SU1728286A1 - Method of obtaining cracking catalyst passivators containing heavy metals - Google Patents

Abstract

The invention relates to petrochemistry, in particular, a method for producing a passivating agent for cracking catalysts containing heavy metals, which can be used to suppress the dehydrogenation reaction of hydrocarbons. The goal is to increase the activity of the passivator. The process is carried out by treating antimony oxide with synthetic fatty Su-Se-carboxylic acids with a molar ratio of 1: (17-30) at 200-250 ° C in an inert gas atmosphere (overpressure of 10-200 mm aq.). The method allows to obtain a passivator, which reduces the formation of hydrogen during cracking from 93 to 25 cm3 / g from the converted material (versus 37 cm3 / g of the converted material by a known method). 1 tab.

Description

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The invention relates to a method for producing a passivating agent for cracking catalysts, which can be used in cracking units, in particular in suppressing the dehydrogenation reaction on nickel, which is part of the cracking catalysts.

The aim of the invention is to increase the activity of the passivator.

Example 1. In a reactor equipped with a stirrer, a reflux condenser, a nozzle for collecting distilled water and a capillary for sparging an inert gas, 59.4 g of FFA SuSe fraction and 6.9 g of antimony oxide (molar ratio of antimony oxide and organic acid 1:17) and with a preliminary 5-fold with respect to the reactor volume purging and constant bubbling of argon with the creation of an overpressure of 100 mm water. in the reactor and stirring, heat the reaction mixture to 200 ° C. While keeping the reaction mixture at the specified temperature for 1 h, the complete dissolution of antimony oxide in organic acids occurs with the formation of a clear solution of antimony tricarboxylates. The resulting solution is cooled to room temperature and the excess acid is distilled off in vacuo. The yield of antimony tricarboxylates is 100% based on the starting antimony oxide.

Example 2. In the reactor described in example 1, placed 157 g FFA fraction and 6.9 g of antimony oxide (molar ratio of antimony oxide and organic acid 1:30) and with a preliminary 5-fold relative to the volume of the reactor purge

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and constant bubbling of nitrogen with an overpressure of 200 mm aq. in the reactor and stirring, the reaction mixture is heated to 250 ° C. While keeping the reaction mixture at the specified temperature for 1 h, the complete interaction of antimony oxide with organic acids occurs with the formation of a clear solution of antimony tricarboxylates. The resulting solution is cooled to room temperature and the excess of acids is distilled off in vacuo. The output of tricarboxyl is v then v; antimony quantitative based on the original antimony oxide.

 Example 3 (comparative). In the reactor described in example 1, 59.4 g of FFA Cj-Cg fraction and 6.9 g of antimony oxide (molar ratio of antimony oxide and organic acid 1:17) are placed and, at the preliminary 5 times with respect to the volume of the reactor and a constant bubbling of argon with an overpressure of 50 mm water column. in the reactor and constant stirring, the reaction mixture is heated to 180 ° C. After keeping the reaction mixture at the same temperature for 3 hours, the reactor is cooled to room temperature and separated from the reaction mixture and the unreacted antimony oxide. The excess acid is distilled off in vacuo. The yield of antimony tricarboxylates is 87%, based on the starting antimony oxide.

PRI me R 4. In the reactor described in Example 1, 93 g of the FFA fraction and 6.9 g of antimony oxide (molar ratio of antimony oxide and organic acid 1:22) are placed and at a preliminary 5-fold with respect to reactor purge volume and constant bubbling of the gels with an overpressure of 100 mm aq. in the reactor and with stirring, the reaction mixture is heated to 220 ° C. When keeping the reaction mass at the specified temperature for 1 h, complete dissolution of antimony oxide in organic acids occurs with the formation of a clear solution of antimony tricarboxylates. The resulting solution is cooled to room temperature and the excess acid is distilled off in vacuo. The output of tricarboxylate antimony quantitative calculated on the original oxide of antimony.

Example 5 (comparative). In the reactor described in example 1, 54 g FFA fraction of the Su-SD and 6.9 g of antimony oxide (molar ratio of antimony oxide and organic acid 1:12) are placed and at the preliminary 5-fold with respect to the volume of the reactor nnom

bubbling nitrogen with an overpressure of 5 mm water column. in the reactor and with stirring, the reaction mixture is heated to 200 ° C. After aging

the reaction mixture at this temperature for 1.5 hours, the reactor is cooled to room temperature, the unreacted antimony oxide is separated from the reaction mixture. Excess acid is distilled into

0 vacuum. The yield of tricarboxylates of antimony is 96%, based on the starting antimony oxide.

The use of organic acids in an amount of more than 30 mol

5 per 1 mole of antimony oxide is impractical, since already at a ratio of 30: 1 a higher yield of antimony tricarboxylates is obtained and its further increase in the ratio leads to an additional consumption of acids.

The interaction of antimony oxide and higher organic acids is carried out in the temperature range 200-250 ° C. The reaction proceeds in non-quantitative yields.

5 at temperatures below 200 ° C. Heating the reaction mixture above 250 ° C is impractical, since already at this temperature, antimony oxide completely interacts with acids to form

0 tricarboxylate antimony.

Example 6. Comparison of the passivating activity of the passivator according to the proposed and known methods.

A portion of the catalyst cracking brand

5 of RSG-6C, containing 0.7% by weight of nickel and subjected to thermocouple stabilization in a stream of 100% water vapor at 750 ° C for 6 hours (standard thermocouple stabilization conditions for

0 of the specified grade of catalyst), is treated with the calculated amount of the passivator, after which the catalyst is dried and calcined in a stream of air at 650 ° C. The content of the passivator on the catalyst prepared in this way is 0.5% by weight, calculated on antimony.

The test of the catalyst before and after the treatment with passivator is carried out in a standard installation for testing cracking catalysts at 500 ° C and a mass feed rate (atmospheric gas oil of Krasnodar oil) 15. Passivator synthesized according to the proposed

5 is more effective than the known passivator of antimony (III) oxide, acetic anhydride and 2-ethylhexanoic acid.

The data obtained are presented in the table.

Thus, the passivator prepared by the proposed method using a fraction of synthetic fatty acids, allows to reduce the formation of hydrogen from 93 to 25 cm3 / g of the converted raw material, which indicates the suppression of the side reaction of dehydrogenation in the cracking process (against 37 cm / g of the converted raw known method).

Claims (1)

Claim method for producing cracking catalyst passivator containing heavy metals tally by the interaction of antimony oxide with carboxylic acids at elevated temperatures in an inert gas atmosphere, characterized in that, in order to increase the activity, synthetic fatty acids with carbon atoms of 7-9 are used as carboxylic acids at a molar ratio of antimony oxide : synthetic fatty acids, equal to 1: (17-30), and the process is carried out at a temperature of 200-250 ° C and an inert gas overpressure of 10-200 mm of water, st.