DE1003384B - Process for reactivating used platinum or palladium-containing catalysts on oxidic carriers - Google Patents

Description

The invention relates to improved methods for reactivating or rejuvenating catalysts, in particular to improved methods for reactivating noble metal catalysts, which up to Inactivities are deactivated or which, in processes for which their use is intended have lost a considerable amount of activity. More particularly, the present invention relates to reactivation spent platinum catalysts on metal oxide supports that are used in hydroforming Find use.

The feed to the hydroforming reaction vessel can be raw, cracked, or Fischer-Tropsch process Use treated petroleum or the like. The load is heated alone or together with a circulated gas to the reaction temperature or the highest possible temperature below Avoidance of thermal decomposition.

It has been found that the platinum catalysts used here are deactivated for various reasons and consumed, e.g. B. as a result of changes in the physical state of the platinum. The latter are z. B. Grain enlargement of the platinum crystals and the speed of their growth are important factors. Also impurities, z. B. by other heavy metals, easily deactivate the catalyst. The resulting Deactivation should be from the simpler, more easily recoverable loss of activity of the catalyst due to carbon deposition from the reaction or the reduction in hydrocracking efficiency due to Halide losses can be distinguished, which result from the addition of a halide to the hydroforming zone, ie can be remedied by regeneration.

Normally one treats therefore »spent platinum catalysts with extraction, separation and Recovery of the platinum used to make fresh catalyst. This is due to the Platinum recovery operations and the cost of manufacturing new catalysts expensive process.

It has now been found that this expensive recovery by the reactivation according to the invention or the refresh process can be completely switched off. The inventive method comprises generally treating the deactivated catalyst with a halogen. After that it will be like that treated catalyst either in a special treatment zone or directly in the designated one Reaction itself, preferably activated with a hydrogen-containing gas. This process reactivates, invigorates or completely refreshes the deactivated or used catalyst so that it can be reused. Experimental data show that this reactivation is more than a so-called recovery Process for reactivating used

Containing platinum or palladium
Catalysts on oxide carriers

Applicant:

Standard Oil Development Company,
Elizabeth, NJ (V.St.A.)

Representative: Dr. W. Beil, lawyer,
Frankfurt / M.-Höchst, Antoniterstr. 36

Claimed priority:

V. St. v. America March 25th, June 22nd, July 17th,
July 22nd and October 5th, 1953

the halogen content of the catalyst. The halogen content of the reactivated catalyst can be below reduce that of the deactivated catalyst, but the catalytic effectiveness is noticeable remains improved.

The precious metals that can be treated according to the present invention include platinum, Palladium. These metals are generally bound and are on an oxide as a carrier, in particular on the oxides of silicon and aluminum. Of course, the catalyst can also consist of two or there are more precious metals and / or two or more of the metal oxide carriers. In still other cases, the Catalyst contain one or more activation components. Those located on alumina are particularly suitable Platinum catalysts.

After the first embodiment of the process according to the invention, various gaseous Use halogens, e.g. B. chlorine, fluorine and bromine. Chlorine is used in terms of effectiveness, cost, safety, corrosion and other factors preferred.

The chlorine-containing gases can either be mixed with oxygen-containing gases, such as air, or with inert gases, such as nitrogen, carbon dioxide, flue gas etc., use mixed.

The amount of chlorine to be used is between 0.1 and 10 percent by weight, preferably 1 and 3 percent by weight, based on the catalyst. For a typical catalyst made up of 0.6% platinum on one through Hydrolysis of aluminum alcoholate obtained alumina

609 837/426

If there is a carrier, the chlorine bound by the carrier is about 2 percent by weight.

The treatment temperature to be used is between 150 and 650 °, preferably 400 and 620 °. the preferred treatment time is 1 to 60 minutes.

In the last stage, the actual activation catalyst, i. H. a hydrogenation or annealing treatment subject. For this reduction process a treatment with hydrogen at 200 to 540 ° is necessary and under hydrogenation pressures from ordinary pressures up to 70 atmospheres typical. Annealing takes place at temperatures between about 370 and 650 °. You can combine several of these working methods with one another. Preferably one reduces, as already mentioned, the catalyst ■ directly in the process itself in which it should be used, e.g. In the hydrogen or hydrocarbon feed to hydroforming.

The first embodiment of the method according to the invention for reactivating a deactivated platinum catalyst can be better understood with the help of the following examples.

Example I.

The following tests were carried out to determine the effect of treating a deactivated catalyst with chlorine gas to show. In these tests, equal amounts of a used, made of 0.6% platinum existing on alumina catalyst under the following temperature and time conditions with the the amounts of chlorine given below. The samples were finally based on their Laue diagrams analyzed the platinum crystallite size. The experimental data show that the platinum crystallite size of this catalyst is less than 50 Å in a highly active state.

Reactivation with chlorine

catalyst Weight percent
Cl ₂ based on
the catalyst temperature
⁰ C Time,
Minutes platinum
crystal size
A. Control sample:
Used catalyst made of 0.6% platinum on alcohol
latton earth 0.42
0.66
1.58
3.00
4.98
4.98
4.98 480
480
480
480
480
440
400 60
10
10
10
10
30th
30th 235 Used catalyst 218
193 128
<50
<50
<50
<50

This table shows that the platinum crystallites are greatly reduced in size by the process according to the invention became.

Example II

40

A catalyst composed of 0.6 percent by weight platinum on activated alumina produced by hydrolysis of aluminum alcoholate, which contained 0.23 residual chloride from the chloroplatinic acid used in the preparation of the mixture, gave a product with at least 5 carbon atoms in the hydroforming of a petroleum Mol and with an octane number of 96.2. Here and in the following, the octane number is always to be understood as the »Research clear octane number ec. After prolonged use, the effectiveness of the catalyst had decreased to such an extent that only one product with the low octane number 75.3 was obtained under the same test conditions. The Laue diagram of the deactivated catalyst showed that the platinum crystal size had increased to over 200 Å, while the crystallite size of the active fresh catalyst had been below 50 Å. The chloride content of the deactivated catalyst was 0.19 percent by weight.

739 g of the deactivated catalyst were in a flow system at 480 ° and under 1 at for 3 hours with 52.9 g (7.2 percent by weight based on the catalyst) brought chlorine into contact. After that the catalyst Annealed in air at 595 ° for 1 hour and reduced in hydrogen at 480 ° for 16 hours. So treated Catalyst was then used for a hydroforming experiment under the conditions described above, a product with an octane rating of 94 was obtained. It was found that the reactivated catalyst after Only 2 hours of use contained 0.13 percent by weight chloride and the platinum crystal size less than 50 Å fraud.

These data show that the fineness of the platinum crystals as well as their activity was improved by the reactivation treatment were practically completely restored according to the present invention. It is particularly noteworthy that the Chloride content of the reactivated catalyst with 0.13% was less than that of the deactivated catalyst at 0.19%; this proves that reactivation is not just based on a simple renewal of the halide content is due.

According to another embodiment of the invention In the process, the deactivated catalyst is treated with oxidizing agents, and then or at the same time the thus oxidized catalyst is treated with a halide of a non-metal, e.g. B. H Cl treated. Afterward the catalyst is dried, reduced and fully reactivated so that it is in a catalytic Reaction system, e.g. B. a hydroforming system, is reusable.

The platinum catalyst can be treated with oxidizing agents in almost any way, e.g. B. by action of oxygen or oxygen-containing gases at normal pressure up to 70 atm and at 370 to 675 °. The temperatures are expediently inversely related to the partial pressure of the oxygen.

An essential part of this reactivation or refreshment procedure is the use of diluted ones aqueous solutions that do not substantially dissolve the catalyst support. It is known in specialist circles that solutions of concentrated acids many substances, such. B. clay, with the formation of soluble salts, e.g. B. aluminum salts, attack. In this way the catalyst carrier is destroyed. In the treatment according to the invention on the other hand, the catalyst is treated with dilute acid, i. H. with about 1 to 30 percent by weight HCl, based on the Catalyst, brought into contact. This acid is in

5 6

about 50 to 500 percent by weight of water, based on that used for hydroforming below 14 atmospheres at 480 °; the on the support catalyst, dissolved. Such hydroformat obtained here, for example, had the octane number 93. According to Acid concentrations do not dissolve the carrier while staying the same with much prolonged use of the catalyst. Accordingly, solutions are preferred which are obtained in a hydroformat with the conditions Liters contain about 0.1 to 3 moles of HCl. 5 low octane number 85.478 g of the deactivated catalyst

Instead of the inorganic halogen acids, sators were with 34 4 g of H Cl (7.2 percent by weight, based on other halogen-containing compounds, for example on the catalyst) and 9.8 g of HNO ₃ (2.1 percent by weight, thionyl chloride, sulfuryl chloride, nitrosyl chloride , under- based on the catalyst) in 754 g (158 weight chlorous acid etc. Also mixtures of gases, such as percent) of water treated. This solution contained oxygen, chlorine, HCl, steam or nitrogen, etc., 10 liters of 1.26 mol of HCl and 0.21 mol of HNO ₃ . The mixture can be used. In addition, perhalogen was dried overnight at 120 ° and reduced by synthetic acids, organic perhalic acids and organic diges annealing at 595 °. After that, the reak halogen acids were used. activated catalyst again for hydroforming

The oxidation treatment can be used before the addition of the under the same conditions as above, inorganic halogen acid, or both can be used. Allow reactants to act at the same time, so that it should be emphasized that this octane number

the oxidation and the dissolution of the platinum by the not only significantly better than that with the deactivated one Acid go on in a stage. A particularly effective catalyst obtained, but even higher than that with Mixture of the oxidizing agent with hydrogen halide - the original activity of the catalyst before its acid consists of 3 parts by weight of H Cl to 1 part by weight of 20 deactivation achieved octane number. Furthermore is solid-nitric acid in the described dilute aqueous bodies that the crystal size of the original fresh Solutions. Catalyst below 50 Å and that of the deactivated catalyst

After adding HCl, the catalyst was thus 210 Å in the lysators. By the above-described contact and reactivation to temperatures below the inventive reactivation, the crystal size of those was heated, the application of which H Cl and HNO ₃ 25 would be expelled from that of the fresh catalyst, ie to less than completely. The pressures, temperature 50 Å, reduced.

Temperatures and times are set accordingly. The chloride content of this reactivated catalyst, preferably heated under atmospheric pressure, was 0.38 percent by weight, which proves that the reacquisition is about 93 °. Thereafter, the excess activation is not due to the mere addition of the halide water and the acid from the catalyst, preferably to the catalyst.
by increasing the temperature until the catalyst is dry

To complete the reactivation process, Example IV

dried catalyst still reduced. This reduction stage can be carried out in various ways in the art, in the same way as in the previous example perform known types, e.g. B. by hydrogenation, described, a hydroforming was carried out, Annealing or treatment with chemical reduction with the exception that the catalyst used is 0.6 weight average. Typical of this reduction process is the percentage of platinum used on alcoholate alumina. Of the Treatment of the catalyst with hydrogen between fresh catalyst resulted in a hydroformat with the 200 and 540 ° and at pressures up to 70 atm. For a 40 octane rating 99; after prolonged use, the octane annealing treatment decreased temperatures of about 595 ° number to 83. Thereafter, 329 g of this entin were treated Question. An advantage of the process according to the invention activated catalyst with 23.7 g of HCl and 6.8 g of SaI-ist the fact that the catalyst immediately applied to the pitric acid in 515 g of distilled water. The catalyst Procedure itself, for which its use is intended, was heated on a steam bath for 2 hours, z. B. in hydroforming, can be reduced. 45 then washed with water and overnight at

Sometimes it is desirable to have the amount of the 120 ° dried. Thereafter, it was minimized and restricted under the same conditions as above for 1 hour at 595 ° of carrier retained halide. The halide can be used for reforming as described by chemical means. With the treatment of the catalyst in a known manner deactivated catalyst was obtained a product with distant, z. B. by washing with water, treatment with 50 of the octane number 103.
Steam or with ammonia. These data again show that the effectiveness of the

The oxidation with nitric acid instead of air-deactivated catalyst by the catalyst according to the invention is particularly effective if the catalyst has been so significantly improved in metallic processes that it even contains impurities. The resulting soluble exceeded that of the fresh catalyst.
As described above, nitrates can be removed by washing 55

remove. For certain other impurities,. .

z. B. arsenic, it is desirable to use the catalyst before Example V

Oxidation stage with a halide of a non-metal

to bring in touch. The arsenic halides are so- To identify the first, without treatment, second

then before reactivation by evaporation from 60 with treatment only with an oxidizing agent, driven. third, treatment with an oxidizing agent, and

This modified embodiment of the HCl of the invention, fourth treatment with HCl alone and fifth Moderate method for reactivating a deactivated one using a certain amount of H Cl in Platinum catalyst is still achievable on the basis of the following connection with an oxidation stage better understandable. 65 kung samples of 20 g of deactivated, from each were made

0.8 weight percent platinum on alcoholate alumina for Example III catalyst according to the one in more detail below procedures described. For the festival

One used from 0.5 weight percent platinum on the commercial position of the influence of these variables Alumina existing hydroforming catalyst was 70 deactivated catalysts, the crystallites of 200 Å

and larger contained. The results are summarized below:

Volume of the
Treat
lung
by means of *)
ecm Γ40
40
40
'40
40
40
'20
40
80 Weight
percent HCl,
Based on the
catalyst Weight
percent ENT _{3 y}
Based on the
catalyst Platinum-
crystal size
Ä I.
II <
III 7.0
7.0
7.0
7.0
7.0
7.0
7.0 4.0
0.5
2.0
8.0
4.0
4.0 ■
4.0 200
200
190
97
76
137
not
determined
30 to 50
76
127

*) Water + acid.

The amount of catalyst support dissolved in this process is a function of time and the concentration of the acids, e.g. B. the HCl and HNO ₃ . The use of acids with a higher concentration than that described in the present application results in a relatively rapid dissolution of the carrier and makes it difficult to monitor the process. The expression "without substantial resolution" used here refers to a generally highest permissible resolution of the carrier of

ίο about 20 percent by weight and preferably not greater than about 5 to 10 percent by weight.

It is particularly pointed out that the method according to the invention using dilute Acids do not affect the properties of the catalyst support.

It has also been found that this expensive recovery process can be eliminated by the reactivation process can be avoided entirely according to another embodiment of the present invention. In this invention The deactivated catalyst is in pill, granule or powder form with a diluted process treated aqueous solution of an inorganic nitrate and an exchangeable halogen-containing compound. The catalyst treated in this way is then used in the

Several conclusions can be drawn from this data.
The data labeled I show that the reaction system obtained without handling is heated in such a way that no significant amounts of the platinum are "extracted" or removed by treatment with the oxidizing agent alone, or by treatment with HCl alone, the will. This "dissolving away"., Of the platinum can be reactivated. The necessary reduction in size of the platinum is achieved by monitoring the length and thickness of the crystallites to be treated. development and preferably only smaller by application

The data marked II prove the importance of regulating the quantities of the treatment solutions, so that the latter speed the concentration of the oxidizing agent and show that it does not need to be separated from the catalyst, the ratio of the concentration by weight to HCl
ENT ₃ of about 3: 1 gives the best results.

The data labeled III show the influence of the treatment volume. These data show that one should only work with so much solution that the

deactivated catalyst is completely wetted. Example VI The system is then warmed to dryness and preferably washed, followed by a reduction treatment by which the catalyst is completely reactivated is so that it can be used in catalyzed reaction systems, e.g. B. in hydroforming systems, can be reused. This is followed by an oxidation treatment, which makes the platinum more sensitive, and a treatment with a version containing an exchangeable halogen

A sample of 20 g of a deactivated catalyst 40 binding, being dispersible, soluble and easily remit With a crystal size of 240 Å, ducible platinum compounds would be formed for 4 hours. At the next

480 °

treated with air at atmospheric pressure and at 480 °. After this treatment, the catalyst became 1 hour on a steam bath with 30 ecm of an HCl solution (15 percent by weight HCl, based on on the catalyst), which contained 2.7 mol of HCl per liter of solution. After that, the catalyst was treated with water washed and heated first to 120 and later to 595 °. The size of the platinum crystals in the treated Catalyst decreased to 85 Å.

The inventive method is suitable for the regeneration of platinum catalysts, which are based on different Types of carriers are located. These carriers include pure or silica-containing clay, boron oxide, Zinc oxide, zirconium oxide, titanium oxide and torch earth. The carrier can also be made entirely of other fabrics or theirs Mixtures with oxides of zirconium, titanium, magnesium, silicon or of activated carbon or the like.

The reactivation can be done in different ways following reduction the catalyst is reactivated. It should be pointed out in particular that in this embodiment of the method according to the invention no platinum losses occur.

In this particular embodiment of the process according to the invention, the catalyst component is treated with a mixture of a metal nitrate and a metal chloride in an aqueous solvent. Since it is usually desirable to avoid contamination of the metal oxide support by other metal oxides, the metal nitrate and metal chloride should preferably correspond to the metal of the metal oxide support. If z. B. the metal oxide in the catalyst component consists of alumina, aluminum nitrate and aluminum chloride are used; if the metal oxide consists of zirconium oxide, then zirconium nitrate and zirconium chloride are used, etc.
Treatment with the aqueous aluminum nitrate

carry out. At a z. B. one brings the deactivated 60 can precede the one with the aluminum chloride, Catalyst in a continuous process with, or preferably, both reactants

HCl and an oxygen-containing gas in countercurrent contact. In another embodiment, oxidized the catalyst with air or oxygen and then saturated with anhydrous HCl gas. Man treated then steam the catalyst to moisten it, dry it and reduce it before entering the Stream of the gases to be treated comes. In another system, the catalyst can be oxygen, Add chlorine and vapor containing gases.

at the same time, so that the oxidation treatment and the dissolution of the platinum take place in one step.

An essential part of this reactivation process is the use of dilute aqueous solutions which do not substantially dissolve the catalyst support. When working according to the present invention, the catalyst is only brought into contact with dilute solutions, ie with about 1 to 30 percent by weight of AlCl ₃ , based on the catalyst. This salt is in

50 to 500 percent by weight of water, based on the catalyst on the support. These concentrations hardly dissolve the carrier. Solutions are preferably used which contain 0.1 to about 3 mol of AlCl _{3 per liter.}

Similarly, it has been found that when using reactants such as aluminum nitrate, about 0.3 to 15 percent by weight of Al (NO ₃ ) ₃ , based on the total catalyst, and 50 to 500 percent by weight of water can work well. A dilute solution is preferably used which contains about 0.01 to 1 mol of A1 (NO ₃ ) ₃ per liter.

After adding the aqueous AlNO ₃ and AlCl ₃ , the catalyst is stirred with it and heated under such conditions to such an extent that there is no loss of treatment agents and solution. The pressures, temperatures and times are set accordingly. Preferably, ¹ Z is _{heated to about 93 ° for 2} to 12 hours under atmospheric pressure; then excess water and acid are removed from the catalyst by evaporation to dryness.

The inventive method for reactivating a deactivated platinum catalyst is based on the the following examples are easier to understand.

Example VII

A catalyst of 0.6 weight percent platinum, similar to that of Example II, was used for a Hydroforming used whose hydroformat had an octane rating of 99.3. After prolonged use of the catalyst Under the same conditions, a hydroformat was created with an octane number of only 66.5.

The carbonaceous deposits were burned off the catalyst by annealing in air at about 540 ° for 4 hours. 357 g of the deactivated catalyst in pill form were treated with a solution of 55.2 g of aluminum chloride hexahydrate and 28.6 g of aluminum nitrate nonahydrate in 360 g of water (corresponding to 8 percent by weight of aluminum chloride and 4.5 percent by weight of aluminum nitrate and about 100 percent by weight of water on the catalyst). This solution contained 0.6 mol of aluminum chloride and 0.2 mol of aluminum nitrate per liter. The mixture was allowed 2 ¹ Z pull on the steam bath _{for 2} hours, it was washed with water, dried it for 16 hours at 120 ° and finally annealed for 1 hour at 595 °. Thereafter, to reduce the halide content, the catalyst was washed twice with 500 ecm 10 weight percent aqueous ammonium nitrate solution, again dried for 16 hours at 120 ° and calcined for 1 hour at 480 °.

ίο The reactivated catalyst has now been on for 16 hours reduced with hydrogen and again under the same conditions as described above for the hydroforming used. The resulting hydroformat had a significantly improved octane number, namely 97.9. In addition, measurement of the platinum crystal size by the Laue diagram revealed that the crystallites of the fresh catalyst less than 50 Å, that of the used catalyst 240 Å and that of the after inventive method reactivated catalyst

less than 50 Å. The experiments described in this example show that the catalyst activity changes inversely proportional to the crystal size.

Example VIII

To the effect of treatment with aluminum nitrate or aluminum chloride alone, as well as the effect of various To show other salts, the series of experiments listed in Table A was carried out. at These tests were based on equal amounts of 20 g each of a used catalyst composed of 0.6% platinum Clay for 2 hours with the specified percentage solutions of the salts contained in 40 ecm of water Treated on a steam bath. The samples were then washed with water, dried at 120 ° and Annealed for 1 hour at 595 °. Finally, the samples were checked for their platinum crystallite size by the Laue diagrams and examined for their platinum content in percent by weight. The platinum crystallite size of this Catalyst in the highly active state before prolonged use was less than 50 Å.

Table A.

Treatment agents

Weight percent
Chloride, related

on the
catalyst

Weight percent
Nitrate, related

on the
catalyst

platinum

Weight percent

A. Only water (blind test)

B. Α1 (ΝΟ ₃ ) ₃ 9Η ₂ Ο alone ...

C. AlCl ₃ '

D. AlCL

E. AlCL

• 6 H ₂ O alone

• 6 H ₂ O + Al (NO ₃ ),
6 H ₂ O + NH ₄ NO ₃

9 H ₂ O

34.0

25.6

8.5

52.8

13.7
5.0

0.59
0.60
0.55
0.57
0.58

300
240
180
50
170

From this table it can be seen that when treated with 53 weight percent aluminum nitrate only one small reduction of the platinum crystallite size by about 20% compared to the blind test carried out with water was achieved. When treated with 34% aluminum chloride, the crystal size increases by about 40% decreased, which means some improvement in the platinum surface available for the reaction. at in the method according to the invention (line D), however, the platinum crystals are reduced to such a fineness reshaped, which corresponds to that of the crystallites occurring in the fresh catalyst. Achieved this as can be seen from the table, by using less chloride and nitrate than in the first experiments (B and C) uses, which has proven the synergistic effect of using both salts side by side. at Experiment E enables the use of only 5% ammonium nitrate to reduce the amount of aluminum chloride from 34% (C) to only 8.5% to achieve the same decrease in crystal size. This is natural a particularly advantageous compound since the presence of the ammonium salt is the next step for removal of the halide simplified.

In a further embodiment of the method according to the invention, inactivated ones with carbon contaminated catalysts in pill, granule or powder form for removing the carbonaceous ones Deposits are oxidized, the decarburized catalyst is treated with a halogen-containing gas and the excess Halogen removed from it. The catalyst treated in this way is then either in a special Treatment zone or right in the reaction zone

609 837/426

11 12

reduced, preferably with a hydrogen-containing test conditions, a hydroformat with at least Gas. In this way, the deactivated catalyst has 5 carbon atoms in the molecule and an octane number of 96.2. fully reactivated so that it can be used again. After a certain aging it became effective It is surprising to find that this effect of this catalyst has decreased so much that one is achieved with gaseous halogens, since gaseous 5 under the same test conditions only one Hydrogen halides obtained on deactivated catalysis product with the low octane number 75.3. the gates do not have the same effect. Reverse Laue diagrams show the deactivated catalyst the data obtained in the experiments indicated that the platinum crystal size increased to over 200 Å this reactivation was more than a so-called re-activation, while the crystallite size of the active fresh production of the halogen content in the catalyst is. The io catalyst had been less than 50 Å. The chloride halogen content of the reactivated catalyst, the content of the deactivated catalyst was 0.19 percent by weight among those of the deactivated catalyst.

press down, but its activity remains substantially 739 g of the deactivated catalyst have been improved in one. Flow system at 480 ° under 1 atm for 3 hours with the amount of chlorine used is about 0.1 15 52.9 g (7.2 percent by weight, based on the Katabis 10, preferably 1 to 3 percent by weight, based on lysator) chlorine in contact brought. Then was on the catalyst. The partial pressure of the chlorine gas for 1 hour in air at 595 ° can be between 0.1 to 100% of the total pressure within the annealed and then for 16 hours at 480 ° in water in the limits mentioned above. Reduced under otherwise the same fabric. The catalyst treated in this way was subject to conditions, the more rapidly the effect, the higher the partial pressure is for an experiment under the above-described partial pressure. Conditions used to obtain a product having the temperature of treatment with the 94 octane halogen. It has been found that it is in the normal temperature range, ie between 15 reactivated catalyst after only 2 hours of use and 675 °, preferably between 425 and 540 °. To contain 0.13 percent by weight of chloride and the size saving in heating energy treated, the catalyst of the platinum crystals in it was less than 50 Å, in general in the case of the analyzer in the plant. ■, _Ύ seeing temperatures. The preferred treatment example Λ. time is a few minutes, but in a further experiment, a sample of the desired degree of reactivation was also possible with other 759 g of the deactivated catalyst at 480 ° and treatment times. 30 under 1 atm for 2 hours with 0.012 cbm (3.9 weight-The halogen is exposed to the catalyst to various percent) of chlorine in contact. Thereafter, species were added which, as well as the treatment time of the catalyst, were heated to 525 ° for 1 hour. After regulating so that the desired amount of halogen in this treatment was the chloride content of the Kata catalyst remains. For a typical catalyst 1.11 percent by weight. The halide content of the analyzer, which consists of 0.6% platinum on an ammonium nitrate solution produced by hydrolysis, was now reduced by washing with a 10% strength aqueous alumina made from aluminum alcoholate. After washing, the carrier contains approximately 2 percent by weight chlorine. When drying and reducing with hydrogen, a unit with a fluidized bed catalyst contained less than 0.01% chloride, and there was no difficulty in doing so, with a unit with a platinum crystal size of less than 50 Å. In the case of a stationary catalyst bed, however, care must be taken for 40 experiments under the conditions described above that the added halogen is obtained uniformly with this catalyst in a hydroformate distributed throughout the catalyst bed and not with an octane number of 95.9.

completely adsorbed by a small fraction of the bed It is surprising to find that this effect

is beer. To achieve a uniform halogen with gaseous halogens is achieved because gaseous

distribution, it is important to 45 hydrogen halide acids on deactivated catalysis during the halogen treatment

to work at high space velocity. gates do not have the same effect. Vice versa

In addition, it is advantageous to show the flow direction more often, the data obtained by the experiments that

change or the halogen from several points in this reactivation more than a so-called re-

to introduce the bed. production of the halogen content in the catalyst is. Even

The excess chlorine is then treated with a usual 50 if the halogen content of the reactivated catalyst

Purge gas, such as hydrogen, nitrogen, flue gases, air, analyzer to below that of the deactivated catalyst

Steam etc. or their mixtures, expelled. Pressing down the lysators, its effectiveness still remains

The chloride content of the catalyst is significantly improved after the expulsion. From the further data goes

is preferably 0.01 to 0.5 percent by weight, furthermore it is apparent that when using the halogen

based on the catalyst. 55 in almost anhydrous form catalysts with the highest

The final stage of the reactivation process is to have effectiveness established.

if necessary, in a reduction of the catalyst. Because of its effectiveness, cheapness, safety and Chlorine is particularly well known for this reduction stage Means, e.g. B. hydrogenation or annealing, is preferred.

serve. 60 It should be emphasized that the inventive method

This procedure according to the invention for reactivating the use of a halogen under dry conditions

Conditions for a deactivated platinum catalyst are provided. The terms “dry

The following examples make it even easier to understand. Conditions «,» anhydrous halogen «or» anhydrous

". _T free chlorine "include the treatment of the catalyst

Example IX _6s containing _{a Clllor 0 (ier an older of (halo}}

A catalyst according to Example II with 0.6 weight gas in which the partial pressure of the water vapor is less percent platinum on activated, by hydrolysis of than 0.02 ata, preferably even less than about 0.01 ata Aluminum alcoholate produced alumina contained 0.23.

residual chloride from the used in its manufacture. The anhydrous chlorine is in an amount between

deten chloroplatinic acid and gave, under certain conditions, 0.1 to 10, preferably 1 to 3 percent by weight, based on

on the catalyst. The partial pressure of the chlorine gas should be between 0.002 and 2 ata can be between 0.1 to 100% of the total pressure within the limits described above. Otherwise Under the same conditions, the higher the partial pressure, the faster the effect. For the treatment of dormant On the other hand, it is preferred to build up a granular or globular catalyst to let a chlorine-containing gas mixture flow through rapidly, which is preferably diluted with dry air in which the partial pressure of the chlorine is between about 0.02 to 0.2 ata. Such a treatment with quickly flowing diluted chlorine gas with a relatively low partial pressure of the chlorine results in a more uniform Treatment than when using higher partial pressures of chlorine.

In the last stage of the process, the catalyst is activated by reduction, i. H. a hydrogenation or subjected to annealing treatment. In this reduction process, it is at 200 to 540 ° and under hydrogenation pressures treated with hydrogen from atmospheric pressure up to 70 atü. One can at about Glow at 370 to 650 °. Different work steps can be strung together. As already mentioned, reduced one preferably directly in the process itself for which the catalyst is to serve, e.g. B. with hydrogen or hydrocarbon feed to hydroforming.

The procedure according to the invention for reactivating a deactivated platinum catalyst is illustrated in detail the following examples are even easier to understand.

Example XI

A catalyst containing 0.6 weight percent platinum was obtained by separating out chloroplatinic acid Alcoholic clay produced. The alcoholate alumina was produced by the hydrolysis of aluminum alcoholate. This catalyst was tested for hydroforming efficiency at 440 ° and under atmospheric pressure for the treatment of a double-distilled crude oil feed with the addition of about 250 cbm of hydrogen examined per hectolitre of petroleum. After a certain amount of aging, the effectiveness of the catalyst decreased. This deactivated catalyst was for 15 minutes at 425 °, at a partial pressure of the chlorine of 1 ata and of the water vapor of less than 0.001 ata, i.e. treated with practically anhydrous chlorine and then treated Activated by annealing at 540 ° for 4 hours. The amount of chlorine used was 2 percent by weight, based on the catalyst. The effectiveness of the hydroforming catalyst was then re-established and the catalysts were also examined for the presence of platinum crystals by means of Laue diagrams. The results obtained are listed in the table below.

catalyst Relative
Effective
ability *) Laue diagrams
(Platinum crystal structure) fresh
deactivated
reactivated with chlorine 122
68
147 no platinum crystals
Platinum crystals present
no platinum crystals

*) Compared to a catalyst with an assumed activity value of 100.

From these data it can be seen that the deactivated catalyst by treatment with the anhydrous Chlorine is even more effective than the fresh catalyst. This restoration of the Activity was due to the desired destruction of the larger platinum crystals of the deactivated catalyst accompanied.

Example XII

A 1 weight percent palladium on alcoholate alumina catalyst was used after loss its hydroforming activity is reactivated by aging with anhydrous chlorine gas. The reactivation consisted of a 15 minute treatment with anhydrous chlorine at 540 ° and under a partial pressure of chlorine 1 ata and a water vapor partial pressure of less than 0.001 ata. The amount of chlorine used was 2 percent by weight, based on the catalyst. The hydroforming effectiveness of the fresh, the deactivated and the reactivated catalyst is shown in the table below.

Catalyst (1% Pd) Relative effectiveness Fresh 50 3 ■ * Deactivated 39 Reactivated 71

40

45 Example XIII

In this experiment, the influence of the temperature and the partial pressure of chlorine from the addition of water to the chlorine was investigated. The data listed in the table below were obtained with samples one of 0.6 percent by weight Platinum on alcoholate existing catalyst, whose activity by aging up to one relative effectiveness (see table below) had decreased from 34. The fresh catalyst had that relative effectiveness 85. The hydroforming tests were carried out at 445 °, atmospheric pressure and below Use of around 250 cbm of hydrogen per hectolitre the crude petroleum feed. After the above-mentioned reactivation treatments with chlorine the catalyst systems are cleaned with air and the catalysts are annealed in air for 4 hours 540 ° activated. The results are shown in the table below:

temperature
⁰ C Cl ₂ - Cl ₂ -TeUdTUCk
ata 1.0 H _a O addition Cl ₂ cleaning in treatment dry Effect of partial chlorine pressure, ata 1.0 dry dry Relative
Effectiveness*) Time
Minutes speed
Parts by weight / hour /
Parts by weight Effect of the temperature of the Cl ₂ 1.0 dry dry 0.08 0.03 dry dry 315 0.08 1.0 dry dry 0.05 0.0025 dry dry 80 f 15 425 0.08 1.0 dry dry 0.05 104 _T 15 540 0.08 dry 104 ¹ 15 650 0.08 100 115 540 104 (15 540 115 II J 22 540 113 (22

15th

16

Time
Minutes

Temperature ⁰ C

Cl ₂ -

speed

Parts by weight / hour /

Parts by weight

Cl ₂ partial pressure
ata

H ₂ O addition

Cl ₂ cleaning

Relative effectiveness *)

Effect of adding H ₂ O during refreshment

22nd 540 0.05 0.03 dry dry 115 22nd 540 0.05 0.03 wet** wet ** 82 15th 425 0.08 1.0 dry dry 104 15th 425 0.08 1.0 dry wet** 100

III

*) Compared to a normal alcoholate-alumina catalyst heated to 480 ° for 2 hours = 100. **) The partial pressure of water vapor in the gas was about 0.025 ata.

These data show that temperatures between leads the catalyst treated in this way into the reaction

425 and 650 ° are equivalent to each other, a temperature zone back in which it is reduced and reactivated.

of 315 °, however, is less effective. This embodiment of the present invention

A very low partial chlorine pressure is just as effective.

like higher partial pressures and, as mentioned above, will be even better understandable with schemes.

In the drawing, the reaction vessel 10 has at the bottom

more uniform action in the entire catalyst 20 an inlet line 11 for the introduction of preheated

bed even preferred. hydrogen-rich or circulated gas

These data also show the importance of the water- the process itself. To ensure even distribution

freedom from chlorine in the reactivation process. With the circulating gas flowing in over the entire To ensure that the upper limit for water vapor cross-section of the reaction vessel 10 is exceeded, even a small one achieved a much worse result. The latter is inside with a horizontal one

Results. perforated plate or a distribution grid 12 provided.

BeisDiel XIV A special, with a distributor ring 14 or the like.

bonded inlet line 13 is used to introduce the

One for 4 hours by heating at 540 ° active petroleum above the grid 12; however, the freshness can fourth, from petroleum charge impregnated with 0.6 percent by weight platinum, also optionally by itself or Alcoholate alumina was used along with the recycle gas below the grid Hydroforming of a crude petroleum at 480 °, one introduced.

Pressure of 14 atmospheres and with the introduction of 89 cbm. The reaction vessel 10 is charged with finely divided

Hydrogen used per hectolitre of feed. split hydroforming catalyst particles and regulates.After some aging, the catalyst lost the surface velocity upwards through the activity and was first heated to 540 ° with boiler 10 in such a way that a stream of dry air was dense to remove the carbon Catalyst fluidized bed 15 forms, reactivated via substance-containing deposits. A dilute chlorine gas, anhydrous in the air, was then added to its upper boundary surface L , and the mixture or disperse phase 16, which was still small quantities, was passed over the catalyst 40 of the gaseous or vaporous reaction products for 20 minutes at 540.degree the chlorine partial pressure 0.025 ata and the entrained catalyst contains. The reaction water vapor partial pressure was less than 0.001 ata. products are removed from the top of the reaction vessel - the total amount of chlorine added was only drawn, preferably through a cyclone separator 17, 1.2 percent by weight, based on the dry catalyst present on or the like for separating the entrained catalysis from the carrier. The hydro- 45ator particles that are then passed through the dip tube attached to the bottom of the formation data are listed below: Cyclone separator into the density

Flow back layer 15. The reaction products are passed through line 18 to fractionation, stabilization and / or storage systems (not shown here). 50 Catalyst particles are continuously withdrawn from the sealed bed 15 through the discharge line 19 and passed into the rinsing cell or boiler 20 located outside. This rinsing cell could also be installed inside the reaction vessel, e.g. B. in the form of a vertical tube or a cell, which preferably extends beyond the mirror L and has a throttle opening for regulating the catalyst flow into the flushing cell. At the lower end of the rinsing vessel there is a feed line 21 for introducing 60 a suitable rinsing gas, e.g. B. nitrogen, purified The data on the yields of hydrocarbons, flue gases or the like, which show that the selectivity of cracked or adsorbed hydrogen or carbon of the reactivated catalyst is better than that of the fresh hydrogen used for the removal of mitgemit at least 5 carbon atoms otherwise it is in the regeneration zone. would be abducted and burned there. The purge gas

Furthermore, the present invention relates to a 65 and the gases carried by it are from the Improved method of maintaining activity. Vessel 20 withdrawn upward and through line 22 and selectivity of the catalyst in the fluidized bed introduced into the upper part of the reaction vessel 10 hydroforming. In this case, the fresh is treated in the event that it contains substantial amounts of the catalyst regenerated Catalyst with halogen-containing! Gas, sators are contained and whose recovery in the cyclone then removes the excess halogen therefrom and separator 17 is desired; or they are through the

catalyst Fresh 2.0 Deactivated Reactivated 3.3 Converted data ouch E is the octane number 95 Loading speed Parts by weight / hour / 82.0 86.0 Parts by weight .... 1.6 of C _s yield and higher coals hydrogen, Volume percentage .... 78.0

Line 23 led to the product outlet line 18 if the flushing gas is not introduced into the reaction vessel want. At the bottom, the pipe 24 connects to the rinsing cell 20 and together with it forms a vertical one Line for the development of such a static flow pressure in the now purified stream of the consumed Catalyst that is sufficient to push the catalyst towards the regenerator side. At the bottom the tube 24 is a slide 25 or the like. To regulate the outflow of the used catalyst from the reaction vessel, and if desired or necessary, one can fluidize the catalyst place one or more feed lines along the pipe 24 for the introduction of fluidizing gas.

The cleaned spent catalyst is introduced from the lower end of the tube 24 into the bypass 26, where it is received by a flow of regeneration gas or air supplied through the line 27 and through an upwardly leading line 28 for the spent catalyst and through the perforated plate or the grid 29 is conveyed into the regenerator 30 in which the carbon is burned away. In order to prevent too much used catalyst from being carried along in the bypass 26 and the riser 28, it is advisable to use only part of the air required for regeneration for conveying the used catalyst into the regenerator and the rest of the air required for regeneration To supply air through a special inlet line 31 or through further lines opening directly into the regeneration vessel. The contaminated with carbon catalyst can first with dilute, z. B. 1 to 2 mole percent O ₂ containing air can be burned at about 480 °. In an advantageous embodiment of the method, the temperature is then with the simultaneous use of higher O ₂ partial pressures, z. B. of 1.4 kg / cm ² O ₂ , or increased by air below 14 atmospheres to 595 °.

The surface speed of the regeneration gases on their way through the vessel 30 is regulated so that a dense fluidized bed 32 is formed from catalyst particles and gas, over the upper boundary surface L ' in the upper part of the regenerator there is a dilute or disperse phase 33, which is still small Contains quantities of the catalyst entrained by the regeneration gases. The regeneration gases are withdrawn from the regeneration vessel 30 upwards, preferably through a cyclone separator 34 or the like, which removes most of the catalyst particles from the gas and returns them to the sealed bed 32 through the one at the lower end of the cyclone separator attached immersion tube is used. The regeneration gases flow through the outlet line 35 and the pressure regulating valve 36 to an exhaust duct.

The regenerated catalyst is withdrawn from dense bed 32 through return line or pipe 38. Chlorine-containing gas is introduced into the return line 38 through the pipe 39. The contact time and Temperatures are set so that the desired degree of reactivation is achieved. The added one Catalyst containing chlorine flows into the rinsing vessel 40, in the lower part of which a rinsing gas, for. B. Hydrogen, is introduced through line 41. Similar to the regeneration vessel, the cleaning vessel also takes place 40 maintain a dense phase. The purge gas that is present flows through the outlet line 42 into an exhaust duct, the catalyst freed from the chlorine through the return line 43 into the dense phase 15 of the Reaction vessel 10. If necessary, the catalyst is in the reaction vessel 10 under hydroforming conditions subjected to a reduction treatment and reactivated for reuse. One Another possibility is that the catalyst prior to its introduction into the reaction vessel 10 reduced in a special boiler with hydrogen.

The charging material is mixed up alone or with circulating gas while avoiding thermal decomposition heated the reaction temperature or the highest possible temperature. Usually one warms the load to temperatures of about 425 to 540 °, preferably to about 510 °. The preheating of the petroleum should be like this be as high as possible, but avoiding thermal decomposition by limiting the residence time in the Avoids diversions or feed lines. The preheated charge can be transferred to the reaction vessel either together with the hydrogen-rich cycle gas or by itself, as indicated, supplied will. The cycle gas, which contains about 90 to 95 percent by volume hydrogen, is before its introduction preheated by line 11 to about 620 to 650 °, preferably about 640 °; it should be at a speed from about 17.8 to 178 cbm / hl petroleum feed be passed through the reaction vessel. It is preferable to supply it in the smallest possible amount, which is just now sufficient to supply the reaction zone with the necessary heat of reaction, but in the case of the carbon deposition remains as low as possible.

The reaction system is charged with a mass of finely divided hydroforming catalyst particles. The catalyst particles are predominantly so fine that they pass through a sieve of 6400 M / cm ² , or about 10 to 200 μ in diameter, of which a larger part is between 20 and 80 μ.

The space velocity or the weight of the feed per hour per 1 kg of catalyst in kg depends on the age or the degree of activity of the catalyst, the nature of the charge and the desired octane number of the product. The space velocity for platinum on alumina gel can e.g. B. between about 2 to about 10 parts by weight of oil / hour / parts by weight of catalyst.

To explain the present invention in more detail, the following table and the Examples of the following working conditions of the various Components listed.

Conditions in reaction vessel 10

More preferred
area Normal range catalyst
together
settlement 0.6% platinum
on Al ₂ O ₃ 0.01 to 2% platinum
on Al ₂ O ₃ Temperature, ⁰ C .. 480.0 to 510.0 450.0 to 540.0 Pressure, atü 14.0 to 35.0 3.5 to 50.0 ratio of
catalyst
to oil 0.02 to 0.1 0.005 to 0.5 cbm circuit
gas / hectolitre 44.5 to 125.0 17.8 to 178.0 concentration
of H ₂ in
Cycle gas,% 90.0 to 95.0 80.0 to 99.0 609 837/426

Conditions in regeneration vessel 30

Example XV

More preferred
area area Temperature, ° C .. 480.0 to 590.0 370.0 to 650.0 Pressure, atü 0.35 to 28.0 0.35 to 50.0 Dwell time, hours 1.0 to 5.0 0.25 to 20.0 speed of whirling up the gas .... 0.4 to 1.0 0.3 to 2.0

In order to show the effect of chlorine treatment of a deactivated catalyst, the following experiments were carried out carried out. In these tests, equal amounts of one were consumed and then with air regenerated catalyst consisting of 0.6 weight percent platinum on alumina in those mentioned below Temperatures and times treated with the specified amounts of chlorine. The Laue diagrams of the samples were used to determine the platinum crystallite size. The experimental data show that the platinum crystallite size is this Catalyst in a highly active state is below 50 Å.

Reactivation with chlorine

Catalyst weight percent
Cl ₂ based on
the catalyst

temperature Time Platinum crystal
prrnße ° C Minutes A. 235 480 60 218 480 10 193 480 10 128 480 10 <50 480 10 <50 440 30th <50 400 30th <50

Blank test: Spent from 0.6 ° / ₀ of platinum on

Alcoholate alumina existing catalyst

Used catalyst

0.42
0.66
1.58
3.00
4.98
4.98
4.98

It can be seen from the data that the platinum crystallites are greatly reduced in size by the method according to the invention had been. The data also show that the catalyst was used at about 3 weight percent Chlorine was fully reactivated within a reasonable time. However, since this chloride content is a increased hydrocracking and low selectivity during the following periods of use with it, is it is an essential aim of the process of the invention to remove this excess chloride by suitable means to remove.

Example XVI

45

55

In another method, a 759 g sample of the deactivated catalyst was contacted with 0.012 cbm (3.9 percent by weight) chlorine for 2 hours at 480 ° and under 1 ata. The catalyst was then heated to 595 ° for 1 hour. After this treatment, the chloride content of the catalyst was 1.11 percent by weight. The halide was then reduced by washing with 2 volumes of a 10 ° / ₀ aqueous solution of ammonium nitrate. After washing, drying and reduction with hydrogen, this catalyst contained less than 0.01% chloride. The platinum crystallite size was less than 50 Å. In an experiment carried out under the abovementioned conditions, this catalyst gave a hydroformate with an octane number of 95.9.

It is advantageous to use large amounts of chlorine and then reduce the chlorine content Achieving faster reactivation of the catalyst; however, excessive hydrocracking in the Reaction vessel are prevented, the use of smaller amounts of the halogen is more expedient.

To minimize corrosion, it is desirable to have the treatment zone and outflow lines to maintain temperatures above the dew point of the chlorine-containing gases. This is why it is also desirable to reduce the partial pressure of the water in the reactivation system, e.g. B. by rinsing with dry Gases, before bringing the system into contact with the halogen.

Claims (11)

Patent claims: 1. Process for reactivating used platinum or palladium-containing catalysts oxidic carriers which have become ineffective during previous use, characterized in that that the ineffective catalysts with a halogen-containing compound for yourself or treated together with an oxidizing agent. 2. The method according to claim 1, characterized in that catalysts which have become ineffective treated first with the oxidizing agent and then with halogen or halogen-containing compounds will. 3. The method according to claim 1 and 2, characterized in that the catalyst with gaseous Treated gases containing chlorine and free oxygen. 4. The method according to claim 1 to 3, characterized in that the deactivating catalysts first with gases containing free oxygen and then with a mixture of chlorine and free oxygen containing gases are treated. 5. The method according to claim 1 and 2, characterized in that the oxidizing agent is nitric acid and the halogen-containing compound is hydrochloric acid. - 6. The method according to claim 5, characterized in that the hydrochloric acid in one concentration from about 0.1 to 3 molar and from about 1 to 30 weight percent in 50 to 500 weight percent Water, calculated on the total amount of catalyst sators, is used and nitric acid in 0.1 to 2.5 molar concentration as an oxidizing agent in an amount of 0.1 to 8 percent by weight, calculated on the total amount of the catalyst. 7. The method according to claim 1 with treatment of the catalyst in a liquid medium, characterized characterized in that it is treated with a dilute aqueous solution of an inorganic nitrate, e.g. B. Aluminum nitrates and a halogen-containing compound such as aluminum chloride and treated him then dries and reduces. 8. The method according to claim ?, characterized in that the concentration of aluminum chloride Is 0.1 to 3 molar and its amount is 1 to 30 percent by weight of the catalyst and that the concentration of aluminum nitrate between 0.01 to 1 molar and its amount between 0.3 to 15 percent by weight is based on the amount of catalyst, the aluminum nitrate and chloride dissolved in 50 to 500 percent by weight of water, based on the catalyst, can be used. 9. The method according to claim 1 to 8, characterized in that for the regeneration of the Carbon-containing deposits on the catalyst prior to reactivation are eliminated, that they are burned away in an oxygen-containing gas. 10. The method according to claim 1 to 9, characterized in that after the treatment of the Catalyst with the halogen so far the excess of the latter before the subsequent reduction removed that only about 0.01 to 0.5 percent by weight, based on the catalyst, remain. 11. The method according to claim 1 to 10, characterized in that to reactivate the Catalyst anhydrous chlorine in an amount of 0.1 to 10 percent by weight, based on the catalyst, can act at temperatures between 370 and 650 °. 1 sheet of drawings © «09 837/426 2.57