KR20140067565A

KR20140067565A - Catalyst for production of light olefin and production method of light olefins through catalytic cracking of hydrocarbons using the catalyst

Info

Publication number: KR20140067565A
Application number: KR1020120134973A
Authority: KR
Inventors: 김미진; 윤민혜; 송보근; 박세호
Original assignee: 롯데케미칼 주식회사
Priority date: 2012-11-27
Filing date: 2012-11-27
Publication date: 2014-06-05
Also published as: KR101448357B1

Abstract

In the catalyst for the production of light olefins for producing light olefins containing ethylene and propylene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms generated after naphtha cracking, it is possible to obtain a catalyst having excellent physical and chemical properties, To thereby improve the production yield of light olefins. The present invention relates to a catalyst for use in the production of light olefins comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms, the catalyst comprising: i) a ZSM-5 catalyst and ii) Wherein the catalyst is a mixed catalyst of at least one zeolite other than the zeolite catalyst.

Description

FIELD OF THE INVENTION The present invention relates to a catalyst for the production of light olefins and a method for producing light olefins by catalytic catalytic cracking of a hydrocarbon mixture using the same. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a catalyst for the production of light olefins and a process for producing light olefins by catalytic catalytic cracking of hydrocarbon mixtures using the same. More specifically, the present invention relates to a catalyst for catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms produced after naphtha cracking, And to the production of light olefins by improving the physical properties of a catalyst for the production of light olefins used in a process for producing light olefins including butene.

Ethylene, propylene and butene are important raw materials for petrochemical products, and their importance is increasing as demand has increased greatly in recent years. Until now, most of light olefins such as ethylene and propylene are produced by pyrolysis of naphtha as a raw material at a high temperature of 800 ° C or higher. Since the production of light olefins through pyrolysis of naphtha consumes about 40% of the energy consumed by the petrochemical industry, the proportion of energy consumption is very large and causes a problem of environmental pollution due to the generation of a large amount of carbon dioxide.

Therefore, catalytic decomposition technology using a catalyst has recently been attracting attention as an energy saving technique that replaces the pyrolysis process in recent years. The catalytic decomposition technique using a catalyst is performed at a reaction temperature as low as about 50 to 200 ° C as compared with the conventional pyrolysis process, so the energy consumption is low. Further, it is possible to minimize the pollution of the environment by reducing the generation of carbon dioxide, and it is possible to control the composition of the produced olefin according to demand.

Typical catalyst systems used for the production of light olefins through catalytic catalytic cracking can be classified into three types: acid catalysts, base catalysts, and transition metal oxide catalysts. As a result of analyzing each catalyst based on representative examples of each catalyst system, the catalytic cracking process using an acid catalyst has shown the greatest economical efficiency. Recently, zeolite has been widely used for catalytic cracking process using acid catalyst. Especially, zeolite is easy to control acidity by changing chemical composition and has shape selectivity, And the yield of the finally obtained light olefin can be easily controlled. ZSM-5, USY, MOR, β-zeolite and the like are used as typical zeolites for catalytic catalytic cracking.

The ZSM-5 catalyst is composed of 10 T (Al or Si) -O bonds and has a medium pore size among the general zeolites, and has a straight channel of 5.4 × 5.6 Å and a sine channel of 5.1 × 5.5 Å sinusoidal channel), it has a uniform pore size and structure. Therefore, it has better shape selectivity than other zeolites, has a low degree of inertness, and has excellent thermal stability due to high Si / Al ratio. Therefore, methanol Conversion reaction, alkylation reaction of toluene, isomerization reaction of xylene (H. Krannila et al., J. Catal., Vol.135, p115, 1992).

As described above, the ZSM-5 catalyst is used in various reactions due to its unique structure and excellent acid characteristics. However, when the reaction proceeds under high temperature and high humidity conditions, the structure is collapsed due to dealumination, There is a problem that it is reduced. Therefore, attempts have been made to introduce various materials to improve the instability of the catalyst, which occurs under high temperature and high humidity reaction conditions. A method for improving the thermal stability of representative catalysts is to add manganese and phosphorus to the zeolite (T. Blasco et al., J. Catal., Vol. 237, p. 267, 2006). When the zeolite such as ZSM-5 is modified with phosphoric acid ions, the Si-OH-Al moiety serving as the Bronsted acid point in the zeolite is modified by the phosphate ion (PO ₄ ^3- ) And stabilizes it to minimize dealumination. However, the method of simply modifying phosphorus in zeolite can contribute to suppressing catalyst deactivation for a long time by improving the hydrothermal stability of the catalyst, but it is inadequate to improve the production of light olefins.

In addition to the efforts to improve the thermal stability of the catalyst, the important thing is to control the product distribution after reaction. In order to maximize the production of light olefins, the production of paraffins and aromatic compounds should be suppressed and the production of olefins should be maximized. This requires an improvement in the reaction process, such as lowering the reaction pressure, raising the reaction temperature, lowering the residence time of the reactants, and appropriately controlling the ratio of the reactants to the catalyst (MA Den Hollander et al., Appl. Catal. A, vol.223, p85, 2002), along with efforts to improve the production of light olefins through the development of new catalysts. As a part of this effort, a method of preparing a catalyst by adding a transition metal or a rare earth metal to a ZSM-5 catalyst has been carried out (N. Rahimi et al., Appl. Catal. A, vol.398, p1, 2011). In this document, it is reported that when a transition metal such as iron or chromium is added to ZSM-5, the reactant hydrocarbon is dehydrogenated to induce a decomposition reaction more easily, thereby producing more light olefins. It has been reported that the addition of rare earth metals such as neodymium, cerium, and lanthanum to ZSM-5 improves the selectivity of light olefins. However, the effect of rare earth metals on the selectivity of light olefins Opinion is divided. When a metal such as a transition metal or a rare earth metal is used, large metal atoms are located at the pore openings of the zeolite, which may cause a problem of lowering the reaction activity when the pores are closed. Therefore, it can be said that there is a limitation in modifying the metal to pure ZSM-5 showing microporous characteristics. To overcome this, it is required to prepare ZSM-5 having micro and medium porosity characteristics.

The MOR catalyst is composed of 12 T (Al or Si) -O bonds and has a larger pore size than the ZSM-5 catalyst. The MOR catalyst has a larger pore size than the 10-membered ring zeolite (MFI, TON, FER, It is characterized by small steric hindrance to the state. In the production of light olefins from an oxygen-containing compound using MOR, propylene and butene can be selectively obtained in light olefins in a high yield, and particularly, butene can be obtained in an extremely high yield of about 30%.

Carbon deposition during the reaction is a major cause of degradation of zeolite catalyst activity. The hydrocarbon intermediate formed during the reaction polymerizes at the catalyst surface and becomes strongly boiling hydrocarbons, which are strongly adsorbed on the catalyst surface. The precipitated carbon covers the acid sites on the surface, blocking the pore openings and reducing activity. In the zeolite catalyst, the carbon deposition and thus the rate of deactivation are different not only by the acidity but also by the pore structure. Depending on the shape of the pores, the type of carbon material deposited differs, and if the pores are narrow and narrow, it is deposited with aliphatic carbon, but if the space is wide and the temperature is high, it is deposited with aromatic carbon. Thus, it is known that the pore structure of the zeolite influences the product distribution and the deactivation. However, the C4-C7 hydrocarbon mixture formed after the naphtha cracking process is subjected to catalytic cracking using a method of mixing zeolite catalysts having different pore shapes The production of light olefins has not been reported yet.

U.S. Patent No. 6,656,345 discloses a process for preparing light olefins from hydrocarbons containing 10-70 wt% olefins and 5-35 wt% paraffins, wherein the pore size is about 7 Å and the Si / Al ratio (MFI, MEL, MTW, TON, MTT, FER, MFS and the like) having a pore size of 200 or more are disclosed. However, the mixing use of two or more zeolites is not mentioned and the pore size is very small, And there is no consideration of hydrothermal stability, so catalyst deactivation is expected.

International Patent Application WO 97/04871 discloses that zeolite catalyst is treated with an acid solution to remove impurities as a result of the catalytic cracking reaction, and the selectivity of butene is improved by increasing the pore size. However, ethylene and propylene There is no mention of creation.

Korean Patent No. 1085046 relates to a process for producing light olefins ranging from C2 to C4 from oxygen-containing compounds such as methanol and dimethyl ether under mordenite catalyst, and a process for obtaining propylene and butene in a yield of 60% or more However, it is expected that the yield of ethylene is low and the yield of hydrocarbons of C6 or higher is high, so that deactivation is expected, and the reactants are very limited.

U.S. Patent No. 6,835,863 discloses a process for the catalytic cracking of naphtha using a shaped catalyst comprising 5 to 75% by weight of ZSM-5 and ZSM-11, 25 to 95% by weight of silica or kaolin, and 0.5 to 10% by weight of phosphorus. However, there is no mention of hydrothermal stability of specific starting materials of phosphorus and shaped catalysts, and no catalyst having mesoporous characteristics is used.

US Patent Publication No. 20060011513 discloses a technique for selecting one of lanthanide, Sc, Y, La, Fe and Ca to zeolites such as ZSM-5, β, mordenite and ferrierite, There is no mention of the specific chemical structure of the phosphate and its description of its role is lacking, and no technology for improving the olefin yield is specified.

U.S. Patent No. 7,531,706 discloses a method for producing light olefins using a pentasil-type zeolite modified with a rare-earth metal, manganese or zirconium with phosphorus, wherein the modified metal has a hydrothermal stability of the catalyst and a yield of light olefin However, it is not enough to interpret the specific role of the metals, and it is only aimed at improving the durability of the zeolite.

Non-Patent Document 1 (G. Zhao et al., J. Catal. Vol. 48, p29, 2007) was intended to improve hydrothermal stability by introducing phosphorus into HZSM-5. As a result, the introduction of phosphorus contributed to improvement of hydrothermal stability. However, the introduction of phosphorus resulted in a drastic decrease in surface area and pore volume due to blocking of the inlet of micropores, and the limitation that phosphorus does not play a role in improving light olefin production have.

Non-Patent Document 2 (J. Lu et al., Catal. Commun., Vol. 7, p199, 2006) studied the preparation of light olefins by catalytic catalytic cracking of isobutane. As a result of preparing a catalyst modified with iron on the basis of ZSM-5 catalyst, it has been reported that the modification of iron makes it possible to produce more light olefins by improving the acid property of the catalyst. However, , The activity was decreased rapidly. This can be attributed to the microporosity of ZSM-5, which is caused by aggregation between iron atoms. Further, the hydrothermal stability of the catalyst is not mentioned.

In a non-patent document 3 (W. Xiaoning et al., J. Rare Earths, vol.25, p321, 2007), while conducting a study to produce light olefins from butane using a ZSM-5 catalyst containing a rare earth metal, The effect of the acid on the acid property of the catalyst is discussed and the effect of the acid property change of the catalyst on the reaction activity is discussed. However, the effect of the rare earth metal on the base property is not considered, The effect of the properties on the mechanism of the degradation reaction is not mentioned.

On the other hand, natural gas crackers for obtaining ethylene from natural gas, which is comparatively less expensive than naphtha due to rising crude oil prices and heavy crude oil, are being added. However, since only ethylene can be selectively produced, imbalance in the supply and demand of propylene and butene Unlike in the case of the rich countries where natural gas is abundant, most of the crude oil importers like Korea depend on naphtha cracking, which is very disadvantageous in terms of reduction of greenhouse gas emissions. In Korea, the amount of ethylene obtained from the naphtha cracking process reaches 5 million tons per year, and the amount of C5 oil discharged as a by-product reaches 700 thousand tons, but it can not be used effectively. Therefore, there is a high need to develop a technology for controlling the supply and demand of ethylene, propylene and butene. For this purpose, a light olefin restructuring technology is required and utilization of C5 oil as a raw material for light olefin restructuring is also important.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a catalyst for the production of light olefins for producing light olefins comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4-7 carbon atoms produced after naphtha cracking And it is intended to provide a catalyst for producing light olefins which can improve the yield of light olefins while maintaining the physical and chemical properties of existing catalysts and exhibiting more excellent pore characteristics.

The present invention also provides a catalyst for preparing light olefins having optimum conditions for maximizing the yield of ethylene, propylene and butene, and a method for producing light olefins including ethylene, propylene and butene using the catalyst.

In order to solve the above problems, the present invention relates to a catalyst used for producing light olefins comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms, wherein the catalyst comprises i) ZSM-5 Catalyst and (ii) at least one zeolite other than the ZSM-5 catalyst. The present invention also provides a catalyst for the production of light olefins.

Also, the ZSM-5 catalyst has a Si / Al atomic ratio of 5 to 500. [

Also, the zeolite is at least one selected from the group consisting of MOR, LTA, BEA, FAU, and TON.

Also, the present invention provides a catalyst for producing light olefins, wherein the zeolite has a MOR structure.

The present invention also provides a catalyst for producing light olefins, wherein the zeolite contains an inorganic metal oxide.

Also, the zeolite has a Si / Al atomic ratio of 2 to 200, and provides the catalyst for producing light olefins.

The inorganic metal oxide may be at least one selected from the group consisting of Al, Si, Mg, Ti, V, Cr, Mn, Y, Wherein the catalyst comprises at least one element selected from the group consisting of neodymium (Nb), molybdenum (Mo), rhenium (Re) and tungsten (W).

Also, the present invention provides a catalyst for preparing light olefins, wherein the zeolite is contained in an amount of 20 to 80 wt% based on 100 wt% of the mixed catalyst.

Also, the present invention provides a catalyst for producing light olefins, wherein the mixed catalyst is cation-substituted.

In addition, the cation exchange are ammonium nitrate (NH ₄ NO _3), ammonium chloride (NH ₄ Cl), ammonium carbonate _{((NH 4) 2 CO 3} ) and ammonium fluoride one member selected from the group consisting of (NH ₄ F) Wherein the catalyst is treated with a solution containing at least one of the above components.

Also, the present invention provides a catalyst for producing light olefins, wherein the mixed catalyst further comprises phosphorus.

In addition, the phosphorus is phosphoric acid (H ₃ PO _4), ammonium phosphate _{((NH 4) H 2 PO} 4), phosphoric acid ammonium _{((NH 4) 2 HPO 4} ) and tricalcium phosphate of ammonium ((NH ₄₎ ₃ PO ₄ The present invention also provides a catalyst for the production of light olefins, which comprises at least one phosphorus precursor selected from the group consisting of the following:

The phosphorus is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the mixed catalyst.

Also, the mixed catalyst may further comprise a rare earth metal or an alkali metal.

The rare earth metal may be selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd) Wherein the catalyst is at least one selected from the group consisting of dysprosium (Dy), holmium (Ho), erbium (Er), thorium (Tm), ytterbium (Yb) and lutetium (Lu).

The alkali metal is at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs).

Also, the rare earth metal or alkali metal content is 2 or less in terms of the atomic ratio to the phosphorus.

Also, the hydrocarbon mixture having 4 to 7 carbon atoms is a C5 oil produced after the naphtha cracking process.

According to another aspect of the present invention, there is provided a process for preparing a light olefin comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms in the presence of a catalyst for preparing a light olefin, Wherein the hydrocarbon mixture is reacted at a reaction temperature at a weight hourly space velocity (WHSV) of 1 to 20 h < ^-1 >.

According to the present invention, it is possible to realize a new type of catalyst having a pore shape and size, which is specific to the catalytic catalytic cracking reaction, by simply mixing the ZSM-5 catalyst and the zeolite of other species among the zeolite catalysts for the cracking reaction, It is possible to provide a catalyst for the production of light olefins having excellent reaction activity in the production of light olefins through catalytic catalytic cracking of C4 to C7 hydrocarbon mixtures compared to pure ZSM-5 catalysts without pretreatment.

It is also possible to control the acid and base properties of the catalyst by introducing cationic substitution, phosphorus, rare earth metals or alkali metals into a catalyst of a new kind and pore shape and size specific for the catalytic catalytic cracking reaction, By providing a catalyst, it is possible to provide a catalyst for the production of light olefins which, when used in the production of light olefins comprising ethylene, propylene and butene from a C4 to C7 hydrocarbon mixture, improves the production of light olefins and is stable over a long period of time and has excellent activity can do.

1 is a graph showing the results of measurement of yields of light olefins according to production examples using catalysts prepared according to Examples 1 to 4 and Comparative Example 1,
FIG. 2 is a graph showing the results of measurement of C5 oil conversion, light olefin selectivity and yield according to production examples using catalysts prepared according to Examples 5 to 8 and Comparative Example 2,
FIG. 3 is a graph showing the results of measurement of yields of light olefins according to production examples using mixed catalysts prepared according to Examples 15 to 18. FIG.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims and their equivalents. It is to be understood that various equivalents and modifications may be substituted for those at the time of the present application.

The present invention relates to a catalyst for use in the production of light olefins comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms, the catalyst comprising: i) a ZSM-5 catalyst and ii) 5 is a mixed catalyst of a zeolite other than the zeolite-5 catalyst.

The catalyst for the production of light olefins according to the present invention is used for producing light olefins containing ethylene, propylene and butene by catalytic catalytic cracking of a C4 to C7 hydrocarbon mixture produced after a naphtha cracking process, Can be used for producing light olefins containing ethylene, propylene and butene by catalytic catalytic cracking of C5 oil produced after the naphtha cracking process.

In the present invention, the ZSM-5 catalyst preferably has an Si / Al atomic ratio of 5 to 500, more preferably 10 to 300, even more preferably 20 to 200, 50 < / RTI > When the Si / Al atomic ratio is less than 5, there is no significant influence on the catalyst activity change. However, there may be a risk of inactivation due to coking or the like due to an increase in the amount of the catalyst, The conversion of the catalytic catalytic cracking reaction of the C4 to C7 hydrocarbon mixture may be lowered.

In the present invention, zeolite other than the ZSM-5 catalyst is simply mixed with the ZSM-5 catalyst. The zeolite to be mixed with the ZSM-5 catalyst may be selected from zeolites having various structures. Preferably, zeolite having any one structure selected from the group consisting of MOR, LTA, BEA, FAU and TON can be selected, A zeolite of the MOR or BEA structure may be selected, and a zeolite of the MOR structure may be selected most preferably.

The method for producing the mixed catalyst is not particularly limited, and can be produced by various known methods. For example, the catalyst may be prepared by simply mixing the ZSM-5 catalyst with other zeolites, and may be produced by a method such as ball milling, extrusion, spray drying, and the like.

The zeolite may contain an inorganic metal oxide for the purpose of improving catalytic activity and increasing the activity duration. At this time, the zeolite preferably has an Si / Al atomic ratio of 2 to 200, more preferably 5 to 50, and most preferably 5 to 20. When the Si / Al atomic ratio is less than 2, the degree of improvement in catalytic activity may not be satisfactory, and when the Si / Al atomic ratio is more than 200, the acid property of the catalyst may deteriorate. If the Si / Al atomic ratio is excessive, it is necessary to adjust it through additional acid treatment.

Examples of the metal that can be used as the inorganic metal oxide include aluminum (Al), silicon (Si), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese ), Zirconium (Zr), neodymium (Nb), molybdenum (Mo), rhenium (Re) and tungsten (W).

Considering the synergistic effect as a mixed catalyst in the present invention, the zeolite is contained in an amount of 20 to 80% by weight, preferably 30 to 60% by weight, more preferably 40 to 50% by weight, % &Lt; / RTI > by weight.

According to one embodiment of the present invention, the mixed catalyst may be cation-substituted. The cation substitution is for exchanging zeolite generally substituted with sodium ion (Na ⁺ ) with a proton (H ⁺ ), and the zeolite catalyst substituted with a proton is more effective in cracking reaction because acid strength is increased compared to other cations. The cation exchange may be carried out by adding the mixed catalyst to a cation exchange solution at 70 to 90 ° C and stirring the mixture at the same temperature for 2 to 4 hours. After the cation-exchanged aqueous solution is filtered and washed, The cation exchange process may be repeated one to three times. The solution used in such cation exchange, the ammonium nitrate (NH ₄ NO _3), ammonium chloride (NH ₄ Cl), the group consisting of ammonium carbonate _{((NH 4) 2 CO 3} ) and ammonium fluoride (NH ₄ F) 1 < / RTI >

The cation-exchanged mixed catalyst is preferably heat-treated. The heat treatment may be performed by firing at 400 to 700 ° C for 3 to 10 hours. When the heat treatment temperature is less than 400 ° C, the ammonium salt that is primarily substituted in the mixed catalyst is not sufficiently removed, so that the acid strength of the zeolite may decrease. When the temperature exceeds 700 ° C, the catalyst collapse and the Bronsted acid point disappear . If the heat treatment temperature is less than 3 hours, it may be difficult to remove sufficient ammonium salt, and if it exceeds 10 hours, power loss may occur. Here, it is preferable that the cation-exchanged mixed catalyst is dried at 100 to 120 ° C for 5 to 15 hours before the heat treatment, and then the heat treatment is performed.

According to another embodiment of the present invention, the mixed catalyst may further include phosphorus. The phosphorus-containing mixed catalyst may be impregnated with the phosphorus precursor or the ion exchange method to the mixed catalyst (which may be a cation-substituted mixed catalyst), but in the present invention, It is preferable to use an impregnation method.

The impregnation of the phosphorus precursor into the mixed catalyst may be performed by, for example, hydrating the phosphorus precursor in water, adding the mixed catalyst to the hydrated solution, impregnating the mixed precursor, and drying and heat-treating the impregnated precursor. Specifically, the phosphorus precursor is dissolved in an amount of water (distilled water) capable of completely dissolving the phosphorus precursor, and the mixture is stirred at 70 to 90 ° C for 5 to 15 minutes. If water is completely evaporated after stirring, it can be prepared by drying in an oven at 90 to 110 ° C. for 10 to 15 hours and then at 500 to 750 ° C. for 1 to 10 hours. Here, the above-mentioned impregnation is carried out at a temperature of 70 to 90 ° C in order to make the framework of the ZSM-5 catalyst and the phosphorus component be more advantageous than to perform at room temperature. If the calcination temperature is less than 500 ° C, the organic and inorganic materials contained in the phosphorus precursor may not be completely removed. If the calcination temperature is higher than 750 ° C, the phosphorus is not preferable from the viewpoint of energy efficiency and is deteriorated. The organic and inorganic removal performance may be deteriorated.

At this time, it is important that the phosphorus precursor introduction amount is set to an optimal range in relation to the amount of carbon in the finally produced mixed catalyst and the amount of carbon deposition according to the catalytic reaction. Therefore, in the present invention, the phosphorus precursor introduction amount is preferably 0.01 to 10 parts by weight, preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the mixed catalyst in the ZSM-5 catalyst and zeolite content range More preferably from 0.1 to 1.5 parts by weight, and most preferably from 0.1 to 1 part by weight.

To the precursor, for example, phosphoric acid (H ₃ PO _4), ammonium phosphate ((NH ₄₎ H ₂ PO _4), phosphoric acid ammonium ((NH ₄₎ ₂ HPO _4), tricalcium phosphate, ammonium ((NH ₄ ) ₃ PO ₄ ) and the like can be used.

According to another embodiment of the present invention, the mixed catalyst in which the phosphorus is introduced may further include a rare earth metal or an alkali metal to realize a mixed catalyst capable of controlling acid and base characteristics of the catalyst. At this time, the rare earth metal or alkali metal may be introduced by treatment with a rare earth metal precursor or an alkali metal precursor, and the introduction of the rare earth metal precursor and the alkali metal precursor may be carried out respectively, The catalyst characteristics can be simultaneously expressed.

The impregnation or ion exchange method is used by the rare earth metal precursor or alkali metal precursor introduction method, but in the present invention, it is preferable to use an impregnation method which is easy to control acid and base properties. The method of impregnating the rare earth metal precursor or the alkali metal precursor with the phosphorus-introduced mixed catalyst can be performed in a similar manner to the phosphorus precursor introduction, that is, the rare earth metal precursor or the alkali metal precursor is hydrated in water, A method may be used in which the phosphorus-containing mixed catalyst is added to the impregnated catalyst, followed by drying and heat treatment. Specifically, the phosphorus precursor is dissolved in an amount of water (distilled water) capable of completely dissolving the rare earth metal precursor or the alkali metal precursor, and the mixture is stirred at 70 to 90 ° C for 5 to 15 minutes. The phosphorus- The mixture is stirred at 70 to 90 ° C. to sufficiently impregnate the water. When all the water is evaporated, the mixture is dried in an oven at 90 to 110 ° C. for 10 to 15 hours and then calcined at 500 to 750 ° C. for 1 to 10 hours.

At this time, it is important that the content of the rare earth metal precursor or the alkali metal precursor is set to an optimum range with respect to the amount of acid, the amount of the base and the amount of carbon deposition according to the catalytic reaction in the final mixed catalyst. Therefore, in the present invention, the rare earth metal precursor or the alkali metal precursor is preferably introduced in an amount of 2 or less in terms of the atomic ratio to the phosphorus in the ZSM-5 catalyst and zeolite content range, and is introduced at an atomic ratio of 0.1 to 1.5 , And most preferably is introduced at an atomic ratio of 0.5 to 0.9.

As the rare earth metal contained in the rare earth metal precursor, lanthanum (La), Ce, Pr, Ne, Prommium, Sm, At least one member selected from the group consisting of terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thorium (Tm), ytterbium (Yb) and lutetium (Lu) Lanthanum may be selected. The alkali metal contained in the alkali metal precursor may include at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs) Preferably potassium, rubidium, and cesium, and more preferably, cesium can be selected. For example, when lanthanum is selected as the rare earth metal, lanthanum nitrate (La (NO ₃ ) ₃ .6H ₂ O) can be introduced in the form of a precursor. When lithium is selected as the alkali metal, lithium nitrate (LiCO ₃ ) .

The mixed catalyst according to the present invention can be used in the production of light olefins including ethylene, propylene and butene by catalytic catalytic cracking of C4 to C7 hydrocarbon mixtures produced after the naphtha cracking process. At this time, the hydrocarbon mixture is reacted at a reaction temperature of 300 to 700 ° C. in the presence of the mixed catalyst at a weight hourly space velocity (WHSV) of 1 to 20 h ^-1 to prepare a light olefin. If the weight-space velocity is less than 1h ^-1 is possible to increase the conversion rate, but may reduce the selectivity due to side reaction, 20h ^- if more than ¹ may reduce the conversion rate and lead to decreased catalyst life.

Example One

(Si / Al atomic ratio of 40, Zeolyst) and BEA structure of zeolite (Si / Al atomic ratio of 16, Zeolyst) were respectively quantitatively determined to have a content of 50% by weight, 100 ml of 1 molar ammonium nitrate (NH ₄ NO ₃ , manufactured by Junsei) was prepared for cation exchange with the mixed catalyst, and the mixture was maintained at 80 ° C. 4 g of the mixed catalyst was added and stirred at 80 ° C. for 3 hours. The cation-substituted aqueous solution was subjected to a further two-step cation exchange process through filtration and washing. The cation-substituted solid product was dried at 110 ° C for 10 hours and calcined at 650 ° C for 5 hours to prepare a cation-substituted mixed catalyst.

Example 2

A mixed catalyst was prepared in the same manner as in Example 1, except that zeolite having a MOR structure (Si / Al atomic ratio 10, Zeolyst) was used instead of zeolite having a BEA structure in Example 1.

Example 3

A mixed catalyst was prepared in the same manner as in Example 1, except that zeolite having a USY structure (Si / Al atomic ratio 15, Zeolyst) was used instead of zeolite having a BEA structure in Example 1.

Example 4

A mixed catalyst was prepared in the same manner as in Example 1, except that ZSM-22 zeolite (Si / Al atomic ratio 85, JGC C & C) was used instead of zeolite having a BEA structure in Example 1.

Comparative Example One

A ZSM-5 catalyst was prepared in the same manner as in Example 1, except that the zeolite of the BEA structure was not mixed in Example 1.

Example 5

A mixed catalyst was prepared in the same manner as in Example 2, except that the amount of zeolite was determined to be 80% by weight of ZSM-5 catalyst and 20% by weight of zeolite of MOR structure in Example 2.

Example 6

A mixed catalyst was prepared in the same manner as in Example 2, except that the amount of zeolite was determined to be 60 wt% of ZSM-5 catalyst and 40 wt% of zeolite of MOR structure in Example 2.

Example 7

A mixed catalyst was prepared in the same manner as in Example 2, except that the amount of the zeolite was determined to be 40% by weight of the ZSM-5 catalyst and 60% by weight of the zeolite of the MOR structure in Example 2.

Example 8

A mixed catalyst was prepared in the same manner as in Example 2, except that the amount of the catalyst was determined to be 20% by weight of the ZSM-5 catalyst and 80% by weight of the zeolite of the MOR structure in Example 2.

Comparative Example 2

A MOR catalyst was prepared in the same manner as in Example 1, except that the ZSM-5 catalyst was not mixed in Example 1.

Example 9

A mixed catalyst was prepared in the same manner as in Example 2, except that the ZSM-5 catalyst having a Si / Al atomic ratio of 140 was used in Example 2.

Comparative Example 3

A ZSM-5 catalyst was prepared in the same manner as in Comparative Example 1, except that the ZSM-5 catalyst having a Si / Al atomic ratio of 140 was used in Comparative Example 1.

Example 10

A phosphorus precursor quantitatively contained in an amount of 0.17 parts by weight based on 100 parts by weight of the mixed catalyst prepared in Example 2 was impregnated by impregnation. To this end, the quantified phosphoric acid (85%, H ₃ PO ₄ , Sigma-Aldrich Co.) was dissolved in 10 ml of distilled water and stirred at 60 ° C. for 10 minutes. Then, 1 g of the cation-exchanged mixed catalyst was introduced and sufficient impregnation Gt; 60 C < / RTI > After distilled water was completely evaporated, it was dried in an oven at 100 ° C for 12 hours and then calcined at 650 ° C for 3 hours to prepare a mixed catalyst having phosphorus introduced therein.

Example 11

A mixed catalyst was prepared in the same manner as in Example 10, except that phosphorus was impregnated in an amount of 0.3 parts by weight in Example 10.

Example 12

A mixed catalyst was prepared in the same manner as in Example 10, except that phosphorus was impregnated in an amount of 0.7 parts by weight in Example 10.

Example 13

A mixed catalyst was prepared in the same manner as in Example 10, except that phosphorus was impregnated in an amount of 1.4 parts by weight in Example 10.

Example 14

A mixed catalyst was prepared in the same manner as in Example 10 except that phosphorus was impregnated to 2.7 parts by weight in Example 10.

Example 15

Lanthanum (La) in the rare earth metal was selected as the mixed catalyst prepared in Example 11, and a lanthanum precursor quantitatively determined to have a lanthanum / phosphorus atom ratio of 0.3 was introduced by an impregnation method. To this end, lanthanum nitrate (La (NO ₃ ) ₃ .6H ₂ O, Sigma-Aldrich) was dissolved in 10 ml of distilled water and stirred at 60 ° C for 10 minutes. Then, 1 g of the mixed catalyst prepared in Example 11 Lt; RTI ID = 0.0 > 60 C < / RTI > to allow sufficient impregnation to take place. After distilled water was completely evaporated, it was dried in an oven at 100 ° C for 12 hours and then calcined at 650 ° C for 3 hours to prepare a mixed catalyst having lanthanum introduced therein.

Example 16

A mixed catalyst was prepared in the same manner as in Example 15, except that the lanthanum precursor was impregnated and impregnated so that the lanthanum / phosphorus atom ratio was 0.7 in Example 15.

Example 17

A mixed catalyst was prepared in the same manner as in Example 15, except that the lanthanum precursor was impregnated and impregnated so that the lanthanum / phosphorus atom ratio was 0.9 in Example 15.

Example 18

A mixed catalyst was prepared in the same manner as in Example 15, except that the lanthanum precursor was impregnated and impregnated so that the lanthanum / phosphorus atom ratio was 1.2 in Example 15.

Example 19

Lithium (Li) in alkali metal was selected as the mixed catalyst prepared in Example 11, and a lithium precursor quantitatively determined so as to have a lithium / phosphorus atom ratio of 0.7 was introduced by an impregnation method. To this end, lithium nitrate (LiNO ₃ , manufactured by Sigma-Aldrich) was dissolved in 10 ml of distilled water and stirred at 60 ° C. for 10 minutes. Then, 1 g of the mixed catalyst prepared in Example 11 was introduced and sufficiently impregnated Lt; 0 > C. After distilled water was completely evaporated, it was dried in an oven at 100 ° C for 12 hours and then calcined at 650 ° C for 3 hours to prepare a mixed catalyst having lithium introduced therein.

Example 20

Potassium (K) in the alkali metal was selected as the mixed catalyst prepared in Example 11, and a potassium precursor quantitatively adjusted to have a potassium / phosphorus atom ratio of 0.7 was introduced by impregnation. To this end, quantitative potassium nitrate (KNO ₃ , Sigma-Aldrich) was dissolved in 10 ml of distilled water and stirred at 60 ° C. for 10 minutes. 1 g of the mixed catalyst prepared in Example 11 was then added and sufficiently impregnated Lt; 0 > C. After distilled water was completely evaporated, it was dried in an oven at 100 ° C for 12 hours and then calcined at 650 ° C for 3 hours to prepare a mixed catalyst having potassium introduced therein.

Example 21

Cesium (Cs) in the alkali metal was selected as the mixed catalyst prepared in Example 11, and a cesium precursor quantitatively determined to have a cesium / phosphorus atom ratio of 0.7 was introduced by impregnation. To this end, cesium nitrate (CsNO ₃ , manufactured by Sigma-Aldrich) was dissolved in 10 ml of distilled water and stirred at 60 ° C. for 10 minutes. Then, 1 g of the mixed catalyst prepared in Example 11 was added thereto and sufficiently impregnated Lt; 0 > C. After distilled water was completely evaporated, it was dried in an oven at 100 ° C for 12 hours and calcined at 650 ° C for 3 hours to prepare a mixed catalyst having cesium introduced therein.

Experimental Example One: ZSM -5 Production of light olefins by catalytic catalytic cracking of hydrocarbons mixture using catalysts and other zeolite catalysts and their effects on catalytic activity

Using the catalysts prepared according to Examples 1 to 4 and Comparative Example 1 for the production yield analysis of light olefins, in particular ethylene, propylene and butene, by catalytic catalytic cracking of hydrocarbon mixtures using the mixed catalyst according to the invention, Was carried out. The hydrocarbon mixture used as the reactant was C5 oil, and the composition thereof is shown in Table 1 below.

[Manufacturing reaction example]

For the catalytic catalytic cracking of the C5 fraction, the catalysts prepared according to Examples 1 to 4 and Comparative Example 1 were filled in quartz reactor in amounts of about 15 to 30 mg, respectively, and nitrogen gas (40 ml) Lt; 0 > C for 1 hour. After the catalytic activation, the reaction proceeded as the reactants passed through the catalyst bed in the reactor continuously. The weight hourly space velocity (WHSV) of the reactant was maintained at 3.5 h ^-1 and the catalytic catalytic cracking reaction temperature of the C5 oil was 600 ° C. The product produced after the reaction was analyzed by gas chromatography. The conversion of C5 oil and the selectivity and yield of light olefins (ethylene, propylene, and butene) were calculated according to the reaction time of each catalyst, and the results of measurement of light olefin yield Is shown in Fig. Here, the conversion of the C5 hydrocarbon mixture, the selectivity of light olefins (ethylene), and the yield of light olefins (ethylene) are calculated according to the following equations (1) to (3).

1, in the reaction (Examples 1 to 4) in which the commercial zeolite having a structure different from the light olefin yield in the case of using the pure ZSM-5 catalyst (Comparative Example 1) was mixed with the ZSM-5 catalyst The yield of olefin was the same or higher. In particular, it was found that the yield of light olefin was the most excellent in the reaction using the mixed catalyst (Example 2) in which the zeolite of the MOR structure was mixed. This difference in reaction activity is due to the fact that the mixed catalyst in which two or more kinds of zeolite prepared according to the present invention are mixed exhibits better physical pore characteristics as the pore structure of the pure ZSM-5 catalyst is changed. This improved physical pore property is due to the fact that the C5 oil used as a reactant and the isomer of the C5 oil produced during the reaction process and the C5 product produced by the polymerization of the carbonium ion are more easily diffused in the large pores, And it is believed that the large pore structure influences the selectivity of the product due to the small steric hindrance to the reactants and the transition state.

Experimental Example 2: ZSM -5 Production of Catalyst and Other Zeolite Mixed Catalysts Catalyzed Catalytic Decomposition of Hydrocarbons Mixture Yield and Catalytic Activity of Light Olefins Mitch Influence

(Example 2) of the ZSM-5 catalyst having the best activity in Experimental Example 1 and the zeolite having the MOR structure (Example 2), the content of the light olefin, particularly ethylene, propylene and butene The production reaction was carried out in the same manner as in the production example of Experimental Example 1 using the catalysts prepared according to Examples 5 to 8 and Comparative Example 2 for the production yield analysis, and the results are shown in FIG. The results for the catalyst prepared according to Example 2 and Comparative Example 1 are also shown for comparison.

Referring to FIG. 2, it can be seen that the yield of light olefin (ethylene + propylene + butene) tends to increase until the zeolite content of the MOR structure is 50% by weight. This is because the developed large pores of the mixed catalyst in the catalytic catalytic cracking of C5 oil alleviate the diffusion limitation of reactants, products and intermediates which may occur in the pure ZSM-5 catalyst, Because. However, it should be noted that the yield of light olefins is not increased anymore but rather decreases even after the zeolite content of the MOR structure increases from 50 wt% or more. As the zeolite content of the MOR structure increases, that is, the larger the pores are, the higher the selectivity of light olefins is. However, the conversion rate decreases gradually, And the control of the optimum mixing ratio of the mixed catalyst has an important influence on the yield of light olefins. On the other hand, as the zeolite content of the MOR structure increases, the selectivity of the aromatic compounds above C6 is decreased as the light olefin selectivity increases. As a result, the mixed catalyst of the ZSM-5 catalyst and the MOR- It is expected to be very advantageous in the long-term in the production of light olefins through catalytic catalytic cracking.

Experimental Example 3: ZSM -5 catalyst and other zeolite mixed catalysts Si / Al At the atomic cost On the production yield and catalytic activity of light olefins by catalytic catalytic cracking of hydrocarbons mixture

Catalysts of hydrocarbon mixtures according to Si / Al atomic ratios of ZSM-5 catalysts and MOR-structured zeolites for the ZSM-5 catalyst and the zeolite-mixed zeolite catalyst (Example 2) The same manufacturing reactions as in the production example of Experimental Example 1 were carried out using catalysts prepared according to Example 9 and Comparative Example 3 for the production yield analysis of light olefins, particularly ethylene, propylene and butene by catalytic cracking, The results are shown in Table 2 below. The results for the catalyst prepared according to Example 2, Comparative Examples 1 and 2 are also shown for comparison.

Referring to Table 2, when the reaction using the pure ZSM-5 catalyst was performed at a relatively low Si / Al atomic ratio (Comparative Example 1), the C5 oil conversion was superior to that of Comparative Example 3, The selectivity of hydrocarbons such as paraffins and C6 is high and the yield of light olefins is similar. In contrast, in the case of a catalyst prepared by mixing a ZSM-5 catalyst with a zeolite having a MOR structure according to the present invention, the catalyst was mixed with a ZSM-5 catalyst having a relatively large Si / Al atomic ratio (Example 9) , The light olefin selectivity was remarkably improved and it was confirmed that it is superior in light olefin yield. That is, even though the conversion of the zeolite having the MOR structure to the pure ZSM-5 catalyst was optimized by increasing the pore size while the conversion was decreased due to the reaction, the selectivity of the light olefin was increased and the yield was higher. At this time, when the mixed catalyst according to the present invention was mixed using an optimal range of ZSM-5 catalyst having a relatively small Si / Al atomic ratio (Example 2), the degree of increase in the conversion rate was higher than that of the light olefin selectivity The yield of light olefins was confirmed.

Experimental Example 4: Effect of catalytic catalytic cracking of hydrocarbons mixture on the yield of light olefins and catalytic activity

Using the mixed catalysts prepared according to Examples 10 to 14 for the production yield analysis of light olefins, in particular ethylene, propylene and butene, by catalytic catalytic cracking of hydrocarbon mixtures using phosphorus-introduced mixed catalysts according to the present invention The conversion reaction rate and yield after 40 hours of reaction were measured according to the above preparation examples, and the results are shown in Table 3 below. The results for the catalyst prepared according to Example 2 and Comparative Example 1 are shown together for comparison, and the hydrocarbon mixture used as the reactant is C5 fraction of the composition of Table 1 above.

Referring to Table 3, it can be seen that the mixed catalyst according to the present invention (Example 2) exhibits better activity than the pure ZSM-5 catalyst (Comparative Example 1). This reaction activity difference is due to the fact that the mixed catalyst according to the present invention has larger pores than the pure ZSM-5 catalyst as described above. That is, in the catalytic catalytic cracking of C5 oil, the diffusion limitations of reactants, products and intermediates that may occur in the pure ZSM-5 catalyst are mitigated, thereby exhibiting better reaction activity.

It can also be seen that the pure ZSM-5 catalyst exhibits rapid catalyst deactivation over a reaction time of 40 hours. This is due to the carbon deposition that occurs during the reaction. The direct cause of such carbon deposition is due to the polymerization between the carbonium ions that occur as a side reaction during the catalytic catalytic cracking of the C5 oil. The micropores of the pure ZSM- In the case of carbon deposition due to the polymerization between the carbonium ions, the active sites inside the micropores can no longer act as an active site for the decomposition reaction of C5 oil. Therefore, as the carbon deposition increases, the catalytic activity is markedly reduced.

On the other hand, the mixed catalyst according to the present invention shows a tendency to be inactivated to some degree as the reaction time elapses, but is lower than that of a pure ZSM-5 catalyst. This is due to the increase of the large pores of the mixed catalyst according to the present invention, and even if the carbon deposition occurs at the inlet of the pore, the C5 oil can penetrate sufficiently into the pores until the large pores are completely clogged, . However, as the reaction time becomes longer, the carbon deposition becomes worse and eventually the pores become clogged and the reaction activity becomes lower. Accordingly, a mixed catalyst that exhibits large pore characteristics and minimizes catalyst deactivation is required, which can be achieved by introducing phosphorus into zeolite mixed catalysts of ZSM-5 catalyst and MOR structure.

It can be seen that the mixed catalysts prepared by introducing phosphorus into the mixed catalysts (Examples 10 to 14) exhibit relatively stable activity over a reaction time of 40 hours. However, when the amount of phosphorus to be introduced is rather low (Example 10), the inactivation tendency is observed with the elapse of the reaction time. However, in the case of the mixed catalyst (Examples 11 to 14) It can be confirmed that the reaction activity is more stable during the reaction time.

Experimental Example 5: Production yields of light olefins by catalytic catalytic cracking of hydrocarbon mixtures using mixed catalysts with phosphorus and rare earth metals and their effect on catalytic activity

Production yields of light olefins, in particular ethylene, propylene and butene, by catalytic catalytic cracking of hydrocarbon mixtures using phosphorus and rare earth metal incorporated catalysts according to the present invention were investigated by means of the mixed catalysts prepared according to Examples 15 to 18 And the production reaction was carried out according to the production reaction. The results are shown in FIG. The results for the catalyst prepared according to Example 11 are shown together for comparison, and the hydrocarbon mixture used as the reactant was C5 fraction of the composition of Table 1 above.

Referring to FIG. 3, it can be seen that the yield of light olefin has a volcanic distribution with respect to the lanthanum / phosphorus atom ratio. That is, the increase of the content of lanthanum has a disadvantage of decreasing the conversion rate of C5 oil by decreasing the amount of catalyst, while it improves the selectivity of light olefins by weakening the hydrogen transfer activity by improving the base characteristics of the catalyst, It was confirmed that a catalyst having a proper lanthanum / phosphorus atom ratio can be prepared so as to adjust the acid and base characteristics of the catalyst to the optimum state as in Example 16, thereby suppressing the deactivation of the catalyst and maximizing the yield of light olefin .

Experimental Example 6: Production yields of light olefins by catalytic catalytic cracking of hydrocarbon mixtures using mixed catalysts of phosphorus and alkali metals and their effect on catalytic activity

The mixed catalyst prepared according to Examples 19 to 21 for the production yield analysis of light olefins, in particular ethylene, propylene and butene, by catalytic catalytic cracking of hydrocarbon mixtures using phosphorus and alkali metal- , And the production reaction was carried out according to the production reaction. The results are shown in Table 4 below. The results for the catalysts prepared according to Examples 11 and 16 are shown together for comparison and the hydrocarbon mixture used as the reactant was C5 fraction of the composition of Table 1 above.

Referring to the above Table 4, it can be seen that, in the case of the catalyst (Examples 19 and 20) in which lithium or potassium was selected as the alkali metal (Example 11) or the catalyst in which phosphorus and lanthanum were introduced ). However, in the case of the catalyst containing cesium (Example 21), the conversion of C5 oil was slightly lower, but the selectivity of the light olefin was improved and the yield was more excellent have. In addition, all of the catalysts into which alkali metal is introduced show a lower selectivity of aromatic compounds than those in which a phosphorus or rare earth metal is introduced, indicating that the introduction of alkali metals is progressed by bispecific decomposition as compared with the introduction of phosphorus or rare earth metals It can be judged that it inhibits the mechanism and activates the reaction mechanism which proceeds by monomolecular decomposition. From these results, it can be seen that the selective introduction of alkali metal into the phosphorus-introduced mixed catalyst more effectively results in the production of light olefins through the catalytic catalytic cracking of C5 oil compared to the catalyst in which the rare earth metal is introduced into the phosphorus- Can be confirmed.

While the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, Such modifications and changes are to be considered as falling within the scope of the following claims.

Claims

A catalyst used for producing a light olefin comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms,
Wherein the catalyst is a mixed catalyst of (i) a ZSM-5 catalyst and (ii) at least one zeolite other than the ZSM-5 catalyst.

The method according to claim 1,
Wherein the ZSM-5 catalyst has an Si / Al atomic ratio of 5 to 500.

The method according to claim 1,
Wherein the zeolite is at least one selected from the group consisting of MOR, LTA, BEA, FAU, and TON.

The method according to claim 1,
Wherein the zeolite has a MOR structure.

The method of claim 3,
The catalyst for the production of light olefins according to claim 1, wherein the zeolite contains an inorganic metal oxide.

6. The method of claim 5,
Wherein the zeolite has an Si / Al atomic ratio of 2 to 200. 2. The catalyst for producing a light olefin according to claim 1,

6. The method of claim 5,
The inorganic metal oxide may be at least one selected from the group consisting of Al, Si, Mg, Ti, V, Cr, Mn, Y, Wherein the catalyst comprises at least one element selected from the group consisting of neodymium (Nb), molybdenum (Mo), rhenium (Re) and tungsten (W).

The method according to claim 1,
Wherein the zeolite is contained in an amount of 20 to 80 wt% based on 100 wt% of the mixed catalyst.

The method according to claim 1,
Wherein the mixed catalyst is cation-substituted.

10. The method of claim 9,
The cation exchange is ammonium nitrate (NH ₄ NO _3), ammonium chloride (NH ₄ Cl), ammonium carbonate _{((NH 4) 2 CO 3} ) and ammonium fluoride at least one selected from the group consisting of (NH ₄ F) &Lt; RTI ID = 0.0 > 1, < / RTI >

The method according to claim 1,
Wherein the mixed catalyst further comprises phosphorus.

12. The method of claim 11,
The phosphorus is a phosphoric acid (H ₃ PO _4), ammonium phosphate _{((NH 4) H 2 PO} 4), phosphoric acid ammonium _{((NH 4) 2 HPO 4} ) and tricalcium phosphate of ammonium _{((NH 4) 3 PO 4} ) Wherein the catalyst comprises at least one phosphorus precursor selected from the group consisting of iron and iron.

12. The method of claim 11,
Wherein the phosphorus is contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the mixed catalyst.

12. The method of claim 11,
Wherein the mixed catalyst further comprises a rare earth metal or an alkali metal.

15. The method of claim 14,
The rare earth metal is selected from the group consisting of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium Wherein the catalyst is at least one selected from the group consisting of Dy, Ho, Er, Tm, ytterbium and lutetium.

15. The method of claim 14,
Wherein the alkali metal is at least one selected from the group consisting of lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs).

15. The method of claim 14,
Wherein the rare earth metal or alkali metal content is 2 or less in terms of the atomic ratio to the phosphorus.

18. The method according to any one of claims 1 to 17,
Wherein the hydrocarbon mixture having 4 to 7 carbon atoms is a C5 oil component produced after the naphtha cracking process.

A process for producing a light olefin comprising ethylene, propylene and butene by catalytic catalytic cracking of a hydrocarbon mixture having 4 to 7 carbon atoms,
A process for producing a light olefin comprising reacting the hydrocarbon mixture at a reaction temperature of 300 to 700 ° C. in the presence of a catalyst according to any one of claims 1 to 17 at a weight hourly space velocity (WHSV) of 1 to 20 h ^-1 .

20. The method of claim 19,
Wherein the hydrocarbon mixture having 4 to 7 carbon atoms is a C5 oil produced after the naphtha cracking process.