CS272632B1 - Method of dehydrogenation catalyst's copper coating - Google Patents

Abstract

The subject of solution consists in copper coating of zinc on iron catalyser with improved quality of copper layer on the catalyser surface. The above mentioned purpose is achieved by copper solution treatment of the moving particles of the coppered catalyser, whose motion is generated by gravitational sedimentation forced by rotation of coppering tank. The average speed of particle movement among one another ranges from 0.6 m/s to 3 m/s and the time of motion of the frictioning particles in the solution ranges from 0.2 to 0.8 of the copper coating process and during the remaining time the particles are frictioned out of the solution.<IMAGE>

Description

The invention solves a method of matching the dehydrogenation catalyst.

The intermediate product of caprolactam cyclohexanone production in the world is mainly produced by oxidation of cyclohexane followed by dehydrogenation of phenol. In both cases, dehydrogenation of cyclohexanol to cyclohexanone is required.

The cyclohexanol dehydrogenation process is carried out catalytically at a temperature S5O of K to 750 K.

^C 6 ^H 11 ^0H ~ ^C 6 ^H 10 ° ^{+ H} 2 _δ Η - 65 kO / mol

The reaction is endothermic! 3a in a tubular reactor ^1, whereby heat is most often supplied by combustion gases from natural gas combustion or hydrogen combustion from a flight process.

The addition of water (RO 79 492) retards the dehydrogenation of cyclohexanol to cyclohexene.

However, the considerable addition of water (OE 2 347 097) can lead to energy disadvantages. The addition of oxygen (PL 136 018) allows the process to carry out adiabatics, but with high safety demands.

The economics of the process of dehydrogenating cyclohexanol to cyclohexanone is largely determined by the catalyst used. A variety of catalysts, as well as industrially utilized, are known in the composition.

On the basis of phosphides, the known nickel catalyst is most commonly prorated with sodium (SU 716 583) in the form of hydroxide and the cobalt catalyst (SU 632 387). The cobalt catalyst is most often used in the form of a so-called natural catalyst. knitted turf / SU 697 177 / / SU 856 939 /. Also known are magnesium catalyst / Emelian N.P. DAN BSSR 12 1968, 10; 914-7) and a palladium-ruthenium membrane catalyst (Basow N.L.

SOV. - fr. seminar after catalysis, Sb. Dokl. Moscow 1983, 34-7].

The zinc catalyst can be deposited on carbon (SU 249 354), in the form of zinc oxide (RO 66 847), in a chromium alloy (Glozman S.S. ... · Tr. Vass. Suction filter. Issled. Why., Inst. Monomerov 1 1969, 1, 82-9, Zakrevsky V.K. Chira, prom. st. Moekva 1980 9

527 - 8 (alsbo in the form of zinc chromene / SU 348 540, RO 79 942),

The classical non-given catalyst for the title-process requires low temperatures and low conversion is required for the conversion required. Orizarsky I, t Geterogenyje Catalysts Trudy Meždu narodnogo Simpozia 3 rd «1975, 'publ, 1978 Izd. BAN Sofia / Vladea R. ··· Chin. 30 1980/8 / 759-62 / ...

For this reason, copper must be used as an alloy in the form of alloys or supported on a support. Copper catalysts are known in combination with manganese (SU 697 179, SU 979 324) and magnesium (SU 411 888, Zrblova I.P. ....: Chim. Proms. Moekva 1979, * 12 (713-14) and calcium (Kozlov N.S. ... j Vesci AN BSSR / Ser, chim. navuk 1978 (5). The copper catalyst in combination with the aluminum is either in the form of an alloy / Peter V.: Chim. Ind. Sofia 1983, 9 (401-3) or in the form of aluraine (SU 522 853). In combination with silicon, it is promoted by potassium oxide / Belskaya R.I. ... ·: Vesci AN BSSR, Ser. chim. navuk 1975 (2) (97-102) or in the form of silica gel (Kocurkova L. .... Chem. pruritus. 30

1980.1 2 (71-4). Copper is deposited on the carbon with palladium / Red L. · ...: Chem.prum. 29

1979.1 3 (127-8) or copper is deposited on so-called sungite (which is a natural mixture of oxides (SU 910 178)),

Copper oxide as a catalyst is most commonly used in combination with chromium trioxide (OP 83 157 741) promoted by barium oxide (FR). Or barium oxide and graphite (SU 574 433). Copper in combination with chromium and magnesium / Belakaja R.I. ...: Vesci AN BSSR / Ser. chim. navuk 1977, - 4 / 41-5 /, · eventually rf *

CS 272632 B1 cobalt (OP 80 136 241) and cefalt based on phobodies (SU 936 989).

Most published and probably used as catalysts of meJ on zinc oxide / CS 151 166ji Emeljanov NjP: DAN BSSR 11 1967, 3, * 233-6 // whereby honey may be clogged in the form of oxalate / FR 2 030 602, US 3 652 460 / followed by oxldation and hydrogenation of the catalyst in three cycles. The modified may be barium / ruthenium oxide in a ratio of 2: 1 (SU 978 909) or sodium carbonate (GB 1 060 484). The catalyst of the medium and zinc may be chromium-modified (Bear's O.N.). First organ products, * Moscow 1982,1 15-22 / or calcium, barium and strontium / BeXskaja R.I ......

Vesel AN BSSR,, Ser. Chim. navuk 1981, 6, 112-6).

Known is the BASF catalyst H 5-10 chemical composition of promoter activated zinc oxide, 3e in the form of axtrudors having a diameter of 4 mm or 6 mm. It is characterized by a bulk density of approximately 1 650 kg / m and a mechanical pavnoef of more than 10 kg,

A lower bulk density of approximately 1400 kg / m aa indicates a catalyst prepared from a galvanized low carbon iron sheet by shearing and forming into non-enclosed tubes of approximately 7 m x 7 mm x 0/5 mm. The zinc content of the catalyst is approximately 7% by weight. The above-prepared catalyst at the shear point of the sheet has an exposed iron support. The average conversion of cyclohexanol at a temperature of about 673 K is about 75%. It allows the conversion to be increased, but the selectivity of the reaction decreases proportionally and, consequently, the raw material costs increase and the purification process of the cyclohexanone is complicated. polymer to charred pitch using air.

This catalyst is improved (PL 102 493) by depositing the medium in an amount of 0.001 to 0/5 kg per square meter of catalyst surface. The average conversion of cyclohexanol as well as the selectivity of conversion to cyclohexanone is somewhat higher than with the use of a zinc-iron catalyst, but nevertheless the economics of the process are marked by the abovementioned shortcomings.

It is an object of the present invention to provide a process for sizing a zon-on-iron dehydrogenation catalyst by chemical precipitation of a medium in the presence of ammonia in a sizing solution. It is characterized in that the mixing solution is in an amount of from 0.3 kg to 1 kg with a media content of from 0.3 kg to 1 kg

^ 3.10 kg to 2.10, and ammonia from 3:10 ^- ^ kg and 10.2 kg ~ ^ is treated per kg of particles having zinc in the range of from 2% by weight. up to 20 wt. on the surface of the iron, which rub against each other in a tightly movable layer / mean particle velocity between 0/6 m / s to 3 m / β for a period of from 2 minutes to 20 minutes, wherein the movement time of the rubbing The amount of particles in the solution ranges from 0/2 to 0/8 the puffing time and the remainder of the time the particles rub off the solution. It is also characterized in that the movement of the particles and their gravitationally-induced return in the tight / slidable layer is forced by rotating a 0/2 to 1 m diameter device about 0 to 50 degrees from the horizontal at a rotation speed of 0, 6 rpm to 60 rpm.

An advantage of the process of this process is that there is no permanent contact area between the individual catalyst particles, so that the copper plating is sufficiently uniform with respect to the catalyst surface. Also, the copper-plated layer is not sufficiently firmly deposited, and the surface is abraded and re-accessed for further coppering. The use of such a catalyst in the cyclohexane dehydrogenation reaction requires a low consumption of natural gas for the course of the reaction (the reaction proceeds with high selectivity).

Example

75 kg of zinc-on-iron catalyst / 45 kg of water and 2.8 kg of ammonia water at a concentration of ammonia of water at an ammonia concentration of about 25% by weight were screened for a 70 cm diameter 80 cm exchange device. The sizing equipment is tilted in the eye by sliding the sizing device through a horizontal of 45 ° and after adding 1 kg of meSnaκ sulphate.

CS 272632 Blt, the device is rotated at a speed of 26 rpm for 7 minutes. Thus, the catalyst particles are constantly discharged from the dipping solution and slipped back into the solution by gravity. After stopping the rotation 3a, the solution decanted off and the catalyst was washed with water pSf times at a rate of 45 kg each time while rotating the apparatus as in the dipping alone. The catalyst is dried at a temperature above 50 ° C, preferably in a hot-air oven. The use of this catalyst in the reaction of dehydrogenation of cyclohexanol to cyclohexanane is characterized by 99% selectivity and a consumption of 27/46 m ^{3 of} natural gas per tonne of cyclohexanone produced (with a duty cycle of at least 30 days and a life of at least 1/5 year).

Claims (2)

OBJECT OF THE INVENTION 1. Method of dipping a zinc-on-iron dehydrogenation catalyst by chemical deposition of a medium in the presence of ammonia, characterized in that: J «V Λ from 0 · 3 kg to 1 kg 8 with a media content of 3.10 kg to 2.10“ ^J kg and ammonia from 3.10 ”kg to 2.10” ² kg is crimped per kilogram of particles · having zinc in the range of 2% % to 20 wt. on the surface of the iron (which rub against each other in a tight / sliding layer) / medium rapid movement of the particles between themselves in the range of 0.6 m / a to 3 m / s for 2 minutes to 20 minutes, the time of movement is opaque The amount of time in the solution ranges from 0.2 to 0/8 of the mixing time, and for the remainder of the time the particles are rubbed off the solution. 2. Catalyst reduction method according to claim 1, characterized in that the movement of the particles and their gravitationally-induced return in the tight, movable layer (s) and forces the device / diameter from 0/2 m to 1 m / about the axis to rotate at 0 ° to 60 ° from horizontal / rotational speed from 0/6 rpm to 60 rpm.