JPS60231793A - Preparation of high-octane gasoline - Google Patents

Abstract

PURPOSE:To prepare a high-octane gasoline consistently with a good yield over a long period, by heat treating methanol and/or dimethyl ether with a specified catalyst. CONSTITUTION:Zeolite such as ZSM-5, ZSM-11 or faujasite is treated with acid or ammonium salt, etc. for removal of at least about 50% of alkalis contained in it. About 20-99wt% of dealkalized zeolite is mixed with about 80-1wt% aluminum fluoride (e.g. hydrous aluminum trifluoride or basic aluminum fluoride). The mixt. is formed into a desired shape and is burned at about 100-700 deg.C to prepare a catalyst. A mixt. of methanol and hydrogen in a molar ratio of about 1:1-5 is subjected to catalytic reaction at about 250-500 deg.C under pressure of about 100atm or lower in the presence of the above catalyst to prepare a high- octane gasoline.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for producing high octane gasoline by bringing methanol and/or dimethyl ether into heated contact with a zeolite catalyst.

[Technical background of the invention and its problems]

Due to the rise in crude oil prices, there is an increasing need to produce petroleum products such as gasoline, kerosene, light oil, and heavy oil from non-petroleum hydrocarbon sources such as coal, sand oil, shale oil, and natural gas, and the development of manufacturing processes is increasing. This has become an urgent and important issue. One of the most important manufacturing processes is indirect liquefaction. Indirect liquefaction is a method of producing synthesis gas by partially combusting the hydrocarbon source at high temperature in the presence of steam and converting the synthesis gas into petroleum products of the desired boiling range. The main indirect liquefaction methods are the Fischer-Tropsch process, which was developed before the Second Medical War and whose commercial plant is currently in operation at Sasol in South Africa, and the methanol via methanol process, which was recently developed by Mopil. The MTG method (
(abbreviation for methanol terror gasoline).

It is known that in the MTG reaction, one molecule of dimethyl ether is produced as a reaction intermediate from two molecules of methanol, which is subsequently converted to gasoline (C, D
.

Chang and A, J, 5ilvestri.
, J. Catal, 47°249 (1977)
,). A method for producing gasoline from methanol using the MTG method is disclosed in JP-A-50-76027.

In the MTG method, methanol is used as a raw material and ZSM-5 zeolite with a special pore structure is used as a catalyst.
By reacting at 50℃ and 1 to 50 atmospheres, C
Light hydrocarbons such as aromatics, olefins, and paraffins below IO can be obtained. However, 28M
It is known that in the MTG reaction using the -5 catalyst, the catalyst activity rapidly decreases due to coke accumulation. For example, 3
The MTG reaction was carried out using a fixed bed bench scale apparatus under the reaction conditions of 00°C, 20 atm, WH8V = 1.6, and recycled gas ratio = 9 (mol 1 mol).
The activity decreased after 25 days, and its recovery required removal of the attached coke-like substance by air calcination (8-
Yurchak, S., E., Voltz and
J.P.

Warner, Ind, Eng, Chem, P
rocess Res, Dev,.

18.813 (1979)'), and therefore, in commercial equipment, multiple glue actors are placed in parallel, and one of them
A swing system is adopted in which the base is sequentially regenerated to ensure continuous operation and uniformity of the product (R, 1, B).
erry, Chem, gng,.

(8), 86 (1980)) is the actual situation.

However, such a semi-regenerative process having a plurality of reaction towers is accompanied by increased construction and operating costs and complicated operation management.

Conventionally, it has been known to use crystalline aluminosilicate, known as a so-called molecular sieve, as a catalyst for the conversion reaction of methanol to gasoline. In particular, ZS in which the zeolite pores consist of a 10-membered or 12-membered oxygen ring
M-5, ZSM-11, mordenite, zeolite Y,
It is known that the dealkalized type of faujasite exhibits excellent MTG reaction activity, but the activity decreases rapidly due to coke accumulation, and under normal reaction conditions, the
It is necessary to regenerate the catalyst by removing accumulated coke by air calcination once a day, and further improvements are desired.

[Purpose of the invention]

The present invention has been made to solve these conventional drawbacks, and aims to obtain a gasoline with a high gasoline yield and high octane number from methanol and/or dimethyl ether using a catalyst with a long life and low coke accumulation. purpose. Another object of the present invention is to reduce the construction cost and operation cost of the equipment used to implement the above method, and to reduce the complexity of operation management.

[Summary of the invention]

That is, the present invention relates to a method for producing high-octane gasoline, which is characterized by bringing methanol and/or dimethyl ether into heated contact with a catalyst consisting of dealkalized zeolite and aluminum fluoride.

Examples of the zeolite used in the present invention include faujasite, gmelinite, zeolite 51 morbunite, zeolite Ω, zeolite , ZSM-11,
Mordenite, zeolite Y, and faujasite are preferably used.

The zeolite is used in the form of powder or granules with a particle size of 0.01 to 1000 microns, preferably 0.1 to 100 microns.

As is already widely known, the MTG reaction is an acid-catalyzed reaction. Therefore, in order to use the above-mentioned zeolite as a catalyst in the method of the present invention, it is necessary to dealkalize it with an acid or an ammonium salt to reduce the proportion of alkali in the zeolite.

The ratio of dealkalization is preferably at least 50 mole of the alkali metal or alkaline earth metal contained in the zeolite, particularly preferably at least 90 mole. In this case, dealkalizing agents include mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, water-soluble organic acids such as formic acid, acetic acid, and malic acid, and compounds containing ammonium ions such as ammonium chloride and ammonium nitrate. However, these acids may be used alone or in combination. Among these, hydrochloric acid, nitric acid, ammonium chloride, ammonium nitrate, etc. are particularly preferred. These acids or salts are used in the form of an aqueous solution.

The acid concentration in this case varies depending on the processing conditions, but is preferably 1 to 6N, and when an ammonium salt is used, the concentration is preferably 1 to 30N, particularly 5 to 15N. The treatment temperature may be room temperature, but to shorten the treatment time it is 5o-ioo℃.
It is best to heat it to . Since the treatment time depends on the temperature, it cannot be stated unconditionally, but generally 5 hours to 3 days is preferable.

The aluminum heptafluoride used in the present invention is, for example, tfE
.

Baud Ann, Chim, Fhys, (8)1
．． 60 (1904 LA Mazzuchelli, A
tti Accad Lincei, (5) 16i, 7
75 (1907) and W. F. Fhrot, F.
T.Frere.

J-Am* Chem, Sac・, 67 64 (19
45) Aluminum trifluoride hydrate prepared by methods such as J,'M.

Cowley, T., R., 5cott, J., Am., Che.
m, Soc, 70105 (1948); R, L, Jo
hnson, B-SiegelNature 210
1256 (1966) is preferred.

Especially a-AIFs @ 3H*Op β-A IF
S.3H20 and aluminum fluoride obtained by firing these at a temperature of 700°C or lower, preferably 200 to 500°C, are preferably used.

Furthermore, aluminum fluoride, which is similarly effective, can also be produced by passing an excess of anhydrous hydrogen fluoride at 200 to 500°C into a reaction tube filled with alumina, aluminum hydroxide, or a mixture thereof. It can also be obtained by passing an excess of anhydrous hydrogen fluoride through a packed reaction tube at 20-400°C. When these aluminum fluorides are prepared as a component of the catalyst in the method of the present invention, it is not necessary to use them in a pure form, and a mixture thereof is sufficient.

The MTG catalyst used in the present invention is prepared in the form of powder or granules (1 to 5 uφ ), for example, by compression molding or the like, and firing at 100 to 700°C, preferably 300 to 600°C.

Firing is usually carried out in air, but it is of course possible to carry out in inert gas such as nitrogen or carbon dioxide, or hydrogen gas.

The composition ratio of the catalyst used in the method of the present invention varies depending on the reaction conditions, but usually the decalized zeolite is 20 to 9
9wt%, preferably 40-9Qwt%, aluminum fluoride 1-f3Qwt, preferably 10-60wt
%.

The catalyst used in the present invention needs to have two essential components as described above, and as shown in the examples below, the MTG reaction can be carried out effectively even if any one component is missing. I can't.

Methanol or dimethyl ether used as a raw material in the present invention may be used alone or in combination, or may contain other organic oxygen-containing compounds, water, etc.

The MTG reaction of the present invention is carried out in the gas phase using 100% raw materials or various gas atmospheres. Examples of the atmospheric gas include hydrocarbon gas, nitrogen, steam, hydrogen, carbon dioxide, etc., and hydrogen is preferably used.

In the present invention, the MTG reaction is preferably achieved in the presence of hydrogen gas. Hydrogen mainly shows the effect of reducing the amount of carbonaceous precipitation. There is no particular restriction on the amount of hydrogen added to methanol, but it is sufficient that the methanol:hydrogen molar ratio is 1:50 or less, and a range of 1:1 to 1:5 is particularly preferred.

Since the catalyst of the present invention has extremely high methanol conversion activity, the reaction proceeds even under normal pressure, but industrially it is preferable to operate under increased pressure, and the reaction pressure is preferably 100 atm or less, particularly around 20 atm. . Reaction temperature is 250-500
The temperature is preferably 300 to 450°C. There is no particular restriction on the raw material methanol supply rate (WH8'lf-methanol/1-cat-hr) per unit weight of catalyst, but in order to obtain a high methanol conversion rate, it is preferably 10 or less, particularly 0.5 to 2. A range of 0 is preferred.

Although the MTG reaction can be carried out by conventionally known fixed bed, fluidized bed or other methods, a fixed bed gas phase reaction is most suitable in view of ease of operation and other factors.

〔Effect of the invention〕

The catalyst used in the present invention has a low coke accumulation and a long life, and by using such a catalyst, a high gasoline yield and high octane number can be obtained.

Further, by using the catalyst of the present invention, it is possible to reduce the construction cost and operating cost of the equipment and to reduce the complexity of operation management when the method of the present invention is industrially implemented.

[Examples of the Invention] The method of the present invention will be specifically explained in detail below with reference to Examples.

(Example-1) After baking the Na type of ZSM-5 at 500°C for 5 hours, acid treatment was performed using 2N hydrochloric acid at a temperature of 90-100°C for 5 hours. After thorough washing with water, the product was dried at 120° C. for 5 hours to obtain dealkalized ZSM-5 (catalyst A).

2 Qwt% of aluminum trifluoride was added to and mixed with the above-mentioned acid-treated catalyst A, which was compression molded into 3×4 φ pellets and calcined at 500° C. for 8 hours (catalyst B).

Using the catalyst 2.01 thus obtained, a temperature of 37
0°C, hydrogen flow rate 4.21/hr, methanol flow rate 2.0 P/hr.

Therefore, molar ratio of hydrogen and methanol = 3.0% WHS
A life test of the MTG reaction was conducted at V=lhr and normal pressure.

The results are shown in Table 1.

Table 1 (*) Immediately after cs + aliphatic + aromatic oil passage (c oil passage time 7 or 8 hr), methanol conversion rate and generated hydrocarbon distribution are compared between A%B catalysts.

The methanol conversion rate for Catalyst A is 100.0%, while that for Catalyst B is 99.9%, which is slightly less than 100%, and it can be said that the initial activity of Catalyst A is higher than that of Catalyst B. .

C! The yield of I+ gasoline is almost the same for Catalysts A and B, but Catalyst B produces a larger amount of propylene and butene, which have higher reactivity and can be easily converted into gasoline.

Next, the activity and selectivity of both catalysts are compared after about 200 hours. In catalyst A, the amount of residual methanol suddenly begins to increase after about 200 hours, and the activity rapidly deteriorates. The methanol conversion rate in 216 hours is 94.8%. On the other hand, catalyst B
The methanol conversion rate in 220 hours is 99.9% and 8 hours
The value was the same as that at r, and no decrease in activity was observed. Catalyst A also has a C5+ gasoline yield based on converted methanol.
mf43. Despite the decrease to s%, catalyst B
The value of 1.41 was maintained at the initial stage of the reaction.

From the above, it can be seen that catalyst B has a long life in the MTG reaction and is a catalyst with excellent selectivity to C5+ gasoline (Example 2) After calcining the Na type of synthetic mordenite at 500 ° C. for 5 hours,
Acid treatment was performed using 2N hydrochloric acid at a temperature of 90-100°C for 5 hours. After thorough washing with water, dealkalized mordenite was obtained by drying at 120° C. for 5 hours (catalyst C).

2Qwt% of aluminum trifluoride was added to and mixed with the acid-treated catalyst C, formed into 3×4axφ pellets, and calcined at 500° C. for 8 hours (catalyst D).

Catalyst thus obtained 2. A lifetime test of the MTG reaction was conducted using Of under the same reaction conditions as in Example-1. The results are shown in Table 2.

Table 2 It can be seen that the catalyst composite treated with aluminum trifluoride has superior selectivity to C5+ gasoline and a longer life than the untreated product C.

(Example-3) After baking the Na type of Y type zeolite at 500°C for 5 hours, 2
Acid treatment was performed using normal hydrochloric acid at a temperature of 90-100°C for 5 hours. After thorough water washing, a dealkalized Y-type zeolite was obtained by drying at 120°C for 5 hours (
Catalyst E).

20 wt % of aluminum trifluoride was added to and mixed with the acid-treated catalyst E, formed into 3×4 IIJIφ pellets, and calcined at 500° C. for 8 hours (catalyst F).

Using catalyst 2.02 thus obtained, a lifetime test of MTG reaction was conducted under the same reaction conditions as in Example-1. The results are shown in Table 3.

Table 3 It can be seen that Catalyst F treated with aluminum trifluoride as a composite has superior selectivity to C5 gasoline and a longer life compared to untreated product E.

Claims (1)

[Claims] 1. A method for producing high-octane gasoline, which comprises bringing methanol and/or dimethyl ether into heated contact with a catalyst consisting of dealkalized zeolite and aluminum fluoride. 2. The method for producing high octane gasoline according to claim 1, wherein the zeolite is ZSM-5, ZSM-11, mordenite Y type or faujasite. 3. The method for producing high octane gasoline according to claim 1, wherein the reaction is carried out in the presence of hydrogen.