DE1667303C - Process for stabilizing a platinum on alumina catalyst activated by a halogenated hydrocarbon and using this catalyst for the isomerization of isomerizable hydrocarbons - Google Patents

Description

i 667 303

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Air existing non-reactive gas, which 'ehloraeetylehlorid. Hie: at one receives a Katalyden catalyst in a volume amount (under sator. The about 0.01 to about 2.0 weight percent normal conditions) of 91 to 15 240 m ³ hrs. M-platinum and about 3J to 12 weight percent chlorine flows through the reactor cross-section, at normal pressure and contains otherwise consists of clay. Others up to 70.3 atü to a temperature of 3Ί6 to 649 C?. According to the invention, dynamically stabilizable catalyst is heated and the catalyst is then obtained. If a mixture of, at a temperature of 66 to 371 ° C. with tetra predominantly alumina and 0.01 to about 1 weight chloroform, methylene chloride. Phos percent platinum, is obtained with an activator such as tetrachloride or trichloroacetyl chloride or in an oxygen carbon, chloroform, methylene chloride, phosgene atmosphere with _ em organochloride with at least io or trichloroacetyl chloride and together with Z carbon atoms and a hydrogen-chlorine molar with the activator among the catalyst activating r:. ^::: nis contacts in such dosage less than 1, that temperature and Druckbedinaungen, preferably (.τ chlorine content of the resulting heated, stabilized catalysis to a temperature of approximately U 9-343 C. K.. IOR set to 3.0 to 10.0 Gewichtsprozem particularly favorable affects the inventive ^{u | I} "d - S;.! abilisierung then out. if one goes from one to the flow rate (under conditions only) ■■ isomerization of isomerizable hydrocarbons, j .. square meters of reacioriiachesu .- !!; which, under normal, especially normal C ₄ -Q-PaTaHr η suitable-1-things' ι ->. 6 C, 1 atm.) starts per square meter of react catalyst, which was then produced! ■: -cross-section flow of gas has been in units of volume. that one em mixture of platinum and ^{1 to} 20 alumina with about 0.0 to 2.0 weight percent platinum ie: a particularly advantageous embodiment for up to 12 hours at a temperature of 371 ° C. The process according to the firing is expediently added up to 704 ° C. a temperature <:; .- .. See stabilization of the catalyst ^ in that of 538 "C and a pressure of 0.25 to 70 atm, '• -.eise by a) the Kalahsator initially usually at a pressure of 1 atmosphere, in '.' up to 6 hours, long in flowing nitrogen '- in the presence of air dehydrated, whereby the used pressure of atmospheric h / w. normal pressure air has a dew point between 12.2 and -73.3 C \:> 2h.i atmospheric and an hourly flow rate preferably -34.4 ° C., the air (.riter normal conditions! from 274 to 6100 rr. ³ each in ² during the last 2 hours in the reverse direction to a temperature of 427 until tune is passed through the catalyst. The de-: heated for 3s, b) the temperature of the hot catalyst is then heated to a temperature ν <n! 4 '> up to 204 C using •.:; Ors a polychlorinated hydrocarbon, such as when it is driven by nitrogen under a pressure of carbon tetrachloride, is activated by flowing this atmospheric or normal pressure up to 28.1 atm. with a dry gas such as air ο the addition of nitrogen for a temperature - nitrogen or helium, in s This amount is introduced into a gas vessel filled with a temperature of 140 to 232 ° C. of an hourly flow rate of the catalyst, so that a length (under normal conditions) of 274 to 4570 m " ^{1 of} chlorohydrocarbon-activated platinum a.if -Tonerdejjj m- reactor cross-section and a pressure ν cn catalyst with 3 to 12 percent by weight of chlorine ent-, umospher- or normal pressure up to 7.03 atm. the catalyst for 1 to 10 hours with after adding 80 '"the required amount ". L-carbon trachloride contacted in one dosage. 40 turns. M: m achieves through this reversal of direction <:; e corresponds to about 0.1 to OJ times the amount required for the .Initial experience, according to experience, a more uniform catalyst production. This mal-activation within the bed and in particular in the frame is expediently in situ, ie in the middle of the reactor and in the gas outlet section. Closer himself carried out, in which the isomerization is stabilized, the catalyst activated in this way and the other conversion of the hydrocarbon before 45 is dynamically undergone in the manner according to the invention. Instead of this, one can also use carbon tetrachloride, which is preferred because of its cheapness because of its low-cost or fluidized bed, as will be described later.

Lenen catalyst for the purpose of stabilization from the dynamic stabilizing hydrocarbon according to the invention The process of removing the conversion reactor can be carried out easily without any significant operation transferred to a separate reactor, cost 50; ·, and requiring expensive equipment in in which the dynamic stabilization takes place. large-scale and even in situ on the Regarding the catalysts which can be stabilized according to the invention and which are located in the isomerization reactor itself include those that are carried out through contactors. So you need the catalyst Bringing a platinum-on-alumina catalyst means zero first from the isomerization or other a temperature of preferably 149 to 427 C 55 coal hydrogen unilateral wall reactor take an organic halogenated hydrocarbon. The catalyst stabilized in this way shows z. B. a chlorinated hydrocarbon, with driving according to a high activity, which durcii at least 2 carbon atoms and a hydrogen-chlorine extreme longevity, especially with n-butane molar ratio below 1.0 under activating conditions as well as penian and he.xan tsomerization on high in a gaseous oxygen-containing 60 activity level.

Atmosphere. Such organic halogen- As already mentioned, one can use an organic

ned hydrocarbons include, for example, niche halogenated hydrocarbons with minor

symmetrical tetrachloroethane, tetrachlorethylene, at least 2 carbon atoms and one hydrogen-chlorine mol-

Hcxachloräthan, Pentachloräthan, Hexachlorbutadin, ratio below 1.0, z. B. with symmetrical tetra

Hexachloropropanone-2, hexachloropropane 65 dilorethane. contained in a gaseous oxygen-

ir-ri rrt rri . working the atmosphere. You can

^{J 2} 'according to the method, however, also in a static one

■ Carry out ktachlorpropane (CCl ₃ -CCU-CCl ₃ ) and tri-heating zone and that when heating

non-reactive gas used. z. B. Oxygen. Nitrogen, helium and / or air over the in the fixed bed any activated catalyst located in or through it. You can do it yourself Use auxiliary means to expose the entire surface of the catalyst to the gas flow by z. B. provides stirring devices for a fixed bed, or with a gas inlet and outlet and lifting strips or baffle-equipped roll barrel, which you can use with gas at the appropriate temperature loaded. The catalyst temperature can then be adjusted to 66 to 37] C and preferably about 177C and constantly supply gas at the specified throughput rate. In large-scale operations, this can be done in generally in the same way as for the heat treatment substep dynamic stabilization happen, d. i.e., you can do both Maintain the same pressure and temperature.

In the production of a permanently highly active catalyst according to the invention, the treatment of the platinum-on-alumina catalyst, which is kept at a temperature of 66 to 371 C, with one of the halogenated hydrocarbons mentioned or another organic chloride with at least 2 carbon atoms and one is decisive Hydrogen / chlorine molar ratio below 1.0 in such a large amount that the finished, stabilized platinum-on-alumina catalyst contains at least 3.0 percent by weight of chlorine: if the dosage is less than this minimum, the catalyst treated in this way does not have the desired activity and / or lifetime. On the other hand, up to 10 and even more percent by weight of chlorine can be incorporated into the stabilized catalyst without disadvantage. But generally contain useful stabilized catalysts 3.0 to 10.0 ^Gev: chtsprozent chlorine. If the chlorine content is above 10%, the catalyst tends to have a lower particle strength without noticeably improved catah tic properties. Since the halogenated hydrocarbons which can be used for the second process step are very different, the required dose cannot be related to the compound itself, but only to the desired catalyst. Obviously, a compound rich in chlorine requires less than a compound poor in chlorine; Furthermore, it is important how easily such a compound transfers its chlorine to the mixture in an oxygen-containing atmosphere. Together with the specified target dose, it is also important that the treatment with the respective halogenated hydrocarbon is carried out for at least 30 minutes, since otherwise the thematic-physical interaction between the lialogcnicrten hydrocarbon and the catalyst is not sufficient to ensure a permanently highly active catalyst from to create the required chlorine content. On the other hand, it is not harmful, but sometimes even advantageous, to treat the catalyst for more than 24 hours. In general, however, a markedly prolonged treatment does not achieve either a longer service life or a higher activity of the catalyst. Carrier gas flow rates (under normal conditions) of at least 155 m per hour are preferably used ^:! per m ² reactor cross-section.

The following examples are intended to explain the foundation in more detail.

example 1

First a platinum-on-alumina catalyst was used

prepared in such a way that one / S-alumina trihydrai

pilled, for 2 hours at a temperature \ - <n

499'-C burned, cooled down to Ryum temperature, ri; an aqueous solution of chloroplatinic acid u: 1

Ethylenediamine impregnated, dried and still; ;

For 2 hours at a temperature of 566

ίο burned. The catalyst obtained passed; mainly made of "/ -Alumina with 0.6 weight per" ■:. [ platinum.

The catalyst obtained was in a 3.6 * ;: · long and 38 mm wide nickel tube filled in ι: ·

then in bed form at a temperature of 38 < and atmospheric pressure with air from the dew. - 3J, 4C with an hourly flow rate. (under normal conditions; from 1318 kg ³ per reactor cross-section and after the dew point

the exhaust air had risen ^{to -28.9: C.} and wähn at gleit ¹ temperature for another 10 hours. ·: four hours of it in counter From durchgebla ^ e ·.. Afterwards, hot air with a dew point of -34.4 at a pressure of w 3.52 kg cm ^{2 was fed into the tube at 246 C}

in an hourly flow rate (under ^{standard conditions) of 1318 kg per m 2 of} reactor cross-section and carbon tetrachloride in an amount *; 11 volumetric units of CCl ₁ per 100 volumetric units of catalyst introduced, the flow direction being reversed _{after 80% of the amount of CCl r was added} Blowing oxygen through: the supply of oxygen was continued until the bed temperature had dropped to about 260 ° C. Thereafter, with oxygen flowing in the same flow rate, 4.5 g of carbon tetrachloride were added in the course of 1 hour, a highly active catalyst which, in addition to platinum and alumina, contained 6.6 percent by weight of chlorine was obtained.

The catalyst prepared in the manner described was used under standard conditions, i.e. H. at a temperature of 149 ° C, a pressure of 21.1 atmospheres, a liquid hourly space velocity of 1 and a hydrogen-hydrocarbon molar ratio of 2: 1, η-hexane isomerized, with a 92.4% conversion of the hexane being 33.4% 2,2-dimethylbutane

so isohexane was obtained. This high degree of isomerization is a sign of high catalytic activity for the catalyst stabilized according to the invention and serves as H's measure of the ability of a catalyst to produce a hexane or light distillation naphtha isomerize.

Example 2

A platinum-on-alumina catalyst activated according to Example 1 was stabilized in such a way that it was first ^{heated to a temperature of 427 1 C for 2 hours while simultaneously passing 30.8 kg of hydrogen per m 3 of} reactor cross-section through it to a temperature of 427 1 C, then below Flushing with nitrogen cooled to a temperature of 260 ⁰ C and at this temperature air in an hourly flow rate of 440 kg per m ^{2 of} reactor cross-section and carbon tetrachloride in an amount of 3 to 4 ml per 100 ml of catalyst.

The catalyst stabilized in the manner described led under isomerization conditions, namely at a temperature of 169C, a pressure of 35.2 aiii, an hourly liquid space velocity of 2.0 and a hydrogen / hydrocarbon molar ratio of 0.2: 1 to a 61 bis 62 ^r 7 ₀ igen primary conversion \ on η-butane to isobutane and at a temperature of 149 C, a pressure of 21.1 atü, an hourly liquid space velocity of 1 and a hydrogen-hydrocarbon molar ratio of 3.2: 1 to a 89 , 4% primary conversion of n-hexane at a isohexane containing ₀ consisted 32.1 ° / of 2,2-dimethylbutane.

Example 3

The stabilization according to Example 2 was repeated in such a way that the hydrogen purging carried out at 1 atmosphere pressure and 3 ml of carbon tetrachloride per 100 ml of catalyst in the course of 45 minutes admitted.

The catalyst resulted in the n-hexane isomerization (at a pressure of 21.1 atmospheres, a flow rate 1, an H ₂ -hexane ratio 3.2 and a temperature of 149 ^J C) with a total conversion of 89 ° / ₀ the same to a isohexane from 2,2-Dimethyibutan consisted of 32.2 ° / _0, and at a temperature \ on 135 "C and 90.8 ° / ₀ by weight total conversion to 34.1% 2.2 Dimcthylbutan. with The catalyst was isomerized to η-butane at a temperature of 169 ° C., a pressure of 35.2 atmospheres, a salt number 2.0 and an H ₂ -butane ratio of 0.2 150 hours, namely to 58 to 59%.

Example 4

ίο The platinum-on-alumina catalyst of Examples 1 and 2 was heated for 2 hours in an air stream of 0.46 m ³ / hour to a temperature of 538 ⁰ C. _{The mixture was then brought into contact with 5 g of CCl 1 for 1} hour at a temperature of 260 "C. in an air stream of 0.092 m? / Hour. The stabilized catalyst contained about 7.2 percent by weight of chlorine and resulted in a 31.2 ° / _o by weight conversion of n-hexane in 2,2-dimethylbutane.

_ao example 5

The platinum-on-alumina catalyst of Example 1 was ^{heated to a temperature of 427 "C for 2 hours in a helium flow of 0.47 m 3} hours. The mixture was then heated for 1 hour in a helium flow of 0.092 m ³ hour with 5 g of CCl ₄ in contact accommodated. The stabilized catalyst contained about 0.9 weight percent chlorine and resulted in a 32.2 ° / _o by weight conversion of n-hexane in 2,2-Dirncthylbutan.

309 618/205

Claims (4)

1 2 preferably between about 2: 1 and 5: 1, for butanes claims: between about 0.1: 1 and 1: 1. A high catalytic activity. 1. Method for stabilizing a through During the mentioned> post-heating "something halogenated hydrocarbon activated platinum chloride either at rest or with a sub-alumina catalyst. for the purpose of removing support from a gas flow flowing through it volatile material including halogen preferably heats hydrogen chloride in a flow rate ratio is, "characterized in that from eUva 0. OiO to 0.015 volume of gas per minute and the catalyst is first removed for 6 minutes until the catalyst is unit volume. The gas stream One made of oxygen in Gesenwart for 20 hours. io displaces the gases released from the catalytic converter Nitrogen. Hydrogen. Helium and or air easily and at the same time creates a uniform existing non-reactive gas, which allows heat to flow through the system. Catalyst in a volume below normal On an industrial scale, preference is given to carbon conditions) from wl to 15,240 m ¹ hour m- hydrogen conversion kings-. e.g. -isorrvation- Aktorquerschniu flows through, at normal pressure 15 catalysts that are used to reactivate. Rain- up to 70.3 aiii to a temperature ⁱ on 316 to rserun-j or stabilization not from the reaction 649 C heated and that you need to take the catalyst vessel. Such catalysts then at a temperature of 66 to must therefore not only be activated in situ, but also: 3 "71" C with carbon tetrachloride. Chloroform. also be stabilizable, including stabilizing, ziernho Methylene chloride. Phosgene or chloroacey- 20 hot gases with high flow velocities. chloride or in an .Saueriiioffatmosphäre with required by the hydrocarbon reactor an organochlond with at least 2 carbon atoms. Experience has shown that in the case of rapid and a hydrogen-chlorine molar ratio below! conduct gas. z. B. air, by a bed of a mn contacted in such dosage. that the chlorine-halogenated hydrocarbons activated plan: - content of the resulting, stabilized catalyst 25 on alumina catalyst this a small, but i'uf 3.0 to ICO weight percent is set. significant proportion se.: ies halogen,: ■ .. B. chlorine content 2. The method according to claim 1. marked thereby withdrawn: its amount is, however, in relation to the draws that the catalyst with tetrachloro gas passed over the catalyst relative carbon treated. insensitive. Probably the ChLv comes from 3. The method according to any one of claims 1 and 2. 30 from a Piaiin-chloro-alumina complex. the door üie characterized in that one. the activity observed is responsible for the catalyst and thus the with 0.1 to 0.3 times that of the anting-active form of the catalyst. These old ones Quaialysatorakii \ ierung required quantity; native to static stabilization can therefore be used in corresponding dose of carbon tetrachloride. large-scale unsuccessful by chloroform, Methylene chloride. Phosgene or tri-35 led because a charge of the kataiychloracetylchlorid contacted. Satorhaltigen reactor with a few, z. B. 0.010 to 4. Process for isomerization of an isomeri- 0.01: * Gasvoluniina per minute and volume unit convertible hydrocarbons, thereby identifying the catalytic converter, costs too much time. draws that one him under isomerization The invention was now based on the object of a conditions with?> nem due to halogens- 40 already due to a halogenated hydrocarbon hydrogen a ¹ activated platinum-on-alumina-catalysis- activated platinum-on-alumina-catalyst in simple Sator contacted, which according to one of the above ways to stabilize so dynamically, d. n. in his going claims dynamically stabilized catalytic. To improve the duration of action that this is. not removed from the conversion reactor 45 must and its catalytic ^ activity in the carbon wa: .hydrogen conversion. especially in the isomerization of hydrocarbons, over a long period of time From de: USA.-Patent 3 242 22S it is already gone, with a consistently good yield of the known, novel isomerization catalysts retained by the desired end product. To create a union of platinum and alumina. 50 The Catalysts Stabilized According to the Invention In the known isomerization catalysts are suitable for hydrocarbon conversion, in particular alumina, the main component: Platinum is in particular in the form of hydrocracking. Alkylation present between 0.01 and 1 weight percent. The alkylable and isomerization of isomerizable carbon catalysts are known when the temperature increases. in particular of nC.-Cj paraffins temperature using a halogenated z. B. chlorinated 55 and naphthenic compounds such as methyl hydrocarbons in chlorinated catalysts with cyciopentane, cyclohexane or dimethylcyclopentane. about 3 to 10 percent by weight of chloride converted The dynamic catalyst stabilization process and optionally then heated so high that ren according to the invention does not require expensive chemicals in part of the chloride is removed again and a cold or relatively long reaction times catalyst is obtained, which is about 2.5 up to 7% by weight is still an expensive piece of equipment that contains chlorine. The invention therefore relates to a process to 204 ⁰ C, an hourly liquid 65 including halogen is heated, which is characterized by space velocity of about 0.5 to 10.0 and characterized in that the catalyst is first hydrogen-hydrocarbon molar ratio between 6 minutes to 20 hours in the presence one of about 0.05: 1 and 5.0: 1. for pentanes and hexanes, oxygen, nitrogen. Hydrogen, helium and / or