SU1426965A1 - Method of joint production of aromatic hydrocarbons and hydrogen - Google Patents

Abstract

The invention relates to cyclic compounds, in particular to the co-production of aromatic hydrocarbons and hydrogen. The goal is to increase the yield of aromatic hydrocarbons with simultaneous high selectivity of the formation of hydrogen. The production of the left-sided compounds is carried out by contacting propane with a catalyst. The latter contains a high-silica zeolite, ultrasil, characterized by a specific X-ray diffraction pattern, promoted to 2.5-3.5 May. % zinc oxide and granulated with an alumina binder, preferably a catalyst containing 40 May is used. % alumina; The catalyst is pretreated with propane at 500-600 ° C for 8-10 hours with intermediate oxidative regenerations every 2 hours with propane treatment. The process is conducted at 560-560 ° C and the volumetric feed rate of the raw material is 60-360 hours. The method provides for increasing the yield of aromatic hydrocarbons by 7.4–8.3 wt.%, Selectivities by 7.5–8.4 wt.%. 2 hp f-ly. 2 tab. Yu

Description

; The invention relates to oil refining and petrochemistry, mainly to ways of obtaining valuable raw materials — aromatic hydrocarbons and hydrogen by catalytic conversion of light paraffinic hydrocarbons.

Aromatic hydrocarbons are used as a high-octane additive to motor fuels, as well as being the most important raw material for such large-scale neatness (catalyst) goes to a stable mode of operation. After that, the activated and stabilized catalyst is brought to a reaction temperature in a stream of dried nitrogen and the feedstock is passed at a predetermined rate for 1 hour. The pressure in the reaction zone is atmospheric. The raw material is propane with a purity of 99.1 wt.% Mixed with ethane (0.6 wt.%) And isobutane (0.3 wt.%). Liquid products

petrochemical syntheses, Kak10 reactions are condensed in the receiver during cooling. Production of surface-active deposition by ice, gaseous products

substances, solvents, plastics, phenol, collected in a gas meter. Composition of products

styrene. , reactions are analyzed by chromatographic

Hydrogen is required for the ta-method. The amount of coke is determined by

of important processes like reforming. I will add hrrcalcium and ascarite powder cleaning of oil raw material, hydrogenation side by side after oxidative regeneration, cataneration) the catalyst goes to a stable mode of operation. After that, the activated and stabilized catalyst is brought to a reaction temperature in a stream of dried nitrogen and the feedstock is passed at a predetermined rate for 1 hour. The pressure in the reaction zone is atmospheric. The raw material is propane with a purity of 99.1 wt.% Mixed with ethane (0.6 wt.%) And isobutane (0.3 wt.%). Liquid products

Rya ang.

The purpose of the invention is to increase the yield of aromatic hydrocarbons with simultaneous high selectivity to form hydrogen.

In the implementation of the method (examples) use a catalyst based on high-temperature domestic zeolite of the type Ultrasil, which has empiricizers,

In tab. 2 shows (examples 1-22) the conditions and results of the method.

20 From tab. 2 it follows that the maximum total yield of aromatic hydrocarbons and hydrogen is achieved in the presence of a zinc form of ultrasil with a molar ratio of SiO2 / A12Oz 45, granulated with 40.0% by weight of aluminum oxide, the formula (0.8-1.4) NaaO-AUOs (30 - 25 „„ „„ 600 ° С and space velocity along J with l-h-, -1,

64) SiO.

In tab. 1 is a radiograph of a zeolite — ultrasil — used to prepare the catalyst used in the proposed process.

The zinc form of the zeolite - ultra-strength is obtained by impregnating the decationic form with a solution of zinc chloride.

To impart the required mechanical strength to the catalyst, it is granulated with a binder of alumina, taken in an amount of 40% by weight.

The method in the laboratory on the sale of raw materials, equal to 120 (example 4). Pre-treatment with propane was carried out for 10 hours. The yield of aromatic hydrocarbons was 43.3 wt.% For the missed propane with a selectivity of aromatization of 44.6 wt.%, The hydrogen yield was equal to 6.0 wt.% With a selectivity of 6.2 wt.%. The hydrogen content in the gaseous reaction products was 57.8% by volume. With an increase in temperature to 650 ° C, the hydrogen yield increased to 6.9 wt.%, Its content in the gaseous reaction products reached 59.3 vol.% (Example 7). However, the yield of aromatic hydrocarbons was reduced to 38.7% by weight, and the yield of coke increased to 7.1% by weight. With

35

accurate installation with a stationary layer of 4Q, increasing the temperature to 700 ° С (example

carried out as follows

18) 16.1 wt.% Coke was obtained for the missed propane, which led to a rapid loss of the catalytic activity of the zeolite. Examples 20-22 illustrate the effect of the volumetric feed rate on the catalysts in a manner.

A 10 cm of catalyst is loaded into a quartz reactor with a grain size equal to

0.25-0.5 mm. Fresh sample of catalyst „„..., „...,„. „...„ „..

p; rokalivayut in the reactor at 550 ° C in the current process of the process. Optimum for the proposed dried air for 5 hours for a successful method of joint preparation of aroline adsorbed water. Then the catalyst is activated by treatment with propane at 500–600 ° C for 8–10 h.

After each two hours of preliminary selectivity of the formation of target treatment, oxidative regenerants are carried out. Conducting the process with a volumetric scopes of the catalyst with dried air at 550 ° C for two hours. As a result of pretreatment, the cracking activity of the catalyst decreases, and the yield and selectivity of the target

Mathematical hydrocarbons and hydrogen from propane is a volumetric rate equal to 120 h, at which time the greatest products are observed to increase. After 8–10 hours of pretreatment (without taking into account time, time spent), the Pus for oxidation with a speckle less than 60 hours is impractical because of the low intensity of catalyst use.

Examples 1-76 illustrate the effect of j5 on the duration of catalyst pre-treatment with propane on the selectivity of the formation of aromatic hydrocarbons and hydrogen. At least 11th exit and

lizators,

In tab. 2 shows (examples 1-22) the conditions and results of the method.

0 From table. 2 it follows that the maximum total yield of aromatic hydrocarbons and hydrogen is achieved in the presence of the zinc form of ultrasil with a molar ratio of SiO2 / A12Oz 45, granulated with 40.0 wt.% Alumina oxide " „600 ° С and space velocity -one,

giving raw materials equal to 120 (example 4). Pre-treatment with propane was carried out for 10 hours. The yield of aromatic hydrocarbons was 43.3 wt.% For the missed propane with a selectivity of aromatization of 44.6 wt.%, The hydrogen yield was equal to 6.0 wt.% With a selectivity of 6.2 wt.%. The hydrogen content in the gaseous reaction products was 57.8% by volume. With an increase in temperature to 650 ° C, the hydrogen yield increased to 6.9 wt.%, Its content in the gaseous reaction products reached 59.3 vol.% (Example 7). However, the yield of aromatic hydrocarbons was reduced to 38.7% by weight, and the yield of coke increased to 7.1% by weight. With

five

Q increasing the temperature to 700 ° С (example

 increasing the temperature to 700 ° C (example

18) 16.1 wt.% Coke was obtained for the missed propane, which led to a rapid loss of the catalytic activity of the zeolite. Examples 20-22 illustrate the effect of the volumetric feed rate of the feedstock on „„ „.,.,„ .. .., „.„ ... „„ ..

 process processors. Optimal for the proposed method of joint production of the Aroi selectivity of the formation of the target products. Conducting a process with volumetric coma tic hydrocarbons and hydrogen from propane is the volumetric rate equal to 120 h, at which the greatest selectivity of the formation of the target products is observed. Conducting a process with a volumetric rate of less than 60 hours is impractical because of the low intensity of catalyst use.

Examples 1-76 illustrate the effect of pre-treatment catalyst pre-treatment with propane on the selectivity of the formation of aromatic hydrocarbons and hydrogen. At least 11th exit and

The selectivity of the formation of target products was obtained on a fresh sample (Example 1). With an optimal o6pa6 JTKH of 10 hours, the aromatization selectivity increased by 7.2, and the selectivity of hydrogen production by 1.9 may. % compared with a fresh sample (example 4).

Example 5 shows that the catalyst, after 10 hours of pretreatment, acquires a stable activity and selectivity and a further increase in its duration is not necessary.

Examples 10-12 illustrate the effect of the 51O2 / A12Oz molar ratio in zeolite on process performance. The most active is the catalyst with a molar ratio of 51O2 / A1203 45, in the presence of which the yield of the target products is greatest. When using zeolites with the silicate module 30 and 64, the degree of propane conversion and, accordingly, the yield of the target products decreased while maintaining the selectivity at about the same level (examples Pi 13).

Examples 14-17 illustrate the effect of zinc oxide on the catalyst. The most selective is a catalyst containing 3.5 wt.% Zinc oxide.

Thus, treatment of the catalyst with propane with alternating cycles of oxidative regeneration of the catalyst leads to a significant (by 7.4-8.3 wt.%) Increase in the yield of aromatic hydrocarbons. The selectivity of the formation of aromatic hydrocarbons increases by 7.5-8.4 wt.% And exceeds the selectivity of the formation of aromatic hydrocarbons in the known method by 3.7-4.9 wt.%.

Claims (3)

1. A process for the joint production of aromatic hydrocarbons and hydrogen by contacting propane with a catalyst containing high silica zeolite of the pentasil type with a silicate module 30-64, promoted with 2.5-3.5 wt.% Zinc oxide and granulated with a binder — alumina; The temperature and atmospheric pressure, characterized in that, for the purpose of increasing. yield of aromatic hydrocarbons with simultaneous high selectivity of hydrogen formation; zeolite-ultrasil is used as a high-silica zeolite, characterized by the X-ray diffraction pattern in Table. 1, and the catalyst is pre-treated with propane at 500-600 ° C for 8-10 h  With intermediate oxidative regenerations every 2 hours with propane treatment. 2. A method according to claim I, characterized in that a catalyst containing 40% by weight of alumina is used. 3. Method according to paragraphs. 1 and 2, characterized in that the process is carried out at 560-650 ° C and the flow rate of the feedstock is 60-360 hours. Table 1 15 20 25 thirty 35 40 45 tagging: / i - relative intensity (s. - is strong, cf.-average, el. -slab, och.s.- very strong); d is interfacial distance.