DE1018176B - Process for converting hydrocarbon mixtures - Google Patents

Description

The invention relates to catalytic conversion of hydrocarbon mixtures containing naphthenes and paraffins. In particular concerns they a process for the transformation of gasoline and heavy gasoline in the presence of hydrogen and Conversion catalysts containing platinum or palladium in association with an acidic carrier contain.

Such catalysts are particularly useful for converting hydrocarbons. Hydrocracking and isomerization of paraffins and dehydrogenation of naphthenes are among the most important reactions that are promoted by these catalysts, and these are able to to increase the octane number of directly obtained gasoline and heavy gasoline to values that are essential are higher than those that can usually be achieved by thermal deformation. aside from that are the ratios of yield to octane number that can be achieved with these catalysts let, far better than the corresponding ratios, which one with the thermal forming and in most of the earlier catalytic conversion processes.

These catalysts have the advantage of extensive activity over a relatively long period Periods of time than previously known reforming catalysts, and they are therefore for industrial use empowered without regeneration. However, they are still deficient in that they are deficient in the course an extended period of use is not always a desirable balanced activity for the various any reactions that occur. This is especially true for hydrocracking and the Dehydration reactions. In order to maximize the yield and octane number of the reformed product Obtaining any given feed is generally an effective dehydration of Naphthenes to aromatics and an effective use of the hydrogen produced in hydrocracking of paraffins for the purpose of forming lower-boiling paraffins with an improved anti-knock value necessary. Therefore, a decrease in the dehydrogenation activity of the catalyst or vice versa can be excessive increase in hydrocracking activity to cleave a substantial proportion of the naphthenes result in less desirable products than the aromatic compounds that would otherwise result from it can be produced by dehydration. Excessive hydrocracking activity also causes overproduction of light gases that are unsuitable as motor fuel and therefore the yield of the latter to decrease. On the other hand, insufficient hydrocracking activity will result in lower yield and

Forming process
of hydrocarbon mixtures

Applicant:

Universal Oil Products Company,
Des Piaines, 111. (V. St. A.)

Representative: Dipl.-Ing. E. Jourdan, patent attorney,
Frankfurt / M., Kronberger Str. 46

Charles Vincent Berger, Western Springs, 111.,

Vladimir Haensel, Hinsdale, 111.,

and Charles William Matthews, Moline, 111. (V. St. Α.), have been named as inventors

Reduce the value of the product and lead to a loss of hydrogen.

The overall transformation reaction is due to the several diverse reactions that take place simultaneously occur and isomerization of paraffins and dehydrocyclization of paraffins to aromatics include, quite complex. Other complicating factors are, first, the activities of the catalyst for the various reactions are not independent of one another and, secondly, that these activities are not necessarily evenly related to one another, be it in relation to a given impulse to act upon it or in relation to one corresponding deactivating influence. For example, it has been observed at times that the carbonaceous deposits on the catalyst during use reduce the dehydrogenation activity more than the hydrocracking activity. This fact can be further intensified if the purpose of increasing the temperature Maintaining the dehydrogenation activity it was found that the hydrocracking response was greater is whereupon carbon deposition occurs to a far greater extent. The importance of maintaining a desired balance between at least the dehydrogenation and hydrocracking activities of the catalyst is therefore clearly visible.

It has been found that by the presence of water in the reaction zone and appropriate control the amount of this water relative to the hydrocracking activity of the catalyst at a suitable level on the dehydration activity during greatly extended periods of time despite the existence of conditions

70? 757 292

which can otherwise easily disturb the balance of these activities, and regardless factors such as gradual contamination of the catalyst by carbonaceous deposits, which easily degrade these activities.

The invention can be practiced using water drawn from an external source is fed to the forming zone, as well as

to about 125 ° and has a final boiling point in the range of about 175 to about 220 °.

The platinum or palladium-containing catalysts with an acidic support, like them in these hydrocarbon conversion processes are preferred, substantial amounts of Contain platinum or palladium, but for reasons of economy and product yield and its constitution becomes the platinum

using compounds which are below the io or palladium content usually within the Be reaction conditions lie within the deformation range of about 0.05 to about 1.5%. This here

zone to release water to control the extent of hydrocracking that occurs therein. The setting and control of the hydrocracking reaction is usually with little influence on the others reactions promoted by the catalyst achieved. The use of regulated amounts of water or equivalent connections in a suitable manner therefore allows greater adaptability in the

Catalyst component, referred to as an "acidic carrier" for convenience, serves as a porous support or a base and also has an important catalytic ^ function, which is evident its sour character. It is this part of the conversion catalyst that is fundamental affects the hydrocracking reaction of the paraffins, d. H. the special combination of cracking and

Composition of the catalyst with the result- 20 hydrogenation reactions leading to the conversion of nis that the life of the catalyst and the relatively heavy or long-chain paraffins lead to lighter, shorter-chain paraffins. The hydrocracking activity of the present process

used catalyst seems to be closely related

The nature of the product can be favorably influenced.

The method according to the invention is based on the production of aromatic hydrocarbons as well as the state of development of the acid activity or to the production of gasolines of enhanced acidity property of the support or backing Anti-knock value applicable. Primarily in the production of aromatic hydrocarbons who

the water in the deformation zone

to stand.

Several well-known cracking catalysts are among the raw materials that perform the dual function of quantities regulated and adjusted so that Hydrokrak- 30 meet acidic carrier in the catalyst, The effect of the naphthenes is essentially suppressed and that necessary for carrying out the method according to the Erdaher larger yields of aromatics possible finding is required. They include compositional powerlessness will. A significant advantage of the precedence of silica or boric acid with an or lying process lies in the simultaneous erasure of several of the oxides of aluminum, magnesium Reaching an improved service life of the catalyst and the metals of the left row of the IV. group of sators and quality of the product in connection with the Periodic System. Any of these compositions dung with the avoidance of a catalyst rain - has the aforementioned necessary acidic effectiveness, ration. As a result, converting systems from this group are the most suitable Operation of the present process without settling those of silica and aluminum regenerators to be built. This amounts to oxide, silica, and magnesia, silica, and signifies great savings in initial investments. Zirconia, Silicic Acid, and Thoroxide, and Association In addition There will be remarkable savings on boric acid with at least one of these Operating costs due to the elimination of the regeneration metal oxides.

level enables. Overall, there is a basic advantage of the A preferred acidic carrier for platinum

present process is that there is the catalytic 45 or palladium in the catalyst consists of one

Composition of a major amount by weight of one or more of the aforementioned metal oxides, especially aluminum oxide, with a minor amount of a halogen, especially fluorine or chlorine.

The platinum- or palladium-containing catalysts of this type as feed in the process according to the 5 °, In the invention, hydrocarbon mixtures used particularly the former, in association with aluminum frames normally liquid hydrocarbon minium oxide and either fluorine or chlorine or by-fractions with naphthenes and paraffins from one of the are used according to the method of Boiling point below about 220 °. Preferred starting invention such a prolonged equilibrium of Mixtures are those that deliver mainly from the 55 dehydrogenation and hydrocracking activities, like naphthenes and paraffins exist, although that a highly effective transformation of gasoline or in some cases aromatics and / or olefins advance heavy gasoline fractions to products of strong earth could be. The preferred class of high anti-knock values or high concentration kungen boils below 220 ° and includes directly won aromatics over many months without exchange or nene petrol, natural petrol. On the other hand, it is often through- 60 regeneration of the catalyst continuously advantageous, thermally cracked gasoline or can be performed, high-boiling fractions thereof in the forming process. The optionally available as an acidic carrier and the

Forming gasoline and similar hydrocarbon mixtures in an unusually smooth manner and enables effective operation without a regeneration device.

method to use. The gasoline can have a full gasoline boiling range with an initial boiling point of about 10 to about 40 ° and an ending boiling point within the range of about 160 to about 220 °, or a selected fraction of gasoline which will usually be a heavy fraction or heavy gasoline and in general an initial boiling point in the range of about 50

Hydrocracking promoting ingredient was used in the catalyst for the present process Compositions of silica or boric acid and metal oxide can all be made synthetically and suitable manufacturing methods are available in the art for this purpose. However, some compositions can be obtained from inexpensive natural soils. Different

The most important aluminum silicates are ζ. B. well suited for use, especially when treated with acid to increase activity. Synthetically produced acidic carriers include silica-alumina, Silica-Zirconia, Silica-Alumina-Zirconia, Silica-Magnesia, Silica-Aluminum Oxide-Magnesia, Silica-Aluminum Oxide-Thoroxide, Alumina-boron oxide. These supports are in the form of cracking catalysts and they can be prepared in any suitable manner involving precipitation takes place separately, one after the other or together. Preferred cracking catalysts include silica-alumina or silica-aluminum-zirconium oxide.

The various acidic supports which are used for the catalyst in the process according to the invention can be used do not behave quantitatively in the same way towards water additives. A platinum-alumina-halogen catalyst, in which z. B. the halogen consists mainly of fluorine, can have a higher water vapor partial pressure to achieve the highest hydrocracking activity require than a similar catalyst, in which the halogen consists mainly of chlorine. In the latter case, the water requirement is related the acidity is often so small that the highest cracking activity is achieved with a quantity of water which is insignificant in relation to the other materials introduced into the deformation zone, see above that in practical operation the addition of water merely has the effect of suppressing hydrocracking seems to have. The halogen concentration in the catalyst also has a direct relationship with that Position of the location of the greatest hydrocracking activity in relation to the partial pressure of water in the reaction zone; which require higher halogen concentrations generally more water for peak hydrocracking activity.

Other variable factors can also affect the effect of water vapor on the hydrocracking reaction affect in the deformation zone. Such variables are e.g. B. the relative concentrations of naphthenic and paraffinic hydrocarbons in the feed, the severity of the transformation treatment and the presence or absence of oxygen compounds in the feed. When trying it was found that the influence of water on the hydrocracking activity of the catalyst in feeds of higher paraffin content is higher. The influence of water on hydrocracking is at be stronger under more severe forming conditions than under milder conditions. Oxygen compounds tend in the feed if they can be converted with water under the forming conditions, to give the same influence or effect as an equivalent amount of water added.

In a particular embodiment, the invention is applied to a mode of operation that is extends over an extended duration of the proceedings. The tendency towards hydrocracking increases during the latter stages to, and according to the invention, the degree of hydrocracking over this process time is im essentially kept constant in that at least during the last stage of the treatment period Water introduced into the deformation zone and its partial pressure is regulated so that the increasing Hydrocracking tendency is suppressed. In some cases the nature of the feed are and the deformation conditions such that the initial stages within the process flow in the absence of added water can be carried out. The method according to the invention can find also in another special embodiment to a mode of operation application in which during the continuous passage of the hydrocarbon mixture and hydrogen through the Deformation zone the deformation temperature is increased at intervals in order to reduce the catalyst activity balance. In this procedure, the water content of the reaction mixture is in accordance with of the invention increased by such controlled amounts that the tendency to increase the hydrocracking reaction is suppressed with the rise in temperature.

In working according to the invention, water or steam can be added to the feed in the required amounts or can also be fed directly to the reaction zone. If desired, raw materials, which form water under the conditions prevailing in the deformation zone, instead of Water can be used. Raw materials of this type are oxygen and certain alcohols, such as tert. Butyl alcohol, Ketones, peroxides, hydroperoxides and phenols. In general, the use of Prefer water because it is low cost and no contaminating organic radicals in the reaction mixture introduces. It is often desirable to control the hydrocarbon feed to achieve close control to fractionate to get dissolved water, oxygen- and oxygen-containing compounds from it to remove and the fractionated feed the desired amount of water or an equivalent Add connection. If one proceeds in this way, the partial pressure of the water be set tight in the conversion zone because it is not due to fluctuating amounts of water or the like. is influenced in the feed. Instead of fractionating the feed to dry it is in some cases it is also convenient to obtain the same results by removing the feed at elevated temperature by a layer of activated aluminum oxide or a similar drying agent directs.

According to the present process, hydrocarbon mixtures using the catalyst in a fluidized bed, a fluidized fixed bed, a suspension or an agitated one Bed can be reshaped. However, it is preferred to use a fixed bed mode of operation mainly because such a mode of operation reduces the abrasion losses of the relatively expensive catalysts reduces to a minimum. One such operation according to the invention is that hydrogen and preheating the hydrocarbon feed to a transition temperature and then mixing it with the required amount of water vapor through a plurality of essentially adiabatic Reaction zones are passed, which have a catalyst made of platinum or palladium and an acidic acting carrier included. Usually the reaction mixture stream is between each two of the successive Reaction zones heated again to the desired reaction temperature to meet the need to cover the heat of reaction. The formed hydrocarbons are recovered, and the Hydrogen is separated off and returned to the reaction zone. In another type of procedure with a fixed bed, which is particularly suitable for certain processes, the hydrocarbon

charging together with hydrogen and the required amount of water through catalyst-containing Pipes routed to the radiant heat of a radiant flame and the resulting hot combustion products are exposed. Here the formed product is recovered and the hydrogen separated and returned to the reaction zone. Hydrocarbon transformations carried out in accordance with the invention are usually carried out at temperatures from about 320 to about 540 °. At temperatures in the vicinity of 320 ° the reaction rates are rather slow, and very low space velocities must be used to get any appreciable conversion. At temperatures above 540 °, a noticeable thermal conversion occurs, that of a poorer one Yield of liquid and more rapid deactivation of the catalyst is accompanied.

The pressures at which the present process is carried out are within the range of about 3.5 to 80 at; a total pressure of at least 13.5 atm is usually preferred. The hourly space velocity by weight, which is the weight of the hydrocarbon feed per hour and per unit weight of catalyst is defined in the deformation zone, shall be within the range from about 0.2 to about 40. The amount of hydrogen fed in with the hydrocarbon mixture should usually be from about 0.5 to about 15 moles per mole of hydrocarbon.

The amount of water required to achieve the desired degree of hydrocracking can be determined in several different ways. For example, it is possible to determine whether the amount of water added to the charge in a multiple adiabatic reaction vessel system, ie, a system of several adiabatic reaction vessels connected in series, is correct by observing the total temperature drop through the reaction vessels. The following should be noted for explanation; if a fresh catalyst gives a satisfactory product distribution for a given total JT (this is the sum of the temperature gradients observed in each of the adiabatic reaction vessels of the system) then the amount of water added as the process time advances and the reaction temperature is increased, be such that the total J T is held substantially constant. When this procedure is followed, the ratio between hydrocracking and aromatization is kept substantially constant and, as a result, the product distribution will remain approximately the same as observed at the start of the same process time or experiment. However, if there is a substantial change in the heat capacity of the reaction mixture in the reforming zone, e.g. B. in the series of adiabatic reaction vessels, e.g. B. has occurred as a result of a change in the composition of the cycle gas or in the ratio of cycle gas to hydrocarbon mixture, this fact should be taken into account. In such a case, a more precise method according to the invention is to adjust and control the water content of the reaction mixture so that the product of heat capacity and AT is kept substantially constant so that the ratio between hydrocracking and dehydrogenation remains substantially constant.

Instead, you can also determine the exact amount of water by looking at the composition of the reaction product mixture is observed because the amount of normally gaseous hydrocarbons which are generated per unit of quantity of the starting hydrocarbon mixture is a An indication of the extent of hydrocracking and the amount of hydrogen being formed at the same time is an indication of the extent of dehydration. The water content of the deformation zone is then adjusted in accordance with the fluctuations in such a composition that the desired degree of hydrocracking is obtained or maintained. This setting occurs in practice favorably increases according to the fluctuations in the production ratio of hydrogen normally gaseous hydrocarbons such that this ratio is essentially constant remain.

The examples serve to illustrate the invention.

example 1

This example illustrates the gradual development of increased hydrocracking activity relative to dehydrogenation activity, which is often observed. A directly obtained gold coast heavy gasoline with a specific gravity of 0.7628 and a boiling range of 88 to 203 ° was transformed at 47.5 at., A liquid hourly space velocity of 2.0 and a molar ratio of hydrogen to hydrocarbon = 6: 1 in the presence of a catalyst, which contained aluminum oxide with 0.3% platinum, 0.2% fluorine and 0.4% chlorine. The feed passed sequentially through three adiabatic reaction vessels with the catalyst. The inlet temperatures to the zones were set so that a product was obtained which, if 0.795 cm ^{3 of} TEL (tetraethyl lead) were added per liter, would have an F-2 octane number of about 80 '. Characteristic results of the tests are summarized in the following table:

1 Peric
² de No.
15th 16 Hours in the stream 115 146 821 870 Temperatures at the inlet of the catalyst layer in ⁰ C
Layer No. 1 508 508 516 516 Layer # 2 496 495 505 505 Layer # 3 484 484 494 496 Octane number
FI Sure 85.3 85.2 84.3 83.6 FI + 0.795 cm ³ TEL / liter 94.5
78.3 96.6
78.3 94.6
78.6 94.2
78.0 F-2 Sure 89.1 89.4 90.0 89.7 F-2 + 0.795 cm ³ TEL / liter

Period no.
2 I 15

16

Formed product in percent by volume of the charge

Aromatics in product as weight percent of the feed

Exploit

Hydrogen as a weight percent of the feed

C ₁ g mole / 100 g feed

C ₂ g moles / 100 g feed

C ₃ g moles / 100 g feed

C ₄ g moles / 100 g feed

C ₅ g moles / 100 g feed

C ₆ g moles / 100 g feed

Total gram moles of hydrocarbon per 100 grams of feed

Increase in g-moles of hydrocarbon per 100 g of feed

"TEL" means tetraethyl lead, liquid; FI and F-2 octane numbers are determined by the test method D 908-51 or the engine method D 357-49 of the ASTM (American Society for Testing Materials). Periods 1 and 2 in the table above mean tests that were carried out at the beginning of the test run and periods 15 and 16 tests that were made at the end of this test run. It was necessary to increase the catalyst temperature substantially if the experiment continued in order to compensate for the decrease in catalyst activity, ie higher temperatures were required towards the end of the experiment in order to produce a reformed product of the same anti-knock value as it was at the lower temperatures at the beginning of the experiment Attempt was generated. On average, the gasoline yield fell by about 2% in the course of the experiment, and the hydrocracking, measured in terms of the molar increase in hydrocarbons, increased by about 25%. The increase in the production of gaseous hydrocarbons was accompanied by a decrease in the net production of hydrogen. This tendency to change in the 93.0
38.7

0.92

0.054

0.037

0.075

0.100

0.108

0.764

1.138
0.245

94.2
37.7

0.88

0.046

0.043

0.077

0.112

0.118

0.765

1.161
0.268

91.2 36.4

0.53

0.076

0.077

0.122

0.100

0.127

0.743

1.245 0.352

91.8 33.5

0.39

0.079

0.081

0.120

0.109

0.120

0.744

1.253 0.360

Product yield and distribution gradually led to a point where hydrogen consumption occurred and when this occurs, the proceedings are no longer entertaining. If there is no outside hydrogen in the System is introduced, the non-regenerative character of the process is destroyed, and the carbon formation on the catalyst increases at a rapid rate until the catalyst is practically has lost all activity. This is evidence that the hydrocracking reaction is necessary to be checked in the course of the forming work with a catalyst of the specified type, and it is made clear that under certain circumstances, as in this example, the hydrocracking control is the Effect of suppressing the tendency to increase the conversion of hydrocracking in the course of the Must have transformation work.

Example 2

The following information shows the influence of the addition of water and was carried out in continuation of the im Example 1 obtained experiment described.

Period no.
20 I 21

22nd

Hours in the stream

Moles H ₂ O / mole hydrocarbon feed

Temperature at the inlet of the catalyst layer in ° C

Layer No. 1

Layer # 2

Layer # 3

Temperature drop within the catalyst layers in ° C

Layer No. 1

Layer # 2

Layer # 3

Yield of reshaped product as a percentage of the volume of the charge

Hydrogen production in liters per liter of feed

*) 'Temperature rise.
**) Not determined due to lack of thermocouples.

1070 0

521 514 517

4.4 *)

92.3 -28.2 1147
0.0137

521
514
517

3.9

3.9 *)

0.6 *)

94.0
-25.5

1234
0.206

521
511
499

22.8

8.9

10.6

95.8 +10.3

1266 0.222

520 519 518

21.2 7.8

95.3 35, *)

70S 757/292

18th

Period no. 21 20th 4.5 13.7 32 33 26.5 44.0 71.4
87.0
67.7
82.6 76.5
89.1
71.8
85.8

22nd

Methane product in liters per liter of feed

Aromatics in the product in percent by weight of the C _e + product

° / o Liquid product with a boiling point of up to 100 ° in an ASTM distillation

Octane numbers of the formed product

F-I Sure

FI + 0.795 cm ³ TEL / liter

F-2 Clear

F-2 + 0.795 cm ⁸ TEL / liter

It can be seen that the addition of water selectively suppressed hydrocracking without dehydration or to significantly influence aromatization. This is partly due to the temperature increases or waste within the catalyst layers. These temperature differences between the Inlets and outlets are the net impact of exothermic hydrocracking and endothermic Dehydration (or aromatization) reaction. In periods 18 and 20, in which the When hydrocracking prevailed, the temperature drop in the No. 1 layer was mild and rises were obtained in layers # 2 and # 3. On the other hand, in periods 21 and 22 became noticeable Temperature drops are obtained in all three layers, indicating that the water is excess Suppressed hydrocracking. This is also expressed in the information on hydrogen and methane production, the aromatic content of the liquid product and the percentage of distillate at 100 ° in the ASTM distillation. With the applied special working conditions and loading and the catalyst, these values indicate that the addition of water should be greater than about 1.5 mol percent the hydrocarbon feed to significantly affect the hydrocracking activity. It should be remembered, however, that this catalyst was rather highly carbonized and that a different amount of water is required with a fresh catalyst of the same composition can be to deliver the same effect.

Example 3

This example illustrates the manner in which a small change in composition the acidic catalyst support can influence the effect of the addition of water to the deformation zone. In this attempt was a heavy gasoline fraction obtained from a Kuwait crude oil with a specific gravity of 0.7678 and a boiling range of 138 to 196 ° at 47.5 at, a liquid hourly space velocity of 3.0 and a molar ratio of hydrogen to hydrocarbon = .8: 1 in the presence of a catalyst reshaped from essentially the following composition;

Platinum 0.4 percent by weight

Fluorine 0.5 percent by weight

Chlorine 0.2 percent by weight

Alumina remainder

Hydrogen was charged sequentially through three adiabatic reaction vessels 19.8

35

46.0

77.5
90.6
72.9
85.7

9.3
39
34.0

78.0
91.0
73.5
86.0

conducts containing layers of the above catalyst. The inlet temperature of each reaction

ao vessel was kept at 493 °. The effluent from the third vessel was cooled and migrated with it a noticeable pressure reduction through a gas separator, where a hydrogen flow is used for the return was removed to the first reaction zone. The liquid withdrawn from the separation vessel was in a Fractionation column stabilized to remove normally gaseous hydrocarbons from the liquid transformation product to separate. Two separate experiments were carried out, each lasting 72 hours. Samples were taken and measurements made at the beginning and at the end of each experiment. In the first attempt, no water was introduced into the reaction zone, while in the second attempt water was added to the feed in an amount = 0.18 weight percent. the The main results were as follows:

Experiment No. 1 Experiment No. 2 test Beginning end end Beginning Added 0.18 0.18 Water in Ge 0 weight percent 0 Gas generation in Liters per liter 35.4 35 feed 64 75 69.5 Separation vessel .. 69 55 Stabilizer .. 60 0.47 0.5 Ratio of 1.16 Gas generation 1.15 Reshaping product Content of Aromatics in 46.2 Weight percent .... 46.5 85.8 82.7 Octane number 81.6 (F-I clear) .. 82.3

The volume of the stabilizing gas is a reliable, semi-quantitative measure of the extent of the Hydrocracking reaction and the volume of separator gas is a comparative measure of the extent of the simultaneous dehydration reaction. The change in the ratio of these reactions to one another is from the ratio of gas production

evident. This is the volumetric ratio of the separator gas generated during a given period of time to the stabilizing gas generated during the same period of time. The values therefore show that in contrast to the hydrocracking suppressing effect of water in Example 2, the Introduction of water = 0.18% by weight of the feed in the present example, the hydrocracking reaction increased. In contrast, the measurements of the aromatic content of the formed product were evidenced the dehydration reaction is not seriously damaged. It should be emphasized that the catalyst in the present Example contained a cracking component in which the halogen consisted predominantly of fluorine.

Example 4

With the same heavy gasoline fraction and under practically the same conditions as in Example 3, but with a catalyst containing 0.3 percent by weight of platinum and one mainly composed of silicon dioxide, combined with 7.5 percent by weight of aluminum oxide contained existing acidic carrier, Further experiments were carried out, which are the following Results with and without additional water in the forming zone provided:

to the rather low level of 0.1% by weight of the feed reduces the initial effect.

Example 5

If the same feed is used under practically the same conditions as in Examples 3 and 4 were used, reshaped, but using a catalyst containing 0.3 weight percent platinum an acidic carrier, which mainly consists of 93.5 percent by weight aluminum oxide and 6.5 percent by weight If there is boric oxide, the following results are obtained with and without the introduction of water obtain:

Added water in
Weight percent of
feed

Ratio of gas generation

Formed product
Aromatic content in percent by weight

Octane number

Experiment no. 1 2 3

0.0 0.95

44.8 78.1

0.05 0.81

44.0 77.1

0.1 0.96

44.0 77.3

35

From the ratio of gas production it can be seen that where the acidic component of the catalyst is a silica-alumina mass was, the influence of the first addition of water is, a less pronounced increase in the hydrocracking activity than in the case of the alumina-fluorine component of the catalyst Example 3, but the influence is far greater than in the case of an alumina-chlorine carrier, which practically only leads to a decrease in hydrocracking activity due to a similar addition of water the deformation zone. While the first water addition of 0.05 percent by weight of the Feed in the present example results in an increase in hydrocracking, the further increase in the water vapor present in the reaction zone

Attempt KTr. 2 1 Added water by weight 0.05 percent of loading 0.0 0.9 Ratio of gas production .. 1.0 Formed product Aromatic content in Ge weight percent 45 0 Octane number 45 0 77.0 Octane number 76.8

The carrier made of aluminum oxide and boron oxide shows a similarity to that of aluminum oxide and contains silica under the conditions of the experiments.

Example 6

A number of experiments were carried out to investigate the effect of increasing water vapor partial pressures in to show the deformation zone. In these trials, a Kuwait range heavy fuel gasoline was used from 93 to 193 ° passed through a single reaction zone containing a catalyst of essentially contained the following composition:

45

Platinum 0.3 percent by weight

Fluorine 0.5 percent by weight

Chlorine 0.05 to 0.1 percent by weight

Alumina remainder

The feed was deformed at 450 ° while passing over the catalyst at a pressure of 34 at, a liquid hourly space velocity of 2.0 and in all cases in the presence of about 10 moles of hydrogen per mole of hydrocarbon was passed. Different amounts of tert. Butyl alcohol were injected into the feed stream as a source of water. The results obtained are compiled in the following table. The values for the amount of water introduced are the Equivalents of the amount of alcohol actually added:

Water as weight percent of the feed. Gas generation in liters per liter of feed

Separator

Stabilizer

Octane number (F-I clear)

2 Attempt no. ^4th 5 1 0.5 3 0.25 0.5 0.0 40.6
23
68.9 0.1 43
31.7
70.4 39.3
24.6
69.0 54.1
19.6
63.3 36.7
29
70.0

39.1 19.7 67.4

These values indicate that for a catalyst containing a fairly high concentration of fluorine, the hydrocracking reaction (measured by stabilizing gas generation) increases to a maximum value with increasing water additions and then decreases again, with a simultaneous decrease in the dehydrogenation reaction (Separator gas generation) ran alongside. The general decrease in activity at higher levels Water concentrations can be attributed to a surface-masking effect of the water.

It should be noted that the values given in these examples are decisive for the charges and the particular conditions used are and that the yield and product distribution are apparent may change with different feeds, for example hydrocarbon mixtures of strong naphthenic nature or different boiling range or when using more or less harsh working conditions. It should also be noted that in the description and claims in each case indicated platinum or palladium content of the catalyst on platinum or palladium as metal calculated is based, but this is not intended to mean that the platinum or palladium necessarily is in the free metallic state in the catalyst during its use. The exact shape in which one of these precious metals is present when the catalyst is completed or used, has not been precisely determined. The noble metal can be in the metal state and / or as a metal compound are present in association or in connection with the other components of the catalyst. In a similar way Way is in the description and claims, as far as halogen is used in the catalyst mass, its amount given as free halogen, although the exact nature of the association between the halogen and the remaining catalyst constituents have not been clearly determined. It is believed, that the halogen has some physical attachment or chemical association with the metal oxide component of the support and / or the platinum or palladium content of the catalyst.

Claims (5)

Claims: 45 1. Process for the transformation of hydrocarbon mixtures, which are normally liquid paraffinic and naphthenic hydrocarbons with a boiling point below about 220 ° contained in a deformation zone at temperatures between 320 and 540 ° under a pressure in the range from 3.5 to 80 at in admixture with hydrogen and in the presence of a platinum or Palladium and an acidic carrier containing catalyst, in particular one about 0.05 to 1.5 percent by weight of platinum and one made of halogen! Aluminum oxide or a mixture catalyst containing silicon dioxide and aluminum oxide carriers, wherein a hydrocracking of paraffins and a dehydrogenation of naphthenes in a predetermined Relationship to each other take place, characterized in that when impaired of the transformation equilibrium as a result of a drop in the production ratio of Hydrogen to normally gaseous hydrocarbons noticeable increase in the ratio of hydrocracking to dehydrogenation caused hydrocracking during operation Controlled provision of water in the deformation zone and the amount of water increased for a long time is until about the predetermined ratio of hydrocracking to dehydrogenation is reached again is. 2. The method according to claim 1, characterized in that a reduction in the catalyst activity during the continuous passage of a hydrocarbon mixture and hydrogen compensated by the deformation zone by increasing the deformation temperature and by increasing the water content of the reaction mixture by this increase in temperature each increased tendency to hydrocracking is suppressed and the ratio of hydrocracking is kept essentially constant for dehydration. 3. The method according to claim 1 and 2, characterized in that with continuous passage a hydrocarbon mixture and the hydrogen through a series of catalyst-containing deformation zone having adiabatic reaction vessels, corresponding to the amount of water Changes in the product (a) the heat capacity of the reaction mixture and (b) the sum of the temperature gradients in the adiabatic reaction vessels is regulated so that this product (a · b) is kept essentially constant. 4. The method according to claim 1 to 3, characterized in that the regulated amount of water is introduced into the reforming zone together with the hydrocarbon mixture. 5. The method according to claim 1 to 3, characterized in that the regulated amount of water in the deformation zone in situ from an oxygen-containing organic compound, in particular an alcohol, is formed under the conditions prevailing in the reforming zone Water is released and added in the appropriate amount to the hydrocarbon mixture to be introduced will. Documents considered: German Patent No. 950398. © 709757/292