JP5813853B2 - Catalyst for producing monocyclic aromatic hydrocarbon and method for producing monocyclic aromatic hydrocarbon - Google Patents

Description

  The present invention relates to a catalyst for producing monocyclic aromatic hydrocarbons and a method for producing monocyclic aromatic hydrocarbons for producing monocyclic aromatic hydrocarbons from oils rich in polycyclic aromatic hydrocarbons.

Light cycle oil (hereinafter referred to as “LCO”), which is a cracked light oil produced by a fluid catalytic cracker, contains a large amount of polycyclic aromatic hydrocarbons and has been utilized as a light oil or heavy oil. However, in recent years, LCO can be used as a high-octane gasoline base material or petrochemical raw material, and a high-added monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms (for example, benzene, toluene, xylene, ethylbenzene, etc.) is obtained. It is being considered.
For example, Patent Documents 1 to 3 propose a method for producing monocyclic aromatic hydrocarbons from polycyclic aromatic hydrocarbons contained in a large amount in LCO or the like using a zeolite catalyst.
However, in the methods described in Patent Documents 1 to 3, it cannot be said that the yield of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms is sufficiently high.

When producing monocyclic aromatic hydrocarbons from heavy feedstock containing polycyclic aromatic hydrocarbons, a large amount of carbonaceous matter is deposited on the catalyst, and the activity declines quickly, so the catalyst regeneration removes the carbonaceous matter. Must be performed at a high frequency. Further, in the case of employing a circulating fluidized bed which is a process of efficiently repeating reaction-catalyst regeneration, the catalyst regeneration temperature needs to be higher than the reaction temperature, and the temperature environment of the catalyst becomes more severe.
Under such severe conditions, when a zeolite catalyst is used as the catalyst, the hydrothermal deterioration of the catalyst progresses and the reaction activity decreases with time, so that improvement of the hydrothermal stability of the catalyst is required. However, in the zeolite catalysts described in Patent Documents 1 to 3, no measures for improving hydrothermal stability are taken, and the practical utility value is extremely low.

As a method for improving hydrothermal stability, a method using a zeolite having a high Si / Al ratio, a method of stabilizing a catalyst by hydrothermal treatment in advance, such as a USY type zeolite, a method of adding phosphorus to the zeolite, A method of adding a rare earth metal, a method of improving a structure directing agent at the time of zeolite synthesis, and the like are known.
Among these, the addition of phosphorus is known not only to improve hydrothermal stability but also to improve the selectivity by suppressing carbonaceous precipitation in fluid catalytic cracking, and to improve the abrasion resistance of the binder. Is often applied.
Catalysts for catalytic cracking in which phosphorus is added to zeolite are disclosed in, for example, Patent Documents 4 to 6.
That is, Patent Document 4 discloses a method for producing an olefin from naphtha using a catalyst containing ZSM-5 to which phosphorus, gallium, germanium, and tin are added. In Patent Document 4, by adding phosphorus, the generation of methane and aromatics is suppressed to increase the selectivity of olefin production, and high activity is ensured even with a short contact time, thereby increasing the yield of olefins. It is aimed.
Patent Document 5 uses a catalyst containing phosphorus on ZSM-5 containing zirconium and a rare earth and a catalyst containing USY zeolite, REY zeolite, kaolin, silica and alumina, and produces high yields of olefins from heavy hydrocarbons. A method of manufacturing is disclosed.
Patent Document 6 discloses a method for producing ethylene and propylene in high yields by converting hydrocarbons using a catalyst containing ZSM-5 carrying phosphorus and a transition metal.

As described above, the addition of phosphorus to zeolite is disclosed in Patent Documents 4 to 6, all of which are mainly aimed at improving the olefin yield, and are monocyclic aromatic carbonization having 6 to 8 carbon atoms. Hydrogen could not be produced in high yield. For example, Table 2 of Patent Document 6 describes the yields of olefins (ethylene, propylene) and BTX (benzene, toluene, xylene), whereas the yield of olefins is 40% by mass, The yield of BTX was as low as about 6% by mass.
Accordingly, it is possible to produce monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms from raw material oil containing polycyclic aromatic hydrocarbons at a high yield, and to reduce the yield of monocyclic aromatic hydrocarbons over time. The actual situation is that there is no known catalyst for producing monocyclic aromatic hydrocarbons that can be prevented.

JP-A-3-2128 Japanese Patent Laid-Open No. 3-52993 JP-A-3-26791 Special Table 2002-525380 JP 2007-190520 A Special table 2007-530266 gazette

  INDUSTRIAL APPLICABILITY The present invention can produce monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms with high yield from a raw material oil containing polycyclic aromatic hydrocarbons, and also monocyclic aromatic carbonization having 6 to 8 carbon atoms over time. It is an object of the present invention to provide a catalyst for producing monocyclic aromatic hydrocarbons and a method for producing monocyclic aromatic hydrocarbons which can prevent a decrease in the yield of hydrogen.

[1] Aromatic hydrocarbons for producing monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms from a feedstock having a 10% by volume distillation temperature of 140 ° C or higher and a 90% by volume distillation temperature of 380 ° C or lower A production catalyst comprising:
A crystalline aluminosilicate and phosphorus are contained, and the molar ratio (P / Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate is 0.5 or more and 1.0 or less. A catalyst for producing monocyclic aromatic hydrocarbons.
[2] The catalyst for producing monocyclic aromatic hydrocarbons according to [1], wherein the phosphorus content is 0.1 to 10% by mass with respect to the catalyst weight.
[3] The monocyclic aromatic hydrocarbon production catalyst according to [1] or [2], wherein the crystalline aluminosilicate is a pentasil-type zeolite.
[4] The catalyst for producing monocyclic aromatic hydrocarbons according to any one of [1] to [3], wherein the crystalline aluminosilicate is MFI type zeolite.
[5] A monocyclic aromatic carbonization according to any one of [1] to [4], wherein a feed oil having a 10 vol% distillation temperature of 140 ° C or higher and a 90 vol% distillation temperature of 380 ° C or lower is used. A method for producing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms, comprising contacting with a catalyst for producing hydrogen.
[6] The method for producing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms according to [5], wherein the raw material oil contains cracked light oil produced by a fluid catalytic cracking apparatus.
[7] The monocyclic aroma having 6 to 8 carbon atoms according to [5] or [6], wherein the feedstock is brought into contact with the catalyst for producing the monocyclic aromatic hydrocarbon in a fluidized bed reactor. For producing aromatic hydrocarbons.

  According to the catalyst for producing a monocyclic aromatic hydrocarbon and the method for producing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms according to the present invention, it is possible to obtain a carbon atom having a high yield of 6 from a feedstock containing polycyclic aromatic hydrocarbons. ˜8 monocyclic aromatic hydrocarbons can be produced, and a decrease in the yield of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms over time can be prevented.

(Catalyst for monocyclic aromatic hydrocarbon production)
The catalyst for producing monocyclic aromatic hydrocarbons of the present invention (hereinafter abbreviated as “catalyst”) is a monocyclic aromatic carbonized carbon having 6 to 8 carbon atoms from a feedstock containing polycyclic aromatic hydrocarbons and saturated hydrocarbons. It is for producing hydrogen (hereinafter abbreviated as “monocyclic aromatic hydrocarbon”) and contains crystalline aluminosilicate and phosphorus.

[Crystalline aluminosilicate]
Although it does not specifically limit as crystalline aluminosilicate, For example, a pentasil type zeolite and a medium pore zeolite are preferable. As the medium pore zeolite, MFI, MEL, TON, MTT, MRE, FER, AEL, EUO type zeolite is more preferable, and since the yield of monocyclic aromatic hydrocarbons is higher, MFI type Zeolite having a crystal structure of MEL type is particularly preferred.
Zeolite of MFI type, MEL type, etc. belong to a known zeolite structure type of the kind published by The Structure Commission of the International Zeolite Association (Atlas of Zeolite Structure. (Distributed by Polycrystalline Book Service, Pittsburgh, PA, USA).
The content of the crystalline aluminosilicate in the catalyst is preferably 10 to 95% by mass, more preferably 20 to 80% by mass, and particularly preferably 25 to 70% by mass when the entire catalyst is taken as 100% by mass. When the content of the crystalline aluminosilicate is 10% by mass or more and 95% by mass or less, sufficiently high catalytic activity can be obtained.

[Rin]
The molar ratio (P / Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum contained in the crystalline aluminosilicate is 0.1 or more and 1.0 or less. When the P / Al ratio exceeds 1.0, the yield of monocyclic aromatic hydrocarbons becomes low, so the P / Al ratio is 1.0 or less, preferably 0.95 or less, more preferably 0.9 or less. It is.
Also, when the P / Al ratio is less than 0.1, the yield of monocyclic aromatic hydrocarbons in the steady state is low, so the P / Al ratio is 0.1 or more, preferably 0.15 or more, Preferably it is 0.2 or more.

The content of phosphorus contained in the crystalline aluminosilicate in the catalyst of the present invention is preferably 0.1 to 3.5% by mass when the total mass of the crystalline aluminosilicate is 100% by mass. Furthermore, the lower limit is more preferably 0.2% by mass or more, and the upper limit is more preferably 3.0% by mass or less, and particularly preferably 2.8% by mass or less. When the content of phosphorus supported on the crystalline aluminosilicate is 0.1% by mass or more, a decrease in the yield of monocyclic aromatic hydrocarbons over time can be prevented, and the content is 3.5% by mass or less. Thus, the yield of monocyclic aromatic hydrocarbons can be increased.
In addition, the upper limit value of the phosphorus content in the catalyst of the present invention is considerably smaller than the upper limit value of the phosphorus content in the catalysts described in Patent Documents 4 to 6. This is considered to be caused by the fact that the feedstock of the reaction to which the catalyst of the present invention is applied contains a large amount of polycyclic aromatic hydrocarbons and has low reactivity. If the amount of phosphorus added is too high, the feedstock oil becomes more difficult to react and the aromatization activity is reduced, leading to a reduction in the yield of monocyclic aromatic hydrocarbons. On the other hand, since the raw material oils in Patent Documents 4 to 6 (for example, vacuum gas oil used as a raw material oil in a fluid catalytic cracking apparatus) are heavy, have a large molecular weight, and are easily adsorbed by the catalyst, Is easy to be disassembled. Moreover, since it is easy to decompose into light olefins, even if a large amount of phosphorus is supported and the aromatization activity is lowered, it does not cause a big problem.

  The method of incorporating phosphorus into the catalyst of the present invention is not particularly limited. For example, a method of supporting phosphorus on crystalline aluminosilicate by an ion exchange method, an impregnation method, etc. Examples thereof include a method of replacing a part of the aluminosilicate framework with phosphorus, a method of using a crystal accelerator containing phosphorus during zeolite synthesis, and the like. The phosphate ion-containing aqueous solution used at that time is not particularly limited, but was prepared by dissolving phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, and other water-soluble phosphates in water at an arbitrary concentration. Can be preferably used.

  The catalyst of the present invention can be obtained by calcining crystalline aluminosilicate containing phosphorus as described above (calcination temperature: 300 to 900 ° C.).

[shape]
The catalyst of the present invention is made into, for example, a powder form, a granular form, a pellet form or the like according to the reaction mode.
For example, in the case of a fluidized bed, it is in the form of powder, and in the case of a fixed bed, it is in the form of particles or pellets. The average particle size of the catalyst used in the fluidized bed is preferably 30 to 180 μm, more preferably 50 to 100 μm. The bulk density of the catalyst used in the fluidized bed is preferably 0.4 to 1.8 g / cc, and more preferably 0.5 to 1.0 g / cc.
In addition, an average particle diameter represents the particle size used as 50 mass% in the particle size distribution obtained by the classification by a sieve, and a bulk density is the value measured by the method of JIS specification R9301-2-3.
When obtaining a granular or pellet-shaped catalyst, if necessary, an inert oxide as a binder or the like may be blended with a crystalline aluminosilicate or catalyst, and then molded using various molding machines.

When the catalyst of this invention contains inorganic oxides, such as a binder, you may use what contains phosphorus as a binder.
Moreover, when a catalyst contains inorganic oxides, such as a binder, after mixing a binder etc. and crystalline aluminosilicate, phosphorus may be added and a catalyst may be manufactured.
When the catalyst contains an inorganic oxide such as a binder, the phosphorus content is preferably 0.1 to 10% by mass relative to the total weight of the catalyst, and more preferably the lower limit is 0.5% by mass or more. The upper limit is more preferably 9% by mass or less, and particularly preferably 8% by mass or less. When the content of phosphorus with respect to the total weight of the catalyst is 0.1% by mass or more, a decrease in the yield of monocyclic aromatic hydrocarbons over time can be prevented, and when the content is 10% by mass or less, the monocyclic aromatics The yield of hydrocarbons can be increased.

(Method for producing monocyclic aromatic hydrocarbons)
The method for producing monocyclic aromatic hydrocarbons of the present invention is a method in which a raw oil is brought into contact with the catalyst and reacted.
In this reaction, by bringing the feedstock into contact with the acid point of the catalyst, polycyclic aromatic hydrocarbons are opened by various reactions such as decomposition, dehydrogenation, cyclization, hydrogen transfer, etc. It is a method to convert to hydrocarbon.

[Raw oil]
The feedstock oil used in the present invention is an oil having a 10 vol% distillation temperature of 140 ° C or higher and a 90 vol% distillation temperature of 380 ° C or lower. An oil having a 10% by volume distillation temperature of less than 140 ° C. produces BTX from a light oil and does not meet the gist of the present invention, so 140 ° C. or higher is preferable, and 150 ° C. or higher is more preferable. Also, when a feed oil having a 90% by volume distillation temperature of the feed oil exceeding 380 ° C. is used, the amount of coke deposited on the catalyst tends to increase, causing a rapid decrease in catalyst activity. The 90% by volume distillation temperature of the oil is preferably 380 ° C or lower, and more preferably 360 ° C or lower.
In addition, the 10 volume% distillation temperature, 90 volume% distillation temperature, and an end point here are the values measured based on JISK2254 "petroleum product-distillation test method".
Examples of the feed oil having a 10% by volume distillation temperature of 140 ° C. or more and a 90% by volume distillation temperature of 380 ° C. or less include cracked light oil (LCO), coal liquefied oil, heavy oil hydrogen produced by a fluid catalytic cracker Examples include hydrocracked refined oil, straight-run kerosene, straight-run light oil, coker kerosene, coker light oil, and oil sand hydrocracked refined oil, and more preferably include cracked light oil (LCO) produced by a fluid catalytic cracker.
Moreover, since the yield of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms decreases when the raw material oil contains a large amount of polycyclic aromatic hydrocarbons, the content of polycyclic aromatic hydrocarbons in the raw material oil ( The polycyclic aromatic content) is preferably 50% by volume or less, and more preferably 30% by volume or less.
In addition, polycyclic aromatic content here is bicyclic aromatic hydrocarbon content (based on JPI-5S-49 "Petroleum products-Hydrocarbon type test method-High performance liquid chromatograph method") ( 2 ring aromatic content) and the total value of the aromatic hydrocarbon content of 3 or more rings (aromatic content of 3 or more rings).

[Reaction format]
Examples of the reaction mode for contacting and reacting the raw material oil with the catalyst include a fixed bed, a moving bed, and a fluidized bed. In the present invention, since a heavy component is used as a raw material, a fluidized bed capable of continuously removing coke adhering to the catalyst and capable of performing a reaction stably is preferable. A continuous regenerative fluidized bed is particularly preferred in which the catalyst circulates between them and the reaction-regeneration can be repeated continuously. The raw material oil in contact with the catalyst is preferably in a gas phase.
Moreover, you may dilute a raw material with gas as needed. Moreover, when unreacted raw materials are generated, they may be recycled as necessary.

[Reaction temperature]
Although the reaction temperature at the time of making a raw material oil contact and react with a catalyst is not restrict | limited, 350-700 degreeC is preferable. The lower limit is more preferably 450 ° C. or higher because sufficient reaction activity can be obtained. On the other hand, the upper limit is more preferably 650 ° C. or lower because it is advantageous in terms of energy and can easily regenerate the catalyst.

[Reaction pressure]
The reaction pressure when contacting and reacting the raw material oil with the catalyst is preferably 1.0 MPaG or less. When the reaction pressure is 1.0 MPaG or less, light gas by-product can be prevented and the pressure resistance of the reaction apparatus can be lowered.

[Contact time]
The contact time between the feedstock and the catalyst is not particularly limited as long as the desired reaction proceeds substantially. For example, the gas passage time on the catalyst is preferably 1 to 300 seconds, and the lower limit is 5 seconds or more. Is more preferably 150 seconds or less. If the contact time is 1 second or longer, the reaction can be performed reliably, and if the contact time is 300 seconds or shorter, accumulation of carbonaceous matter in the catalyst due to coking or the like can be suppressed. Or the generation amount of the light gas by decomposition | disassembly can be suppressed.

In the method for producing monocyclic aromatic hydrocarbons of the present invention, the polycyclic aromatic carbonization is carried out by bringing various reaction such as decomposition, dehydrogenation, cyclization, hydrogen transfer, etc. by bringing the feedstock oil into contact with the acid point of the catalyst. Hydrogen is opened to obtain a monocyclic aromatic hydrocarbon.
In the present invention, the yield of monocyclic aromatic hydrocarbons is preferably 15% by mass or more, more preferably 20% by mass or more, and further preferably 25% by mass or more. If the yield of monocyclic aromatic hydrocarbons is less than 15% by mass, the concentration of the target product in the product is low and the recovery efficiency is lowered, which is not preferable.

  In the production method of the present invention described above, since the above-described catalyst is used, monocyclic aromatic hydrocarbons can be produced with a high yield, and a decrease in the yield of monocyclic aromatic hydrocarbons over time can be prevented.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to these Examples.

( Reference Example 1 )
From 1706.1 g of sodium oxalate (J sodium silicate No. 3, SiO ₂ : 28 to 30% by mass, Na: 9 to 10% by mass, balance water, manufactured by Nippon Chemical Industry Co., Ltd.) and 2227.5 g of water Solution (A), Al ₂ (SO ₄ ) ₃ · 14 to 18H ₂ O (special reagent grade, manufactured by Wako Pure Chemical Industries, Ltd.), 64.2 g, tetrapropylammonium bromide, 369.2 g, H ₂ SO ₄ (97% by weight) of 152.1 g, NaCl (326.6 g), and 2975.7 g of water (B) were prepared.

Next, the solution (B) was gradually added to the solution (A) while stirring the solution (A) at room temperature.
The resulting mixture was vigorously stirred with a mixer for 15 minutes to break up the gel into a milky homogeneous fine state.
Subsequently, this mixture was put into a stainless steel autoclave, and crystallization operation was performed under a self-pressure under conditions of a temperature of 165 ° C., a time of 72 hours, and a stirring speed of 100 rpm. After completion of the crystallization operation, the product was filtered to recover the solid product, and washing and filtration were repeated 5 times using about 5 liters of deionized water. The solid substance obtained by filtration was dried at 120 ° C., and further calcined at 550 ° C. for 3 hours under air flow.

As a result of X-ray diffraction analysis (model name: Rigaku RINT-2500V), the obtained fired product was confirmed to have an MFI structure. The fluorescent X-ray analysis (model name: Rigaku ZSX101e) _by, SiO 2 / _Al 2 _{O 3} ratio (molar ratio) was 64.8. Moreover, the aluminum element contained in the lattice skeleton calculated from this result was 1.32% by mass.
A 30% by mass ammonium nitrate aqueous solution was added at a rate of 5 mL per 1 g of the obtained fired product, heated and stirred at 100 ° C. for 2 hours, filtered, and washed with water. This operation was repeated 4 times, followed by drying at 120 ° C. for 3 hours to obtain an ammonium type crystalline aluminosilicate. Thereafter, baking was performed at 780 ° C. for 3 hours to obtain a proton-type crystalline aluminosilicate.

Next, 30 g of the obtained proton-type crystalline aluminosilicate was impregnated with 30 g of a diammonium hydrogen phosphate aqueous solution so that 0.2 mass% of phosphorus (a value where the total weight of the catalyst was 100 mass%) was contained. Dry at 0C. Then, it baked at 780 degreeC under air circulation for 3 hours, and obtained the catalyst containing crystalline aluminosilicate and phosphorus.
The obtained catalyst had a molar ratio (P / Al ratio) of phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate of 0.14, and the phosphorus content with respect to the total weight of the catalyst was 0. It was 2% by mass.

  The obtained catalyst was tableted by applying a pressure of 39.2 MPa (400 kgf), coarsely pulverized to a size of 20 to 28 mesh, and a granular catalyst 1 (hereinafter referred to as “granulated catalyst 1”). .)

(Example 2)
Adjust the concentration of diammonium hydrogen phosphate aqueous solution so that 30 g of proton-type crystalline aluminosilicate contains 0.7% by mass of phosphorus (the total catalyst weight is 100% by mass) and impregnate with 30 g of the aqueous solution. Except that, granular catalyst 2 (hereinafter referred to as “granulated catalyst 2”) was obtained in the same manner as in Reference Example 1 .
The obtained catalyst had a molar ratio (P / Al ratio) of phosphorus contained in the crystalline aluminosilicate to aluminum of the crystalline aluminosilicate of 0.50, and the phosphorus content with respect to the total weight of the catalyst was 0. 0.7% by mass.

(Example 3)
The concentration of the phosphoric acid aqueous solution was adjusted so that 30 g of proton-type crystalline aluminosilicate contained 1.2% by mass of phosphorus (the value where the total weight of the catalyst was 100% by mass) was impregnated with 30 g of the aqueous solution. Except for the above, a granular catalyst 3 (hereinafter referred to as “granulated catalyst 3”) was obtained in the same manner as in Reference Example 1 .
Further, the obtained catalyst had a molar ratio (P / Al ratio) of phosphorus contained in the crystalline aluminosilicate to aluminum of the crystalline aluminosilicate of 0.86, and the phosphorus content with respect to the total weight of the catalyst was 1 It was 2% by mass.

Example 4
18 g of fumed silica was impregnated with 30 g of a diammonium hydrogen phosphate aqueous solution so as to contain 16.2% by mass of phosphorus, and dried at 120 ° C. Then, it baked at 780 degreeC under air circulation for 3 hours, and obtained the fumed silica containing phosphorus. 18 g of fumed silica containing phosphorus and 2:12 g of the catalyst prepared in Example 2 were mixed, and the resulting catalyst was subjected to tableting by applying a pressure of 39.2 MPa (400 kgf) and coarsely pulverized to 20 A granular catalyst 4 (hereinafter referred to as “granulated catalyst 4”) was obtained in a size of ˜28 mesh.
The obtained catalyst had a molar ratio (P / Al ratio) of phosphorus contained in the crystalline aluminosilicate to aluminum of the crystalline aluminosilicate of 0.50, and the phosphorus content relative to the total weight of the catalyst was 10 It was mass%.

(Example 5)
Sodium silicate in dilute sulfuric acid (J sodium silicate No. _3, SiO 2: 28 to 30 mass%, Na: 9 to 10 wt%, balance water, Nippon Chemical Industrial Co., Ltd.) mixed solution of 106g of pure water The solution was added dropwise to prepare an aqueous silica sol solution (SiO ₂ concentration 10.2%). Meanwhile, distilled water was added to 20.4 g of the catalyst 2: 20.4 g containing crystalline aluminosilicate and phosphorus prepared in Example 2 to prepare a zeolite slurry. The zeolite slurry and 300 g of silica sol aqueous solution were mixed, and the prepared slurry was spray-dried at 250 ° C. to obtain a spherical catalyst. Then, it baked at 600 degreeC for 3 hours, and obtained the powdery catalyst 5 (henceforth "the powdery catalyst 5") with an average particle diameter of 84 micrometers and a bulk density of 0.74 g / cc.
The obtained catalyst had a molar ratio (P / Al ratio) of phosphorus contained in the crystalline aluminosilicate to aluminum of the crystalline aluminosilicate of 0.50, and the phosphorus content with respect to the total weight of the catalyst was 0. It was 28% by mass.

(Comparative Example 1)
The concentration of the diammonium hydrogen phosphate aqueous solution was adjusted so that 30 g of proton-type crystalline aluminosilicate contained 2.0 mass% phosphorus (the total catalyst weight being 100 mass%) and impregnated with 30 g of the aqueous solution. Except that, granular catalyst 6 (hereinafter referred to as “granulated catalyst 6”) was obtained in the same manner as in Reference Example 1 .
The obtained catalyst had a molar ratio (P / Al ratio) of phosphorus contained in the crystalline aluminosilicate to aluminum of the crystalline aluminosilicate of 1.43, and the phosphorus content relative to the total weight of the catalyst was 2 It was 0.0 mass%.

(Comparative Example 2)
A granular catalyst 7 (hereinafter referred to as “granulated catalyst 7”) was obtained in the same manner as in Reference Example 1 except that the proton-type crystalline aluminosilicate was used as it was.

  The catalytic activity of the obtained granulated catalyst at the beginning of the reaction and the catalytic activity after hydrothermal deterioration were evaluated as follows.

[Evaluation of catalytic activity at the beginning of the reaction: Evaluation 1]
Using a flow-type reaction apparatus filled with a granulated catalyst (10 ml), a feedstock having the properties shown in Table 1 is brought into contact with and reacted with the granulated catalyst under the conditions of reaction temperature: 550 ° C. and reaction pressure: 0 MPaG. It was. At that time, nitrogen was introduced as a diluent so that the contact time between the raw material oil and the granulated catalyst was 7 seconds.
The reaction is carried out for 30 minutes under these conditions to produce a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms, and the composition of the product is analyzed by an FID gas chromatograph directly connected to the reaction apparatus. Evaluated. The evaluation results are shown in Table 2.
The heavy components in the products in Table 2 are hydrocarbons having 6 or more carbon atoms other than monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms, and light naphtha is a hydrocarbon having 5 to 6 carbon atoms. The liquefied petroleum gas means a hydrocarbon having 3 to 4 carbon atoms, and the cracked gas means a hydrocarbon having 2 or less carbon atoms.

[Evaluation of catalytic activity after hydrothermal degradation: Evaluation 2]
Each of the granulated catalysts 1 to 4 and 7 is pseudo-degraded catalyst 1 to 4 which has been subjected to pseudo hydrothermal degradation by hydrothermal treatment in an environment of a treatment temperature of 650 ° C., a treatment time of 6 hours, and water vapor of 100% by mass. 7 were produced.
In the same manner as in Evaluation 1, except that the pseudo-degradation catalysts 1 to 4 and 7 were used in place of the granulated catalysts 1 to 4 and 7, respectively, the raw material oil was reacted and the resulting product was subjected to composition analysis and hydrothermal. The catalytic activity after deterioration was evaluated. The evaluation results are shown in Table 2.

[Measurement of monocyclic aromatic hydrocarbon yield at the initial stage of the reaction: Evaluation 3]
Using a flow-type reaction apparatus filled with a powdered catalyst (400 g) in a reactor, a raw material oil having the properties shown in Table 1 is brought into contact with the powdered catalyst under the conditions of reaction temperature: 550 ° C. and reaction pressure: 0.1 MPaG. Reacted. At that time, a powdered catalyst was filled in a reaction tube having a diameter of 60 mm. Nitrogen was introduced as a diluent so that the contact time between the raw material oil and the powdered catalyst was 10 seconds.
The reaction is carried out for 10 minutes under these conditions to produce a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms. The composition of the product is analyzed by an FID gas chromatograph directly connected to the reaction apparatus, and the initial catalytic activity is obtained. Evaluated. The evaluation results are shown in Table 2.
The heavy components in the products in Table 2 are hydrocarbons having 6 or more carbon atoms other than monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms, and light naphtha is a hydrocarbon having 5 to 6 carbon atoms. The liquefied petroleum gas means a hydrocarbon having 3 to 4 carbon atoms, and the cracked gas means a hydrocarbon having 2 or less carbon atoms.

[Evaluation of catalytic activity after hydrothermal degradation: Evaluation 4]
The powder catalyst 5 was hydrothermally treated in an environment of a treatment temperature of 650 ° C., a treatment time of 6 hours, and a water vapor of 100% by mass to produce a pseudo-degraded catalyst 5 that was pseudohydrothermally degraded.
Except for using the pseudo-degraded catalyst 5 instead of the powdered catalyst 5, the raw material oil was reacted in the same manner as in Evaluation 3, and the composition of the obtained product was analyzed to evaluate the catalytic activity after hydrothermal degradation. The evaluation results are shown in Table 2.

[Catalyst degradation]
Carbon in the catalytic activity evaluation (evaluation 2 or evaluation 4) after hydrothermal degradation with respect to the amount of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms (mass%) in the catalytic activity evaluation (evaluation 1 or evaluation 3) at the initial stage of the reaction Amount of monocyclic aromatic hydrocarbons of 6 to 8 (mass%) ([Amount of monocyclic aromatic hydrocarbons of 6 to 8 carbon atoms (mass%) in Evaluation 2 (or 4)] / [Evaluation 1 (or 3 The value of the amount of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms (mass%)]) was calculated, and the degree of catalyst deterioration was determined. The results are also shown in Table 2. In addition, it means that catalyst deterioration is hard to occur, so that this value is large. Further, the amount of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms may be abbreviated as the amount of monocyclic aromatic hydrocarbons.

[result]
In Reference Example 1 and Examples 2 to 5 using the granulated catalyst 1 to 4 and the powdered catalyst 5, the amount of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms in the initial reaction was 39% by mass, 34 mass%, 22 mass%, 23 mass%, and 31 mass%, and the amounts of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms after hydrothermal degradation were 27 mass%, 30 mass%, and 23, respectively. % By mass, 22% by mass, and 28% by mass, and the degree of catalyst deterioration ([monocyclic aromatic hydrocarbon amount (% by mass) in evaluation 2 (or 4)] / [monocyclic aromatic in evaluation 1 (or 3) Group hydrocarbon amount (mass%)] was 0.69, 0.90, 1.06, 0.96, and 0.9, respectively.
In Reference Example 1 and Examples 2 to 5 using the granulated catalysts 1 to 4 and the powdered catalyst 5, both the catalytic activity at the initial stage of the reaction and the catalytic activity after hydrothermal deterioration are good, and the target carbon of this application It has been found that monocyclic aromatic hydrocarbons of several 6 to 8 can be obtained in good yield both at the initial stage of the reaction and after hydrothermal deterioration.
On the other hand, in Comparative Example 1 using the granulated catalyst 6 having a large P / Al ratio, the amount of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms in the initial reaction is 5% by mass, and a large amount of phosphorus is added. It was also found that the yield of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms in the product was significantly reduced even at the initial stage of the reaction.
In Comparative Example 2 using the granulated catalyst 7 having a P / Al ratio of 0, the production amount of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms in the initial reaction was 38% by mass, and the number of carbon atoms after hydrothermal deterioration was 6 The production amount of monocyclic aromatic hydrocarbons of ˜8 is 10% by mass, the degree of catalyst deterioration ([monocyclic aromatic hydrocarbon amount in evaluation 2 (% by mass)] / [monocyclic aromatic hydrocarbon amount in evaluation 1 ( Mass%)]) is 0.26, and when a catalyst containing no phosphorus is used, the yield of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms at the beginning of the reaction is good, but the yield after hydrothermal deterioration is low. It was found that the rate was lowered, catalyst deterioration was remarkable, and it was not practical.

Claims (7)

A catalyst for producing aromatic hydrocarbons for producing monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms from a feedstock having a 10 vol% distillation temperature of 140 ° C or higher and a 90 vol% distillation temperature of 380 ° C or lower Because
A crystalline aluminosilicate and phosphorus are contained, and the molar ratio (P / Al ratio) between phosphorus contained in the crystalline aluminosilicate and aluminum of the crystalline aluminosilicate is 0.5 or more and 1.0 or less. A catalyst for producing monocyclic aromatic hydrocarbons.   The catalyst for producing monocyclic aromatic hydrocarbons according to claim 1, wherein the phosphorus content is 0.1 to 10% by mass with respect to the catalyst weight.   The catalyst for producing monocyclic aromatic hydrocarbons according to claim 1 or 2, wherein the crystalline aluminosilicate is a pentasil-type zeolite.   The catalyst for producing monocyclic aromatic hydrocarbons according to any one of claims 1 to 3, wherein the crystalline aluminosilicate is MFI-type zeolite.   A feedstock having a 10% by volume distillation temperature of 140 ° C or higher and a 90% by volume distillation temperature of 380 ° C or lower is used as the catalyst for producing monocyclic aromatic hydrocarbons according to any one of claims 1 to 4. A method for producing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms, wherein the method comprises contacting them.   The method for producing a monocyclic aromatic hydrocarbon having 6 to 8 carbon atoms according to claim 5, wherein the raw material oil contains cracked light oil produced by a fluid catalytic cracking apparatus.   The production of monocyclic aromatic hydrocarbons having 6 to 8 carbon atoms according to claim 5 or 6, wherein the feed oil is brought into contact with the catalyst for producing monocyclic aromatic hydrocarbons in a fluidized bed reactor. Method.