JPH11180902A - Production of lower olefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the formation of a by-product at an industrially advantageous low temperature and efficiently produce the objective compound in high selectivity by using a catalyst containing a specific amount of a rare earth element supported on a zeolite when catalytically cracking a hydrocarbon. SOLUTION: A >=2C hydrocarbon raw material is brought into contact with a catalyst supporting a rare earth element in an amount of 0.4-20 expressed in terms of atomic ratio to the aluminum in a crystalline aluminosilicate zeolite thereon. The hydrocarbon raw material is preferably subjected to dehydrogenating treatment and then brought into contact with the catalyst to improve the yield. ZSM-5 or ZSM-11 or both are preferred as the zeolite. Lanthanum, cerium and the like are preferred as the rare earth element. The catalyst preferably further contains 0.1-10 wt.% phosphorus supported thereon. The catalytic cracking reaction is preferably carried out in the presence of steam at 600-700 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catalyst for catalytically cracking a hydrocarbon feedstock using a catalyst to produce a lower olefin,
It mainly relates to a method for producing ethylene and propylene.

[0002]

2. Description of the Related Art Lower olefins such as ethylene and propylene are important substances as basic raw materials for various chemical products. Conventionally, as a method for producing these lower olefins, a method in which a gaseous hydrocarbon such as ethane, propane, butane or a liquid hydrocarbon such as naphtha is used as a raw material and is thermally decomposed in a steam furnace in an externally heated tubular furnace. Is widely practiced. However, this method has an economic disadvantage that a high temperature of 800 ° C. or more is required to increase the olefin yield, and that expensive equipment materials must be used. For this reason, various catalytic cracking methods for hydrocarbons using a catalyst have been studied. Among them, when a solid acid, particularly zeolite, is used, it can be decomposed at a relatively low temperature (350 to 700 ° C.), so that many examples have been reported. For example, a series of patents of Asahi Kasei Kogyo Co., Ltd. (JP-A-60-222428, JP-A-61-721)
8, JP-A-3-130236, JP-A-6-19213
4, JP-A-6-192135, JP-A-6-19970
7, JP-A-6-228017, JP-A-6-346062
In ZS, the acid amount and acid strength are controlled to specific ranges.
Although a catalytic cracking method of n-hexane and naphtha using an M-5 type catalyst is disclosed, this method generates a large amount of aromatic components (benzene, toluene, xylene, BTX) and efficiently converts olefins. You can't get it. JP-A-1-213240 and JP-A-3-504737 disclose catalytic cracking by ZSM-5 in which the α value which is an index of cracking activity is controlled to a specific range. However, even with these catalysts, a large amount of BTX is generated. And C ₂
Olefin yields -C ₄ is about 40% or less.
In JP-A-2-1413 and JP-A-2-184846,
A catalytic cracking method for paraffins using a ZSM-5 catalyst supporting copper, cobalt, silver or the like is disclosed. Although it is reported that propylene can be obtained in this method in a yield of 40 to 60%, it is a data of the pulse reaction under a very dilute condition, and there is difficulty in commercial implementation. Also, the yield of ethylene is as low as 20% or less. Numerous catalytic cracking by a catalyst obtained by modifying ZSM-5 with another component such as a rare earth element has been reported. US Patent 5,232,6
Nos. 75 and 5,380,690, EP 72
No. 7,404 discloses a ZS containing 0.01 to 0.3 rare earth element at an atomic ratio to aluminum in ZSM-5.
A catalytic cracking method for paraffins using an M-5 catalyst is disclosed. However, the yield of ethylene is 10% or less, and the yield of propylene is 20% or less. Furthermore, it has been reported that when hydrocarbons containing a large amount of unsaturated components such as butenes, pentenes, and hexenes are brought into contact with zeolites, a large amount of aromatics including BTX is produced (for example, in particular). No. 56-42639, Japanese Patent Publication No. 4-5712, U.S. Pat. No. 3,845,150,
US Pat. No. 3,960,978), when attempting to crack hydrocarbons containing unsaturated components, the yield of light olefins such as ethylene and propylene was low. Many methods for producing olefins by decomposing paraffin using a metal oxide catalyst other than zeolite have been reported (for example, JP-B-48-13523, JP-B-46-25370,
JP-B-49-45364, JP-B-52-12162, JP-B-53-23806, JP-B-56-5435, JP-B-56-5436, JP-B-56-29919, and JP-B-60
−41054). However, in these examples, the decomposition temperature is generally equivalent to that of the current pyrolysis method (700 to 800 ° C.).
Above) and there is a problem that a large amount of carbon monoxide and carbon dioxide are generated. As described above, a method for efficiently producing olefins, particularly ethylene and propylene, by decomposing light hydrocarbons using a catalyst has not been established.

[0003]

DISCLOSURE OF THE INVENTION The present invention suppresses the production of by-products such as aromatic hydrocarbons and heavy substances when catalytically cracking a hydrocarbon raw material using a catalyst, and reduces the production of ethylene, propylene and the like. It is an object of the present invention to provide a method for producing a lower olefin efficiently.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have conducted catalytic cracking of hydrocarbon raw materials using a catalyst in which a specific range of rare earth elements is supported on zeolite. By doing so, it has been found that the production of by-products such as aromatic hydrocarbons and heavy substances can be suppressed at a low temperature that is industrially advantageous, and ethylene and propylene can be produced with high selectivity, and the present invention has been completed. That is, according to the present invention, there is provided a process for producing a lower olefin, which comprises catalytically cracking a hydrocarbon raw material using a zeolite catalyst supporting a rare earth element in a specific range.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As the hydrocarbon raw material used in the present invention, gaseous or liquid hydrocarbons at normal temperature and normal pressure can be used. Generally, it has 2 to 30 carbon atoms, preferably 2 carbon atoms.
~ 20 paraffins or hydrocarbon raw materials containing the same as a main component (10 wt% or more) are used. Examples of such hydrocarbon raw materials include paraffins such as ethane, propane, butane, pentane and hexane, and light hydrocarbon fractions such as naphtha and light oil. The raw material components are not limited to saturated hydrocarbons, and those containing components having unsaturated bonds can also be used. Further, an aromatic component may be contained. One of the features of the present catalyst is that BTX conversion can be suppressed and ethylene / propylene can be obtained in high yield even with a fraction containing an unsaturated component. For this reason, a higher ethylene / propylene yield can be obtained by decomposing a fraction having a large amount of unsaturated content or a fraction having undergone the dehydrogenation step of paraffin with the present catalyst, rather than decomposing paraffin as it is with the present catalyst. can get. Examples of the catalyst used in the dehydrogenation step prior to the decomposition step with the present catalyst include a chromia-supported alumina catalyst and a platinum and tin-supported zinc aluminate catalyst.

[0006] The catalyst of the present invention is mainly composed of a zeolite supporting a rare earth element. As the zeolite, a high silica type zeolite, particularly ZSM-5 and / or ZSM-1
1 is preferred. The SiO ₂ / Al ₂ O ₃ ratio of the zeolite is 2
It is 5-800, preferably 50-600, and more preferably 100-300. Any rare earth element can be used, but preferably, lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, dysprosium and the like can be used. The rare earth elements may be used alone or in combination of two or more. The catalyst is a solution of various salts of rare earth elements, for example, acetate, nitrate, halide, sulfate, carbonate, or alkoxide, acetylacetonate, etc. It can be easily prepared by drying, baking and baking. According to these supporting methods, a part of the rare earth element enters the pores of the zeolite and a part exchanges ions with the protons of the zeolite, but most of the rare earth element is supported as an oxide on the zeolite. It is important that the rare earth element is supported on the zeolite, and the effect of the present catalyst cannot be obtained only by physically mixing the zeolite and the rare earth oxide.

[0007] In the catalyst of the present invention, the amount of the rare earth element carried is 0.4 as an atomic ratio with respect to the aluminum in the zeolite.
-20, preferably 1-10, more preferably 2-5
When the supported amount is smaller than these values, the generation of aromatic hydrocarbons and heavy substances is not suppressed, and when the supported amount is too large, the catalytic activity is sharply reduced and the olefin yield is reduced. Although the effect of the rare earth element is not yet clear, the activity is not obtained when the rare earth element is supported on silicalite having almost no acid sites, as shown in the following Examples. ) Itself is considered to be inert to the decomposition of hydrocarbons.
From this, the decomposition reaction is based on the acid site of the zeolite as the active site, and the rare earth element (oxide) promotes the elimination of the produced olefin from the zeolite, probably due to its basic action. It is assumed that the generation of aromatics and heavy substances as a reaction was suppressed.

[0008] The shape of the catalyst of the present invention is not particularly limited, and may be any shape such as a powder or a molded product. Among these, phosphorus is effective in improving the durability of the catalyst. For example, phosphorus can be supported by impregnating the present catalyst supporting a rare earth element with an aqueous solution of diammonium hydrogen phosphate. It is preferable that phosphorus is contained in the present catalyst in an amount of 0.1 to 10% by weight, preferably 1 to 7% by weight, more preferably 2 to 5% by weight. Furthermore, these catalysts may contain components other than zeolite and rare earth, for example, alkali, alkaline earth, transition metal, noble metal, halogen, phosphorus, binder and the like. It is also possible to use a mixture with a filler such as silica, alumina, magnesia or quartz sand.

The catalytic cracking reaction of the present invention is carried out by using a reactor of a type such as a fixed bed or a fluidized bed, and supplying a hydrocarbon raw material to a catalyst bed packed with the above-mentioned catalyst. At this time, the hydrocarbon raw material may be diluted with nitrogen, hydrogen, helium, steam, or the like. Among these diluents, steam has the effect of maintaining the active state of the catalyst,
A preferable steam supply amount is 0.1 to the feed hydrocarbon.
To 1 wt%, more preferably 0.3 to 0.7 wt%. The reaction temperature is 350-780 ° C, preferably 500
To 750 ° C, more preferably 600 to 700 ° C. It can be carried out at temperatures above 780 ° C., but the production of methane and coke increases sharply. If the temperature is lower than 350 ° C., sufficient activity cannot be obtained, so that the yield of olefin per one pass decreases. The reaction pressure can be carried out at normal pressure, reduced pressure or increased pressure, but usually from normal pressure to slightly increased pressure is employed. By carrying out the method of the present invention under the above conditions, it is possible to efficiently decompose a hydrocarbon raw material at a lower temperature as compared with a conventional pyrolysis method, and to selectively produce lower olefins such as ethylene and propylene. Can be.

[0010]

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

Example 1 A powdery proton type ZSM-5 aluminosilicate as a zeolite (SiO ₂ / A measured by fluorescent X-ray analysis)
4 g of l ₂ O ₃ molar ratio, BET surface area: 360 m ² / g, particle diameter: 150 μm or less), and an aqueous lanthanum acetate solution containing 0.4 g of lanthanum corresponding to 10 wt% [0.
9877 g of lanthanum acetate hemihydrate (La (CH ₃
COO) ₃ · 0.5H ₂ O) was impregnated with what was dissolved in deionized water 60cc] and stirred for 1 hour at 40 ° C.. The resulting slurry was stirred at 40 ° C. to 60 ° C. under reduced pressure to evaporate water for about 2 hours to obtain a white powder. After drying the obtained powder in air at 120 ° C. for 8 hours, the temperature was raised to 600 ° C. in a muffle furnace for 4 hours, and
Calcination was performed at 5 ° C. for 5 hours. The obtained white solid was pulverized in a mortar and passed through a 150 μm sieve to obtain 10% La / Z
This was an SM-5 catalyst (La / Al atomic ratio = 4.3). An inert filler (quartz sand) is added to 1 g of this catalyst in a quartz reaction tube (with an inner diameter of 4 mm and a thermocouple insertion tube of 4 mm in outer diameter) having an inner diameter of 10 mm and a length of 330 mm so that the length of the catalyst layer becomes about 70 mm.
And filled together. Quartz sand was filled above and below the catalyst layer.
The temperature of the catalyst layer was raised to 650 while flowing air at 40 cc / min (0 ° C., 1 atm conversion, the same applies hereinafter) through this reactor.
The temperature was raised to ° C., and the pretreatment was performed for 1 hour. After completion of the pretreatment, the temperature of the catalyst layer was maintained at 650 ° C., and as raw materials, 2.8 cc / min of normal butane, 5.7 cc / min of nitrogen and steam, and 0.01 g / mi of nitrogen and steam, respectively.
n was supplied at a flow rate of n to perform a catalytic cracking reaction of normal butane. 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 (% by weight) = (weight of each component / weight of feed)
× 100 Raw material conversion rate (%) = (1−weight of unreacted raw material / weight of supplied raw material) × 100 The reaction results are shown in Table 1.

Comparative Example 1 In the same manner as in Example 1, powdery proton-type ZSM-
5 Aluminosilicate (Si measured by fluorescent X-ray analysis
O ₂ / Al ₂ O ₃ molar ratio 200, BET surface area 360 m ² /
g, a particle diameter of 150 μm or less) to prepare a catalyst carrying 0.5% by weight of lanthanum.
A ZSM-5 catalyst (La / Al atomic ratio = 0.2
2). Using 1 g of this catalyst, a catalytic decomposition reaction of normal butane was carried out in the same manner as in Example 1. Table 1 shows the reaction results. As can be seen from this example, when the amount of the rare earth carried is too low, BTX is high and the olefin yield is low.

Comparative Example 2 Proton type ZSM-5 aluminosilicate in powder form (SiO ₂ / Al ₂ O ₃ molar ratio measured by fluorescent X-ray analysis: 20)
(0, BET surface area: 360 m ² / g, particle size: 150 μm or less) The catalytic cracking reaction of normal butane was carried out under the same conditions as in Example 1 except that 1 g was charged as a catalyst. Table 1 shows the reaction results. As can be seen from this example, the catalyst not carrying a rare earth element generates a large amount of BTX and has a low ethylene and propylene yield.

Comparative Example 3 Instead of proton type ZSM-5 aluminosilicate, silicalite (SiO ₂ , BET surface area: 360 m ² / g, particle size: 150 μm or less) was used, and lanthanum was impregnated and carried in the same manner as in Example 1. A 10% La / silicalite catalyst was prepared. Using 1 g of this catalyst, a decomposition reaction of normal butane was carried out under the same conditions as in Example 1. Table 1 shows the reaction results. As can be seen from this example, the decomposition activity is not seen in the catalyst in which the rare earth element is supported on silicalite having no solid acid point.

[0015]

[Table 1]

Examples 2 and 3 and Comparative Examples 4 and 5 These examples are based on the case where the amount of rare earth carried is 0.4 or more and 0.3 or less with respect to the aluminum in zeolite.
This shows that there are significant differences between the ethylene / propylene yield and the BTX yield. 10% L as catalyst as in Example 1
a / ZSM-5 catalyst (La / Al atomic ratio = 4.33),
And 1% La / ZSM prepared in the same manner as in Example 1.
0.5 g of each of the -5 catalyst (La / Al atomic ratio = 0.43) was placed in the same reaction tube as in Example 1 and the length of the catalyst layer was about 5 g.
It was filled together with an inert filler (quartz sand) so as to be 0 mm. While flowing air through this reactor at 40 cc / min, the temperature of the catalyst layer was raised to 650 ° C.
Time pretreatment was performed. After completion of the pretreatment, the temperature of the catalyst
Maintained at 50 ° C., 2.8 c of normal butane as a raw material
c / min, 12.2 c each of nitrogen and steam
The catalyst was supplied at a flow rate of 0.0047 g / min at a rate of c / min to perform a catalytic decomposition reaction of normal butane. The results are shown in Table 2 as Example 2 and Example 3. Further, the same 0.5% La / ZSM-5 catalyst (La / Al atomic ratio = 0.22) as in Comparative Example 1 and the same unsupported HZSM-5 catalyst as in Comparative Example 2 were used as Example 2. The catalytic cracking reaction of normal butane was carried out under the same conditions as in Examples 1 to 3. The results are shown in Table 2 as Comparative Examples 4 and 5. Table 2
As is apparent from the above, the La / Al atomic ratio was set to 0.4 to 0.1.
When it is reduced to 3 or less, the production of BTX increases remarkably,
Ethylene propylene yield decreases.

[0017]

[Table 2]

Example 4 This example shows a catalytic cracking reaction using a catalyst obtained by further adding phosphorus to the catalyst of Example 1. 10% La prepared in Example 1
/ ZSM-5 catalyst is impregnated in an aqueous solution of diammonium hydrogen phosphate containing 0.02 g of phosphorus corresponding to 2 g of the catalyst (0.1706 g of diammonium hydrogen phosphate dissolved in 20 g of deionized water). And stirred at 40 ° C. for 1 hour. The resulting slurry is heated at 40 ° C to 60 ° C under reduced pressure.
The water was evaporated over about 2 hours while stirring at し な が ら ° C. to obtain a white powder. After the obtained powder was dried in air at 120 ° C. for 8 hours, the temperature was raised to 600 ° C. in a muffle furnace over 4 hours and calcined at 600 ° C. for 5 hours. The obtained white solid was crushed in a mortar and passed through a 150 μm sieve to obtain a 10% La-2% P / ZSM-5 catalyst. (La
/ Al atomic ratio = 4.3) Using 1 g of this catalyst, the same reaction as in Example 1 was carried out. Table 3 shows the reaction results.

Comparative Example 6 The same powdery proton type ZSM as used in Example 1
-5 aluminosilicate (S measured by fluorescent X-ray analysis
iO ₂ / Al ₂ O ₃ molar ratio 200, BET surface area 360 m ²
/ G, particle diameter 150 μm or less) 2 wt% for 4 g
Diammonium hydrogen phosphate aqueous solution containing 0.08 g of phosphorus (0.3411 diammonium hydrogen phosphate)
g in 40 g of deionized water).
Stirred at 0 ° C. for 1 hour. The resulting slurry is reduced under reduced pressure to 4
The water was evaporated over about 2 hours while stirring at 0 ° C to 60 ° C to obtain a white powder. The obtained powder is placed in air at 12
After drying at 0 ° C. for 8 hours, the temperature was raised to 600 ° C. in a muffle furnace for 4 hours and calcined at 600 ° C. for 5 hours. The obtained white solid was crushed in a mortar and passed through a 150 μm sieve to obtain a 2% P / ZSM-5 catalyst. Using 1 g of this catalyst, the same reaction as in Example 1 was performed. Table 3 shows the reaction results. As can be seen from this example, the catalyst supporting only phosphorus has a low olefin yield.

[0020]

[Table 3]

Examples 5-7 The same as Example 1 except that cerium acetate monohydrate, praseodymium nitrate hexahydrate and samarium acetate tetrahydrate were used instead of lanthanum acetate hemihydrate. A catalyst supporting 10 wt% of a rare earth element was prepared by a suitable method. (Atomic ratio: Ce / Al = 4.3, Pr / Al = 4.3, Sm /
(Al = 4.00) 0.5 g of each of these catalysts was 10 mm in inner diameter and 33 mm in length.
A 0 mm quartz reaction tube (with an inner tube for a thermocouple having an outer diameter of 4 mm) was filled together with an inert filler (quartz sand) so that the length of the catalyst layer was about 50 mm. Quartz sand was filled above and below the catalyst layer. 40cc / m of air into this reactor
while raising the temperature of the catalyst layer to 650 ° C. while flowing in,
Pretreatment was performed for 1 hour as it was. After completion of the pretreatment, the temperature of the catalyst layer was maintained at 650 ° C., and normal butane was supplied as a raw material at a flow rate of 2.8 cc / min, nitrogen and steam at a flow rate of 12 cc / min and 0.0047 g / min, respectively. A catalytic cracking reaction was performed. Table 4 shows the results.

[0022]

[Table 4]

Example 8 This example shows the catalytic cracking of a mixture of saturated and unsaturated hydrocarbons with a rare earth supported catalyst. 0.5 g of a 10% La / ZSM-5 catalyst prepared in the same manner as in Example 1 was charged into the reactor in the same manner as in Examples 5 to 7. The temperature was raised to 650 ° C. while flowing air at 40 cc / min into the reactor, and pretreatment was performed for 1 hour. After preprocessing,
The temperature of the catalyst layer was maintained at 650 ° C., and as a raw material, a normal butane / 1-butene mixed gas containing 30 vol% of 1-butene was 2.8 cc / min, nitrogen and steam were 12 cc / min and 0.0047 g / min, respectively. The catalyst was supplied at a flow rate to perform a catalytic cracking reaction of a normal butane / 1-butene mixed gas. Table 5 shows the results.

Example 9 This example shows an example of catalytic cracking of unsaturated hydrocarbons with a rare earth supported catalyst. 10% L prepared in the same manner as in Example 1
a / ZSM-5 catalyst 0.3 g with an inner diameter of 10 mm and a length of 33
A 0 mm quartz reaction tube (with a thermocouple inner tube having an outer diameter of 4 mm) was filled together with an inert filler (quartz sand) so that the length of the catalyst layer was about 30 mm. Quartz sand was filled above and below the catalyst layer. 40cc / m of air into this reactor
while raising the temperature of the catalyst layer to 650 ° C. while flowing in,
Pretreatment was performed for 1 hour as it was. After completion of the pretreatment, the temperature of the catalyst layer was maintained at 650 ° C., and 1-butene was used as a raw material at 1.8 cc / min, and nitrogen and steam were added at a rate of 1 respectively.
The catalyst was supplied at a flow rate of 5 cc / min at a flow rate of 0.0078 g / min to perform a catalytic decomposition reaction of 1-butene. Table 5 shows the results.

[0025]

[Table 5]

Example 10 This example shows an example of catalytic decomposition of hexane using a rare earth supported catalyst. 10% La / Z prepared in the same manner as in Example 1
0.5 g of SM-5 catalyst is 10 mm in inner diameter and 330 mm in length
Quartz reaction tube (with 4 mm outside diameter thermocouple inner tube)
Was filled with an inert filler (quartz sand) so that the length of the catalyst layer was about 50 mm. Quartz sand was filled above and below the catalyst layer. 40cc / min of air into this reactor
Then, the temperature of the catalyst layer was raised to 650 ° C. while flowing at, and pretreatment was performed for 1 hour as it was. After the pretreatment, the temperature of the catalyst layer was maintained at 650 ° C., and 0.42 g / h of normal hexane and 2 cc of nitrogen and steam were used as raw materials.
/ Min, 0.0047 g / min, and 11 cc /
The catalyst was supplied at a flow rate of min to perform a catalytic decomposition reaction of normal hexane. Table 6 shows the results.

Comparative Example 7 A powdery proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O ₃ measured by fluorescent X-ray analysis) was used as a catalyst.
Molar ratio 200, BET surface area 360 m ² / g, particle size 1
The catalytic decomposition reaction of normal hexane was carried out under the same conditions as in Example 10 except that 0.5 g of 50 μm or less was charged. Table 5 shows the results. When no rare earth element is supported, BTX is high and the olefin yield is low.

Example 11 This example shows an example in which a dehydrogenation catalyst was charged before the rare earth-supported catalyst to perform catalytic cracking of paraffin. 0.5% of 10% Pr / ZSM-5 catalyst prepared in the same manner as in Example 6.
g into a quartz reaction tube with an inner diameter of 10 mm and a length of 330 mm (with an inner tube for thermocouple with an outer diameter of 4 mm) together with an inert filler (quartz sand) so that the length of the catalyst layer becomes about 50 mm. did. 3 g of a platinum-based dehydrogenation catalyst (for example, described in US Pat. No. 5,344,805) was filled in the upper part of the catalyst layer, and quartz sand was filled in the upper part and the lower part of the catalyst layer. While flowing air through this reactor at 40 cc / min, the temperature of the catalyst layer filled with the dehydrogenation catalyst was raised to 580 ° C, and the temperature of the catalyst layer filled with the 10% Pr / ZSM-5 catalyst was raised to 650 ° C. Time pretreatment was performed.
After the completion of the pretreatment, the temperature of the catalyst layer is kept at 580 ° C. and 650 ° C., and 2.8 of normal butane is used as a raw material.
cc / min, nitrogen and steam each at 2 cc / min.
min, 0.0078 g / min, hydrogen at 11 cc / m
The catalyst was supplied at a flow rate of in to perform a catalytic decomposition reaction of normal butane. Table 6 shows the results.

[0029]

[Table 6]

Example 12 This example shows data relating to the durability of a rare earth supported catalyst. Using 1 g of the catalyst prepared in the same manner as in Example 2, the reaction was carried out under the same conditions as in Example 1. Table 7 shows the reaction results 1 hour after the start of the reaction and 4 hours after the start of the reaction. Thus, no remarkable deterioration was observed in the present catalyst.

Comparative Example 8 Powdered proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O ₃ measured by fluorescent X-ray analysis) as a catalyst
Molar ratio 200, BET surface area 360 m ² / g, particle size 1
The same reaction as in Example 10 was carried out using 1 g of 50 μm or less. Table 7 shows the reaction results 1 hour after the start of the reaction and 4 hours after the start of the reaction. As described above, the catalyst which does not support the rare earth element has a low olefin yield and deteriorates quickly.

[0032]

[Table 7]

[0033]

According to the method of the present invention, the production of by-products such as aromatic hydrocarbons and heavy substances is suppressed using gaseous or liquid hydrocarbons as raw materials, and lower olefins such as ethylene and propylene are selected. It can be manufactured in a special way. Furthermore, in the case of the present invention, it is possible to lower the reaction temperature by 100 ° C. or more as compared with the conventional thermal decomposition method.

[Procedure amendment]

[Submission date] January 28, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

[0008] The shape of the catalyst of the present invention is not particularly limited, and may be any shape such as a powder or a molded product. Also,
These catalysts are components other than zeolites and rare earths,
For example, alkali, alkaline earth, transition metal, precious metal,
Logen, phosphorus, a binder and the like may be contained. Among these, phosphorus is effective in improving the durability of the catalyst. For example, phosphorus can be supported by impregnating the rare earth element-supported catalyst with an aqueous solution of diammonium hydrogen phosphate. Phosphorus is 0.1 to 10% by weight based on the weight of the catalyst;
Preferably, the content is 1 to 7% by weight, more preferably 2 to 5% by weight. It is also possible to use more silica, alumina, mixed with fillers such as magnesia or quartz sand.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

Comparative Example 7 A powdery proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O measured by fluorescent x-ray analysis) was used as a catalyst.
The catalytic cracking reaction of normal hexane was carried out under the same conditions as in Example 10 except that 0.5 g of a ₃ molar ratio of 200, a BET surface area of 360 m ² / g, and a particle size of 150 μm or less were filled.
Table 6 shows the results. When no rare earth element is supported, BTX is high and the olefin yield is low.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

Comparative Example 8 A powdery proton type ZSM-5 aluminosilicate (SiO ₂ / Al ₂ O measured by fluorescent X-ray analysis) was used as a catalyst.
_The same reaction as in Example 1 was carried out using 1 g of ₃ molar ratio, 200 g of BET surface area, 360 m ² / g, particle diameter of 150 μm or less. Table 7 shows the reaction results 1 hour after the start of the reaction and 4 hours after the start of the reaction. As described above, the catalyst which does not support the rare earth element has a low olefin yield and deteriorates quickly.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // C07B 61/00 300 C07B 61/00 300 (71) Applicant 000221627 Tonen Chemical Co., Ltd. 1-39, Hiroo 1-chome, Shibuya-ku, Tokyo (71) Applicant 000231682 Nippon Petrochemical Co., Ltd. 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo (71) Applicant 000157603 Maruzen Petrochemical Co., Ltd. 2- 25-10, Hatchobori, Chuo-ku, Tokyo (74) 5 Attorney Toshiaki Ikeura (72) Inventor Yuji Yoshimura 1-1-1, Higashi, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor Kazuhisa Murata 1-1-1, Higashi, Tsukuba, Ibaraki Industrial Technology (72) Inventor Takashi Hayakawa 1-1-1, Higashi, Tsukuba, Ibaraki Pref. (72) Inventor Kunio Suzuki 1-1-1, Higashi, Tsukuba, Ibaraki Pref., National Institute of Advanced Industrial Science and Technology (72) Inventor Katsuomi Takehira 1-1, Higashi, 1-1, Higashi, Tsukuba, Ibaraki Pref. ) Inventor Kenichi Wakui 3-6-6 Kasumigaseki, Chiyoda-ku, Tokyo Japan Chemical Industry Association (72) Inventor Koji Shiozawa 3-2-6 Kasumigaseki, Chiyoda-ku, Tokyo Japan Chemical Industry Association (72) Inventor Koichi Sato 3-2-6 Kasumigaseki, Chiyoda-ku, Tokyo Within the Japan Chemical Industry Association (72) Inventor Goro 3-6-6 Kasumigaseki, Chiyoda-ku, Tokyo Japan Chemical Industry In association

Claims (5)

[Claims] When producing a lower olefin by contacting a hydrocarbon raw material having 2 or more carbon atoms with a catalyst, a crystalline aluminosilicate zeolite carrying a rare earth element is used as a catalyst, and the amount of the rare earth element carried by the catalyst is reduced. A method for producing a lower olefin, wherein the atomic ratio of aluminum to zeolite is in the range of 0.4 to 20. 2. The method for producing a lower olefin according to claim 1, wherein the crystalline aluminosilicate zeolite is a ZSM-5 type and / or ZSM-11 type zeolite. 3. The method for producing a lower olefin according to claim 1, wherein said catalyst further contains 0.1 to 10% by weight of phosphorus. 4. The method for producing a lower olefin according to claim 1, wherein the catalytic reaction is carried out in the presence of steam. 5. The method for producing a lower olefin according to claim 1, wherein a catalytic reaction is carried out by passing a hydrocarbon material having 2 or more carbon atoms through a dehydrogenation step and then passing through a catalyst layer containing the catalyst. .