DE2340337A1 - PROCESS FOR HYDROGENATING AROMATIC COMPOUNDS CONTAINING SULFUR-CONTAINING POLLUTION - Google Patents

Description

Process for the hydrogenation of aromatic compounds, which contain sulphurous impurities

The present invention relates to a process for hydrogenation of aromatic compounds, in particular of benzene, alkylbenzenes, polycyclic aromatic hydrocarbons and their alkyl derivatives, in pure form or diluted in various petroleum fractions, in the presence of a composite catalyst system; the method has the advantage that an increased content of sulfur-containing compounds is permitted can be and that a product is obtained that is not only dearomatized, but also desulfurized at the same time.

An important application of this invention is in hydrogenation of aromatic compounds that are present in certain petroleum fractions, e.g. white spirit ("white spirit"),

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which are often used in various industries, e.g. in the production of dyes, rubber, agricultural Solvents etc.

Another, no less important use is hydrogenation of aromatic hydrocarbons present in the. Kerosene- There are fractions that are used as fuels to improve the "smoke point"; this empirical The index is in fact proportional to the hydrogen / hydrocarbon ratio in the fraction in question. This relationship H / 0 is directly related to the heat of combustion, which is the greater, the greater the ratio h / C, i.e. the more complete the aromatic hydrocarbons are hydrogenated. This property is particularly in demand for fuels for jet aircraft, for example, and their demand steadily increasing (consumption in France: 850,000 tons in 1965 »1,500,000 tons in l ° 70, approx. 2,700,000 tons expected in 1975) »whereby the material norms regarding the maximum content of aromatic compounds because of the beginning the supersonic transpcrte are likely to become stricter and stricter.

The previously known processes for the hydrogenation of . Aromatic hydrocarbons can be grouped into two categories, both of which have a number of disadvantages.

The first category of these procedures are one-step procedures, which catalysts use the metals from the iron group (bison, cobalt, nickel) together with metals from the group VXA of the periodic table. In these processes, the catalysts are active in the sulfurized state. The ones in this category the catalysts used in the process

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early hydrodesulfurization of the batch and some hydrogenation of aromatic compounds. Despite the use of hydrogen under pressure and at elevated temperatures (e.g. 35o ° C and 60 kg / cm2) is the residual content of aromatic hydrocarbons however, generally large (at least 3 - 5 vol .- ^); man does not receive a sufficiently dearomatized solvent. About that- In addition, a certain hydrocracking is observed in this type of process, so that subsequent fractionations are required,

Ke> f

which affect the economics of the process.

The second category of procedures are two-step procedures, in which one uses catalysts which consist of metals of group VIII, which after reduction in the metallic state works.

The catalysts used are generally those based on nickel or based on noble metals, such as platinum. These catalysts are particularly sensitive in the presence of Sulfur compounds and / or hydrogen sulfide. One must therefore Desulfurize the batches before hydrogenation and remove the hydrogen sulfide, so that the hydrogenation catalyst with a batch is treated, the sulfur content of which in general is less than 50 ppm (parts per million).

The removal of the hydrogen sulfide between the two stages makes the process very complex. In the case of a single hydrogen circuit scheme, a washing device is required for the recycle gases; if you want to omit the gas scrubbing, so in this case you need two independent circuits. Whichever scheme is used, the process is relative complex and the procedural costs are high.

In certain processes that work with platinum-based catalysts, it is possible to treat batches of up to

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Contains 300 ppm sulfur. Under these conditions, however, the residual aromatic hydrocarbon content becomes rapidly too high to be able to use the product as a solvent; on the other hand it becomes necessary to work at higher temperatures, to compensate for the loss of activity of the catalyst, which is thermodynamically unfavorable and both the yield of the process as well as its profitability, there - as with the processes of the first category - a certain hydrocracking entry·

The method according to the invention brings about the solution to these various Disadvantage.

One can treat petroleum fractions, which up to 1,000 ppm Contain sulfur, which is practically completely dearomatized Obtained fractions which practically no longer contain sulfur (generally less than 1 ppm) with the yield loo wt .- ^ achieved.

The inventive method consists in that at least one aromatic hydrocarbon in the presence of hydrogen at 2oo to k ^ o C, preferably 25o to 35o C, under a pressure of 10 to 2oo kg / cm2, preferably 2o to 7 ° kg / cm2, treated in a reaction system which contains the following stages in sequence: 1. A hydrodesulfurization catalyst with the property of binding the hydrogen sulfide formed in the course of hydrodesulfurization, 2. a hydrogenation catalyst, without intermediate fractionation. For example, benzene, alkylbenzenes (e.g. toluene, xylenes, ethylbenzene), polynuclear aromatic and alkylaromatic hydrocarbons can be treated, either alone or in a mixture or diluted with petroleum fractions, such as white spirit or kerosene, these aromatic hydrocarbons or these mixtures and / or fractions can contain up to 1,000 ppm sulfur.

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The batches used generally have a normal boiling range from 5o to 35o ° C and can come from direct distillation of the petroleum or from other purification and / or conversion processes of the petroleum fractions. You can for example 1 to about 100 aromatic hydrocarbons contain.

That in the method of the invention for simultaneous removal the sulfur compounds from the batch and for binding of the hydrogen sulfide formed during the hydrodesulfurization The catalyst used basically consists of the following components:

a) at least one element that is hydrodesulfurization causes and is known to the person skilled in the art, e.g. molybdenum and / or tungsten with or without nickel and / or cobalt, preferably cobalt-molybdenum, Nicke! -Molybdenum, cobalt-tungsten, nickel-tungsten etc., especially in the oxidized or sulfurized form.

b) alumina.

c) iron oxide or a material which contains iron oxide, the weight ratio Al ₂ O_ / Fe ₂ O "in the catalyst being 0.25 to k _t, preferably 0.65 to 1.8.

Bisen minerals can be used as material containing iron oxide, e.g., hematite, bauxite, or preferably a material called "red mud", a residue of alumina manufacture with the following average composition:

Fe calculated in Fe ₂ O- .......... 3o - 6o $ of the dry weight.

Ti "" TiO ₂ 1 to Io

Si "» SiO ₂ 5 to 2o

Na «·· ^Na 2 ^C0 3 ^{5 to 15}

Al ·· " ^A1 2 ° 3 ^{5 to} 3o

Various ... 0 to 5 (e.g. CaO -

P ₂ O ₅ - V ₂ O ₅ )

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The isolation of the red mud is described, for example, in Kirk and Othmer, Encyclopedia of Chemical Technology, second Ed ₁ Vol. 1 (1963), pages 937-9 ^ 1;

Ullraann's Encyclopedia of Industrial Chemistry, Third Ed, Vol. 3 Pages 375-385, Urban & Schwarzenberg, Munich.

In Bayer's process for producing aluminum oxide, bauxite is dissolved in caustic soda; of the sodium aluminate solution obtained separates an insoluble residue called red mud. The Rotschlamtn is then washed with pure water, to remove the lye and sodium aluminate it contains.

An iron salt can also be used as an iron source, e.g. nitrate, acetate, carbonate, sulphate or chuperide; however are these less preferred.

The amount of the active elements, oxides and / or sulfides of molybdenum, tungsten, cobalt and / or nickel in the catalyst is generally 2 to ho fo _t based on the weight of the corresponding metal. A preferred catalyst contains 5 to 35 wt .- ^ molybdenum and / or tungsten and 1 to 10 wt .- ^ nickel and / or cobalt, based on the metal. The catalyst generally has a specific surface area of 50 to 400 m 2 / gram, preferably 100 to 300 m 2 / gram.

In certain cases the material also contains iron oxide Alumina, for example in the case of red mud; this red mud alone does not generally provide a catalyst with the required specific surface area unless it is used with a mixed with a certain amount of common aluminum oxide, e.g. aluminum oxide gel.

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The catalyst composed in this way is particularly interesting because it allows hydrodesulfurization to take place for a relatively long time can perform without being in the outflowing gases and / or Liquids hydrogen sulfide occurs - like this with the classical hydrodesulfurization catalysts are the case, for example cobalt-molybdenum, nickel-molybdenum, or nickel-tungsten and alumina. The one used in the present invention Catalyst is also of particular interest because it can be regenerated more easily through a simple treatment with steam is, whereby the process according to the invention is particularly economical and is really continuously feasible.

The metal compounds that provide the active ingredients used for hydrodesulfurization can be introduced into the catalyst either by adding them to the mixture of aluminum oxide and iron oxide or red mud or by impregnating them into the shaped (e.g. extruded) mixture of aluminum oxide and iron oxide or red mud . A weight ratio of aluminum oxide / red sludge between 9 and ο.11 % is preferably used for the catalyst support, preferably the ratio 2.3 to 0.43, although these values are not restrictive.

Another technique is to extrude (e.g., extrude) the particles of the conventional hydrodesulfurization catalyst mixed as homogeneously as possible with the particles (e.g. extruded) of the iron oxide and / or red sludge.

As hydrogenation catalysts one can use all generally known - i.e. the metals of group VIII of the periodic table, e.g. nickel, cobalt, platinum, rhodium, rubidium, palladium etc., which are incorporated into or deposited on any carrier are, e.g. aluminum oxide, silicon dioxide, silicon dioxide-aluminum oxide etc. These metals can be used alone or

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in the form of a mixture and / or alloy with one another or with an element from group VIA or VIIA (for example tungsten, molybdenum, rhenium). The content of metals of Group VIIX is generally from 0.1 to 1.5 wt. -Fo of the catalyst.

There is no listing of the compounds of molybdenum, tungsten, nickel, cobalt or precious metals, which are useful for the preparation of the catalysts mentioned; these compounds are well known to those skilled in the art.

The two catalysts used for the process according to the invention can be used in a number of ways.

You can first use the two catalysts in succession Introducing beds into a reactor, the first bed consisting of the hydrodesulfurizing, absorbent catalyst, while the second bed consists of the hydrogenation catalyst.

A second possibility is that you can use the two catalysts introduces into two successive reactors, through which the entire reactants passed in turn will.

Another variant of the process, which is generally preferred, is that the hydrodesulfurizing, absorbent Introduces catalyst into two reactors connected in parallel, which are used alternatively, one for regeneration and the other in function; the hydrogenation catalyst is located in a third reactor which is in operation on the The hydrodesulfurization reactor located there follows.

There is an important property of the method according to the invention in that - whichever of the solutions is chosen, a single reactor or successive reactors - in

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each case has an integrated system with no intermediaries Treatment of the outflowing gases or liquids is required (cooling, separation, gas expansion ...). Furthermore the reaction conditions are such that hydrocracking is practical Is zero; there is therefore no need for a device for fractionating the liquid product.

The regeneration of the hydrodesulfurizing, absorbent catalyst can easily be effected by passing water vapor of, for example, 100 to 600 ° C., preferably 35 ° to 70 ° C., through the catalytic bed, these values not being intended to be limiting. This treatment can relate to the hydrodesulphurizing, absorbent catalyst alone or to the two catalysts according to the invention. The water vapor can be pure or diluted with inert gases; For example, the combustion gases of hydrocarbons are suitable. A water vapor content of at least 10 $ in the regeneration gas is preferred.

This regeneration is intervened as soon as the presence of a significant amount of free hydrogen sulfide is observed in the outflowing gases of the first catalytic zone. During the regeneration process, hydrogen sulfide is released from the catalyst. You can do the regeneration interrupt as soon as there are no noticeable amounts of hydrogen sulfide more to be released.

The duration of the regeneration is generally 10 minutes to k8 hours, depending on the amount of water vapor used.

The regeneration is preferably followed by a hydrogen flush follow, so that the remaining hydrogen sulfide expelled will.

The usual p.p.h. conditions, i.e. the hourly weight - amount of the batch based on the weight of the catalyst - are

- Io -

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- Io -

as follows: in the case of the hydrodesulfurizing, absorbent catalyst it is advantageous to use a p.p.h. between o, l and Io, preferably 0.5 to 5> the optimal p.p.h. is a function the sulfur content of the charge and the alumina / iron oxide ratio in the catalyst; for batches with a content of 300 to 600 ppm sulfur, which are treated with a catalyst in which the alumina / red mud ratio is the same 1, you can be a p.ph. Use from 0.5 to 2.

The p.p.h. the hydrogenation catalyst depends on the hydrogenated Product desired amount of aromatic hydrocarbons; in general it is between 1 and 20, preferably 5 to 15.

These different p.p.h. values are only given as examples; In special cases one also obtains satisfactory results if one uses p.p.h.- ¥ values outside the limits given above.

The invention is explained in more detail in the following examples.

example 1
In this example three catalysts are made.

The first catalyst is a hydrodesulfurization catalyst comprising molybdenum oxide and Cobaltaxid, namely h _t 7 wt .- ^ o CoO and 13.6 wt .- ^ S MoO "in Geraisch with Alurainiumoxid gel. The metal oxides are incorporated in the usual way, for example by mixing the aluminum oxide gel in the presence of a little water with the desired amounts of cobalt nitrate and ammonium paramolybdate; the paste obtained in this way is extruded

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and then calcined in air at 55o C, so that you get the appropriate Obtains cobalt and molybdenum oxides. There is another equivalent method of incorporating the metal oxides in that the previously shaped aluminum oxide is impregnated with aqueous solutions of the catalytic metal salts, whereupon - as described above - calcined in air at 55o ° C.

The second catalyst is a hydrogenation catalyst consisting of o, 3 wt _# -% of platinum, which is deposited on an alumina support. The platinum is deposited in the usual way by impregnating the carrier with an aqueous solution of hexachloroplatinic acid. It is dried and calcined at 55o C.

The third catalyst is a hydrodesulfurizing, absorbing catalyst consisting of 4.7 wt .- ^ cobalt oxide and 13.6 wt .- fo molybdenum oxide; it is obtained by mixing cobalt nitrate and ammonium Moiybdat with a carrier as alumina, red mud, wherein the ratio of aluminum oxide - red mud is 0.67, ie ko -fo weight alumina and 60 wt -fo red mud... It is extruded as indicated above and calcined at 55oC. The composition of the red mud used to make this catalyst is as follows:

₂ O h6, ko weight- fo

Ti O ₂ 4.80

Si O ₂ 13.2o Al 0 _

Na CO "lo, 15 weight ratio" ^X » ⁸

Al ₂ O ₃ 17.57 ^J.

Mn ₂ O ₃ 0.49

V ₂ O ₅ 0.09

P ₂ ° 5 ° »39

H ₂ O 6.2o

Various ο, 71

loo, 00 - 12 -

k 0 9 8 T 0/1 2 1 0

The properties of the solid catalysts used in this example can be summarized as follows:

Hydrodesulfurization catalyst (CATA, HDS)

- Shape: compacts 1.5 mm in diameter.

- Density of the filling / 0.69 g / cm3.

- Total porous volume: 0.5 ^ 5 cra3 / g.

- Specific surface: 324 m2 / g (method B.E-T.).

Hydrogenation catalyst (CATA.H)

- Shape: compacts with a diameter of 1.5 mm "

- Density of the filling: 0.6l g / cm3.

- Total porous volume: 0.7 cm3 / g.

- Specific surface: 214 m2 / g (Method B.B.T.).

Hydrodesulfurizing Absorbent Catalyst (CATA.HDS.A)

- Shape: compacts 1.5 mm in diameter.

- Density of the filling: o.73 g / cm3.

- Total porous volume: ο.5 ^ 6 cm3 / g.

- Specific surface: 188 m2 / g (Method B.E.T.).

The charge to be hydrogenated consists of a petroleum fraction direct distillation, of the white spirit type with the following Characteristics:

- Distillation range ASTM: 152 - 195 ° C.

- Density at 15 ° C: 0.792.

- Aromatic content: 17f5 vol .- ^ o.

- Sulfur content (in the form of sulfur compounds): 40 ppm (Parts by weight).

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The aim is to obtain a product which can be used as a chemical agent and which does not contain more than 3 vol% aromatic compounds,

The following Y «rsnche are carried out:

X) The first time you hydrogenate white alcohol over one Platinum hydrogenation catalyst (CATA. H) under the following conditions?

- temperature * 3oo G »

- Total 45 kg / cm2.

- pph, j h.

- Hg / batch: 1.5 mol / mol.

2) In the second attempt you hydrogenate the same white Spirit in a reactor in which there are two consecutive Catalyst beds are located: the first bed consists of the Hydrodesulph Alloy Catalyst (CATA. HDS), made up of the second bed the platinum hydrogenation catalyst (CATA. H).

The pressure and temperature conditions and the H ₂ / charge ratio are the same as in experiment 1; the pp "h, - ¥ ert is the same for each of the two catalysts4"

3) The third attempt is hydrogenating the same white spirit, but in a reactor in which the hydrodesulfurizing, absorbing catalyst (CATA * HDS.A) is located, whereupon a bed with the platinum hydrogenation catalyst (gATA.h) follows.

The pressure and temperature conditions as well as the ratio H "/ Batch are the same as in experiments 1 and 2j the p.p.h, values each catalyst are as follows:

- CATA. HDS.A p.p.K. = 1.35

- CATA. H. p.p.h. = 8

4Q981Ü / 12tQ

- l4 -

As can be seen from the following Table 1, the device with a pph value of S bsini platinum hydrogenation catalyst gives better results than the device in the experiment. 2 with ppti. = h = 8/2 for the hydrogenation catalyst «

The results of the three experiments are compiled in Table 1, the vol. P of the remaining aromatics being given as a function of the running time of the catalytic system.

Table 1

Number of
Experiments Catalytic
System. VoI . - ° / o aromatics 4o 6o in the Product after. 15o 2oo | 2.4 i
I.
( 4.5 1 CATA. H Io 2o 5.4 So loo: I. 22 nd year 2 / CATA »HDS
\ CATA. H 1.1 2.5 2.4 4.9 ir
C. 3 / CATA. HDS.A
\ CATA. H 1 1.5 <o, 5 <o, 5 1.5 so, 5 <o, 5 <s>, 5 ο, 6

As can be seen, only in experiment no. 3, which after the Process according to the invention is carried out with the recommended catalysts, for a long time a product with the Desired properties (vol .- ^ aromatics less than 3). Furthermore the product is obtained during the entire experiment in a yield of about 100% by weight with a sulfur content less than 0.3 ppm (weight).

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B e i s ρ i e 1 2

The catalytic system of the experiment no. 3 in Example 1, after a period of use of 22o hours (after the supply has stopped from hydrogen and charge and flushed with hydrogen) '2h hours treated with steam of Uoo ° C, anschlies- send 15 hours on a stream of hydrogen at * 100 ° C to remove all of the hydrogen sulfide contained in the system.

Now is an experiment with this regenerated catalytic system carried out entirely with experiment no. 3 of the example 1 is identical; the results compiled in Table 2 are obtained.

Table 2

Time in hours Vol .- ^ o aromatics im Yield (wt .- $) • 99.5 product Io <o, 5 loo , 5 2o <o, 5 ko <o, 5 6o <o, 5 loo, 5 8o - <o, 5 loo ο, 6 loo 15o 1.5 99 2oo 22o

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The sulfur content of the product is below 0.3 ppm in this experiment as well.

This example shows that the system according to the invention is easy is regenerable.

Example 3

In this example, kerosene is treated, the smoke point of which is to be improved} a partial hydrogenation is used for this purpose the aromatic hydrocarbons it contains .

The properties of kerosene are as follows:

- dj ⁵ : o, 821.

- Sulfur ppm (weight): 329 (in the form of sulfur compounds),

- Aromatics: 19 vol .- $ (AFNOR M07 02 **).

- Smoke point: 18 mm (AFNOR M07 028).

- ASTM distillation:

- Starting point: 16h C.

- 5o # distilled: 2ok, 5 ° C

- End point: 2kk, 5 ° C.

You want to get a product with a smoke point higher than 23 mm is; this corresponds approximately to a content of aromatic hydrocarbons of less than Io $

The device used to carry out the experiment is as follows: Bring the hydrodesulfurizing, hydrogen sulfide-absorbing Catalyst in two reactors connected in parallel, one of these two reactors in regeneration is while the other is in function; the hydrogenation reactor follows the reactor in operation,

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but without an intermediate fractionation device. The catalysts used CATA. HD8.A and CATA. H are with identical to those described in Example 1.

The pressure and temperature conditions and the hydrogen ratio / Batch are the same for the two reactors used:

- Qesatntdruck; 55 kg / cm2.

- Temperature: 3oo C. ~>

- H ₂ / batch: 1.5 mol / mol.

The p.p.h. values for each of the two reactors are as follows:

- CATA. HDS.A: 1.35 (for the reactor in operation,

the other is in regeneration).

- CATA. H: S.

The results obtained are summarized in Table 3,

Table 3

Reaction time
in hours 5o loo 15o 2oo 22o 26th 26o 28o 3oo Smoke point in
mm >> * 3o 29 28.5 27 5.8 24.5 23.5 23 Vol .- # remaining
Aromatics (o, 5 o, 5 1.7 2.2 loo, 5 8.2 lo, 3 11, c Yield (wt .- ^) loo

After 300 hours of continuous testing, the limit is reached the desired smoke point (23 mm) reached; the first reactor,

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which contains the hydrodesulf taring, absorbent catalyst, is now regenerated with a stream of steam, such as described in Example 2, while the second reactor with hydrodesulf taring, absorbent catalyst is put into operation until one has reached the limit of the breath point.

Example 4 *

In this example, an experiment similar to that in Experiment No. 3 of Example 1 is carried out, a hydrodesulfurizing, absorbent catalyst being used which, however, does not contain cobalt and molybdenum as hydrodesulfurizing agents, but rather nickel and molybdenum, as a catalyst as in Example 1 described made from nickel nitrate and ammonium molybdate; it consists of k, 7 wt .- ^ S nickel oxide and 13.6 wt -. ^r molybdenum oxide, the Aluminiurnoxid Rotschlarntn-carrier has a weight ratio aluminum oxide / red mud of 0.67.

The hydrogenation catalyst is the same as in the third experiment of Example 1. Also, the reaction conditions are identical with those of Experiment No. 3 of Example 1. The results obtained are summarized in the following table:

..-% aromatic hydrocarbons in the product

after hours

Io: 2o: ko : 80: I80: 2oo: 21o

<ζο.5: <o.5: <o.5 s <o.5: 1.6: 2.9: ^ .6

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As in Experiment No. 3 of Example 1, the product is obtained with the desired properties after a long time with a Yield of about 100% by weight and a sulfur content of less as o.5 ppm (weight).

example

Another experiment is carried out which is identical to the experiment No. 3 of Example 1, but using a hydrodesulfurizing, absorbent based catalyst Nickel-tungsten.

The catalyst is as described in Example 1 from nickel- Nitrate and ammonium volarate produced; it contains 4.7 wt .- ^ Nickel oxide and 21.8 wt .- $ tungsten oxide, the alumina red mud carrier has a weight ratio of aluminum oxide / red mud = 0.67 «

As in Example No. k , the reaction conditions and the hydrogenation catalyst are unchanged.

The results obtained are summarized in the following table:

Vol .- ^ aromatic hydrocarbons in the product after hours

Io: 2o: 4o: 80: loo: 15o: I80: 2oo <o.5: <o.5: <o.5: <o.5: <o.5: <0.5: 2.3:

As in the previous example, a product of at least 3 vol .- ^ o aromatics is obtained in one yield after a long test period of about 100% by weight with a sulfur content below 1 ppm (Weight).

- 2o - / claims

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Claims (1)

claims A process for the hydrogenation of aromatic compounds _t the sulfur-containing impurities, characterized in that dripping a mixture of water and at least one aromatic compound, <lie a sulfur-containing impurity includes at 2oo to h ^ o C and a "pressure of Io to 2oo kg / ctn2 is brought into contact with the following catalysts in sequence: (a) A catalyst consisting of: a) at least one desulfurizing element from the Group of oxides and / or sulfides of molybdenum, tungsten, nickel and cobalt; b) alumina and c) iron oxide, the weight ratio a1 “O_ / Oo of this catalyst being 0.25 to k ; (Β) a metallic hydrogenation catalyst. 2. The method according to claim 1, characterized in that the desulfurizing element (based on metal) is two to ho percent by weight of the catalyst (A). 3. The method according to claims 1 and 2, characterized in that that the desulfurizing element is in the form of the sulfide. - 21 - 409810/1210 H. Process according to Claims 1 to 3, characterized in that the iron oxide is in the form of red mud, a residue from the production of alurainium oxide. 5. The method according to claim k, characterized in that the red mud 3o to 6o wt .- % iron (as Fe ₂ 0 "), 1 to 10 wt .-% titanium (as TiO ₂ ), 5 to 2o wt .- $ & includes silicon (as sxo _2), 5 to 15 wt. ~ 5i sodium (as Na C0 ") and 5 to ¹ weight Jo Jo aluminum (as Al ₂ O,). 6. The method according to claims 1 to 5 »characterized in that the weight ratio Al ₂ Q / Pe ₂ O_ in the catalyst (a) is 0.65 to 1.8. 7. The method according to claims 1 to 6, characterized in that that the specific surface of the catalyst (A) 5o to 4oo m2 / g. 8. The method according to claims 1 to 6, characterized in that that the specific surface area of the catalyst (A) is 100 to 3 ° o m2 / g. 9. The method according to claims 1 to 8, characterized in that the catalyst 5 to 35 wt. -Fi of an oxide or * sulfide of molybdenum and / or tungsten and 1 to 10 wt. - ^ of an oxide or sulfide of nickel and / or Contains cobalt (as a metal). 10. The method according to claims 1 to 9 »characterized in that that the hydrogenation catalyst contains at least one Group VIII metal in metallic form. 11. The method according to claim 10,> ^! characterized in that the metal is platinum. - 22 409810/1210 7340337 12. The method according to claims 1 to 11, characterized in that the temper;
7o kg / cm2. that the temperature 25o to 35 ° C and the pressure 2o to 13. The method according to claims 1 to 12, characterized in that that one treats a hydrocarbon fraction which 1 to 100 wt .- ^ o aromatic hydrocarbons and 1 to Contains l, ooo ppm (weight) sulfur. 14. The method according to claims 1 to I3, characterized in that that after a certain period of use of the catalytic system this regenerated by the Catalysts (A) and (B) passes steam at a temperature of 100 to 600 C, whereupon the hydrogenation is restarted records. 15. Process according to Claims 1 to 14, characterized in that that after a certain period of use of the catalytic system, the catalyst (a) is regenerated by at a temperature of 100 to 600 C passes water vapor, whereupon the hydrogenation is resumed. 409810/1210