JPS59148728A - Conversion of hydrocarbon - Google Patents

Abstract

PURPOSE:To convert a paraffin-containing aliphatic hydrocarbon to an aromatic hydrocarbon in high conversion and selectivity, by contacting the aliphatic hydrocarbon with a zeolite catalyst containing the oxide of Cu, Zn or Cr and having excellent durability, under high temperature and pressure. CONSTITUTION:A hydrocarbon mixture containing 1-10C paraffin (e.g. light naphtha) is converted to a mixture containing aromatic hydrocarbon, by carrying out the catalytic conversion reaction at 300-700 deg.C and <=100 atm using a zeolite catalyst containing the oxide of Cu, An or Cr. The zeolite catalyst can be prepared by using a mineral having zeolite structure or a zeolite-like structure and having a pore size of 3-15Angstrom , immersing the mineral in an aqueous solution of the oxide of Cu, Zn or Cr, and drying and calcining the immersion product. USE:Gasoline and raw material of chemical industry.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for converting aliphatic hydrocarbons to aromatic hydrocarbons.

] 1 [Specifically, in a method for producing a hydrocarbon mixture containing aromatic hydrocarbons using a hydrocarbon mixture containing paraffins having 1 to 1 carbon atoms as a raw material, copper, zinc,
This invention relates to a method for obtaining aromatic hydrocarbons with high conversion and high selectivity using a zeolite catalyst containing one or more oxides of chromium.

Mixtures of aromatic hydrocarbons are widely used as raw materials for gasoline or the chemical industry. Generally they can be obtained by distillation of petroleum or by conversion of heavier petroleum distillates, such as catalytic cracking, pyrolysis. In order to improve the octane number of the hydrocarbon mixture thus obtained,
A method of catalytically modifying this material is used to increase the aromatic content. It has been well known that crystalline aluminosilicate zeolite catalysts have been used in the reforming and conversion reactions of petroleum distillates. Many patent applications have been filed for methods for decomposing hydrocarbons into low molecular weight products and methods for improving the octane number of hydrocarbon mixtures (US Pat. Nos. 5,140,249, 5,140,251, 5,140).
No. 255, Specification No. 5400072, etc.).

The present invention does not relate to the general hydrocarbon conversion method described above, but rather aliphatic hydrocarbons, i.e., paraffins having 1 to 10 carbon atoms, obtained by a lid, a thermal decomposition reaction, etc.
The present invention relates to a method for producing aromatic hydrocarbon mixtures useful as gasoline components from hydrocarbons containing olefins.

Conventionally, the zeolite catalyst described above has been widely used as a catalyst for converting such aliphatic hydrocarbons into aromatic hydrocarbons having a boiling point range of gasoline, and an example of a patent application related to this is Japanese Patent Publication No. 56-42659. There are public notices, etc.

However, these catalysts, for which patent applications have already been filed, have the problem of low yields of aromatic hydrocarbons (and short catalyst life).

The present inventors conducted intensive experimental studies to solve the above-mentioned problems of the prior art, and found that a zeolite containing one or more oxides of copper, zinc, and chromium can be used to remove the aliphatic hydrocarbons. It has been discovered that it is extremely effective as a catalyst for the conversion reaction to aromatic hydrocarbons, and has revolutionary effects such as far improved activity, selectivity, and durability compared to conventional catalysts.

That is, the present invention provides a method for producing an aromatic hydrocarbon mixture using a hydrocarbon mixture containing rough fins (having 1 to 10 carbon atoms) as a raw material.
Under conditions of 0 to 700°C and a reaction pressure of 1100 at or less,
It is characterized by contacting with a zeolite catalyst containing one or more oxides of copper, zinc, and chromium,
The present invention provides a method for producing aromatic hydrocarbons in high yield.

In the present invention, the hydrocarbon mixture containing C1-C10 nokurafin refers to paraffin alone or a mixture containing olefins, naphthenes, aromatic hydrocarbons, etc. (with a boiling point range of about Light naphtha having a weight of 10"O"Q or less can be preferably used as the raw material.

In addition, the hydrocarbon mixture containing aromatic hydrocarbons as used in the present invention refers to hydrocarbon mixtures containing 1% or more of aromatic hydrocarbons, and mixtures containing other paraffins, olefins, naphthenes, etc. means.

The method of the present invention can be carried out at a reaction temperature of 600 to 700°C, preferably 400 to 600°C, and a reaction pressure of 1100 atm or less, preferably 50 atm or less.

The reason why the reaction temperature is limited to 500 to 700°C is that 30
This is because at temperatures below 0°C, paraffin hardly reacts, and at temperatures above 700°C, the rate of coking reaction and decomposition reaction into methane increases, resulting in a short catalyst life.

The reaction pressure is limited to H) Oatm or less.
This is because the equilibrium conversion rate of the conversion reaction of aliphatic hydrocarbons to aromatic hydrocarbons becomes smaller at higher pressures, and there is no advantage in increasing the pressure above 1100 at.

Furthermore, the zeolite used in the present invention refers to a zeolite having a pore diameter of 6 to 15 A and a structure similar to that of zeolite, and the following zeolites are used as examples.

(OA type zeolite (1) X type spanning Y type zeolite (faujasite) (ill) Mordenite or modified mordenite (
1v) Natural zeolite (erionite, clinoptilolite, etc.) (V) ZSM-5 type zeolite (Special Public Sho dI-1ooba
, 55-25280, ・Unexamined Japanese Patent Publication No. 5Q-54598, 51
-67298,52-45800,115800,54
-52699,99799, IQ7499.15750
0.151600.55-116619.121912
56-9212.92114 Each publication basket (VD
Crystalline silicate (% Publication No. 56-40084.
5-y', q8.76825.162419.56-2
2625.59619.96719.57-10684
, No. 190084, No. 197227, No. 190084, No. 197227, No. 1, No. 1, No. 190084, No. 197227, No. 1, No. 1, No. 190084, No. 197227, No. 190084, No. 197227, No. 190084, No. 197227, No. 190084, No. 197227, No. 1, No. 197227. Zeolite catalysts containing one or more oxides of copper, zinc, and chromium as used in the present invention refer to zeolite catalysts containing one or more oxides of copper, zinc, and chromium. Refers to catalysts supported on zeolite by an impregnation method, etc., or catalysts physically mixed with zeolites by a precipitation method, etc., and the Kuramado ratio of one or more oxides of copper, zinc, and chromium to zeolite is 1000. ~10:1, preferably 5:100-1
:1.

A catalyst preparation method using an impregnation method includes impregnating zeolite with an aqueous solution of one or more compounds of copper, zinc, and chromium, followed by drying and calcining, and a catalyst preparation method using a precipitation method includes copper, zinc, and chromium. After adding an alkali such as aqueous ammonia to a mixture of an aqueous solution of one or more compounds of zinc and chromium and zeolite to form a precipitate, filtration,
Methods such as drying and baking are used.

The catalyst obtained in the above manner was prepared using K as shown in the examples.
This catalyst exhibits high selectivity and durability not found in conventional catalysts in reactions for producing aromatic hydrocarbon mixtures from hydrocarbon mixtures containing C1 to C1O nocrystalline carbon.

Hereinafter, the present invention will be specifically explained with reference to Examples.

[Example 1] Yfi zeolite with a particle size of 2 to 4 (NH, -Y type zeolite manufactured by Union Carbide Co., Ltd., called 8-41, calcined at 300°C, referred to as Comparative Catalyst 1) was dissolved in nitric acid. Copper, zinc nitrate, or chromium nitrate were immersed in an aqueous solution of 5 weight parts each of oxidized steel, zinc oxide, and chromium oxide.
A supported catalyst 1.2.5 was prepared containing -cents.

The experiments were carried out using these catalysts under the conditions shown in Table 1, and the results are shown in Table 2.

Hereinafter, aromatic selectivity refers to the proportion (weight percent) of aromatic hydrocarbons in the produced hydrocarbons.

[Example 2] In the same manner as in Example 1, Catalyst 4, in which copper oxide and zinc oxide were supported at 5 East weight percent each, and zinc oxide and chromium oxide were supported at 5 East weight percent each, using Y-type zeolite as a carrier. Catalyst 5, catalyst 6 each carrying 5% of oxidized steel and 5% of chromium oxide were prepared.

The experiment was carried out using these catalysts under the same conditions as in Table 1 of Example 1, and the results are shown in Table 5.

[Example 6] In the same manner as in Example 2, a particle size of 2 to 4 lllOH type mordenite (Jlll Zeolon 90
0 H, using copper oxide as a carrier (referred to as comparative catalyst 2),
Catalyst 7 supported with 5 East weight percent each of zinc oxide; Catalyst 8 supported with 5 parts by weight each of zinc oxide and chromium oxide; Catalyst 9 supported with 5 East weight percent each of oxidized steel and chromium oxide. Each was prepared.

The experiment was carried out using these catalysts under the same conditions as in Table 1 of Example 1, and the results are shown in Table 4.

[Example 4] 28M-5 type zeolite was synthesized as follows.

Water glass, aluminum sulfate, sodium hydroxide, water 56 Nal O@Ax, o, 1180 8 i
1,600 H,0, and added an appropriate amount of sulfuric acid to make the PL of the above mixture around 9, and then added tetrapropylammonium bromide as the organic compound. A l, 2 of the number of moles of O8
Add 0x, mix well, and place in a 50cc stainless steel autoclave.

While stirring the above mixture at about 50 Orpm,
The reaction was carried out at 0°C for 5 days. After cooling, the solid content was filtered and washed, dried at 110°C for 12 hours, and calcined at 550°C for 5 hours.

The crystal grain size of this product is around 1μ, and the composition excluding organic compounds is expressed in dehydrated form [15A/a, Oa A1103 * 80 8
It was i0°. The X-ray diffraction pattern of this powder was the same as that of ZSM-5 type zeolite described in Japanese Patent Publication No. 16-10064.

This zeolite was immersed in #IN hydrochloric acid and heated to 80°C for 5 minutes.
Processed for days. After washing and filtering this, it was heated to 110℃ for 1
Dry for 2 hours and bake at 550℃ to obtain H-ZSM-5.
(Comparative catalyst 5) was prepared.

This) l-ZSM-5 has a particle size of 2 to 411! Catalysts 10, 11, and 12 were prepared in the same manner as in Example 1 using the molded product as a carrier, each containing 5 percent of each of copper oxide, zinc oxide, or chromium oxide.

The experiment was carried out using these catalysts under the same conditions as in Table 1 of Example 1, and the results are shown in Table 5.

Table 5 [Example 5] In Example 4, ltl#JIll! Catalyst 13, in which copper oxide and zinc oxide were supported at 5% each by the same method as in Example 2, using H-ZSM-5 molded to a particle size of 2 to 4 as a carrier, zinc oxide, Catalyst 14 was prepared in which 5% of each of copper oxide and 5% of chromium oxide was supported, and catalyst 15 was prepared in which 5% of each of copper oxide and chromium oxide were supported.

In addition, a mixture of copper, zinc or chromium hydroxides is prepared in advance by using an aqueous solution of copper, zinc or chromium nitrate as a raw material and adding soda carbonate, and these and I(
-Copper oxide by mixing with ZBM-5 and firing
Zinc oxide mixture (Zn/Cn''2) and H-ZSM
Mixed catalyst 16 with zinc oxide, oxidized shim mixture (Zn/Cr=6) and H-ZSM-5
7. Mixture of copper oxide and chromium oxide (eu/Cr=1)
A mixed catalyst 18- of H-ZSM-5 and H-ZSM-5 was prepared.

Using these catalysts, the experiment was carried out under the same conditions as in Example 10 Table 1, and the results are shown in Table 6.

Table 6 [Example 6] Crystalline silicate was synthesized as follows.

Water glass, sodium hydroxide, water 56 Na2O 80810. - 1600 H2O
A crystalline silicate was prepared using the same method as in Example 4, except that an appropriate amount of sulfuric acid was added thereto so that the pH of the mixture was around 9.

This crystalline silicate, molded to a particle size of 2 to 4 mm, is immersed in an aqueous solution of copper nitrate, zinc nitrate, or chromium nitrate, and supported so that the content of steel oxide, zinc oxide, and chromium oxide is 5 percent each. Catalysts 19.20.21 were prepared.

Using these catalysts, the experiment was carried out under the same conditions as in Example 10, Table 1, and the results are shown in Table 7.

Table 7 [Example 7] The reaction was carried out using Catalyst 19 under the same conditions as in Table 1 except that the reaction temperature was changed. The results are shown in Table 8.

[Example 8] The reaction was carried out using Catalyst 19 under the same conditions as in Table 1 except that the reaction pressure was changed. The results are shown in Table 9.

[Example 9] The experiment was carried out using Catalyst 19 under the same conditions as in Table 1 except that the raw materials were changed. The results are shown in Table 10.

・Here, the light naphtha is approximately 40 yt% pentane.
, hexane approximately 50 wt%, other rosefish approximately 10
ivt% composition was used.

In addition, in catalysts 1 to 21 of Examples 1 to 6, 10 to 50 wt% of C1 to C4 olefins were produced in addition to aromatics. The production of olefins is also possible.

As shown in the examples above, by using the catalyst of the present invention, a hydrocarbon mixture containing aromatic hydrocarbons can be obtained with high selectivity from a hydrocarbon mixture containing paraffins having 1 to 10 carbon atoms. It also has excellent durability and can be operated for a long time.

It should be noted that the examples shown below are merely illustrative and do not limit the present invention.

In addition, in the examples, results were shown for a fixed bed, but
This does not particularly limit the reactor type, and it goes without saying that a fluidized bed, pneumatic conveyance type, or other type of reactor may be used.

Claims (1)

[Claims] In a method for producing a hydrocarbon mixture containing τ aromatic hydrocarbons using a hydrocarbon mixture containing paraffins having 1 to 10 carbon atoms as a raw material, the raw material is heated at a reaction temperature of 500
A method for converting hydrocarbons characterized by contacting with a zeolite catalyst containing one or more oxides of copper, zinc, and chromium under conditions of ~700"Q and slope stress of 1100 at or less."