JP5288256B2 - Catalyst for producing lower olefin, process for producing the same, and process for producing lower olefin using the same - Google Patents

Description

  The present invention relates to a catalyst for producing a lower olefin, a production method thereof and a production method of a lower olefin using the same. More specifically, the present invention relates to a zeolite catalyst that can efficiently produce a lower olefin and has high durability in a high-temperature steam atmosphere, a production method thereof, and a production method of a lower olefin using the same.

  Lower olefins such as ethylene and propylene are important substances as basic raw materials for various chemicals. Conventionally, as a method for producing these lower olefins, gas hydrocarbons such as ethane, propane and butane, or liquid hydrocarbons such as naphtha are used as raw materials, and heat decomposition is performed in a steam atmosphere in an externally heated tubular furnace. Is widely implemented. However, this method requires a high temperature of 800 ° C. or higher in order to increase the olefin yield, and it is known that not only olefin but also aromatic components are produced under such temperature conditions. Since this aromatic component can be easily produced by a production method other than the method of thermally decomposing, a technique for selectively producing lower olefins has been demanded. For this reason, various methods for producing olefins using catalysts have been studied, and among them, when a solid acid, especially a zeolitic catalyst is used, the above raw material can be decomposed at a relatively low temperature (350 to 700 ° C.). Therefore, many examples of this method have been reported.

  For example, Patent Document 1 discloses a method for producing a lower olefin using ZSM-5 (crystalline aluminosilicate) in which the α value that is an index of cracking activity is controlled within a specific range, and Patent Document 2 discloses an acid amount. And a catalytic cracking method of naphtha using a ZSM-5 type catalyst in which the crystal size of ZSM-5 is controlled in a specific range. However, in these methods, aromatic components (benzene, toluene, xylene, hereinafter referred to as “BTX”) are produced in an amount of about 20 to 25% by mass, and the yields of ethylene and propylene remain at about 35 to 45% by mass. The olefin could not be obtained efficiently.

  Patent Document 3 discloses a method for producing a lower olefin using methanol as a raw material by ZSM-5 carrying calcium and phosphorus, and the selectivity and catalyst life of the lower olefin by introducing calcium and phosphorus. Has been shown to improve. However, since it contains oxygen atoms in the molecule, it does not contain methanol that can be subjected to catalytic cracking under relatively mild conditions.If other hydrocarbon raw materials are used, catalytic cracking is performed at a higher temperature. A lot of aromatic and coke components were produced, and the effect of improving selectivity and catalyst life of lower olefins was not sufficient.

  Similarly, Patent Documents 4 and 5 are known as a method for producing a lower olefin using a catalyst supporting an alkaline earth metal and phosphorus. Patent Document 4 discloses a method for producing olefins using ZSM-5 containing a water-insoluble metal salt such as magnesium oxide or calcium oxalate and a phosphoric acid compound as a catalyst, but the raw material conversion is 80% by mass or less. In addition, the yield of ethylene and propylene is as low as less than 40% by mass, and Patent Document 5 discloses a method for producing olefins using a catalyst in which magnesium and phosphorus are supported on ZSM-5, but the raw material conversion is 70. It was as low as less than mass%, and the effect of suppressing deterioration of the catalyst activity was insufficient.

  Furthermore, Patent Document 6 discloses a catalyst for producing a lower olefin containing a zeolite containing magnesium and phosphorus or calcium and phosphorus, and exhibits excellent activity stability even when the catalyst is exposed to a steam atmosphere under high temperature conditions. It has been shown to have sex. However, its performance has not been industrially satisfactory.

As mentioned above, several methods for the production of olefins by alkaline earth metal and phosphorus supported ZSM-5 have been disclosed, but their performance is still not industrially satisfactory and further olefin yields Improvement of the catalyst and suppression of catalyst activity deterioration have been desired.
Japanese Patent Publication No. 3-504737 JP-A-6-346062 Japanese Patent Laid-Open No. 61-15848 US Patent Publication No. 2007 / 0082809A1 Chinese Patent Publication No. 14104068 Japanese Patent Laid-Open No. 11-192431

  An object of the present invention is to provide a zeolite catalyst that can efficiently produce lower olefins and has high durability in a high-temperature steam atmosphere, a method for producing the same, and a method for producing lower olefins using the same. .

  In the conventional method for preparing an alkaline earth metal and phosphorus-supported catalyst, the present inventors impregnated zeolite with a slurry-like mixed liquid containing an insoluble salt when supporting the above components. As a result of intensive investigations to solve the above-mentioned problems, it is possible to efficiently produce a lower olefin by carrying it using a water-soluble salt containing an alkaline earth metal and phosphorus, The inventors have found that a highly durable catalyst in a high-temperature steam atmosphere can be obtained, and have completed the present invention.

  That is, the present invention provides the following means in order to solve the above problems.

[1] A crystalline aluminosilicate having an MFI structure in which an alkaline earth metal and phosphorus are supported by a process including an impregnation process, a drying process, and a firing process, and the alkaline earth metal and phosphorus are mixed with alkaline earth metal and phosphorus. A catalyst for producing a lower olefin, which is supported by a water-soluble salt contained therein.

[2] The catalyst for producing a lower olefin according to [1], wherein the solubility of the water-soluble salt in water is 1 g / 100 ml or more at 20 ° C.

[3] The catalyst for producing a lower olefin according to [1] or [2], wherein the water-soluble salt is an alkaline earth metal dihydrogen phosphate or hypophosphite.

[4] The catalyst for producing a lower olefin according to [1] or [2], wherein the water-soluble salt is an alkaline earth metal salt of a polyol phosphate.

[5] The catalyst for producing a lower olefin according to any one of [1] to [ 4 ], wherein the crystalline aluminosilicate is ZSM-5.

[6] The catalyst for producing a lower olefin according to any one of [1] to [ 5 ], wherein the content of the alkaline earth metal is 0.1 to 20% by mass.

[7] The catalyst for producing a lower olefin according to any one of [1] to [ 6 ], wherein the phosphorus content is 0.1 to 20% by mass.

[8] The catalyst for producing a lower olefin according to any one of [1] to [ 7 ], further comprising a rare earth element.

[9] the crystalline aluminosilicate having an MFI structure, impregnation step, drying step and making the lower olefin production catalyst for carrying the alkaline earth metal and phosphorus by a process comprising calcining step, the alkaline earth in the impregnation step method for producing lower olefins production catalyst, which comprises using a metalloid and a water-soluble salt containing phosphorus.

[10] The method for producing a catalyst for producing a lower olefin according to [ 9 ], wherein the solubility of the water-soluble salt in water is 1 g / 100 ml or more at 20 ° C.

[11] The method for producing a catalyst for producing a lower olefin according to [ 9 ] or [ 10 ], wherein the water-soluble salt is an alkaline earth metal dihydrogen phosphate or hypophosphite.

[12] The method for producing a catalyst for producing a lower olefin according to [ 9 ] or [ 10 ], wherein the water-soluble salt is an alkaline earth metal salt of a polyol phosphate.

[13] A method for producing a lower olefin using the catalyst for producing a lower olefin according to any one of [1] to [ 8 ].

[14] The method for producing a lower olefin according to [ 13 ], which is carried out in the presence of water vapor.

  The catalyst for producing a lower olefin of the present invention can suppress the production of aromatic components, can produce a lower olefin efficiently, and can further suppress catalyst deterioration under a high-temperature steam atmosphere. Can be suitably used as a catalyst for the production of lower olefins.

The catalyst of the present invention comprises a crystalline aluminosilicate as a main component and supports an alkaline earth metal and phosphorus. As the main component crystalline aluminosilicate, one having an MFI structure, ZSM-5 is particularly preferable. The SiO ₂ / Al ₂ O ₃ molar ratio of this crystalline aluminosilicate is preferably 20 to 600, more preferably 22 to 300, and particularly preferably 25 to 100.

  As the alkaline earth metal supported on the crystalline aluminosilicate, any of magnesium, calcium, strontium, barium and the like can be suitably used, and among these, magnesium and calcium are particularly preferable. The alkaline earth metals may be used alone or in combination of two or more. The content of the alkaline earth metal is preferably 0.1 to 20% by mass, more preferably 0.2 to 15% by mass, and particularly preferably 0.5 to 10% by mass in terms of elements with respect to the catalyst of the present invention. It is.

  The phosphorus content is preferably 0.1 to 20% by mass, more preferably 1.0 to 15% by mass, and particularly preferably 1.5 to 10% by mass in terms of elements with respect to the catalyst of the present invention.

  The catalyst of the present invention can be obtained by using a water-soluble salt containing an alkaline earth metal and phosphorus when the alkaline earth metal and phosphorus are supported on the crystalline aluminosilicate. The water-soluble salt preferably has a water solubility of 1 g / 100 ml or more at 20 ° C., and specific water-soluble salts include alkaline earth metal dihydrogen phosphate and hypophosphorous acid. Examples thereof include inorganic salts such as salts and salts of polyol phosphate esters such as glycerophosphate. As a method of supporting alkaline earth metal and phosphorus using these water-soluble salts, a method of impregnating a proton-type crystalline aluminosilicate in an aqueous solution in which the water-soluble salt is dissolved, drying, and firing. Can be mentioned.

  For example, when dihydrogen phosphate, hypophosphite, etc. are used, the ratio of phosphorus to alkaline earth metal is 2: 1 (molar ratio), but you want to change the ratio of phosphorus to alkaline earth metal May carry alkaline earth metal and / or phosphorus in a separate step before or after loading with a water-soluble salt.

  Examples of the method for supporting the alkaline earth metal include various salts of alkaline earth metal such as acetate, nitrate, halide, sulfate, carbonate or alkoxide, water in which acetylacetonate is dissolved, ethanol and the like. Examples of the method include impregnating the crystalline aluminosilicate in a solution, drying, and firing.

  As a method for supporting phosphorus, for example, the above crystalline aluminosilicate is impregnated in a solution of water, ethanol or the like in which a phosphorus compound such as phosphoric acid, ammonium dihydrogen phosphate, or diammonium hydrogen phosphate is dissolved, dried, The method of baking can be mentioned.

  As the impregnation method in preparing the catalyst, a normal impregnation method such as an evaporation to dryness method, an incipient wetness method, or a pore filling method can be used. The impregnation time is usually about 0.5 to 2 hours, the drying temperature is usually 80 to 200 ° C., the firing temperature is usually 400 to 800 ° C., and the firing time is usually about 1 to 12 hours.

  In addition to the crystalline aluminosilicate, alkaline earth metal, and phosphorus, the catalyst of the present invention may carry a rare earth element, alkali metal, transition metal, noble metal, halogen, or the like. Furthermore, the catalyst of the present invention can be diluted with silica, alumina, quartz sand or the like.

  For example, as a method for supporting a rare earth element, various salts of rare earth elements, such as acetate, nitrate, halide, sulfate, carbonate or alkoxide, acetylacetonate, etc. dissolved in water, ethanol or the like, Examples of the method include impregnating the crystalline aluminosilicate, drying, and firing.

  The catalyst of the present invention thus obtained can efficiently produce lower olefins in the production of lower olefins by catalytic cracking reaction, and can suppress catalyst deterioration under a high-temperature steam atmosphere. It can be suitably used as a catalyst for producing lower olefins using various hydrocarbons as raw materials. The reason why such an effect can be obtained by using a water-soluble salt containing an alkaline earth metal and phosphorus is not clear, but by using a water-soluble salt for one, each component is contained in the catalyst. This is presumed to be uniformly supported on the surface. On the other hand, in the conventionally used method, it is presumed that a salt containing an alkaline earth metal and phosphorus insoluble in water is formed into a slurry and is not uniformly supported in the catalyst.

  In the production of the lower olefin by the catalytic cracking reaction using the catalyst of the present invention, as the hydrocarbon raw material, a gaseous or liquid hydrocarbon at normal temperature and normal pressure, or an oxygen-containing compound such as methanol, ethanol or dimethyl ether can be used. In general, paraffins having 2 to 30 carbon atoms, preferably 4 to 10 carbon atoms, or hydrocarbon raw materials based on these are used. Examples of such hydrocarbon raw materials include ethane, propane, Examples thereof include paraffins such as butane, pentane and hexane, and light hydrocarbon fractions such as naphtha and light oil. Further, the hydrocarbon raw material is not limited to saturated hydrocarbons, and those containing components having unsaturated bonds can be used, and further aromatic components may be included.

  The catalytic cracking reaction is carried out by supplying a hydrocarbon raw material to a catalyst layer filled with the catalyst of the present invention using a reactor of a fixed bed type, fluidized bed type or the like. At this time, the hydrocarbon raw material may be diluted with nitrogen, hydrogen, helium, water vapor or the like. Among these diluents, water vapor is particularly preferable because it suppresses the production of coke components and maintains the activity of the catalyst. The supply amount of water vapor is 0.1 to 1, preferably 0.3 to 0.7 in terms of mass ratio with respect to the raw material hydrocarbon. The reaction temperature is usually 350 to 780 ° C, preferably 500 to 750 ° C, more preferably 600 to 700 ° C. Although it can be carried out at a temperature exceeding 780 ° C., the production of methane and coke components increases rapidly, and sufficient activity cannot be obtained at a temperature below 350 ° C., so that the olefin yield per pass is reduced.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1
(1) Catalyst preparation 10 g of powdered proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O ₃ molar ratio = 40), calcium hypophosphite aqueous solution {1.36 g of calcium hypophosphite (special grade), ion-exchanged water The product dissolved in 100 g} was impregnated and stirred at 40 ° C. for 1 hour. While stirring the produced slurry at 40 to 60 ° C. under reduced pressure, water was evaporated for about 1 hour to obtain a white powder. The obtained powder was dried in air at 120 ° C. for 12 hours, then heated to 600 ° C. over 4 hours in a muffle furnace, and fired at 600 ° C. for 5 hours. The obtained white solid molded into 10 to 14 mesh (1.2 to 1.7 mm) was used as a catalyst. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 2.6% by mass and 3.9% by mass, respectively, in terms of element.

(2) Reaction evaluation The obtained catalyst (2.2 g) was packed in a stainless steel reaction tube (made of SUS316) having an inner diameter of 10 mm so that the length of the catalyst layer was 40 mm. The upper and lower sides of the catalyst layer were filled with quartz sand. While flowing nitrogen into the reactor, the temperature of the catalyst layer was raised to 650 ° C., and n-hexane (special grade) was supplied as raw materials at a flow rate of 8 g / hr, nitrogen at 10 ml / min, and water vapor at a flow rate of 4 g / hr. -Catalytic decomposition reaction of hexane was performed. The reaction product was analyzed by gas chromatography, and the product yield and the raw material conversion were calculated by the following equations.

Product yield (C-mol%) = (number of moles of each component based on carbon / number of moles based on feed carbon) × 100
Raw material conversion (mass%) = (1-unreacted raw material weight / feed raw material weight) × 100

  Table 1 (column before steaming treatment) shows the product yield and the raw material conversion rate after 6 hours from the start of the raw material supply.

(3) Hydrothermal stability evaluation Next, the hydrothermal stability of the catalyst was evaluated. That is, 5 g of the obtained catalyst was filled in a quartz tube, steamed at a steam supply rate of 10 g / hr, a nitrogen flow rate of 10 ml / min, and 700 ° C. for 40 hours, and the treated catalyst was subjected to the same conditions as in (2) above. The reaction was evaluated. The results 6 hours after the start of the reaction are shown in Table 1 (column after the steaming treatment).

Comparative Example 1
Calcium acetate solution {6.34 g of calcium acetate monohydrate (special grade) dissolved in 300 g of ion-exchanged water} and ammonium dihydrogen phosphate solution {4.14 g of dibasic phosphate in a 90 ° C. warm bath A solution of ammonium hydrogen (primary) dissolved in 300 g of ion-exchanged water} was mixed to obtain a slurry-like mixed solution. To this mixed solution, 10 g of powdery proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O ₃ molar ratio = 40) was added and stirred at 40 ° C. for 1 hour. The produced slurry was filtered under reduced pressure, washed with ion exchange water, dried in air at 120 ° C. for 12 hours, heated to 600 ° C. over 4 hours in a muffle furnace, and calcined at 600 ° C. for 5 hours. The obtained white solid molded into 10 to 14 mesh (1.2 to 1.7 mm) was used as a catalyst. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 8.9 mass% and 4.6 mass%, respectively, in terms of element.

  Using the obtained catalyst, the above (2) reaction evaluation and (3) hydrothermal stability evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

  As is apparent from Table 1, when the catalytic activity before the steaming treatment is compared, the catalyst of Example 1 supported by using an aqueous salt solution containing calcium and phosphorus is a mixed solution of calcium and phosphorus in a slurry state. Compared with the catalyst of Comparative Example 1 supported by using a higher yield of lower olefin (C2 + C3 yield) and lower aromatic component yield (BTX yield), superior in lower olefin selectivity It can be seen that it is. Further, when the catalytic activity after the steaming treatment is compared, the catalyst of Example 1 maintains the lower olefin yield (C2 + C3 yield) and the conversion rate remarkably higher than those of Comparative Example 1, and is hydrothermal stable. It turns out that it is excellent in property.

Example 2 and Comparative Example 2
Example 1 and Comparative Example 1 were used, respectively, except that the amount of n-hexane supplied was changed to 2.6 g / hr and the amount of water vapor supplied was changed to 1.3 g / hr. The reaction was evaluated by the method. FIG. 1 shows the change in the raw material conversion with respect to the amount of hexane treated per 1 g of the catalyst, and FIG. As is apparent from FIG. 1, although the initial conversion rate in Comparative Example 2 is slightly higher than that in the Example, the conversion rate decreases as the amount of hexane increases, whereas in Example 2, the conversion rate is low. It can be seen that the ratio is kept almost constant and the decrease in the conversion rate is suppressed. As is clear from FIG. 2, the catalyst of Example 2 maintains a lower olefin yield (C2 + C3 yield) higher than that of Comparative Example 2, and can efficiently produce the lower olefin.

Example 3
A catalyst was prepared in the same manner as in Example 1 except that the amount of calcium hypophosphite was changed from 1.36 g to 0.68 g. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 1.3% by mass and 2.0% by mass, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 2 shows the raw material conversion rate and product selectivity after 4 hours from the start of the reaction.

Example 4
A catalyst was prepared in the same manner as in Example 1 except that the amount of calcium hypophosphite was changed from 1.36 g to 1.02 g. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 2.0% by mass and 3.0% by mass, respectively, in terms of elements. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 2 shows the raw material conversion rate and product selectivity after 4 hours from the start of the reaction.

Example 5
The catalyst was the same as in Example 1 except that the impregnation solution was changed to calcium dihydrogen phosphate aqueous solution {1.01 g of calcium dihydrogen phosphate monohydrate (special grade) dissolved in 100 g of ion-exchanged water}. Prepared. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 1.2% by mass and 2.1% by mass, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 2 shows the results after 5 hours from the start of the reaction.

Example 6
A catalyst was prepared in the same manner as in Example 1 except that the impregnation solution was changed to a magnesium hypophosphite aqueous solution {1.04 g of magnesium hypophosphite (special grade) dissolved in 100 g of ion-exchanged water}. When the Mg and P concentrations in the prepared catalyst were measured by ICP-MS, they were 0.9% by mass and 3.5% by mass, respectively, in terms of elements. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 2 shows the results after 5 hours from the start of the reaction.

  From Table 2, it can be seen that a catalyst having a high olefin yield and a high conversion rate can be obtained even if the supported amount of alkaline earth and phosphorus, the type of precursor, and the type of alkaline earth metal are changed.

Example 7
10 g of powdery proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O ₃ molar ratio = 40) and calcium acetate aqueous solution {0.71 g of calcium acetate monohydrate (special grade) are dissolved in 100 g of ion-exchanged water. Was impregnated and stirred at 40 ° C. for 1 hour. While stirring the produced slurry at 40 to 60 ° C. under reduced pressure, water was evaporated for about 1 hour to obtain a white powder. The obtained powder was dried in air at 120 ° C. for 12 hours, then heated to 600 ° C. over 4 hours in a muffle furnace, and fired at 600 ° C. for 5 hours. The obtained fired product was impregnated with a calcium hypophosphite aqueous solution {1.36 g of calcium hypophosphite (special grade) dissolved in 100 g of ion-exchanged water} and stirred at 40 ° C. for 1 hour. While stirring the produced slurry at 40 to 60 ° C. under reduced pressure, water was evaporated for about 1 hour to obtain a white powder. The obtained powder was dried in air at 120 ° C. for 12 hours, then heated to 600 ° C. over 4 hours in a muffle furnace, and fired at 600 ° C. for 5 hours. The obtained white solid molded into 10 to 14 mesh (1.2 to 1.7 mm) was used as a catalyst. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 4.2% by mass and 4.3% by mass, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 3 shows the results after 5 hours from the start of the reaction.

Example 8
Similar to Example 7 except that the calcium hypophosphite aqueous solution was changed to calcium dihydrogen phosphate aqueous solution {1.02 g of calcium dihydrogen phosphate monohydrate (special grade) dissolved in 100 g of ion-exchanged water}. A catalyst was prepared. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 4.2% by mass and 4.3% by mass, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 3 shows the results 6 hours after the start of the reaction.

Example 9
A catalyst was prepared in the same manner as in Example 7 except that the order of loading with calcium acetate and calcium hypophosphite was reversed. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 4.2% by mass and 4.3% by mass, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 3 shows the results 6 hours after the start of the reaction.

Example 10
A catalyst was prepared in the same manner as in Example 8 except that the order of loading with calcium acetate and calcium dihydrogen phosphate was reversed. When the Ca and P concentrations in the prepared catalyst were measured by ICP-MS, they were 4.2% by mass and 4.3% by mass, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 3 shows the results after 5 hours from the start of the reaction.

Example 11
A catalyst was prepared in the same manner as in Example 9 except that 0.95 g of lanthanum acetate hemihydrate (purity 99.9%) was used instead of calcium acetate. When the Ca, P, and La concentrations in the prepared catalyst were measured by ICP-MS, they were 2.7 mass%, 4.2 mass%, and 1.3 mass%, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 3 shows the results after 5 hours from the start of the reaction.

Example 12
A catalyst was prepared in the same manner as in Example 11 except that the amount of lanthanum acetate hemihydrate (purity 99.9%) was changed to 2.63 g. When the Ca, P, and La concentrations in the prepared catalyst were measured by ICP-MS, they were 2.7 mass%, 4.2 mass%, and 3.6 mass%, respectively, in terms of element. Using this catalyst, the reaction was evaluated in the same manner as in Example 1. Table 3 shows the results 6 hours after the start of the reaction.

  As shown in Table 3, before or after supporting the alkaline earth metal and phosphorus using a water-soluble salt, the supporting ratio of the alkaline earth metal and phosphorus can be increased by separately supporting the alkaline earth metal compound. Can be adjusted. The catalysts of Examples 7 to 10 thus obtained also have a high conversion rate and lower olefin yield as shown in Table 3, and can be suitably used as a catalyst for catalytic cracking.

  Further, as shown in Examples 11 and 12, rare earth elements can be supported on the catalyst of the present invention. The catalysts of Examples 11 and 12 loaded with rare earth elements also have a high conversion rate and lower olefin yield as shown in Table 3, and can be suitably used as a catalyst for catalytic cracking.

It is the figure which showed the change of the conversion rate in Example 2 and Comparative Example 2. FIG. It is the figure which showed the change of the C2 + C3 olefin yield in Example 2 and Comparative Example 2.

Claims (14)

A crystalline aluminosilicate having an MFI structure carrying an alkaline earth metal and phosphorus by a process including an impregnation process, a drying process, and a baking process , and the alkaline earth metal and phosphorus are soluble in water containing alkaline earth metal and phosphorus. A catalyst for producing a lower olefin, which is supported by a salt of   The catalyst for producing a lower olefin according to claim 1, wherein the solubility of the water-soluble salt in water is 1 g / 100 ml or more at 20 ° C.   The catalyst for producing a lower olefin according to claim 1 or 2, wherein the water-soluble salt is an alkaline earth metal dihydrogen phosphate or hypophosphite.   The catalyst for producing a lower olefin according to claim 1 or 2, wherein the water-soluble salt is an alkaline earth metal salt of a polyol phosphate. The catalyst for producing a lower olefin according to any one of claims 1 to 4 , wherein the crystalline aluminosilicate is ZSM-5. The catalyst for producing a lower olefin according to any one of claims 1 to 5 , wherein the content of the alkaline earth metal is 0.1 to 20% by mass. The catalyst for producing a lower olefin according to any one of claims 1 to 6 , wherein the phosphorus content is 0.1 to 20% by mass. Furthermore, a lower olefin production catalyst according to any one of claims 1 to 7 including a rare earth element. A crystalline aluminosilicate having an MFI structure, impregnation step, making the drying process and lower olefin production catalyst for carrying the alkaline earth metal and phosphorus by a process comprising calcining step, the alkaline earth metals in the impregnation step method for producing lower olefins production catalyst, which comprises using a water-soluble salt containing phosphorus. The method for producing a catalyst for producing a lower olefin according to claim 9 , wherein the solubility of the water-soluble salt in water is 1 g / 100 ml or more at 20 ° C. The method for producing a catalyst for producing a lower olefin according to claim 9 or 10 , wherein the water-soluble salt is an alkaline earth metal dihydrogen phosphate or hypophosphite. The method for producing a catalyst for producing a lower olefin according to claim 9 or 10 , wherein the water-soluble salt is an alkaline earth metal salt of a polyol phosphate. Any method for producing lower olefins with lower olefin production catalyst according to claim 1-8. Lower process for producing an olefin according to claim 1 to 3, carried out in the presence of water vapor.