, vanadium pentoxide 6.3
g, copper oxide 1.1 g, and arsenic trioxide 1.3 g, and the mixture was heated under reflux for 3 hours. A second solution obtained by dissolving 2.3 g of cesium nitrate in 100 ml of water was added to the obtained raw material solution.
A third solution in which 13.5 g of aqueous ammonia was dissolved in 70 ml of water was simultaneously mixed. The obtained mixed solution was spray-dried as it was, and formed into tablets each having a diameter and a height of 3 mm. Then fired at 350 ° C for 10 hours in air,
Pulverized to 44-149 μm, P / Mo / V / As / C
A composite oxide catalyst having an u / Cs atomic ratio of 1.4 / 12 / 1.2 / 0.22 / 0.24 / 0.2 was obtained. 0.1 ml of the obtained catalyst was
mm into a glass reaction tube and 400 ° C under nitrogen flow.
Temperature. Next, 2 ml of a mixed gas consisting of 5% by volume of propane and 95% by volume of air was reacted at a contact time of 0.3 second, and the product was directly analyzed by gas chromatography. The reaction results are shown in Table 2.

Example 2 18.7% of 85% phosphoric acid while stirring and heating 600 ml of water.
g, molybdenum trioxide 100 g, vanadium pentoxide 1
2.6 g, 1.0 g of copper oxide and 1.0 g of cobalt oxide were added, and the mixture was heated under reflux for 3 hours. 28% in the obtained raw material solution
A second solution in which 13.5 g of aqueous ammonia was dissolved in 70 ml of water was mixed. After that, P / M is performed in the same manner as in the first embodiment.
A composite oxide catalyst having an o / V / Cu / Co atomic ratio of 2.8 / 12 / 2.4 / 0.22 / 0.22 was obtained. An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 3 A composite having an atomic ratio of P / Mo / V / Cu / Ni of 1.4 / 12 / 1.2 / 0.24 / 0.22 in the same manner as in Example 2 except that nickel oxide was used instead of cobalt oxide. An oxide catalyst was obtained.
An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 4 P / Mo / V was obtained in the same manner as in Example 2 except that arsenic trioxide and zinc oxide were used without using copper oxide and cobalt oxide.
A composite oxide catalyst having an atomic ratio of / As / Zn of 1.4 / 12 / 1.2 / 0.22 / 0.44 was obtained. An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 5 Potassium nitrate was used in place of cesium nitrate, and the other oxides were used as starting materials, and the atomic ratio of P / Mo / V / Sb / Cu / Se / K was obtained in the same manner as in Example 1. Is 1.5 / 12
/0.6/1.0/0.30/1.09/0.05 was obtained. An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 6 P / Mo / V / Cu / Ba / T was prepared in the same manner as in Example 5.
The atomic ratio of e / Fe / Ce / Ag / K is 1.5 / 12 / 0.5 / 0.1 /
A composite oxide catalyst having a ratio of 1.0 / 0.1 / 0.1 / 0.05 / 0.1 / 0.05 was obtained. An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

Example 7 Phosphorus molybdic acid, H3 PM manufactured by Nippon Inorganic Chemical Industry Co., Ltd.
An activity test was conducted in the same manner as in Example 1 using o12O40. The results are shown in Table 2.

Example 8 An activity test was carried out in the same manner as in Example 1 using 11-molybdo-1-vanadophosphoric acid and H4PMo11VO40 manufactured by Nippon Inorganic Chemical Industry Co., Ltd. The results are shown in Table 2.

Comparative Example 1 A divanadyl pyrophosphate catalyst containing gold was produced according to the method of Japanese Patent Application No. 3-344667. A reactor equipped with a condenser and a water separator was charged with 15.0 g of vanadium pentoxide, 60 ml of benzyl alcohol and 90 ml of isobutanol, heated under reflux for 2 hours, cooled to room temperature, and added thereto chloroauric acid tetrahydrate. 1.00 g, 85% phosphoric acid 20.1 g, and isobutanol 20 ml were added in this order, and the mixture was heated again under reflux for 2 hours. The obtained slurry was filtered, and 130 ° C, 7
Dried for hours. Water is again added to form a paste, heat-treated at 500 ° C. for 2 hours in a nitrogen atmosphere, and after cooling,
Milled to 9 μm. An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 2 A divanadyl pyrophosphate catalyst was produced in the same manner as in Comparative Example 1 except that gold was not added. Table 2 shows the results of the activity test.
The divanadyl pyrophosphate-based catalyst has a higher propane conversion rate than the catalyst of the present invention, but the selectivity to acrolein and acrylic acid is low at a reaction temperature of 400 ° C.

Comparative Example 3 In a 500 ml four-necked flask equipped with a reflux condenser, an aqueous solution of zirconium oxynitrate (20 g in solid content) and 200 g of 85% phosphoric acid were stirred and mixed, and then heated to reflux for 24 hours. The resulting precipitate was filtered, dried and calcined in air at 500 ° C. for 2 hours to obtain a phosphate having a P / Zr atomic ratio of 3.7. An activity test was performed in the same manner as in Example 1. The results are shown in Table 2.

[0023]

[Table 1]

[0024]

[Table 2]

[0025]

As is clear from the examples, the catalyst of the present invention has a high selectivity of the total of acrolein and acrylic acid,
It is excellent as a catalyst for industrially producing acrylic acid from propane.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C07C 57/05 C07C 57/05 // C07B 61/00 300 C07B 61/00 300 (72) Inventor Wang Kim ▲ Kai ▼ Kanagawa 1190 Kasama-cho, Sakae-ku, Yokohama City Examiner, Mitsui Toatsu Chemicals Co., Ltd. Eiko Shigeta (56) References JP-A-59-19545 (JP, A) JP-A-4-63139 (JP, A) JP-A 2- 83348 (JP, A) JP-A-55-62041 (JP, A) JP-A-2-157237 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 21/00-37 / 36 C07B 61/00

Claims (4)

(57) [Claims] 1. A catalyst for producing acrolein and / or acrylic acid from propane comprising a heteropolyacid containing phosphorus and molybdenum as essential components or a salt thereof. 2. A catalyst according to the general formula: Pa Mob Vc Ad Xe Ox (wherein P is phosphorus, Mo is molybdenum, V is vanadium, A is arsenic and / or antimony, X is tin,
Lead, cerium, cobalt, iron, zirconium, thorium, tungsten, germanium, nickel, rhenium, bismuth, chromium, boron, magnesium, calcium, barium, strontium, selenium, tellurium,
At least one element selected from the group consisting of silver, aluminum, zinc, copper, titanium, potassium, rubidium, cesium and thallium, O represents oxygen, and b = 1
In the case of 2, a = 0.5-3, c = 0.01-3, d = 0-3,
2. The catalyst according to claim 1, wherein e = 0 to 3, and x is a number determined by the oxidation state of each constituent element. 3. A method for producing acrolein and / or acrylic acid by reacting propane with molecular oxygen, wherein a catalyst comprising a heteropolyacid containing phosphorus and molybdenum as essential components or a salt thereof is used. And a method for producing acrolein and / or acrylic acid. 4. A catalyst according to the general formula: Pa Mob Vc Ad Xe Ox (where P is phosphorus, Mo is molybdenum, V is vanadium, A is arsenic and / or antimony, X is tin,
Lead, cerium, cobalt, iron, zirconium, thorium, tungsten, germanium, nickel, rhenium, bismuth, chromium, boron, magnesium, calcium, barium, strontium, selenium, tellurium,
At least one element selected from the group consisting of silver, aluminum, zinc, copper, titanium, potassium, rubidium, cesium and thallium, O represents oxygen, and b = 1
In the case of 2, a = 0.5-3, c = 0.01-3, d = 0-3,
4. The method according to claim 3, wherein e = 0 to 3, and x is a number determined by the oxidation state of each constituent element.