JP3481672B2 - Hydroisomerization of benzene-containing hydrocarbon oils for high octane gasoline sources - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hydroisomerizing a benzene-containing hydrocarbon oil for a high octane gasoline material source, and more particularly to a catalytic reforming oil which is a material for improving the octane number of gasoline. The present invention relates to a method of reducing the benzene concentration and maintaining the octane number, and a method of reducing benzene in light naphtha and improving the octane number.

[0002]

2. Description of the Related Art Hydrocarbon oil containing benzene is desirable as a source of high-octane gasoline material, but due to the recent increase in environmental problems, measures to reduce it have been sought. Various methods for reducing the content have been studied.

As one of the methods, there is a method of hydroisomerizing benzene to obtain a mixture of cyclohexane and methylcyclopentane. This method has already been put on the market as a process, for example, UOP's Penex-Plus method, IF
The company's Hydroisomerization method is available. Each of these methods is a so-called two-stage method in which the hydrogenation reaction and the isomerization reaction are carried out in separate reactors.

As seen in both processes, the hydrogenation reaction and the isomerization reaction have conventionally been separately researched and developed. The hydrogenation reaction of benzene has already been industrially established as a technique for producing cyclohexane, and is carried out using a Raney nickel catalyst, a nickel-supported solid catalyst or the like.

Most of the product in this benzene hydrogenation reaction is cyclohexane. Since the octane number of cyclohexane is 83 and that of methylcyclopentane is 91, the octane number can be increased by further isomerizing cyclohexane. There are many studies on the isomerization reaction of cyclohexane to methylcyclopentane using various zeolites such as HY zeolite, H mordenite, platinum-supported mordenite, and palladium-supported mordenite, and a catalyst such as chlorine-modified alumina.

There is another example in which benzene-containing normal hexane was reacted with a platinum-supported ZSM-5 catalyst, but the objective reaction is normal hexane isomerization reaction, and aromatic is considered to be a substance that inhibits the isomerization reaction. It was In that case, at the reaction temperature of 375 ° C., the selectivity of the reaction is 95% for cyclohexane and 5% for methylcyclopentane, and it is not mentioned that methylcyclopentane is produced with high selectivity.

[0007]

The conventional technique is to combine two established reactions, namely, a hydrogenation reaction of benzene and an isomerization reaction of produced cyclohexane,
It carries out hydroisomerization reaction of benzene, requires two reactors with different reaction conditions, and has a complicated equipment configuration.
Equipment costs are also high. The method of the present invention is intended to reduce equipment construction costs and operating costs by simultaneously performing a hydrogenation reaction and an isomerization reaction in the same reactor.

In the hydroisomerization reaction, in order to minimize the decrease in octane number due to the hydrogenation of benzene, it is necessary to increase the conversion rate so that methylcyclopentane is produced as much as possible. It is necessary to suppress the rate decrease as much as possible and to have a high methylcyclopentane selectivity. Further, for industrialization, a catalyst having a catalyst life as long as possible is required.

[0009]

[Means for Solving the Problems] As a result of earnest studies on a method for carrying out a hydroisomerization reaction of a benzene-containing hydrocarbon oil in a single-step reaction with a high selectivity, the present inventors have found that the MFI alumino By carrying out a reaction at a reaction temperature of 200 to 300 ° C. using a catalyst in which a Group 8 metal is supported on a silicate and / or a mixture catalyst of an MFI-type aluminosilicate and an oxide supporting a Group 8 metal, hydrogen of benzene can be obtained. The isomerization reaction was found to be carried out at a high conversion rate. Hereinafter, the present invention will be described in detail.

Industrially, as a large amount of benzene-containing hydrocarbon oil obtained, there are catalytic reforming oil, light naphtha, cracked light oil, coke dry distillation oil and the like. Among benzene-containing hydrocarbon oils, catalytic reformate is the most important source of gasoline mixture. The catalytic reforming oil is produced by catalytically reforming heavy naphtha.

The feedstock particularly desirable for the present invention is a light catalytic reforming oil containing a large amount of benzene fraction in the catalytic reforming oil. The light catalytic reformed oil can be produced by further distilling and separating a liquid product having 5 or more carbon atoms from which a fraction having 4 or less carbon atoms of the catalytic reforming product is removed. That is, since the boiling point of benzene is 80 ° C., a catalytic reformed oil fraction having a boiling range of 30 to 100 ° C. is a preferable feedstock. In the boiling point range of 30 to 100 ° C, hydrocarbons having 5 to 7 carbon atoms are contained, and the benzene concentration is about 10 to 40%. The feedstock oil becomes a gasoline material source after the hydroisomerization reaction, and in order to avoid heat generation due to the hydrogenation reaction of benzene, the benzene concentration does not need to be so high and about 20 to 30% is suitable.

Further, light petroleum naphtha can be used as a feedstock oil. The light naphtha is mainly composed of a hydrocarbon having 4 to 6 carbon atoms and contains about 0.5 to 2% of benzene. Of these, there are many straight-chain paraffins with an octane value of 50-7.
Although it is 5, the octane number can be increased to 80 to 90 by the isomerization reaction. Since the catalyst of the present invention has both hydrogenation ability and isomerization ability, benzene can be hydroisomerized and removed, and at the same time, linear paraffins can be isomerized into branched paraffins to increase the octane number.

Other feedstocks containing benzene include, for example, cracked gas oil, which is a by-product of ethylene production, and gas gas oil, which is dry distillation oil of coal. In the case of cracked gas oil or gas gas oil, it contains impurities that become catalyst poisons such as unsaturated components, sulfur components, nitrogen components, oxygen components, and metal components.Before this hydroisomerization reaction, before hydrorefining, etc. Processing is required.

As a typical example of the MFI type aluminosilicate, there is ZSM-5 invented by Mobile Corporation of the United States. ZSM-5 has a 10-membered ring of oxygen that does not exist in nature at the entrance of the pores, and is industrially used for reactions such as synthesizing gasoline from methanol and ethylbenzene to produce ethylbenzene. It is used, and its application to various other reactions is being studied.

The catalyst used in the present invention is prepared by the following method. ZSM-5 which is MFI type aluminosilicate
Is typically synthesized by the method described in JP-A-46-10064. Many other synthesis methods have been proposed, and any of them can be used. The synthesized catalyst is protonated and activated by the well-known ammonium salt ion exchange method.

MFI type aluminosilicate is SiO2 / Al2O3
Characterized by the ratio. When the SiO2 / Al2O3 ratio is low, the acid amount is high and the activity is high, but the decomposition reaction is also increased, the liquid yield and the methylcyclopentane selectivity are lowered, and the coke is easily generated to shorten the catalyst life. When the SiO2 / Al2O3 ratio is high, the opposite tendency is exhibited, the amount of acid decreases, and the activity also decreases. When the activity decreases, high temperature is required, so that the decomposition also increases and the catalyst life also decreases. Therefore, the SiO2 / Al2O3 ratio has an appropriate range, and 20 to 500 is suitable. More preferably 3
0 to 300.

The Group 8 metal carried is F
Examples include e, Co, Ni, Ru, Rh, Pd, Ir, Pt and the like. The metal not only hydrogenates benzene on the metal surface but also plays a role of spillover for activating hydrogen molecules and supplying hydrogen to the catalyst surface. Spillover hydrogen is
It is also related to the isomerization reaction at the acidic point and is said to have the action of suppressing the decomposition reaction and removing the coke precursor on the catalyst.

Among the Group 8 metals, Pd and Pt have high benzene hydrogenation activity and high spillover ability. Since other metals have a slightly low activity, they require a large supported amount, and a large supported amount has an adverse effect such as a decrease in acidic activity. The amount of supported metal is 0.01 to 5%, more preferably 0.05 to 3%.

The method of supporting the metal is typically a method well known to those skilled in the art such as an impregnation method in an aqueous solution and an ion exchange method, but any method can be used as long as it can be highly dispersed and uniformly supported on a carrier. .

The metal compound used for supporting is
Any of various water-soluble salts such as chlorides, bromides, iodides, sulfates, nitrates and ammine complex salts can be used.

The catalyst supported in the aqueous solution is activated through the steps of drying, calcination and reduction well known to those skilled in the art.

Even more surprisingly, the metal is not always M
It does not need to be supported on the FI-type aluminosilicate, and it works effectively even if it is supported on a suitable oxide carrier.
This is because the hydrogenation reaction of benzene takes place on the metal and the isomerization reaction of cyclohexane takes place at the acidic point.
It is thought that it depends on the original function. It is also presumed that the spillover hydrogen is able to move to a remote location on the carrier if the catalyst is tightly bound.

As the oxide, those having a high surface area and capable of uniformly supporting the metal in a high dispersion and not adversely affecting the metal are preferable, and examples thereof include silica gel and γ-alumina. When a metal is supported on these oxides, there is a feature that the metal supporting operation has no influence on the acid point of the MFI aluminosilicate, and the acid activity of the MFI aluminosilicate is maintained unchanged. Therefore, M
Despite the small amount of FI type aluminosilicate,
On the contrary, a surprising phenomenon that the activity was increased was also recognized.

When the metal is supported on the oxide, the metal-supported oxide and the MFI aluminosilicate are uniformly mixed in order to form a close bond with the MFI aluminosilicate, and then pressure-molded to obtain spherical, disc-shaped, granular, etc. It is used after being molded into various shapes.

The catalyst activity can be adjusted appropriately by adjusting the mixing ratio of the MFI aluminosilicate and the oxide. The oxide also functions as a binder to keep the catalyst in a certain shape. Mixing ratio of oxide is 5-80
%, More preferably 10 to 60%.

Regarding the reaction conditions, temperature and pressure are important. Since the hydrogenation reaction of benzene is an exothermic reaction in which the number of molecules decreases, it is desirable to use low temperature and high pressure, and the temperature is 300 ° C.
Below, at a pressure of 5 kg / cm2 or more, thermodynamic equilibrium is approximately 10
It is 0% hydrogenated. In terms of thermodynamic equilibrium, the cyclohexane isomerization reaction has a larger amount of methylcyclopentane at higher temperatures, but the temperature dependence is small and the decomposition reaction increases at higher temperatures. Further, since the reaction rate is low at 200 ° C. or lower, 200 to 300 ° C. is the preferable range after all. A higher pressure suppresses the decomposition reaction and prolongs the catalyst life, but on the other hand, the equipment cost and pressurization power cost increase, so 50 Kg / cm 2 or less is desirable. That is, the preferred pressure range is 5 to 50 kg / cm2, more preferably 5 to 3
It is 0 kg / cm2.

[0027]

EXAMPLE 1 The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples without departing from the spirit of the present invention.

[0028]

【Example】

(1) Preparation of catalyst A ZSM-5 was synthesized as follows. Ion-exchanged water 1
80 g, aluminum sulfate 13 g, sulfuric acid 18.6 g, and tetrapropylammonium bromide 22.6 g are mixed to prepare a solution A. Ion-exchanged water 133 g and water glass (JIS No. 3) 270 g are mixed to prepare a solution B. Ion-exchanged water 313g and sodium chloride 7.8g are mixed,
This is Solution C. The solutions A and B are placed in a dropping funnel and added dropwise to the solution C over 30 minutes with vigorous stirring. This mixed solution is put in a stainless steel 1 L autoclave and reacted at 160 ° C. for 48 hours. After the reaction, the product is separated by filtration and washed with ion-exchanged water until the pH of the filtrate becomes 8. After washing, it is dried at 110 ° C. for 16 hours and baked at 530 ° C. for 3 hours. 50 g of the calcined ZSM-5 was immersed in 300 ml of a 1N aqueous ammonium nitrate solution to make it into a proton form, kept at 90 ° C. for 8 hours, and then the solution was exchanged, which was repeated 4 times. The solution is filtered, dried at 110 ° C. for 16 hours, and calcined at 530 ° C. for 3 hours. Protonated ZS
Immerse 10 g of M-5 in 100 ml of deionized water,
5 ml of an aqueous solution in which 0.086 g of tetraammineplatinum trichloride was dissolved was added dropwise thereto with stirring. The mixture is gently stirred as it is for about 20 hours to sufficiently ion-exchange the platinum salt, the solution is filtered off, dried at 110 ° C. for 5 hours, and then calcined at 530 ° C. for 3 hours. This is designated as catalyst A.
The SiO2 / Al2O3 ratio of the catalyst A is 50, and the amount of platinum supported is 0.5%.

(2) Preparation of catalyst B In the preparation of catalyst A, other operations are carried out in exactly the same manner except that the amount of aluminum sulfate in solution A is changed to 1.6 g. This is designated as catalyst B. The SiO2 / Al2O3 ratio of catalyst B is 4
00, the amount of platinum carried is 0.5%.

(3) Hydroisomerization reaction catalyst of benzene-containing hydrocarbon oil Using catalysts A and B, a model benzene-containing hydrocarbon oil obtained by mixing nC5, nC6, nC7 and benzene was reacted as a feedstock Is shown in Table 1. The reaction conditions are a temperature of 260
C., pressure 10 kg / cm @ 2, liquid hourly space velocity 10 g / h.g-cat, hydrogen ratio 10 mol / mol.

[0031]

Example 2 (1) Preparation of Catalyst C 10 g of silica gel manufactured by Wako Pure Chemical Industries, Ltd. was immersed in 500 ml of ion-exchanged water, and 5 ml of an aqueous solution containing 0.43 g of tetraammineplatinum trichloride dissolved therein with stirring. Is dripped. After gently stirring as it is for about 20 hours to sufficiently ion-exchange the platinum salt, the solution is filtered off,
After drying at 110 ° C. for 5 hours, baking is performed at 530 ° C. for 3 hours.
1 g of this and 4 g of protonated ZSM-5 in the preparation of catalyst A of Example 1 are mixed and molded in a tablet molding machine. This is designated as catalyst C. The silica gel of catalyst C is 20%, and the amount of platinum supported is 0.5%.

(2) Preparation of catalyst D In the preparation of catalyst C, the procedure is exactly the same except that silica gel is changed to alumina gel. This is designated as catalyst D.

(3) Table 1 shows the results of the reaction with the same feedstock as in Example 1 using the hydroisomerization catalysts C and D for benzene-containing hydrocarbon oil. The reaction conditions are a temperature of 230 ° C. and a pressure of 3
0Kg / cm2, liquid space velocity 10g / h ・ g-cat, hydrogen ratio 10mol /
mol.

[0034]

Example 3 (1) Preparation of catalyst E In the preparation of catalyst A of Example 1, other operations were carried out in the same manner except that tetraammine platinum trichloride was replaced with 0.12 g of tetraammine palladium trichloride. . This is designated as catalyst E. The amount of palladium loaded on the catalyst E is 0.5%.

(2) Preparation of catalyst F In the preparation of catalyst C of Example 2, other operations were carried out in exactly the same manner except that tetraammineplatinum trichloride was replaced by 0.58 g of tetraamminepalladium trichloride. This is designated as catalyst F. The amount of palladium supported on the catalyst F is 0.5%.

(3) Table 1 shows the results of the reaction using the same feedstock as in Example 1 using the catalysts E and F for hydroisomerization of benzene-containing hydrocarbon oil. The reaction conditions are a temperature of 290 ° C. and a pressure of 3.
0Kg / cm2, liquid space velocity 10g / h ・ g-cat, hydrogen ratio 10mol / mo
l.

[0037]

Example 4 (1) Preparation of catalyst G In the preparation of the catalyst of Example 2, 0.17 g of tetraammine platinum trichloride, 2.5 g of platinum-supported silica gel and 2.5 g of ZSM-5 are mixed. Other operations are exactly the same, except that This is designated as catalyst G. The silica gel of the catalyst G is 50%, and the amount of platinum supported is 0.5%.

(2) The results obtained by using the same feedstock as in Example 1 using the catalyst G for hydroisomerization of benzene-containing hydrocarbon oil are shown in Table 1. The reaction conditions are a temperature of 230 ° C. and a pressure of 30 kg.
The liquid hourly space velocity is 10 g / h · g-cat, and the hydrogen ratio is 10 mol / mol.

[0039]

[Table 1]

[0040]

[Comparative Example 1] (1) Preparation of catalyst H In the preparation of catalyst A of Example 1, a catalyst not carrying tetraammine platinum trichloride is used as catalyst H.

(2) Table 2 shows the results of the reaction under the same conditions using the same feedstock as in Example 1, using the catalyst H for hydroisomerization of benzene-containing hydrocarbon oil.

[0042]

Comparative Example 2 (1) Using the catalyst A for hydroisomerization of benzene-containing hydrocarbon oil, the hydrogenation and isomerization reaction of Example 1 was repeated except that hydrogen was replaced by nitrogen. To do. The results of the reaction are shown in Table 2.

[0043]

[Table 2]

[0044]

According to the method of the present invention, it becomes possible to economically carry out the hydroisomerization reaction of a benzene-containing hydrocarbon oil conventionally carried out by the two-step reaction method by the one-step reaction method.
Moreover, since hydrocarbons other than benzene are also isomerized, when light naphtha is used as the feedstock, the octane number improves,
When the light catalytic reformed oil is used as the raw material oil, the decrease in octane number is small.

Continuation of front page (51) Int.Cl. ⁷ Identification code FI C07C 13/18 C07C 13/18 C10G 45/54 C10G 45/54 45/64 45/64 // C07B 61/00 300 C07B 61/00 300 ( 56) References JP-A 1-279992 (JP, A) JP-A 59-232912 (JP, A) JP-A 6-237391 (JP, A) JP-A 64-38143 (JP, A) JP Japanese Patent Laid-Open No. 9-13049 (JP, A) Japanese Patent Laid-Open No. 9-3459 (JP, A) Japanese Patent Laid-Open No. 9-3460 (JP, A) Special Table Japanese Patent Laid-Open No. 7-500854 (JP, A) US Patent 5210348 (US, A) US Patent 5264441 (US, A) US Patent 4175033 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10G 35/095 C10G 45/52-45/54 C10G 45/64 C07C 5 / 13 C07C 13/10-13/12 C07C 13/18-13/19 C07C 5/10 CA (STN) REGISTRY (STN)

Claims (6)

(57) [Claims] 1. A hydrogenation reaction and an isomerization reaction are simultaneously carried out in the same reaction vessel, and a hydrocarbon oil containing benzene is used as a feed oil to hydroisomerize under a hydrogen pressure to produce cyclohexane and methylcyclopentane. In the hydroisomerization method of a benzene-containing hydrocarbon oil for a high octane gasoline source for producing oil, MF is used for the hydroisomerization reaction.
A catalyst in which a Group 8 metal is supported on a type I aluminosilicate and / or a mixture catalyst of an MFI type aluminosilicate and a group 8 metal-supported oxide is used at a reaction temperature of 200 to 300 ° C to hydroisomerize benzene, A method for hydroisomerizing benzene-containing hydrocarbon oil for a high octane gasoline material source, which comprises removing straight-chain paraffin and isomerizing it to branched paraffin to increase the octane number. 2. The method for hydroisomerizing benzene-containing hydrocarbon oil for a high octane gasoline material source according to claim 1, wherein the Group 8 metal is platinum or palladium. 3. MFI type aluminosilicate SiO ₂ /
The method for hydroisomerizing benzene-containing hydrocarbon oil for a high octane gasoline material source according to claim 1 or 2, wherein the Al ₂ O ₃ ratio is 20 to 500. 4. The benzene-containing hydrocarbon oil for a high octane gasoline material source according to claim 1, wherein the oxide is SiO ₂ or Al ₂ O ₃ , and the mixing ratio thereof is 5 to 80%. Method for hydroisomerization of. 5. A method for hydroisomerizing benzene-containing hydrocarbon oil for a high octane gasoline material source according to any one of claims 1 to 4, wherein the hydrogen pressure is 5 to 50 Kg / cm ² , and the reaction temperature is 200 to 300 ° C. . 6. A hydroisomerization of a benzene-containing hydrocarbon oil for a high octane gasoline material source according to claim 1, wherein the feedstock oil is a catalytic reforming oil having a boiling point range of 30 to 100 ° C. or a light naphtha. Method.