SU373987A1 - Catalyst for oxidation dehydrogenation of paraffin hydrocarbons - Google Patents

Description

(54) CATALYSTS FOR OXIDATIVE SHEDIRING OF PARAFFIN HYDROCARBONS

 one

A known catalyst for the oxidative dehydrogenation of paraffinic: hydrocarbons based on magnesium oxides, and molybdenum. Such a catalyst has insufficient activity. In order to increase the activity of the catalyst, it is proposed to introduce vanadium oxide in its composition in an amount of Q, pl - l O wt.%. The composition of the catalyst can vary widely. The content of magnesium oxide in the finished catalyst can be 20-99% by weight, preferably 50-95% by weight, and molybdenum oxides 1-80% by weight, preferably 5-50% by weight. The amount of vanadium oxide promoter additive will vary from the atomic ratio in the catalyst and will be 0.61 to 10 wt.% With respect to the total weight of the finished catalyst.

The catalyst can be prepared by any of the known methods: by joint deposition, evaporation of solutions of the starting salts, etc. The promoter can be introduced both simultaneously with the preparation of the main components of the catalyst, and the subsequent deposition on the surface of the finished oxide magnesium molybdenum catalyst,

for example, comprocessing from a solution of a water-soluble salt.

The finished catalyst can be easily formed into granules, tablets, | 5 etc. The catalyst has sufficient mechanical strength and is used in the form of a powder for carrying out the process in a suspended catalyst bed.

The catalyst is also applied supported on an inert carrier (corundum, aluminosilicates, silica gel, etc.). Paraffins, in particular n-butane, are used as the initial hydrocarbon feedstock. The molar ratio of hydrocarbon-oxygen can vary within Is (O, 1-3). Oxygen can be used either in pure form or in a mixture with nitrogen (air). The process is carried out in the presence of an inert diluent (water vapor, nitrogen, argon, etc.). The molar ratio of hydrocarbon: inert diluent can vary within 1. (1-50).

The process is carried out at atmospheric pressure in a wide range of temperatures (400-700 ° C) and volumetric feed rates of paraffin hydrocarbons (20-1000 hh. Promotion of an oxide magnesium molybdenum catalyst by vanadium oxides allows its activity to increase, as can be seen from the examples given below.

Example 1. Preparation of the catalyst. 45 g of magnesium oxide powder is mixed with a solution of 6.15 g of ammonium q-molybdate in distilled water. The resulting wet paste is formed into pellets in the form of worms, which are then dried at 110-120 ° C for 10 hours and calcined for 10 hours at. Thereafter, the catalyst was crushed and a fraction of 0.8-1.25 mm in size was collected. 25 cm of the catalyst that has been separated is impregnated with a solution of 0.073 g of ammonium m-vanadate in 12.5 ml of distilled water until the solution is completely absorbed. Then the catalyst is dried at 110-120 ° C for 10 hours and calcined in a stream of air for 10 hours. The obtained sample of catalyst is loaded with an E amount of 10 CMS in a flow-type quartz reactor. Uglet

 invention 1, a catalyst for the oxidative dehydrogenation of paraffinic hydrocarbons based on oxides of magnesium and molybdenum, which, in order to increase the activity

hydrogen feedstock (n-butane) in a mixture with air and steam is fed to the upper part of the reactor.

Example 2. Samples with different γ-contents were prepared and tested as indicated in Example 1. The conditions and test results are shown in the table.

As can be seen from the table, the addition of vanadium oxide to the magnesium molybdenum catalyst significantly increases the efficiency of the oxidative process.

of the process, mol.% - 23, 1 77.3 77.725.715.4 51.6 38.8 64.5 61.054.334.6 57.5 76.3 81.325.823.2 59.2 65.340.4t67, 241.8 catalyst, elro composition introduced vanesschi oxide. -. The catalyst according to claim 1, about 1 ton of doping of paraffinic hydrocarbons into mono- and diolefinic hydrocarbons, increases the conversion of the hydrocarbon feedstock, while increasing the yield of the target products and the selectivity of the process. Magnesium molybdenum catalyst promoted by vanadium oxides allows the process of oxidative dehydrogenation of paraffinic hydrocarbons at temperatures of 100-120 ° C lower than that of a non-promoted catalyst. - 16.046.020.8 60.034.8 - 21.545.625.8 54.747.0 - 33.053.5.39.2 63.561.7 29.827.455.732.265.749.2 60.2 36.654.743.0 64.367.0 39.2 34.458.340.2 68.059.0 due to vanadium oxide introduced into the catalyst with an amount of 0.01-10 wt.%.