JP2007290991A - Method for producing olefin from oxygen-containing compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing olefins in high yield from ethanol as feedstock, and a method capable of efficiently improving propylene yield. <P>SOLUTION: The method for producing the olefins comprises catalyzing ethanol as the feedstock with a pentasil type-structured zeolite catalyst modified with zirconium and phospgorus. In another version of this method, propylene content of the olefins produced can be controlled by using dimethyl ether and/or methanol together with ethanol as feedstoks and controlling their feed ratio. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an olefin by contacting an oxygen-containing compound as a raw material with a catalyst, and more specifically, a method for producing an olefin in a high yield using ethanol as a raw material using a zeolite catalyst, and a yield of propylene. It is related with the method which can improve efficiently.

Light olefins such as ethylene and propylene are widely used as basic raw materials in the chemical industry. As the production method, thermal cracking of saturated hydrocarbons such as naphtha or catalytic cracking of heavy hydrocarbons is mainly carried out. On the other hand, reforming natural gas such as methane to make synthesis gas (mixed gas of hydrogen and carbon monoxide), producing methanol using this synthesis gas as raw material, and dehydrating condensation using zeolite catalyst, producing olefin It is also known that it can be done.
Although natural gas is difficult to liquefy and transport, it can be easily transported as a liquid by converting it to a compound such as methanol or dimethyl ether. It can be used as a raw material. Since natural gas is widely distributed all over the world as compared with petroleum-based resources, various olefin production via derivatives from such natural gas have been studied. Among these light olefins, ethylene can be efficiently produced by thermal decomposition of ethane, but propylene has a low yield in thermal decomposition, and therefore production technology for producing more propylene is available. It is desired.

On the other hand, a method in which ethanol (ethyl alcohol) is used as a raw material and is brought into contact with a solid catalyst and converted into olefin (ethylene) by a dehydration reaction has been known for a long time. Since ethanol can be produced by fermentation of biomass such as plant raw materials, it has attracted attention as a raw material for chemical production from the viewpoint of substituting petroleum resources and reducing carbon dioxide emissions. Since ethanol produced from biomass is generally obtained as an aqueous solution, it is desirable to use a method in which the reaction can be carried out as it is without performing operations such as distillation and concentration.
In addition, methanol and dimethyl ether produced using synthesis gas produced by biomass gasification can also be used as carbon-recycling resources, and these oxygenated compounds can be efficiently converted into olefins. Technology is desired.

There have been many reports on the production of olefins using ethanol as a raw material. As the catalyst, a method using a solid acid catalyst such as silica alumina or zeolite is disclosed. (For example, refer to Patent Documents 1 and 2 and Non-Patent Documents 1 and 2)
However, amorphous solid acid catalysts such as silica alumina are severely deteriorated by coking, and therefore, continuous regeneration in a fluidized bed reactor and regeneration by periodic burning are required. On the other hand, in the method using zeolite such as ZSM-5, it can be operated under relatively low temperature deterioration conditions, and in Patent Document 2, the raw material ethanol is diluted with other alcohols such as water and methanol. However, it is described that the reaction proceeds at a high yield.
Ethylene is mainly obtained from ethanol, but it may be necessary to make more propylene due to market demands. Patent Document 2 describes that when a mixture of ethanol and methanol is reacted as a raw material, the proportion of propylene can be increased by increasing the proportion of methanol, but the propylene selectivity at a methanol amount of 20% by mass is described. Is 9%, but even when the amount of methanol is 50% by mass, the propylene selectivity is 12%, and the propylene selectivity is low.

Non-Patent Document 3 discloses a dimethyl ether using a catalyst (H ₃ PO ₄ /12.5%-ZrO ₂ / H-ZSM-5) in which ZSM-5 type zeolite modified with zirconium is treated with phosphoric acid. Although it has been reported that propylene selectivity is improved in the reaction (propylene / ethylene ratio (carbon ratio) = about 10 to 16), this is a small-scale experiment using an expensive quartz reactor, In particular, when steel is used as a reactor, it is predicted that the heavy content will increase due to the influence of elution of metal from the reactor by phosphoric acid.
Non-Patent Document 3 also describes the result of comparison of the acid strength of the catalyst by the ammonia adsorption method. According to it, it is shown that the amount of acid increases by carrying phosphoric acid, and it is suggested that the function of phosphoric acid as an acid is important. However, the reactivity of ethanol is unknown.
Patent Document 3 discloses an example of a zirconium-containing catalyst treated with phosphoric acid or sulfuric acid in the same manner. However, both phosphoric acid and sulfuric acid must be acids. Non-patent document 4 discloses the interaction between H ₃ PO ₄ and ZrO ₂ . However, the use of corrosive substances such as phosphoric acid is disadvantageous in terms of cost, such as measures for preventing corrosion of the apparatus during catalyst preparation and neutralizing treatment of waste phosphoric acid.

U.S. Pat. No. 4,134,926 U.S. Pat. No. 4,698,452 JP 2006-016345 A Chemistry Letters, 105, 249 (2005) Proceedings of the 35th Petroleum and Petrochemical Discussion Conference, page 253 (2005) Chemistry Letters, 34, 970 (2005) Journal of Physical Chemistry, 105, 10653 (2001)

As described above, when producing olefins using ethanol as a raw material, a method for obtaining olefins in a high yield and a reaction method capable of coping with improvement in the yield of propylene have not been developed. In addition, the use of corrosive substances such as phosphoric acid has disadvantages in cost, such as measures for preventing corrosion of the apparatus during catalyst preparation and neutralizing treatment of waste phosphoric acid.
An object of the present invention is to provide a method for producing olefins with a high yield using ethanol as a raw material, and a method capable of efficiently improving the yield of propylene.

  As a result of intensive studies on the above problems, the present inventors have obtained olefin (ethylene) in a high yield by reforming ethanol using a zeolite catalyst in which a zeolite having a pentasil structure is modified with zirconium and phosphorus. It has been found that by mixing methanol or ethanol with ethanol, the selectivity to propylene can be increased, the production ratio of propylene / ethylene can be changed, and light olefins can be produced stably and economically advantageously over a long period of time. The present invention has been completed based on such findings.

That is, the present invention provides the following method for producing olefins.
1. A process for producing olefins, characterized in that ethanol as a raw material is contacted with a zeolite catalyst having a pentasil structure modified with zirconium and phosphorus.
2. The method for producing olefins according to 1 above, wherein dimethyl ether and / or methanol is used as a raw material together with ethanol, and the amount of propylene in the generated olefin is adjusted by controlling the supply ratio of dimethyl ether and / or methanol to ethanol.
3. The method for producing olefins according to 2 above, wherein the supply ratio of dimethyl ether and / or methanol to ethanol is 70% or less by carbon atom ratio.
4). The method for producing an olefin according to any one of the above 1 to 3, wherein the zeolite having a pentasil structure is ZSM-5 and / or ZSM-11.
5). The method for producing an olefin according to any one of 1 to 4 above, wherein the silica / alumina molar ratio of the zeolite having the pentasil structure is 20 to 700.
6). The olefin according to any one of 1 to 5 above, wherein the zeolite catalyst having a pentasil structure modified with zirconium and phosphorus is obtained by modifying a zeolite having a pentasil structure modified with zirconium with a phosphate and / or an organic phosphorus compound. Manufacturing method.
7). The method for producing an olefin according to any one of 1 to 6 above, wherein the raw material is brought into contact with a zeolite catalyst pretreated at a temperature of 300 to 1000 ° C in the presence of steam.
8). The method for producing an olefin according to any one of 1 to 7 above, wherein the raw material is brought into contact with the zeolite catalyst in the presence of steam.

According to the present invention, olefin (ethylene) can be produced with high yield from ethanol as a raw material, and propyl ether and / or methanol can be used as a raw material together with ethanol, and in particular, the yield of propylene can be efficiently increased. You can also.
In addition, according to the present invention, the ethylene / propylene ratio can be adjusted by controlling the supply ratio of ethanol and dimethyl ether and / or methanol, and olefins can be produced efficiently with respect to market demand. be able to.
Furthermore, in the present invention, the zeolite catalyst used for the production of olefins can be prepared by a method that does not use a corrosive substance, so that it is possible to prevent corrosion of the apparatus at the time of catalyst preparation and to neutralize waste phosphoric acid. Without need, the catalyst can be produced economically advantageously.
In the present invention, ethanol from biomass can be used as a raw material as it is, and therefore it is not necessary to concentrate ethanol from biomass to remove moisture.

Ethanol used as a raw material in the present invention can be used in an aqueous solution of any ratio, or a mixture with other hydrocarbons or alcohols.
Moreover, what mixed ethanol and dimethyl ether and methanol can be used as a raw material used for reaction in this invention, and this can raise the yield of propylene efficiently and can adjust ethylene / propylene ratio.
Furthermore, as a raw material used in the present invention, ethanol or a mixture of ethanol and dimethyl ether or methanol diluted with other hydrogen, nitrogen, steam, hydrocarbon or the like can be used. Moreover, what contains light olefins, such as ethylene, propylene, and butenes which are products, can also be used for a raw material.
In addition, since it is preferable to react in steam coexistence as mentioned later, the ethanol from the moisture containing biomass can be used as a raw material as it is.

That is, in the present invention, by using dimethyl ether and / or methanol together with ethanol as a raw material and controlling the supply ratio of dimethyl ether and / or methanol to ethanol, the amount of propylene in the produced olefin is adjusted, and the yield of propylene is increased. be able to.
At this time, the supply ratio of dimethyl ether and / or methanol with respect to ethanol shows a remarkable effect of improving the propylene yield up to about 70% in terms of carbon atom ratio, but in a region higher than 70%, the effect of improving the propylene yield. However, there is a tendency to peak. For this reason, it is preferable to make this supply ratio into 70% or less, and it is still more preferable to set it as 10 to 50%.
In addition, ethanol, dimethyl ether, and methanol may be mixed and supplied to the reactor, or may be supplied separately.

The catalyst used in the present invention is a zeolite catalyst obtained by modifying a zeolite having a pentasil structure with zirconium and phosphorus.
As this pentasil type zeolite, ZSM-5 and ZSM-11 are particularly preferable. The zeolite has a SiO ₂ / Al ₂ O ₃ molar ratio of usually 20 to 700, preferably 40 to 600, and more preferably 80 to 300.

Zirconium is introduced into the zeolite by, for example, zirconyl nitrate dihydrate (ZrO (NO ₃ ) ₂ .2H ₂ O), chlorinated zirconium oxide octahydrate (ZrCl ₂ O.8H ₂ O), zirconyl acetate (ZrO ( CH ₃ COO) ₂ ), zirconium sulfate (IV) tetrahydrate (Zr (SO ₄ ) ₂ .4H ₂ O) and other ion exchange methods, impregnation methods, hydrothermal synthesis methods, etc. Can be done by the method.

  The content of zirconium is usually 0.1 to 30% by mass, preferably 1 to 20% by mass, and more preferably 5 to 15% by mass with respect to the zeolite. When the zirconium content is 0.1% by mass or more, the selectivity for propylene when dimethyl ether or methanol is used is improved, and when the content is 30% by mass or less, the catalytic activity is improved.

  The zeolite catalyst of the present invention contains phosphorus as an essential component in addition to zirconium, but the modification of phosphorus is preferably carried out using various phosphates or organic phosphorus compounds instead of phosphoric acid. Phosphoric acid is associated with water molecules through hydrogen ion bonds in the solution, but when used as a phosphate, the charge on the phosphate ion is neutralized and the hydration state of the phosphate ion changes. The pores of pentasil type high silica zeolite are known to have hydrophobicity, but the modification of the active sites in such zeolite pores is greatly influenced by the hydration state of ions.

When phosphoric acid is used in the form of a salt, the modifying component, phosphorus, easily accumulates in the pores due to changes in the hydration state, resulting in improved activity and selectivity compared to the case where phosphoric acid alone is used. The control effect can be enhanced. Organophosphorus compounds are also easy to introduce into the hydrophobic pores. Furthermore, phosphoric acid (H ₃ PO ₄ ) is a corrosive substance whose pH of the aqueous solution is about 2, and it is necessary to take measures against corrosion of the equipment and neutralization treatment at the time of disposal, whereas phosphate (sodium salt, potassium salt) Rather) is known to exhibit a corrosion-inhibiting effect. The organophosphorus compound is a hydrocarbon compound containing phosphorus in the molecule, and some of them are highly toxic, but generally are not corrosive and can be handled in the same manner as ordinary organic compounds.

  As the organic phosphorus compound, for example, phosphines, phosphine oxides, phosphonic acid esters, phosphoric acid esters, phosphorous acid esters, phosphoric acid amides and the like can be used. Among these phosphates or organophosphorus compounds, use ammonium phosphate salts (such as ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, etc.) that have low toxicity and are used in food additives More preferably.

  The modification amount of phosphorus is usually 0.1 to 20% by mass, preferably 1 to 10% by mass, and more preferably 2 to 8% by mass with respect to the zeolite in the catalyst. When the amount of modification of phosphorus is 0.1% by mass or more, the selectivity for propylene is improved, and when it is 20% by mass or less, the catalytic activity is improved.

The order of introduction of zirconium and modification of phosphorus in the zeolite is not particularly limited. Phosphorus modification can be performed simultaneously with the introduction of zirconium using a mixture containing both zirconium and phosphorus. After the introduction of, modification with a phosphorus compound is performed.
In the catalyst of the present invention, it is important that phosphorus and zirconium are supported or contained on the zeolite, and the effect of the catalyst of the present invention can be sufficiently obtained only by physically mixing the zeolite, the zirconium compound and the phosphorus compound. I can't.

  The shape of the catalyst in the present invention is not particularly limited, and may be any shape such as powder or molded product. In addition, these catalysts may contain components other than zeolite, zirconium and phosphorus, for example, alkali elements, alkaline earth elements, rare earth metal elements, transition metals, noble metals, halogens, binders and the like. It is also possible to use a mixture with a filler such as silica, alumina, magnesia or quartz sand.

In the present invention, the zeolite catalyst is further pretreated in the presence of steam after introduction of zirconium and modification with phosphorus, whereby the activity is further improved and the olefin selectivity can be improved.
The pretreatment with steam can be performed by passing the steam through a column packed with a catalyst. The steam used at this time may be steam diluted with an appropriate diluent gas (nitrogen, hydrogen, hydrocarbons, etc.), and it is also possible to use ethanol, dimethyl ether, or methanol as the raw material for the steam diluent. It is.
The temperature of the catalyst layer during the steam pretreatment is usually 300 to 1000 ° C, preferably 400 to 900 ° C, more preferably 500 to 800 ° C.

The reaction mode of ethanol or a mixture of ethanol and dimethyl ether or methanol in the present invention is not particularly limited, but usually a catalyst in which a reactor such as a fixed bed, moving bed, fluidized bed or the like is used and packed with the above catalyst is used. This is performed by supplying a raw material containing ethanol or the like to the layer. At this time, the raw material may be diluted with nitrogen, hydrogen, hydrocarbon, steam or the like.
Since steam has an effect of suppressing coking, it is preferable to carry out a reaction for producing olefins in the presence of steam, and the presence of steam improves the selectivity for propylene. Ethanol from biomass contains water, but such ethanol does not need to be particularly concentrated to remove water, and water-containing ethanol can be used as a raw material as it is.

The reaction temperature in this invention is about 300-700 degreeC normally, Preferably it is 350-650 degreeC, More preferably, it is the range of 400-600 degreeC. By setting the temperature to 300 ° C. or higher, it becomes an activity that provides a suitable olefin yield per pass, and by setting the temperature to 700 ° C. or lower, generation of methane and coke is avoided.
The reaction pressure can be any of normal pressure, reduced pressure, or increased pressure. Usually, increased pressure from normal pressure to about 1 MPa is employed.

According to the present invention, light olefins can be advantageously produced using ethanol or ethanol and methanol or dimethyl ether as raw materials. Propylene can be efficiently and economically produced by using ethanol, methanol or dimethyl ether as raw materials. Can be advantageously produced.
Moreover, in this invention, since ethanol from biomass can be used as it is, without concentrating, it is advantageous.
Furthermore, in the present invention, the catalyst can be prepared by an advantageous method because the catalyst can be prepared by a method that does not use a corrosive substance, and further, the corrosion in the reactor is eliminated because the catalyst can be made non-corrosive. The reactor can be stably operated for a long time. In addition, it is advantageous because it is possible to eliminate the need for countermeasures against corrosion of the catalyst production apparatus and the reaction apparatus and neutralization treatment when the catalyst is discarded.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In the following examples and comparative examples, the reaction products were analyzed by sampling the reactor outlet gas online (all the products were vaporized) at a predetermined time after starting the feed of raw materials and analyzing them by gas chromatography. The product yield and the raw material conversion were calculated by the following formula.
Product yield (carbon basis:%) =
(Molar amount of carbon in each component / molar amount of carbon in the feedstock) x 100
Raw material conversion rate (%) = (1-unreacted raw material mass / feed raw material mass) × 100
In addition, the methanol produced | generated in a trace amount was calculated as a raw material (equivalent to ethanol).
When dimethyl ether (sometimes represented by DME) was used together with ethanol (sometimes represented by EtOH) as a raw material, the following numerical values were shown as reference values.
Raw material dimethyl ether ratio (% by mass) =
[(DME supply amount) / (EtOH supply amount + DME supply amount)] × 100
Propylene production rate (mass%) =
[(Propylene yield) / (Raw material dimethyl ether ratio)] × 100

Example 1
Powdered proton type ZSM-5 zeolite as zeolite (SiO ₂ / Al ₂ O ₃ molar ratio measured by fluorescent X-ray analysis = 90, specific surface area 390 mm ² / g (measured by BET method), particle diameter of 150 μm or less) An aqueous solution containing 1.38 g of zirconium corresponding to 10% by mass with respect to zeolite [1.18 g of zirconyl nitrate dihydrate [ZrO (NO ₃ ) ₂ .2H ₂ O] was dissolved in 400 mL of deionized water. The solution was suspended at a temperature of 80 ° C. and stirred for 2 hours. After the stirred aqueous solution was cooled to room temperature (about 25 ° C.), aqueous ammonia (2.5 mol / L) was added dropwise with stirring to adjust the pH of the aqueous solution to 9. The aqueous slurry adjusted to pH = 9 was stirred at room temperature for 2 hours and then filtered, washed and recovered. The white slurry recovered was dried at 120 ° C overnight, then heated to 550 ° C for 4 hours and calcined at 550 ° C for 3 hours. (In air atmosphere) to obtain a white powder. The whole amount of this powder was put into an automatic mortar (manufactured by Nissho Science Co., Ltd., ANM1000 type), and an aqueous solution of phosphate containing 0.8% by mass of phosphorus with respect to zeolite [0.8528 g of diammonium hydrogen phosphate [(NH ₄ ) ₂ HPO ₄ ] dissolved in 2 mL of deionized water] was added and kneaded in an automatic mortar for 2 hours. The kneaded slurry was dried at 120 ° C. overnight, then heated to 550 ° C. over 4 hours, baked at 550 ° C. for 3 hours (in an air atmosphere), pulverized in a mortar and sieved with a 150 μm sieve. The one passed through was designated as 5% P-10% Zr / HZSM-5 catalyst. No corrosive waste liquid was generated during the modification with this phosphate.

This catalyst was compressed, pulverized and sieved to give 1 g of a molded product having a particle size of about 1 mmφ, and filled into a stainless steel reaction tube having an inner diameter of 14 mm (with an inner tube for thermocouple having an outer diameter of 3 mm). The length of the catalyst layer was about 16 mm. The catalyst layer was filled with quartz wool on the top and bottom to hold the catalyst, and the other part of the reaction tube was filled with 2 mmφ alumina balls (manufactured by Fujimi Incorporated, A-901 type). The temperature of the catalyst layer was raised to 600 ° C. while flowing nitrogen at 60 cm ³ / min (0 ° C., converted to 1 atm, the same applies hereinafter) into this reaction tube, and calcined for 1 hour. Thereafter, nitrogen (60 cm ³ / min) and steam (2 g / h) were circulated at 600 ° C. for 12 hours to perform high temperature steam treatment. After completion of the steam treatment, the temperature of the catalyst layer was maintained at 500 ° C., and ethanol reaction was performed by supplying a 50% by mass aqueous solution of ethanol as a raw material at a flow rate of 4.1 g / h and nitrogen at 20 cm ³ / min. . Since ethanol is supplied as an aqueous solution and the reaction temperature is 500 ° C., the reaction is in the presence of steam.
Table 1 shows the results of analyzing the product at the outlet of the reactor 3 hours after starting the feed of the raw materials. Ethanol conversion was 100% and ethylene yield was as high as about 99% or more. Thus, when the supply ratio of dimethyl ether and / or methanol is zero, ethylene can be obtained in a high yield, but the yield of propylene is low.

Comparative Example 1
The same proton type ZSM-5 zeolite as used in Example 1 was molded and pretreated without modification with an aqueous solution containing zirconium and an aqueous solution of phosphate, and reacted with ethanol under the same conditions. It was. Table 1 shows the results of analyzing the product at the outlet of the reactor one hour after starting the feed of the raw materials. As a result, the ethanol conversion was 100%, but the ethylene yield was as low as about 40% and the propylene yield was not controlled, and the total yield of light olefins (C _{2 to} C ₄ ) was About 56%, the yield of light olefins was low.

Example 2
In Example 1, the ethanol aqueous solution was supplied for 4 hours, and then the temperature of the catalyst layer was 500 ° C., the flow rate of the ethanol 50 mass% aqueous solution was 4.1 g / h, dimethyl ether 0.25 g / h, nitrogen 20 cm ³ / min. Were simultaneously fed to the reactor (raw material dimethyl ether ratio = 10.8% by mass). The results of analyzing the product at the outlet of the reactor after 1 hour are shown in Table 1 (total feed time of raw materials: 5 hours). As a result, the conversion rates of ethanol and dimethyl ether were both 100%, the ethylene yield was 81.3%, and the propylene yield was 10.6%. According to Non-Patent Document 3, the propylene production rate when only dimethyl ether is reacted is about 45%, whereas in this example, the propylene production rate is 98.1%. It can be seen that propylene production is promoted by the reaction of dimethyl ether and ethanol.

Example 3
After carrying out the reaction of Example 2 for 2 hours, the temperature of the catalyst layer was kept at 500 ° C., the flow rate of the 50% by weight ethanol aqueous solution was changed to 3.64 g / h, and the flow rate of dimethyl ether was changed to 0.49 g / h ( (Dimethyl ether ratio of raw material: 21.2% by mass). One hour after changing the flow rate, the results of analyzing the product at the outlet of the reactor are shown in Table 1 (total feed time of raw materials: 7 hours). As a result, the conversion rates of ethanol and dimethyl ether were both 100%, the ethylene yield was 66.1%, and the propylene yield was 16.7%. The propylene production rate is about 79%. In this way, by controlling the supply ratio of ethanol and dimethyl ether and / or methanol, ethylene and propylene can be obtained at the desired ratio, and efficient olefin production can be performed in response to market demand. Can do.

The terms used in Table 1 have the following meanings.
1) Distribution time: Elapsed time after starting the supply of raw materials to the reactor 2) Aromatic: benzene + toluene + xylene + ethylbenzene 3) C5 +, coke: hydrocarbons with 5 or more carbon atoms and adhering coke (adhering coke) Min is less than about 1%)
4) COx: carbon monoxide + carbon dioxide

Claims (8)

  A process for producing olefins, characterized in that ethanol as a raw material is contacted with a zeolite catalyst having a pentasil structure modified with zirconium and phosphorus.   The method for producing olefins according to claim 1, wherein dimethyl ether and / or methanol is used as a raw material together with ethanol, and the amount of propylene in the generated olefin is adjusted by controlling the supply ratio of dimethyl ether and / or methanol to ethanol.   The method for producing olefins according to claim 2, wherein a supply ratio of dimethyl ether and / or methanol to ethanol is 70% or less in terms of carbon atom ratio.   The method for producing olefins according to any one of claims 1 to 3, wherein the zeolite having a pentasil structure is ZSM-5 and / or ZSM-11.   The method for producing olefins according to any one of claims 1 to 4, wherein the pentasil-type zeolite has a silica / alumina molar ratio of 20 to 700.   6. The pentasil-type zeolite catalyst modified with zirconium and phosphorus is a zirconium-modified pentasil-type zeolite modified with a phosphate and / or an organophosphorus compound. Of producing olefins.   The method for producing olefins according to any one of claims 1 to 6, wherein the raw material is brought into contact with a zeolite catalyst pretreated at a temperature of 300 to 1000 ° C in the presence of steam.   The method for producing olefins according to any one of claims 1 to 7, wherein the raw material is brought into contact with the zeolite catalyst in the presence of steam.