EA002139B1 - Catalst and method for converting alyphatic hydrocarbons c2-c12 into high-octane gasoline or aromatic hydrocarbon concentrate - Google Patents

Abstract

1. A catalyst for converting of aliphatic hydrocarbons C2-C12 into high-octane gasoline or aromatic hydrocarbon concentrate, comprising pentasyle group zeolite with molar ratio SiO2/Al2O3(20-150, zinc oxide and bonding agent, characterised in that it additionally comprises at least two oxides selected from the group comprising ferric oxide (III), magnesium oxide, and calx, taken in any ratio to each other, wherein percentage of each oxide is between 0,01 to 2,0% wt with total content of above-mentioned oxides not more than 4% wt, the zeolite content is between 20,0 to 90,0% wt, zinc oxide content is between 0,1 to 6,0% wt, the rest is bonding agent. 2. A method of converting of aliphatic hydrocarbons C2-C12 into high-octane gasoline or aromatic hydrocarbon concentrate comprising putting into contact with aliphatic hydrocarbons C2-C12 catalysts under high temperature and pressure, characterised in that the catalyst used contains pentasyle group zeolite with molar ratio SiO2/Al2O3(20-150 in the amount of 20,0 to 90,0% wt, zinc oxide is between 0,1 to 6,0% wt, at least two oxides selected from the group comprising ferric oxide (III), magnesium oxide, and calx, taken in any ratio to each other, wherein percentage of each oxide is between 0,01 to 2,0% wt with total content of above-mentioned oxides not more than 4% wt, and bonding agent. 3. The method according to Claim 2, characterised in that it is conducted under the temperature of 250-629 degree C, pressure of from 0,4 to 3,5 MPa and volumetric raw material flow rate from 0,4 to 11 hour<-1>.

Description

The invention relates to the field of chemistry of the processing of natural hydrocarbons, namely, to the field of processing of aliphatic hydrocarbons into aromatic, and can be used in petrochemicals.

A number of methods are known for producing high-octane gasolines and aromatic hydrocarbons from raw materials containing aliphatic hydrocarbons using zeolite catalysts. Typically, a binder and zeolites of the pentasil group are used in the composition of the catalysts, which makes it possible to limit the composition of the products to C ₁ -C ₁₂ hydrocarbons. The zeolite content in the catalyst may be different, and alumina, silica, aluminosilicates are used as a binder component. Catalysts also contain metals or metal oxides (promoters) as components that increase their activity, selectivity and stability in dehydrocyclization reactions. The content of promoters in the catalyst, as a rule, is 0.1-10 wt.%.

From US patent No. 4120910 (C 07C 15/02, 1978), a method is known for producing aromatic hydrocarbons by contacting a gas containing ethane, in the absence of air or oxygen, with a catalyst comprising a zeolite with a molar ratio of 81O ₂ / A1 ₂ O ₃ not less than 12, and 0.01-30 wt.% Metal or metal oxide from groups VIII, 11B and 1B of the Periodic system of elements.

From US patent No. 4097367 (C 106 35/06, 1978), a method for processing olefin-containing gasolines is known, comprising contacting gasoline at 482-648 ° C, a pressure of 0.1-2.8 MPa and a weight feed rate of 0.3-30 hours ^-1 with a catalyst containing zinc and at least one metal from groups I B and VIII of the Periodic system of elements. It is preferable to use a noble metal and zeolite with a molar ratio of 8Yu ₂ / A1 ₂ O ₃ more than 12.

US Pat. No. 4,554,396 (C 07C 2/02, 1985) discloses a method for processing lower olefins by contacting a feed under oligomerization conditions with a medium-pore acidic aluminosilicate containing iron mainly in tetrahedral coordination.

From US patent No. 4831201 (C 07C 2/04, 1989), a method for oligomerizing C ₂ -C _{1 0} olefins at a temperature of 220-350 ° C, a weight feed rate of 0.1-10 h ^-1 on a synthetic zeolite containing silicon oxides is known titanium and iron.

From the USSR author's certificate No. 1325892 A1 (C 106 11/05, 1983), a method is known for producing gasoline fractions by contacting hydrocarbon feed with an aluminosilicate catalyst at elevated temperature and elevated pressure, and aluminosilicate of the composition (0.02-0.32 ) IA ₂ O-A1 ₂ O ₃ · (0.003-2.4)

EE _p O _t (28-212) 81О ₂ , where UE _p O _t - one or two oxides of elements of the II, III, V, VI, VIII groups of the Periodic system, or aluminosilicate of the specified composition deposited on a carrier in an amount of 30-70 wt .%, or a catalyst of the specified composition, modified 0.05-0.5 wt. % palladium.

The disadvantage of all the above processes is their low efficiency.

An effective and affordable promoter of catalysts for the conversion of aliphatic hydrocarbons to aromatic is zinc. The disadvantage of zinc-containing catalysts is the need to use high temperatures, which leads to the entrainment of the zinc-containing catalyst and the need for regeneration of the catalyst, as well as insufficiently high yield of aromatic hydrocarbons.

The closest analogue of the present invention can be recognized as well-known US patent No. 3760024 (C 07C 5/27, 1973), which describes a catalyst containing a zeolite of the pentasil group, with a molar ratio of 8U ₂ / A1 ₂ O ₃ more than 10, and zinc, as well as the method for producing aromatic hydrocarbons, including contact of C ₂ -C ₄ paraffins, olefins or a mixture thereof with a catalyst containing a zeolite of the pentasil group, with a molar ratio of 81O ₂ / A1 ₂ O ₃ more than 10, and zinc, at a temperature of 100-700 ° C, pressure to 7 MPa, a weight hourly space velocity of 0.5-400 h ^-1 and a hydrogen respect to the yz Euodias to 20.

The technical problem to which the present invention is directed is to develop a new catalyst for the processing of aliphatic hydrocarbons into high-octane gasoline or an aromatic hydrocarbon concentrate.

The technical result obtained as a result of the implementation of the invention is to increase the yield of the target product.

According to the invention, the catalyst for the conversion of aliphatic hydrocarbons to high-octane gasoline or an aromatic hydrocarbon concentrate contains a zeolite of the pentasil group with a molar ratio of 8Yu ₂ / A1 ₂ O ₃ = 20-150 in an amount of 20.0-90.0 wt.%, Zinc oxide in an amount 0.1-6.0 wt.%, At least two oxides from the group consisting of iron (III) oxide, magnesium oxide and calcium oxide, taken in any ratio to each other, and the content of each oxide is from 0.01 to 2.0 wt.% With a total content of these oxides not exceeding 4.0 wt.%, And the binder is total.

The use of the claimed catalyst in the method of converting aliphatic hydrocarbons to high-octane gasoline or an aromatic hydrocarbon concentrate at elevated temperature and pressure, the volumetric feed rate determined by the process conditions, leads to an increase in the yield of aromatic hydrocarbons compared to that for the catalyst according to the closest analogue, which is explained by modifying the influence of additional components on the acid and diffusion properties of zeolite.

The high-silica zeolites of the pentasil group used in the catalyst composition in decationized form have the following characteristics: molar ratio

810 ₂ / A1 ₂ 0 ₃ = 20-150, when the content of sodium oxide is less than 0.2 wt.%, The degree of crystallinity by x-ray analysis is not lower than 95% and the static capacity for heptane is not less than 0.14 cm ³ / g.

The promoter metals zinc, iron, magnesium, and calcium are introduced prior to the stage of forming the catalyst by ion exchange with solutions of the corresponding salts, in the form of oxides or salts that decompose upon calcination, upon mixing the catalyst mass, or upon impregnation of the catalyst with a salt solution.

The catalyst according to the invention can be prepared in various ways.

The catalyst described above can be used in the method of converting aliphatic hydrocarbons to high-octane gasoline or an aromatic hydrocarbon concentrate at elevated temperature and pressure, as well as the volumetric feed rate selected depending on the equipment used and other process parameters.

When using the specified composition of the catalyst, it is preferable to use a temperature of 250-629 ° C at a pressure of 0.4-3.5 MPa and a volumetric feed rate of 0.4-11 h ^-1 . Although other ratios of temperature, pressure and consumption of raw materials are possible.

The following are examples of the preparation of catalysts and methods for their use.

Example 1. 90 g of dry zeolite with a molar ratio of 8Yu ₂ / A1 ₂ O ₃ = 41 in an ammonium form containing less than 0.1 wt.% Sodium oxide is exchanged with 1 l of a 0.2 n solution of zinc chloride at 55 ° C, the suspension is cooled, filtered, the zeolite on the filter is washed with distilled water, dried and calcined at 550 ° C for 4 hours in a muffle furnace (hereinafter, the calcination conditions are the same). The zinc content in zeolite is 1.4%. The resulting zeolite in an amount of 65 g is mixed with 149.1 g of aluminum hydroxide with a moisture content of 77%, the mass is mixed, evaporated and formed by extrusion. The catalyst granules are dried and calcined. Chilled catalyst granules are poured into 140 ml of a solution containing 0.9 g of iron nitrate, 0.7 g of magnesium nitrate and 0.6 g of calcium nitrate, kept at room temperature for 2 hours and evaporated. The catalyst is dried and calcined.

The composition of the obtained catalyst (wt.%): Zeolite 63.9 Zinc oxide 1,1 Iron oxide 0.3 Magnesium oxide 0.2 Calcium oxide 0.2 Binder 34.3 Example 2 The catalyst is prepared according to example 1, but fed with a solution containing 0.5 g of nitrate zinc, 0.6 g of calcium nitrate and 0.9 timber. The composition of the catalyst (wt.%): g of nitrate Zeolite 63.9 Zinc oxide 1.3 Iron oxide 0.3 Calcium oxide 0.2 Binder 34.3 Example 3 The catalyst is prepared by mixing 73.0 g of su-

zeolite (loss on ignition 13%) with a molar ratio of 8Yu ₂ / A1 ₂ 0 ₃ = 41 in an ammonium form containing less than 0.1 wt.% sodium oxide, with 142.2 g of aluminum hydroxide, 10 ml of an aqueous solution containing 3.7 g of zinc nitrate, 14 ml of a solution containing 0.9 g of iron nitrate, 10 ml of a solution containing 0.6 g of calcium nitrate and 15 ml of a solution containing 0.7 g of magnesium nitrate. The mass is thoroughly mixed, evaporated and extruded. The catalyst granules are dried and calcined.

The composition of the catalyst, wt.%:

Zeolite65.0

Zinc Oxide 1.6

Iron Oxide 0.3

Magnesium Oxide 0.2

Calcium Oxide 0.2

Binder 32.7

The resulting catalysts were used in the conversion of C ₂ -C ₁₂ aliphatic hydrocarbons to high-octane gasoline or an aromatic hydrocarbon concentrate provided that the above process conditions were used.

When using gas condensate gasoline as a source of aliphatic hydrocarbons, the use of the catalyst obtained in Example 1 in a flow unit with a catalyst loading of 20 cm ³ at a temperature of 400 ° C, a pressure of 3.1 MPa and a feed volumetric flow rate of 1.6 h ⁻¹ percent high-octane yield gasoline was 81.8.

When used in similar conditions, the catalyst obtained in example 2, the percentage yield was 80.6.

When used under similar conditions, the catalyst obtained in example 3, the percentage yield was 80.9.

When using the propane butane fraction as the source of aliphatic hydrocarbons, the use of the catalyst obtained in Example 1 in the same flow-through installation at a temperature of 590 ° C, a pressure of 2.1 MPa and a volumetric feed rate of 2.1 h ^{−1, the} percentage yield of aromatic hydrocarbon concentrate was 28.2.

When used under similar conditions, the catalyst obtained in example 2, the percentage yield was 27.8.

When used under similar conditions, the catalyst obtained in example 3, the percentage yield was 28.0.

The percentage of yield of the target product exceeded the same value for the closest analogue by an average of 5.9%. Changing these process conditions slightly reduces or increases the yield of the target product from the above values. However, the use of a catalyst of the specified composition is a necessary condition for achieving the specified technical result.

The use of the invention allows to increase the yield of the target product without increasing its cost.

Claims (3)

CLAIM 1. A catalyst for the conversion of aliphatic hydrocarbons C ₂ -C ₁₂ to high-octane gasoline or an aromatic hydrocarbon concentrate containing a zeolite of the pentasil group with a molar ratio of Ю ₂ / A1 ₂ O ₃ = 20 150, zinc oxide and a binder component, characterized in that it further comprises at least two oxides selected from the group consisting of iron (III) oxide, magnesium oxide and calcium oxide, taken in any ratio to each other, and the content of each oxide is from 0.01 to 2.0 wt.% with a total content of these oxides not exceeding 4.0 wt.%, the zeolite content is from 20.0 to 90.0 wt.%, the content of zinc oxide is from 0.1 up to 6.0 wt.%, the binder is the rest. 2. A method of converting aliphatic hydrocarbons C ₂ -C _{1 2} into high-octane gasoline or an aromatic hydrocarbon concentrate, comprising bringing into contact with a catalyst aliphatic hydrocarbons C ₂ -C _{1 2} at elevated temperature and pressure, characterized in that they use a catalyst containing a zeolite of the pentasil group of c the molar ratio of Ю ₂ / A1 ₂ O ₃ = 20-150 in an amount of from 20.0 to 90.0 wt.%, zinc oxide in an amount of from 0.1 to 6.0 wt.%, at least two oxides from the group consisting of iron (III) oxide, magnesium oxide and calcium oxide, taken in any ratio among themselves, wherein the content of each of them is from 0.01 to 2.0 wt.% with a total content of these oxides not exceeding 4.0 wt.% and a binder. 3. The method according to claim 2, characterized in that it is carried out at a temperature of 250-629 ° C, a pressure of from 0.4 to 3.5 MPa and a bulk feed rate of from 0.4 to 11 h ^-1 .