SU413656A3 - - Google Patents

Description

Ilquoteranne relates to the manufacture of catalysts for the hydrogenation of phenol to cyclohexanone.

A known catalyst for this process containing palladium on a carrier is alumina.

This catalyst has insufficient activity and mechanical strength.

The purpose of the invention is to increase the activity of the catalyst and its mechanical strength.

This goal is achieved by taking aluminum spiele as a carrier, including one of the following metals: cobalt, magnesium, lithium, nickel, zinc,

Getting a catalyst.

Example 1. 2.86 l of a ball-shaped oxo Y-aluminum with a diameter of 4-6 mm and an inside surface of about 250 is impregnated at 30 ° C with 1 l of an aqueous solution to which 296 g of formic acid and 233 g of 54% aqueous acid are successively added. lithium hydroxide solution. The impregnated alumina is dried at 150 ° C in vacuum, impregnated again with the same solution and again dried in vacuum at 150 ° C. In conclusion, the carrier is burned at 1050 ° C for 6 hours prior to the formation of chineal, as determined by X-ray examination. The ready-made carrier has an internal surface.

about

25 M- / G and an average pore width of 700A. After soaking with 82.7 g of palladium (II) chloride hydrate with a hydrochloric acid solution and reducing alkali metal with formalin, the finished catalyst contains 1.8 wt. % palladium. Fracture strength of 99% of the balls is not less than 0.0 kg / ball.

Example 2. 1.2 l of balls with a diameter of 4 mm from active alumina with an inner surface of 288 m- / g are sprayed three times at a usual temperature of 1600 g of a saturated aqueous solution of cobalt nitrate. Heating the impregnated and dried nitratecobalt balls to 500 ° C turns them into oxide, which is heated for 8 hours to 1050 ° C to form spinel, as confirmed by X-ray diffraction data. The nosnel obtained in this way has an inner surface of 40 and an average width of

well then 760 A.

To obtain the catalyst, the impurity is impregnated with a hydrochloric acid solution of palladium (II) chloride hydrate. Palladium is reduced by alkaline formalin. The content of palladium in the finished catalyst is 1.8 wt. % and 99% of the finished catalyst have a fracture strength of at least 8.9 kg / balloon. Example 3 The catalyst was prepared according to example 2, but using 1800 g of saturated r.odpogo solution of Magpi nitrate. This produces 60% spinel (according to X-ray diffraction analysis). The carrier is impregnated with a solution of 50 g of palladium chloride (I) hydrate. The finished catalyst contains 1.8 pes. % palladium and 99% HiapHKOB have a fracture strength of at least 8.8 kg / ball. II p. 4. In order to obtain a catalyst carrier, 1.2 l of 7-zlumini oxide in bundles mm and with an inner surface of 300 several times sprinkle 1600 g of a saturated solution of zinc nitrate. As a result, a zinc aluminum spinel is formed in a stoichiometric composition. The impregnated support is dried and heated to 500 ° C, with the nitrate decomposing to oxide. Then the carrier is heated for 6 hours to 1050 ° C. The resulting carrier consists (according to X-ray diffraction analysis) of zinc aluminine spinel and has an inner surface of 20 and an average width of 800 h. After impregnation with a hydrochloric acid solution of 5.5 g of nalladium (II) chloride hydrate, recover for 2 hours in a stream of hydrogen at a temperature of 200 ° C and rinse with chloride, the catalyst contains 1.8 wt. % palladium. The fracture strength of 99% of the finished catalyst balls is at least 8.3 mg / cylinder. Example 5. Comparative (alumina without additives). For 1000 g of a ballarium oxide with a diameter of 4-6 mm and an inner surface of 280 m / t, a hydrochloric acid solution of 36 g of palladium II chloride hydrate is applied. The catalyst used in the reduction with aqueous alkaline formalin contains 1.8 wt. % palladium. Fracture strength of 95% of Nshriks does not exceed 2.6 kg / ball. Example 6 (comparative: alumina without additives). For 1000 g of a-alumina oxide in the form of extruded tows about 5 mm long and with a diameter of 30 cm and inner Horsepx of 30 grams, put nrn three times with an intermediate dried hydrochloric acid solution 36 g nalldi P. chloride hydrate. % palladium. The fracture strength of 95% of the balls is not more than 4.5 kg cylinder. Example 7. Hydrogenation. 2000 ml of catalyst according to number 1 of this type, ayut 50 m wide and long I m in length into the reaction. After treatment of the catalyst with hydrogen / tolume at 200 ° C over 24 hours, 660 g of vaporized phenol with 990 liters of hydrogen are conducted over the catalyst, and the reaction heat is removed through the oil filling of the casing. Contact temperatures are set to 150-220 ° C, with a distinct peak temperature being formed. The molar ratio of phenol to hydrogen is 1: 6. The resulting reaction product contains, on average, 93% cyclohexanone, 6% cyclohexanol and about 1% of contaminants, whereas the phenol content is lower than 0.1%, i.e., the conversion can be considered as 100%. The reaction product is purified by distillation under vacuum and cyclohexanone of special purity (according to gas chromatographic analysis) is added after 2500 hours of reaction, the selectivity is below 90%, the conversion also decreases. 1 liter of catalyst gives 830 kg of cyclohexapone. The same results are obtained when using the catalysts of examples 2-4. Example 8. Hydrovascular (comparative). If, under the conditions of Example 7, the catalyst of Example 5 or 6 is used, the selectivity and the degree of conversion decrease after 130 hours. In these experiments, 1 liter of catalyst gives 58 kg of cyclohexanone. The subject of the invention A catalyst for the hydrogenation of phenol to cyclohexanone containing palladium on an alumina carrier, characterized in that, in order to increase the activity and mechanical strength of the catalyst, cobalt is taken as a nose-1 aluminum. , magnesium, lithium |, nickel, nink.