SU1719053A1 - Method of passivation of cracking catalyst - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular the passivation of a cracking catalyst, which can be used in petrochemistry. The goal is to increase the activity and selectivity of the catalyst. For this, crystalline aluminosilicate of the fuzzite type is treated with a solution of copper nitrate.

Description

This invention relates to catalytic cracking and can be used in the oil refining industry.

There is a method of increasing the activity of deactivated cracking catalysts with 0.1% metal deposits. According to this method, the catalyst is regenerated in a stream of air at 690-788 ° C. The oxide form of the metals nickel and vanadium is then converted to nitride by contact with ammonia. Passively similarly, the catalyst is returned to the reaction zone.

The disadvantage of this method is the use of a passivation unit using highly toxic explosive

agents requiring additional safety measures in the operation of the equipment.

A method of passivating cracking catalysts is also known, according to which the regenerated catalyst is in contact with cracking or reforming gases containing unsaturated hydrocarbons at 600-800 ° C, previously passing through the adsorbent.

The disadvantage of this method is to increase the passivation temperature using an additional adsorption unit.

There is a method for passivating cracking catalysts with a gas mixture, containing

About SP

with

hydrocarbons with 1.2 and 3 carbon atoms at temperatures above 705 ° C.

The disadvantage of this method is the additional passivation unit, which is operated at elevated temperatures, with the use of toxic, explosive substances.

A known method for the passivation of cracking catalysts containing nickel and vanadium, according to which the hydrocarbon feedstock is in contact with the catalyst and the passivating agent, which is used as a spent catalyst containing antimony compounds, in an amount of 0.4-10% per element.

The disadvantage of the known method is the complexity in the technology of catalyst impregnation with antimony compounds and the toxicity of the components used, requiring additional safety measures.

The immediate solution of the problem is a method of passivating a cracking catalyst containing nickel and vanadium, which consists in the fact that the regenerated catalyst is treated with hydrogen, carbon monoxide or their mixture at 600-850 ° C. The catalyst is then transferred from the reduction zone to the reaction without further processing.

The disadvantage of this method is the low activity and selectivity of the catalyst in the formation of gasoline, the high content of gas and coke,

The aim of the invention is to increase the activity and selectivity of the catalyst.

The goal is achieved by the fact that a catalyst containing nickel of 0.2-0.4% (based on metal) is treated with an amount of copper nitrate in an amount of 0.02-0.4% based on copper and reduced with hydrogen at 350 -550 ° C for 0.16-60 min.

The aluminosilicate cracking catalysts containing nickel and vanadium metal impurities in their composition significantly lose their activity during the production of light-colored metals due to the fact that nickel compounds are reduced to metal during the reaction and lead to C-C bond hydrogenation reactions. , dehydrocyclization, which leads to an increase in the yield of gas and coke.

The described passivation method consists in the formation of a copper – nickel alloy after treating the catalyst with hydrogen, which has a lower

compared with pure nickel, the activity in the reaction of hydrogenolysis and dehydrogenation. The essence of the method is as follows. Pre-baked on

air at 550 ° С 100 g of dry cracking catalyst are treated with 100 cm of an aqueous solution of Cu (NO3) 2 with a concentration of 0.006– 0.120 g / l. Then the catalyst was dried at 110 ° C in air for 2 hours and calcined at 550 ° C for 1 hour. The reduction with hydrogen was carried out at 350-500 ° C for 0.16-60 minutes. This concentration of an aqueous solution of a copper salt provides a Cu / NI atomic ratio in the catalyst of 0.10-0.93,

5 A decrease in the copper content in the atomic ratio of copper: nickel less than 0.10 does not lead to the effective formation of a copper-nickel alloy and does not contribute to the neutralization of the dehydrogenating activity of solid metals.

An increase in the time of treatment with hydrogen over 60 minutes and a temperature of more than 550 ° C leads to a slight decrease in the yield of gasoline and a change in the selectivity

5 in the direction of gas and coke formation, which is obviously associated with a change in the acid activity of the catalyst due to its prolonged contact with hydrogen at elevated temperature. Reduction

0 processing time less than 0.16 minutes and a temperature below 350 ° C leads to a decrease in the yield of the target product and to an increase in coke and gas formation.

5 EXAMPLE 1. Cracking catalyst having a composition,%: NaaO 0.5; 20; Zyug 76.4; 1 a20z2.0; RegOZO, 1 and containing impurities N1 о, 4: V 0,6, previously calcined at 550 ° С in air, are treated

0 100 cm of an aqueous solution of copper salt Cu (MO3) 2 with a concentration of 0.006 g / l (amount of copper 0.04%). The catalyst is then dried at 110 ° C in air for 2 hours and calcined at 550 ° C for 1 hour. The reduction with hydrogen is carried out at 500 ° C for 30 minutes.

After the cracking of the kerosene-gas soot fraction (CHF) is carried out under the following conditions: temperature 500 ° С, ratio

0 amount of catalyst to the amount of raw material 4: 1, reaction time 6 s, the experiment is conducted in a flow of helium, the reaction products are analyzed on a chromatograph.

Catalyst activity at the exit

5 gasoline is 49.6%, the yield of gas, light gas oil, coke is 12.3, 13.4 and 1.7%, respectively.

The effect of metal content, promoter, temperature and time of hydrogen treatment on the catalyst activity is given in the table.

From the data in the table it can be seen that the maximum catalytic activity and selectivity in the formation of gasoline is attributed to a catalyst containing nickel of 0.2–0.4%, promoted by copper in an amount of 0.02–0.4% (atomic ratio Cu / Ni 0.10 -0.93) followed by treatment with hydrogen at a temperature of 350-550 ° C for 0.16-60 minutes.

When comparing the passivation methods, it can be seen that the catalyst promoted with copper is more selective in the formation of gasoline and coke, has a lower gas yield than the catalyst treated by a known method under equal testing conditions.

As can be seen from the above examples, the promotion of copper cracking catalysts followed by treatment with hydrogen leads to the passivation of impurity compounds of nickel and vanadium deposited in the process of cracking of crude oil,

This method allows to increase the activity of the catalyst in the formation of ben0

Zina 3.8-6.2%, improving the selectivity of the process by 4.6-5.8% compared with the known method.

The present method makes it possible to reduce the coke content on the catalyst and to reduce the content in the gases of regeneration of harmful impurities that worsen the ecology of the air basin.

Claims (1)

Invention Formula The method of passivation of a cracking catalyst based on crystalline aluminosilicate of the faujasite type. including hydrogen reduction at elevated temperature, distinguishing that, in order to increase the active ™ and selectivity of the catalyst, before reduction, the catalyst is treated with a solution of copper nitrate in an amount of 0.02-0.4%, in terms of copper, from the mass catalyst, and reduction is carried out at 350-550 ° C for 0.16-60 minutes.