SU845320A1 - Catalyst of hydrogenation of sulfolene into sulfolane - Google Patents

Abstract

CATALYST FOR HYDROGENING SULFOLEN TO SULFOLAN, which is an active component on a carrier, characterized in that, in order to increase the activity, palladium oxide is used as the active component.

Description

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N3 A known catalyst for hydrogenating sulfolene to sulpholane is supported palladium metal. The known catalyst is not sufficiently active and cannot be subjected to repeated regeneration. In order to increase the activity, a catalyst has been proposed for the hydrogenation of sulfolene to sulfolane, which is palladium oxide on a carrier. The procedure for preparing the palladium oxide catalyst is as follows. The support (alumina, silica gel, silica-alumina) is impregnated with a saline solution of palladium chloride. The content of hydrochloric acid varies from 0.25 to 2% by weight, depending on the amount of the palladium salt applied. Impregnation of the carrier is carried out until complete discoloration of the solution. The grain size of the carrier can be varied over a wide range from 0.1 to 5 mm. If different grains are used, before impregnation, they must be moistened with a hydrochloric acid aqueous solution in order to achieve uniform impregnation. At the end of the impregnation, the liquid is drained and the catalyst is dried at. Then the catalyst is treated with dry hydrogen sulfide at a temperature of 120 ° C for 3 hours. The sulfurized catalyst is reduced by hydrogen at a temperature of 250 ° C and a hydrogen transmission rate of 10 liters per liter of catalyst per hour to the absence of hydrogen sulfide in the hydrogen leaving the reactor. The catalyst is cooled to 100 ° C in a stream of nitrogen to the complete absence of hydrogen in the outgoing nitrogen. Then, air is added to nitrogen at such a rate that the catalyst temperature does not exceed 250 C. After the complete replacement of nitrogen with air, the catalyst is oxidized with air at 250 ° C for 3 hours. If the catalyst is not sulphurised with hydrogen, the reduction is must be kept at a temperature of 300 ° C until there are no chlorine ions in the outgoing hydrogen. The remaining operations remain unchanged. t. A catalyst prepared according to this method can be used in the hydrogenation of sulfolene using metal catalysts. However, the activity of palladium oxide supported on a carrier is higher than that of a metal, and the regeneration of the deactivated catalyst is significantly simplified. Regeneration consists in treating the catalyst with air or oxygen containing gas with a temperature not higher than 300 ° C, preferably at 150-250 ° C for 1-2 hours, while the regeneration of the metal / catalyst requires long-term treatment with hydrogen and nitrogen. at high temperature. Catalyst regeneration by the proposed method can be carried out repeatedly, and no decrease in catalyst activity is observed. Example 1. The catalyst was prepared by impregnating alumina with a solution of palladium chloride, followed by drying and reduction with hydrogen at. The content of metal palladium in the catalyst is 0.4 wt.%. The catalyst and sulfole dissolved in a mixture of sulfolane and isopropyl alcohol are loaded into the autoclave (the weight ratio of sulfolane and alcohol is 1: 5). The ratio of catalyst and sulfene 1: 2. The grain size of the catalyst 0,250, 5 mm. Hydrogenation is carried out at a temperature of 20 ° C, atmospheric pressure and with vigorous stirring of the contents of the autoclave. The rate of hydrogenation is 280 g of sulfolane, calculated as 1 g of palladium per hour. PRI mme R 2. The catalyst is ready, with impregnation of alumina with a hydrochloric acid solution of chloropalladium (hydrochloric acid content in a solution of 0.25 wt.%), Sugary, hydrosulfuric sulfonation with hydrogen, with hydrogen. ° s The hydrogenation is carried out under the conditions described in Example 1. The hydrogenation rate is 1850 g of sulfolane, calculated as 1 g palladium per hour. Example 3. Example 1 was repeated with the difference that a catalyst containing 2% by weight of palladium was prepared and the hydrogenation of sulfolene was carried out at a pressure of 30 atm. The ratio of sulfolene and catalyst is 10: 1. The rate of hydrogenation is 1500 g of sulfolane, calculated as 1 g of palladium per hour. Example 4. Example 3 was repeated with the difference that the sulfene was hydrogenated in the presence of palladium oxide supported on alumina, prepared as described in Example 2. The content of palladium was 2 wt.% The hydrogenation rate was 4500 g of sulfolane, calculated as 1 g palladi per hour. EXAMPLE 5 A catalyst, a metallic palladium supported on alumina, prepared as described in Example 1, was loaded into a continuous reactor. The palladium content was 1% by weight. The grain size of the catalyst is 4.5-5.5 mm.

Through the catalyst bed, I continuously pass a 10% w / w solution of sulfene in a mixture of sulfolane and isopropyl alcohol. The volumetric feed rate of the liquid raw material is 1–4, the temperature is 20 ° C and the pressure is 90 atm. The molecular ratio of hydrogen and sulfene 10: 1. The output of sulfolane was 31%.

Example 6. Example 5 is repeated with the difference that palladium oxide applied on alumina, also prepared as the catalyst of example 1, is used as a catalyst, with the difference that after the reduction of the palladium salt with hydrogen, it is subjected to air oxidation at 250 ° C. The palladium content of 1 wt.% The yield of sulfolane i was 90%.

Example 7. A continuous oxide reactor was loaded with palladium oxide supported on alumina, prepared as described in Example 2 (palladium content was 1% by weight), and the sulfene was hydrogenated under the conditions of Example 6. The catalyst activity decreased after hydrogenation thereon 1140 g of sulfolane, counting on 1 g of palladium per hour. After that, the hydrogenation is stopped and the catalyst is regenerated by treating it with air. The activity of the catalyst is equal to the original. Regeneration is repeated 15 times. The activity of the catalyst is equal to the original.

Claims (1)

CATALYST FOR HYDROGENING SULFOLENE TO SULFOLAN, which is an active, supported component, characterized in that, in order to increase activity, palladium oxide is used as the active component.