SU1759448A1 - Method of producing catalyst for dehydrogenation of higher paraffins - Google Patents

Abstract

Use: petrochemistry. SUMMARY OF THE INVENTION: the carrier — alumina is impregnated with a solution of milligrate (II) acetate, tetrabasic or iron nitrate ill), hydrated, dried in air, and calcined at 600 ° C. in a stream of hydrogen. Impregnated with ammonium perrhenate solution. Activate at 700-900 ° C in a stream of hydrogen. The original components are taken in an amount to ensure the following content in the catalyst, wt.%: Rhenium 0.1-1.0, iron or manganese 0.1-5.0, alumina else. Characteristics of the catalyst: productivity of 3.5-21.7 g of monoolefin with 1 g of catalyst per 1 h, yield of n-monoolefins 13.3-18.5%. 2 tab.

Description

The invention relates to the preparation of catalysts, in particular, to a method for the preparation of a catalyst for dehydrogenating Sb.sub.1b-paraffins to n-monoolefins, which is a valuable raw material for the production of plastics, lubricants and additives thereto, as well as surfactants and synthetic detergents.

A known method for producing rhenium-containing dehydrogenation catalyst of St-Stm-paraffins (0.2-2% Re with 0.2-2% Sn, Ge or Pb promoters on a carrier — alumina) by impregnating the carrier with an aqueous solution of a mixture of rhenium acid and salt promoter (Sn, Ge or Pb), subsequent drying in air at 130 ° C, calcining in air at 500 ° C and activating the catalyst at 530 ° C in a stream of hydrogen 1. The dehydrogenation process on the prepared specified catalyst method is carried out at a temperature of 4QO-500 ° s Рн2 1-6 atm, space velocity (Voe) 10-30 and ph2 (molar ratio of hydrogen and

paraffin wax). The yield of n-monoolefins is 4-12% with a selectivity of 85-98%.

The disadvantages of this method for producing a catalyst include the need to use hard-to-obtain rhenium acid; low activity (yield 4–12%) of the catalyst obtained, even at low volumetric rates V06 10–30 h, which does not ensure the achievement of equilibrium yields (15–20%) of monoolefins; low productivity of the obtained catalyst (1.3-5.5 g of mono-olefins / g of catalyst-h).

The closest to the invention to the technical essence and the achieved result is a method of obtaining a catalyst for the dehydrogenation of C-C14 n-paraffins, which includes 0.05-2% Re and 0.05-2% of a promoter of molybdenum or tungsten on a carrier ( 96-99.1%) 2, by joint impregnation of the carrier y-Al2 O3) with an aqueous solution of a mixture of ammonium perrhenate and promoter salt (metamolybdate or meta-tungsten ammonium) followed by

by drying by calcination in air at 300--600 ° C and by activation in a stream of hydrogen at 350-700 ° C. On the catalyst obtained by the method (activation at 530-575 ° C. There are no examples with other temperatures) at T 300-600 ° C, 1-10 atm, V06 0.1-30 and 0.1-30 output N of monoolefins from the mixture Syu-C-paraffins 13.4 15.1% (which is close to equilibrium) with a selectivity for mono-olefins of 90- 92%,

The disadvantages of this method include: low productivity of the resulting hydrogen-containing promoted catalyst (0.79-0.89 g of monoolefins / g cat-h); the need to conduct the process at low volumetric paraffin rates (according to examples 3-4), which indicates a low activity of the obtained catalyst.

The purpose of the invention is to provide a method for producing a catalyst with increased productivity.

The goal is achieved by the proposed method of producing a catalyst for nysew impregnation of a carrier with ammonium perrhenate solution and promoter salt, followed by drying, calcining and activating hydrogen in yucca at elevated temperature, a distinctive feature of which is that manganese (II) acetate is used as promoter salt four-water or iron (111) nitrate is dihydric, impregnation is first carried out with a solution of a salt of a thunderstorm dried, calcined in a stream of hydrogen, then impregnated with ammonium perrhenate solution and the initial components ut in an amount to provide the following content in the catalyst, wt.%: rhenium 0.1-1.0; manganese or iron 0.1-5; alumina, the rest. The method is characterized in that the activation is carried out at 700-900 ° C.

Dehydrogenation of Sb Sb-parzphins to n-mono-olefins on the catalyst obtained by the proposed method is carried out at T 450-520 ° C, Ph 2 of 1-4 atm. V06 40-100,.

The invention is illustrated by the following examples.

Examples 1-14. Preparation of the catalyst. To 10 g of y-AlaOs, 20 ml of an aqueous solution of the corresponding salt of the Mn (CH3COO) 2 4H20 promoter or Fe (MO3) s EKO are added. dried 24 hours in air at

five

0

promoted y-AlaOj at room temperature and then calcined for 3 hours at 600 ° C in a stream of hydrogen (6 l / h). 20 ml of an aqueous solution of ammonium perrhenate is poured into the produced promoted alumina, maintained at 700–900 C in a stream of hydrogen directly in the reactor (see Table 1).

0 Examples 15-30. Catalyst test

The catalyst obtained by the proposed method is tested in the dehydrogenation of Ce-Cie paraffins to the corresponding n-monoolefins in a flow-through installation with a fixed catalyst bed (0.3-0.5 g) at T - 450-520 ° С, PH2 1-4 atm, V05 40-100, on2 6-10. The test results of the obtained catalysts are given in table 2.

The proposed method for producing a promoted alumina catalyst provides an increase in the productivity of the obtained catalyst by 11–24 times while maintaining the yield of n-monoolefins close to the equilibrium (13.3-18.5%) and carrying out the process in its presence at a higher volumetric rate (40 -100h 1)

Claims (2)

Invention Formula 1. A method for preparing a catalyst for dehydrating Ce-C-paraffins, which includes impregnation of an alumina carrier with a solution of ammonium perrhenate and promoter salt, drying, calcining in air and activating in a stream of hydrogen at elevated temperature, characterized in that with increased productivity, manganese (II) acetate four-water or iron (III) nitrate is used as promoter salt, impregnation is carried out first with a solution of promoter salt, dried, calcined in a stream of hydrogen, then p opityvayut solution of ammonium perrhenate and starting components are taken in an amount to provide the following contents by weight of the catalyst.% Rhenium0,1-1,0 Iron or manganese 0.1-5.0 Alumina Rest. 2. A method according to claim 1, wherein the activation is carried out at 7005 900 ° C. five 0 five ABOUT five 0 Table Composition of promoted alumina catalysts for cede paraffin dehydrogenation Dehydrated steric C-C, 5-paraffins HI prs from the international agomorenia cat / mea tooo 0.1 0.21) 0.5 0.25 1.0 0.1 About 5 0.5 0.35 0.35 0.15 0.3: 0.35 1.0 1.5 0.0t Np1.0 Ih3.0 "P0.1 Kp4,0 MP2.5 te5.0 Ta0.5 Fe3.0 Mt5.0 Kp5 E Ig0.05  five Ng2.5 PE2.5 CP1.0 98, H 96.75 99.4 95./5 S6.5 94.9 99.0 96.5 91.65 94.65 99.65 9S.6 93.15 96.5 96.0 9S.95 800 / 00 -00 800 Sco 750 900 SOO 750 600 600 750 750 1000 900 800 3 2 3 3 2 g 2 g g 2 2 3 3 2 i-gekin -Hexdenan h-dean h-tetradext h-Hexalehan f-Tetrzdei n K-Gechsadekan n-Yaodekai Table 1 0 0 0 0 0 5 0 0 0 0 O 0 0 0 0 0 50 50 50 55 70 .five 45 100 40 40 40 40 40 70 70 50 2.S 2.5 1.5 1.5 ".With 3.0 1.0 2.5 1.5 1.5 1.5 1.5 1.5 1.5 4.0 4.0 2.5 8 6 to 13.3 15.8 18.5 14.9 13.8 15.4 14.4 14.1 15.8 6.S 5.6 a.7 15.0 9.8 9. 6.3 91 92 90 92 91.5 92.5 94 91 93.5 88 69 83 92.5 90 89 Part 8 11.7 13.7 10, V 13.7 10.1 9.S 21.7 E, 6 4.2 3.5 5.3 9.1 10.6 10.1 4.7