JPS5915482A - Conversion of gaseous hydrocarbon - Google Patents

Abstract

PURPOSE:To obtain liquid hydrocarbon with a high octane number efficiently by performing catalytic conversion of gaseous hydrocarbon in the presence of a crystalline silicate catalyst and effecting a 2nd-step catalytic conversion of the separated gaseous hydrocarbon. CONSTITUTION:First-step catalytic conversion of 2-4C gaseous hydrocarbon is performed at 100-400 deg.C in the presence of a crystalline silicate catalyst. The reaction product is separated into liquid and gaseous hydrocarbons and the latter hydrocarbons are subjected to a 2nd-step catalytic conversion at 400-700 deg.C in the presence of the crystalline silicate catalyst. The aqueous hydrocarbons to be used are usually butane-butene fractions, etc. produced by fluid bed catalytic cracking and preferred composition is a mixture in which paraffinic and olefinic hydrocarbons are present each in less than 75wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for converting gaseous hydrocarbons, and more specifically, a gaseous hydrocarbon having 2 to 4 carbon atoms is used as a raw material, and the process is carried out in a relatively low-temperature first stage and a high-temperature stage. It relates to a method for efficiently producing liquid hydrocarbons such as gasoline with a high octane number by carrying out a catalytic conversion reaction in two stages.

Generally, the butane-butene fraction (EE fraction) produced from fluidized bed catalytic cracking (FOO) has an olefin content of about 5
Since it contains 0%, it is unsuitable for commercial sale as fuel, and so far it has been consumed exclusively as in-house fuel in refineries and the like.

Therefore, various efforts have been made to convert the EB fraction from FCC into hydrocarbons suitable for commercial fuel. For example, a method has been developed for converting the BB fraction into a liquid hydrocarbon rich in aromatics in one step.

However, in the one-stage reaction as described above, since the reaction is carried out under conditions that allow a large amount of aromatic components to be obtained, there is a drawback that a large amount of light hydrocarbons are produced as by-products.

The present inventor has conducted extensive research in order to overcome the drawbacks of the conventional methods described above and to develop a method for efficiently producing liquid hydrocarbons with a small amount of light gas by-product and a high octane number. As a result, they discovered that the objective could be achieved by carrying out the conversion reaction in two stages, by carrying out the reaction at a relatively low temperature in the first stage, and at a slightly higher temperature in the second stage.1. completed.

That is, the present invention uses a gaseous hydrocarbon having 2 to 4 carbon atoms as a raw material, a crystalline silicate catalyst, and a temperature of 100 to
After carrying out the first stage catalytic conversion reaction at 400°C and then separating the first stage reaction product into liquid hydrocarbon and gaseous hydrocarbon, the gaseous hydrocarbon is used as a raw material to form a crystalline silicate catalyst. 2nd at a temperature of 400 to 700°C.
The present invention provides a method for converting gaseous hydrocarbons, which is characterized by carrying out a catalytic conversion reaction in stages.

The raw material hydrocarbon in the method of the present invention is a gaseous hydrocarbon having 2 to 4 carbon atoms as described above, and the BE fraction produced from FOO is usually used. This feedstock hydrocarbon is
As long as the main component is a gaseous hydrocarbon having 2 to 4 carbon atoms, its composition is not particularly limited and various types can be mentioned, but the preferred composition is paraffinic hydrocarbons.
less than 5% by weight, and olefinic hydrocarbons are also less than 75% by weight.
Mixed compositions ranging from less than % by weight can be mentioned.

In the method of the present invention, the first stage catalytic conversion reaction is first performed using the gaseous hydrocarbon having 2 to 4 carbon atoms as a raw material.

The reaction temperature at this time is 100 to 400°C, preferably 250 to 350°C.

If the temperature exceeds 400''C in this first stage reaction, the amount of gaseous hydrocarbons such as methane and ethane produced will increase, which is undesirable. When this is carried out, the olefin content in the raw gaseous hydrocarbon reacts preferentially, producing methane,
There are almost no by-products of ethane and ethylene, and because the octane number contains a large amount of olefinic hydrocarbons, gasoline can be obtained in high yield.

In addition, there are no particular restrictions on other conditions for the first stage catalytic conversion reaction in the method of the present invention, such as the type of catalyst used,
It may be selected appropriately depending on the type of raw material hydrocarbon, etc.1
Usually the pressure is normal pressure to 5゜kg7cm''G, preferably normal pressure to 2okg/♂G, and the weight hourly space velocity (W) Is
V) 0.1-50 hr', preferably 0.5
It should be ~10 hr"-'. Furthermore, in order to prevent catalyst deterioration, hydrogen can be supplied to the reaction system if desired. The amount of hydrogen supplied is not particularly limited and may be determined as appropriate. However, the hydrogen/raw material hydrocarbon molar ratio is generally 0.1 to 6, preferably 1 to 5.

Furthermore, it is necessary to use a crystalline silicate as a catalyst in the first stage catalytic conversion reaction of the method of the present invention. Various types of crystalline silicates can be used here, and they may be appropriately selected and used depending on each condition. Specific examples of crystalline silicates include X-type zeolite, Y-type zeolite, A-type zeolite, and L-type zeolite.

There are ZSM type zeolites and zeolites similar to these, and there are also those in which these are exchanged with hydrogen ions and those in which various metal ions are exchanged. Among these, 28M type, particularly ZSM-5 type or similar crystal structure zeolites are preferred. These ZSM-type zeolites, zeolites, and similar zeolites can be broadly classified into silica-alumina, silica-alumina-active metal, and silica-active metal. 12 to 3000 is preferred.

Specific examples of the crystalline silicates that can be used in the method of the present invention are as follows (1) to (2) below.

■ Silica, alkali metals 6 periodic table 111A, T
V.A.

VA, mB, [VI3. 'V13. VI:B,
Using one or more metals belonging to group II and water as raw materials, and crystallizing agents such as heterocyclic compounds such as morpholine and oxazolidine, amino alcohols such as ethanolamine and globanolamine, amino acids such as alanine and serine, or acetamide. Add the amides of
Crystalline zeolite obtained by reacting at 80 to 300°C until crystalline zeolite is sufficiently produced (JP-A-57-
Publication No. 7817).

(2) A crystallized aluminosilicate zeolite obtained by adding alumina to the raw material (1) above and reacting it with a crystallizing agent (Japanese Unexamined Patent Publication No. 7818/1983).

■) Silica, alumina, alkali metal and water are used as raw materials, crystalline zeolite powder is present as a seed crystal, and the temperature of the reaction system is maintained at 9 to 12.
Crystalline ``aluminosilicate zeolite'' obtained by reacting at 300°C until sufficient crystal formation
-781.9 Publication).

■ Silica, alumina, alkali metals and water are used as raw materials, and morpholine is used as a crystallizing agent.

By adding a heterocyclic compound such as oxazolidine, 80~
Crystalline aluminosilicate zeolite obtained by reacting at 300°C until sufficient crystal formation
Publication No. 7816).

■ Expressed as the molar ratio of oxides (dehydrated form), (0,
1~2.0) Re/n O・[aM, o8HbA
' 90g:1 ・y 81011 (in the above formula, 几:
One or more of the above monovalent or divalent cations/, a:R
Valency 1M: one or more trivalent transition metal cations, a-1-b=l.

L7 has a chemical composition of a≧Q, b≧o, y≧12), and further includes alcohols, organic amines, and ethers.

Crystalline transition gold organosilicate containing ketones, esters, and/or organic sulfur compounds or derivatives thereof (Japanese Patent Application Laid-Open No. 5710684).

■ (a) a crystalline aluminosilicate zeolite having a uniform pore size in the range of about 6 to 15'A and a silica to alumina molar ratio of at least about 3; (b) an inorganic oxide matrix; and (c) loose alumina particles. 5), wherein the zeolite has a unit cell size of about 24.11 or more before being composited with component 0), and the alkali metal oxide/M'Sl ratio of the zeolite is 00.
24 or less, and the weight ratio of the rare earth metal oxide/the zeolite is about 0.01 to
A crystalline zeolite catalyst containing a rare earth metal in an amount of oo8 (Japanese Unexamined Patent Publication No. 57-91741).

■ It has a specific X-ray diffraction pattern, and the molar ratio of oxides is 090.2 M2/n (1: WQOs: bY
Os: ZH510 (where M is a cation, n is the valence of the cation, 'W&'X, aluminum or gallium, Y is silicon or germanium, and 2 is 0-40, b is at least 5, preferably from 15 to 300) or 0,9-+0.2 MQ/n O' Al, o8' 1
5 to 300 S 102 ' zH20 (wherein M is an alkali metal cation, especially an alkali metal cation) and a tetraalkylammonium cation (the alkyl group preferably contains 2 to 5 carbon atoms); , n+Z is the same as above.) ZSM-5 series zeolite.

L has a specific X-ray diffraction pattern, and the molar ratio of oxides is 0.9±0.2 M2/n O' Al:s08:1
5-300 S 1o11: 7. H2O (where M is at least one cation, n is its valence, and 2 is from 0 to 40) or 09,000,0.2 Ms/H
O: AlgOs' 15~60 Sl, 02'z
Zeolites of the ZSM-8 series, such as H40, where M is selected from the group consisting of a mixture of alkali metal cations, especially sodium ions and tetraethylammonium cations.

It has a specific X-ray diffraction pattern and the molar mass of oxide is 0,9 +0.3 MQ/nO' A le Oa
'20-90810Il: zH20 (wherein 1M is at least one cation, n is its valence, 2
is 6-12. ) or 0.9 + (1,3M
a/n O: A, 'i0a' 20~90 Si
(12: 7.1?20, where M is selected from the group consisting of a mixture of alkali metal cations, especially sodium ions and tetrabutylammonium cations). 1970
-521 (, No. 14 Publication).

■ (a) has a specific X-ray diffraction pattern and (b) is converted to the silicate form Ii-form at 2 x 10''9 bar.
After vacuum treatment for 16 hours at 0 °C, the absorption of n-hexane is a minimum of 0.8 μIJ mole/9 when measured at hydrocarbon pressure sxi o ” bar and 100 °C, and 2,2- The absorption rate of dimethylbutane is at least 05 mmol/g, and the absorption rate of n-hexane/
The ratio of the absorption rates of 2,2-dimethylbutane is at least 1.5, and the composition expressed in moles of (C) oxide has the formula: y-
(t, o±0.3) M2. 'H0・7-Al@OB
- Sj'Og (in the formula, 1M is hydrogen, an alkali metal or an alkaline earth metal, n is the valence of M, and 0<y≦001). Publication No. 125195).

■ A silica/alumina molar ratio of at least 12 and
Crystalline zeolite (ZSM-5) with control index of 120
, 28M-11, ZSM-12, ZSM-23, 28M
-35, ZSM-38, ZSM-48 and their similar substances), by treating the zeolite with one of the compounds containing metal elements of group IITA of the periodic table or with a compound containing a metal element in group IITA of the periodic table. Both 0.5% by weight
A crystalline zeolite obtained by precipitating the above elements (Japanese Patent Application Laid-Open No. 57-95922).

In addition to the above-mentioned crystalline silicates, various other materials can be used in the method of the present invention.1. It is not limited to these. Further, the particle size of the crystalline silicate used as a catalyst is not particularly limited, but is generally from o.oos to 30 microns. Although this crystalline silicate may be used as it is, it is mixed with alumina or the like as a binder and extruded to form an appropriate shape, for example, a cube, a round shape, or a spherical shape.

It is preferable to mold it into a cylindrical or star-shaped irregular shape for convenient handling.

In the method of the present invention, after the first stage catalytic conversion reaction is completed, the obtained reaction product is separated into liquid hydrocarbons and gaseous hydrocarbons. The separated liquid hydrocarbons contain a large amount of high-octane gasoline fraction, while the gaseous hydrocarbons are mostly paraffins, i.e. methane, ethane,
It consists of propane, butane, etc.

In the method of the present invention, the second stage catalytic conversion reaction is carried out using the above gaseous hydrocarbon as a raw material. The reaction temperature at this time is 400 to 700" C1, preferably 450 to 550 °C, and should be higher than the first stage conversion reaction described above. At a temperature below 400 °C, liquid carbonization Conversion to hydrogen is small, and on the other hand, if the temperature exceeds 700°C, the catalyst deteriorates significantly, and operating costs also increase, making it impractical.On the other hand, in the range of 400 to 700°C, the second stage catalytic conversion When the reaction is carried out, a liquid hydrocarbon rich in aromatics is obtained in high yield.

In addition, other conditions for the second stage catalytic conversion reaction in the method of the present invention are not particularly limited;
The pressure may be selected as appropriate depending on the composition of the gaseous hydrocarbon to be supplied, but usually the pressure is between normal pressure and 50 kg/c+w''.
G, preferably normal pressure to 20 kg/cm2G, W
H8V O, 1-50 hr-', preferably 0.5
〜], Ohr-''.Furthermore, as in the case of the first stage catalytic conversion reaction described above, hydrogen can be added to the reaction system if desired in order to prevent catalyst deterioration. The amount of hydrogen supplied at this time is not particularly limited and may be adjusted appropriately, but it is generally 0.1 to 6 (molar ratio), preferably 1 to 5 (molar ratio) relative to the gaseous hydrocarbon introduced. ).Although this hydrogen may be newly supplied, the hydrogen supplied to the first stage reaction may be used as is.

Furthermore, in the second stage catalytic conversion reaction of the method of the present invention, it is necessary to use a crystalline silicate as a catalyst.

This crystalline silicate may be the same as or different from the crystalline silicate used in the first stage catalytic conversion reaction. Specifically, those mentioned above are preferably used.

According to this second-stage catalytic conversion reaction, liquid hydrocarbons rich in aromatic components can be efficiently obtained. Further, the gaseous hydrocarbons produced by-product here can be recycled to the first or second stage reaction system after being separated.

As described above, according to the method of the present invention, liquid hydrocarbons with a high octane number can be obtained in high yield from gaseous hydrocarbons having a carbon number of 2 to 4, which have low utility value, and methane gas with low reactivity can be obtained. By-products can be suppressed.

Therefore, the method of the present invention can be effectively used industrially as a method for efficiently producing high octane gasoline.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 +11 Preparation of catalyst Aluminum sulfate (18 hydrate) 752 chloride, sulfuric acid (97%
) 17.69 and 250 ml of water (1
), water glass (8), 02 37.6 xi, Na
-@017.5 1% by weight, 449% water) and 300 ml of solution (II), 79 ml of sodium chloride and 122 mJ of water (1,11
) were prepared in two batches.

Then, solution (D) and solution (IT) were added into the above solution (m).
were gradually added dropwise at the same time while stirring at room temperature (to obtain a mixture).
After adding the solution, the temperature was adjusted to 100 ml, and the mixture was placed in an 11-volume autoclave at 170° C. with stirring at 200 rpm and allowed to react under autogenous pressure for 20 hours. Thereafter, the reaction mixture was cooled and washed five times with 2.1 g of water. Then, solid matter was separated by RI filtration and dried at 120°C for 3 hours, yielding 405 crystalline aluminosilicate zeolites. This crystalline aluminosilicate olide was confirmed by X-ray diffraction and was found to be ZSM-5.

Note that this ZSM-5 has the following composition in terms of molar ratio.

0, 9 NF190' 60 SjOg' 1.
OAt@C)s ZSM-5 obtained by the above method was ion-exchanged twice with 5 rrrl of ammonium nitrate per sample, dried at 120°C, and then burned in air at 550°C for 6 hours. It was made into an H type. Furthermore, this 1■ type Z
A 20 weight system of alumina was added as a binder to SM-5, mixed, extruded and molded for 17 minutes, dried at 120°C for 3 hours, and fired in air at 550°C for 6 hours to form a diameter of 1 block. Cylindrical catalyst particles having a length of 5 to 6 mm are obtained.

121 Conversion Reaction A stainless steel reaction tube is filled with the catalyst and catalyst obtained in (1) above, and a gaseous hydrocarbon having the composition shown in Table 1 is passed through it to form the first stage under the prescribed conditions. A conversion reaction was carried out.

Subsequently, the product obtained in the above conversion reaction was separated into gas and liquid, and the generated gaseous hydrocarbon was passed through a stainless steel reaction tube as a raw material to perform a second stage conversion reaction under predetermined conditions. . The results are shown in Table 2.

Example 2 +1+ Catalyst 1・■ Preparation The crystalline silicate obtained in Example 1 (1) (simply ion-exchanged twice with ammonium nitrate and dried) was mixed with lQml/g of 0.5N zinc nitrate. Ion exchanged twice. Further, the product was thoroughly washed with ion-exchanged water, filtered, dried at 120"C, and then calcined in air at 550C for 6 hours to obtain a zinc-exchanged Z8M-5 catalyst.

(2) Conversion reaction Example 1 (2) using the catalyst obtained in Example 1 (1)
The first stage conversion reaction was carried out in the same manner as above.

Subsequently, after gas-liquid separation of the product, the second stage was carried out in the same manner as in Example 1 (2) using the obtained gaseous hydrocarbon as a raw material and the catalyst obtained in Example 2 (1). A conversion reaction was carried out. The results are shown in Table 2.

−、−／ Table 1 (Raw material composition)

Claims (1)

[Claims] (1) Using a gaseous hydrocarbon having 2 to 4 carbon atoms as a raw material, using a crystalline silicate catalyst, at a temperature of 100 to 400°
After carrying out the first stage catalytic conversion reaction at C, and then separating the first stage reaction product into liquid hydrocarbon and gaseous hydrocarbon, a crystalline silicate catalyst is prepared using the gaseous hydrocarbon as a raw material. A method for converting gaseous hydrocarbons, characterized in that the second stage catalytic conversion reaction is carried out at a temperature of 400 to 700°C.