SU429572A3 - METHOD OF PREPARATION OF CATALYST FOR HYDRAULIC EFFICIENCY - Google Patents

Description

one

A known method of preparing a catalyst for hydrodesulfurization, which consists in impregnation with an aqueous solution of compounds of the activating metal of groups VI and VIII of the periodic system of the carrier, which is a refractory oxide, for example ABO3, followed by thermal treatment of the catalyst.

In order to increase the activity of the catalyst, it is proposed to carry out heat treatment in two stages, with the first stage being carried out at 260-371 ° C in an oxidizing medium containing air and more than 20% by volume of water, and the second at 427-649 ° C in an oxidizing environment containing air and ne more than 10% by volume of water vapor.

The impregnating solution comprises a compound of a metal of group VIB and a compound of a metal of group VIII. Suitable soluble compounds VHI group metal include nitrate nickel sulphate nickel chloride, nickel bromide, nickel fluoride, nickel iodide, nickel acetate nickel formate, nickel nitrate cobalt sulfate cobalt fluoride, cobalt fluoride, iron, ferrous bromide, iron nitrate, iron sulfate, iron formic acid, acetic acid

iron, chlorine platinum, hydrochloric acid salt, hydrochloric acid, palladium chloride, etc. Of the metals of group VIB, molybdep is preferred. Group VIB metal is used in an amount of about 5-20 wt. % by weight of the final composition of the catalyst. The metal of the group, which is preferably cobalt, produces an effective

the impact in the amount of 0.1-10 wt.% from the weight of the final composition of the catalyst.

Impregnate the catalyst carrier by known methods.

The composition containing the catalyst carrier and the compound of the catalytically active metal components is further calcined. In accordance with the proposed method, the calcination is carried out in two stages. In the first stage, roasting is carried out in an oxidizing environment containing more than 20% by volume of steam for at least 0.5 hours at approximately 260 (500) -37 ° C (700 ° F). In this case, the catalytic product is obtained with better quality if the amount of air decreases and

in the medium used for firing, steam prevails. Thus, preferably, the first firing step is carried out using as the medium a mixture of air and steam, the amount of which is 50-95% by volume. It is also preferred that the first firing step lasts no more than 2 hours. In the second calcination step, the composition is oxidized in contact with air or another gas containing free oxygen at about 427 (800) -649 ° C (1200 ° F) for 1-4 hours. The oxidizing medium in the second firing stage contains not more than 10% by volume of steam. Example 1. A catalyst carrier with a specific surface area of 220 and an average specific pore volume of 0.65 prepared from alumina is impregnated with 2 wt.% Cobalt and 12 wt.% Molybdenum from an impregnating solution consisting of ammonium molybdate and ammonium cobalt nitrate hexahydrate dissolved in 12 wt.% diluted ammonium hydroxide. The impregnation is carried out by immersing the alumina balls in an impregnating solution contained in a drum dryer with a steam jacket. The balls are treated in solution for 10 minutes at room temperature, after which steam is fed into the steam jacket, under which the solution is evaporated to a dry state in contact with the catalyst carrier for 2.5 hours. Impregnated balls have a loss on ignition at 500 ° C to about 30% by weight. Dried balls are then conveyed through a two-zone oxidizing furnace using a belt conveyor. The balls are heated in the first zone. In contact with an air stream containing 10 vol.% Of steam. The balls are transported through the first zone at a speed that provides an average time spent in it for 1 hour, and through the second zone at a speed corresponding to 2 hours of stay. In the first zone, the temperature is maintained at 343 ° C (650T), and in the second zone, 593 ° C (1100 ° F). The spherical catalytic product has a specific surface 177 and an average specific pore volume of 0.43. Example 2. A catalyst prepared in the same manner as described above is tested in the conversion process of the sulfur contained in the residual petroleum product. A portion of the residual oil product contains 3.73% by weight of sulfur, 8.84% by weight of asphaltenes insoluble in heptane, and has beats. at. 0.980 (15.6 ° C / 15.6 ° C). About 100 cm of the catalyst is dispersed in moving layers with a volume of 25 cm each. A portion of the petroleum product flows down through the catalyst beds in a single pass operation at a rate of 1.0 hour and mixed with reusable hydrogen. Hydrogen is returned to the vertical tubular reactor with a volume feed of 891 per volume of liquid hydrocarbon batch. A portion of the petroleum product is heated when it enters the catalyst bed with a tem- perature of 368 ° C (695F) at a pressure of 137 atm (200 psi) of hydrogen. Maximum catalyst temperature is 397 ° C (745 ° F). The effluent from the reactor enters the high-pressure separator, in the upper part of which excess hydrogen is released. After 36 hours of the working cycle, the liquid product contains 0.98% by weight of sulfur, but compared to 3.73% by weight of sulfur in the starting product and has beats. at. 0.9254 (15.6 ° C / 15.6 ° C). Froze A. The spherical catalyst is prepared essentially as described above, the catalyst is heated in the first zone of the oxidizing furnace in contact with a stream of substantially dry air. The catalyst is evaluated in accordance with the process described in Example 2, wherein the liquid product contains 1.35% by weight of sulfur. B. The spherical catalyst is prepared according to the described method, but is heated in the first zone of the oxidizing furnace in contact with an air stream containing 20% by volume of steam. The catalyst is evaluated in accordance with the method indicated in Example 2, wherein the liquid product contains 1.2% by weight of sulfur. It follows that the proposed catalytic oxidation method provides an improved catalyst for the desulfurization process in a hydrogen medium, while a continuous improvement in catalytic properties is observed with an increase in the steam content in the initial oxidizing medium. Example 4. When preparing a pressed catalytic mixture, 45 kg of finely powdered aluminum oxide monohydrate is displaced dry from 9.5 kg of finely ground molybdenum anhydride and 2 kg of finely ground cobalt carbonate, and then the mixture is mixed with 42.9 kg for 0.5 hour 5% by weight of nitric acid to form an easily extruded plastic mass or paste. The mixture has a calcination loss at 500 ° C in the order of 53.5% by weight. The dried particles are then processed in a two-zone oxidizing furnace mainly as described above, while in the first zone of the furnace the particles are heated in contact with an air stream containing 50% by volume of steam. The oxidized particles have a specific surface of 267 and an average specific volume of 0.5 holes. When the molded catalyst is evaluated in the manner described, the liquid product contains 1.10 wt.% Sulfur, compared to 3.73 wt.% Sulfur in the initial residual oil product. When the catalyst is prepared in essentially the same way, but the particles are heated in the first zope of the oxidizing furnace in contact with an air stream containing only 20% by volume of steam, the sulfur content in the liquid product rises to 1.26% by weight under identical conditions. test The subject of the invention is a method for the preparation of a catalyst for the desulfurization by impregnating with an aqueous solution compounds of the active metal of Group VI and Group VIII of the periodic carrier system, which is a refractory oxide, for example ABOz, followed by heat treatment of the catalyst-5, characterized in that catalyst activity, 6 heat treatment is carried out in two stages, with the first stage being carried out at 260-37 GS in an oxidizing medium containing air and more than 20% by volume of water vapor, and the second — at 427-649 ° C in oxide tion medium comprising air and less than 10 vol.% water vapor.