DE1667121A1 - Process for the transformation of hydrocarbons with steam - Google Patents

Description

The priority of registrations in Great Britain from 2.3.1967, 21.7 * 1967 and 31.1.1968 has been claimed .

The invention relates to a method for reforming hydrocarbons with steam, catalysts for the process as well as a process for the production of certain catalysts for the procedure.

In earlier processes for the conversion of gaseous hydrocarbons with steam, e.g. in the twenties

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published procedures, consisted of the proposed catalysts usually made of nickel with a minor. Amount of an oxide serving as a promoter, such as aluminum oxide or Oeroacyd »optionally on pumice tain as a preformed carrier. Such catalysts were, however, for the transformation of un-

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Saturated hydrocarbons are unsuitable even under atmospheric pressure, as they lead to the formation of carbon as a by-product tended to reform such hydrocarbons composite catalysts were therefore used with steam, which brought together the handle and the carrier material to produce them were that powdery nickel compounds mixed with powdery carriers in the wet state and often shaped with the aid of a hydraulic binder. For the transformation of even higher hydrocarbons (e.g. from naphtha), in particular under atmospheric pressure, catalysts were invented in which the deposition of carbon was prevented by the presence of alkali metal compounds. Such catalysts are in particular in the applicant's British patent specification 953,877. It has also been suggested for that Transformation of liquid hydrocarbons with steam as well to use such catalysts »those made of nickel and other compounds preventing the deposition of carbon, like 25.B. Copper, chromium and manganese compounds exist.

It has now been found that certain catalysts, in general the catalysts published in the 1920s similar, for the transformation of liquid hydrocarbons are very active »show depending on the operating conditions they have a reduced tendency towards carbon deposition even at low steam ratios and with relatively small or no amounts of compounds which the Able to prevent deposition of carbon. In particular, these catalysts are very suitable for the conversion with steam at moderate temperatures, for which technically usable Catalysts with sufficient activity have so far been difficult to find.

According to the invention, a continuous process is sur Transformation of a normally liquid hydrocarbon

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BATH

charge with a boiling point below 35O ⁰ C carried out over a catalyst, which consists of a preformed carrier, the a metal or oxide with a catalytic effect for the conversion of hydrocarbons with steam and at least one acting as a promoter compound of beryllium or magnesium or an element of groups III to ¥ 11 of the table of the periodic system with an atomic number of 90 or less and possibly also a compound that prevents carbon deposition.

Some of the catalysts that can be used according to the invention are presumably new. Therefore, the invention creates a new material - a catalyst which consists of a metal of the cobalt or platinum group, at least one compound of beryllium or magnesium serving as a promoter or an element from groups III to V of the table of the periodic table with an atomic number of at most 90 and a preformed carrier material which preferably contains less than 65% by weight of silica or, if the silica content is above 65% by weight, less than 12 5% of alumina. Also, certain preferred nickel-containing catalysts of the type below are likely to be new. According to the invention, precursor materials are created from which such catalysts by simple processes, such as. Calcination, or mostly reduction, can be produced. '

The most widely used catalytic metals for the transformation of hydrocarbons with steam are Uiekel, cobalt and the six platinum metals. These can be in Process according to the invention individually or together with other metals of the same type or with other catalytic Metals are used. In particular, combinations of nickel or cobalt with one or more of the six result Platinum metal catalysts with a usefully high activity.

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Bathroom original

The preformed support for the catalyst can have any of the usual shapes such as rings, cylinders, and irregular lumps or agglomerates. The rings or cylinders can have a regular shape, such as is formed, for example, by pelletizing, or a less regular shape, such as is formed, for example, by extrusion. The shaping can be done by granulating, extruding, compacting or by chopping up coarse pieces.The material can be a natural or a synthetic material, or it can be a mixture of these, e.g. W is held together.

The size gradation of the carrier for the catalyst depends on the operating conditions of the process in which the catalyst is to be used. For the production of lean town gas or of synthesis gas for the formation of ammonia or methanol or for use in the carbonylation or the synthesis of "oxo" compounds, the hydrocarbon conversion is carried out with steam at high temperatures, for example above 75O ⁰ O, at very low temperatures The chemical reactions that occur are strongly endothermic in the end result. The rate of reaction is therefore dependent on the heat transfer; therefore, what is needed is a catalyst with a moderate surface area to volume ratio. In the production of town gas, the heat absorbed by the hydrocarbon conversion with steam is partially compensated for by the heat given off during the methane formation, so that preferably catalysts with a larger surface area to volume ratio are used. At even lower temperatures, at which the heat emitted from methane formation is equal to or greater than the heat absorbed from hydrocarbon conversion by steam, the larger surface-to-volume ratios are appropriate. Of course, there is a limit to the fact that too great a pressure drop across the catalyst

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"bed should be avoided. In a procedure in which the endothermic and exothermic reactions take place in different zones, catalysts can be used according to the invention a relatively low surface to volume ratio in the endothermic zones and catalysts with a relatively high ratio of that. Surface can be used to volume in the exothermic zones.

The following can be mentioned as examples of a suitable ratio of surface area to volume:

a) for the mentioned high-temperature processes less than al3 daa { corresponding ratio for a tablet in the form of a straight cylinder with a length of 12 mm and a diameter of 12 mmj

b) for the town gas process mentioned, the same as the corresponding ratio for tablets in the form of straight lines Cylinders with length and diameter in the range of each 3 to 12 mm, in particular 4 to 9 mm.

The carrier preferably has a relatively large average pore radius, preferably in the range of 500% or more, particularly over 1000 JL It is preferably so * porous that he g more than 20 at 9O ⁰ C, in particular more than 30 g water per 100 g of the carrier absorbed. Such large mean pore radii and porosities are usually accompanied by small surfaces, e.g. of less than 15 or 8 m / g in the case of clays with mean pore radii of 500 or 1000 pounds, as can be achieved, for example, by heating active alumina to suitable temperatures:
can be produced.

suitable temperatures above 100O ⁰ O, for example 1100 to 1500 ⁰ O,

The catalysts in which the active metal is or contains nickel, the promoter is a compound of an element of the groups III to V of the table of the periodic table and

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the preformed carrier material has the aforementioned mean pore radius and / or has the aforementioned water absorption and less than 65 wt. # silica or at a silica content of more than 65% by weight less than 12 jS; alumina contains are also presumably new masses.

Alumina is very expediently used as the Tägerst & ff. Magnesia, titanium dioxide, zirconium earth, chromium earth, silica, alumina / silica mixture and magnesium silicates can also be used for this purpose. These substances can be used as natural products, as long as absent for the catalytic metals ψ toxic contaminants or removed v> jrden and as long as have the desired mikromeritisohen properties (in the preferred catalysts) the excipients, or obtained by, for example, calcination can. For example, the carrier fits the catalyst used according to the invention can be formed from bauxite, kaolin, pumice stone or heerschaum. The carrier contains a we lateral amount of divalent and trivalent oxides _s so "these least to a third party, preferably with spinel structure exists. Is! The carrier kieselerdehaltig" so the proportion of silica is preferably little as 5 #, especially less than $ 1.

The carrier toi J can be held together e.g. by Sinter odes -iaroli a hydraulic cement like portland cement or a low silica alumina cement or chrome cement. Alumina types with high Binding force such as that described in Applicant's British Patent 1,028,753 can be used.

The promoters which can be incorporated into the catalysts to be used according to the invention are preferred the oxides of aluminum, beryllium, magnesium or metals of the Α-subgroups of groups III to VII of the table of periodic system and include the oxides of the rare earth

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metals »scandium, yttrium, titanium, zirconium ^ hafnium, -Thorium, Vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese and rhenium. The oxide of aluminum gives very good results. More than one promoter can optionally be used. If the element of the promoter is a proportionate has volatile or low-melting oxide, and if it is initially present in the form of this oxide, it should be Oxide preferably be reduced to a non-volatile oxide before allowing the catalyst to reach operating temperature for the transformation process is heated.

In addition to the aforementioned promoter, a uranium compound can also be present. If the catalyst contains an auxiliary compound, i.e., a compound that can reduce the deposition of carbon, this compound is suitably a compound an alkali metal or alkaline earth metal. The alkali metal content can e.g. range up to 5 wt .-? * (Calculated as KgO equivalent) if both the carrier as well as the promoter consist essentially of clay. Pure a given batch, a given vapor ratio and For a given pressure, the minimum content of these compounds appears to increase with an increase in the operating temperature of the procedure.

Is used as active metal cobalt or contains the active metal a platinum group metal, the promoter can be uranium or an alkaline earth metal. As a modification of the procedure it is therefore proposed according to the invention that the catalyst consists of cobalt or a metal of the platinum group and the element of the promoter is uranium or an alkaline earth metal. In particular, the active metal exists according to this modification from one or more base metals of Group VIII of the table of the periodic table in Mixture with one or more platinum group metals.

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The catalysts used in this modification and the premasses from which they are made in a simple manner, e.g. by Calcination or (mostly) reduction can be produced, are probably also new. Calcium oxide is preferred as a promoter.

The proportions of the catalytic metal, the promoter and the auxiliary connections on the one hand to preformed beams on the other hand can vary within wide limits depending on the desired The activity of the catalyst will vary as long as the amounts of catalytic metal, promoter and auxiliary connections are sufficient to achieve a layer firmly attached to the preformed carrier. For example is attached a catalytic layer of nickel, alumina and potassium carbonate the nickel content (calculated as NiO) is expediently in the range from 4 to 40 $ based on the total catalyst.

In the material applied to the preformed catalyst support, the concentration of the active metal is preferably high. "High" should be understood to mean over 20 $> (calculated as monoxide based on the total material of monoxide and other ^{constituents stable at 900 0} O) if a base Metal, such as Nickel or cobalt is present. This concentration is preferably above 50 μl, in particular in the range from 70 to 98 μl. If a platinum metal is present alone or in a mixture with such a base metal, the concentration of the platinum metal (calculated as metal based on the total material of this metal and other ^{components stable at 90O 0} C of the material to be applied to the preformed catalyst support) is available - • preferably in the range of 3-90 wt .- #, in particular 10 80 wt .- #.

The concentration of the promoter based on the total catalyst is preferably at least 0.01 wt .- # (calculated as oxide), e.g. in the range 0.1 to 5 wt. given

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At any rate, however, higher concentrations, e.g. up to 20 Gew "- $, can be used.

The catalysts to be used according to the invention can be produced by impregnating a preformed carrier material with compounds of the catalytic metal, promoters and auxiliary compounds. The bonds to be applied by impregnation can be in the form of pastes or finely divided precipitates. However, it is preferred to apply them as salts which can be thermally or hydrolytically decomposable to oxides, in particular salts. Organic salts, especially pormates, can be used when using the | wants to have catalytic metal in the reduced state as a result of thermal decomposition. The concentration of the impregnation solution is chosen so that the desired ratio of catalytic metal and promoter to the preformed support is achieved, the impregnation process being repeated several times if necessary. The auxiliary connections can be applied at the same time. However, they are preferably applied subsequently, in particular after the compounds of the catalytic metals and promoters have been dried and calcined, unless, as in the modification according to the invention, the active metal is a metal of the platinum group and also a compound of an alkaline earth metal is available. If the auxiliary compound is an alkali metal compound or a compound of an alkaline earth metal, it is added at preferential rates in the form of a solution of a compound which is alkaline in aqueous solution and which can be converted to a compound of greater alkalinity by thermal decomposition Carbonates and Hydrojcyde of the alkali metals and bicarbonates, iiitrafce, iTItrite and organic salts of the alkali metals or the alkaline earth metals can be used. The use of alkali metal hydroxide lab very expedient «

During the impregnation, the carrier material can be the final

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Have design, or it can at least partially are impregnated as discrete particles, which after one or more impregnation processes are given their final shape to be brought.

It has been found that it is advantageous if the erfindungsgeraäß Catalysts to be used which contain a metal of the platinum group are produced in that ' first a preformed carrier material is impregnated with a compound serving as a promoter and then the so treated Carrier with a metal of the platinum group or with a compound reducible to such a metal is impregnated.

In British Patent 1,029,235 there is one method described for the reforming of hydrocarbons with steam, which consists in that hydrocarbons at elevated temperature reacted with steam in the presence of a platinum group metal-containing catalytic mass will. However, the catalysts described there do not contain any compound serving as a promoter.

According to a further feature of the invention, a method for hexification of a catalyst is proposed, which consists in _f that a preformed carrier material with a promoter dieue & the compound of beryllium, magnesium, aluminum or an element of subgroups A of groups II to VII of the table of periodic system is impregnated and the so treated carrier is subsequently impregnated with a metal of the platinum group or with a compound reducible to such a metal.

This process has the advantage that it creates a catalyst which has a high activity in urogenesis processes by means of steam, however, has a relatively low content of the expensive platinum group metal.

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Moreover, the catalyst has a reduced tendency to carbon deposition even at a low steam ratio without an alkali metal compound (eg, a potassium compound), lead their volatility zn Eorrosionserscheinungen and the formation of interfering projections on the inner wall of the steam generator tubes downstream of the catalyst can _r with incorporated needs to ground.

The preferred platinum group metal used for the catalysts made by this preferred process is rhodium, although other metals of the group or mixtures of two or more such metals λ can be used. Other catalytically active metals such as nickel and cobalt can also be present. In particular, nickel or cobalt can be used in admixture with one or more of the platinum group metals. The proportion of the metal of the platinum group (or of the compound reducible to such a metal) is preferably 0.01 to 5 wt .- ^ (for example 0.1 to 2.5 wt .- #) calculated as metal; if necessary, however, higher concentrations, for example up to 20 wt .- ^, can also be used. This proportion is based on the total catalyst including the preformed support.

In the catalysts prepared by this process, the preferred promoters are the oxides of aluminum and alkaline earth metals, especially calcium, strontium or barium oxide, and mixtures of these.

The fourths of temperature, pressure and steam ratio used for this process are in the usual range Areas for steam formation processes and straightening depends on the desired composition of the product gas. In addition to steam, hydrogen and / or carbon dioxide can also be used to be available.

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As examples of suitable temperatures one can ^{mention 200 "to 1000 0} C for the transformation process in general, with temperatures up to about 450 ⁰ C for the production of natural gas substitutes, temperatures from 4-00 to 60O ⁰ C for the. Production of gases enriched in methane, temperatures from 550 to 750 ° C for the production of coal gas substitutes, temperatures from 700 to 800 ⁰ C for the production of lean gases serving as fuel gas and temperatures of 750 ⁰ C and above for the production of synthesis gases that can be used for the production of ammonia or methanol or higher alcohols, and gases which give essentially pure hydrogen by post-treatment are suitable. These temperature ranges overlap and can vary depending on the operating pressure and steam ratio.

The range 1.3 to 8 can be mentioned as examples of suitable steam ratios, the lower part of this range (e.g. up to 4) for the production of motor gases and the upper part (especially 3 to 6) for the production synthesis gas and hydrogen are suitable.

The method of the invention is particularly suitable for operation at temperatures below 75O ⁰ C, in particular in the range 600 to 700 ⁰ C, at which it is possible gases with a substantially methane content by single-stage reaction of the batch with steam, or by reaction of a hydrocarbon with steam in the presence of a methanatable gas mixture.

, In particular, a catalytic process for the transformation of a normally liquid hydrocarbon proposed by steam, the atmospheres at a steam ratio of 1.3 to 5.5, a temperature of 550 to 75O ⁰ C and a pressure of at least 7 (where the vapor ratio, Temperature and

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the pressure taking into account other variables, such as the system and catalyst dimensions and the space velocity, be chosen in such a way that the equivalent methane content of the gas produced is at least 10 vol- #) and, compatible with these variables, is carried out at a space velocity chosen so low that at least 92 V0I-9S the hydrocarbon charge is not formed.

This procedure is in the British paterite 1 052 751 by the applicant and can be used with the additional Advantage of the present invention can be carried out with a high throughput. ™

In a further important embodiment of the invention, the catalyst defined above is used in the secondary reforming stage the method according to British patent specification 1 032 753 or 1 102 801, according to which a fuel gas, which can be used immediately or after small changes as town gas, is generated in that at the same time Carbon oxides with hydrogen to form methane Reaction brought and a Uaphthacharge is converted (reformed) by steam.

Especially with those that can be carried out at moderate temperatures In a process as mentioned, for example, in the two preceding paragraphs, it is advantageous to preheat the reaction unit to a temperature in the upper part of the temperature ranges that are now usually used, for example 500 to 65O ⁰ O, in particular 550 to 625 ⁰ C, before it comes into contact with the catalyst to insure that the desired reaction temperature is maintained substantially throughout the catalyst bed. The preheating can take place in a special heat exchanger, or if the process is carried out over a catalyst in externally heated tubes, the preheating can be effected by a short bed at the inlet of the catalyst bed

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made of heat transfer material with little or no catalytic effect.

The batches used according to the invention can consist of single hydrocarbons or of mixtures and are preferably rock oils. The boiling point of the batch is preferably in the range up to 270 ^° C., in particular up to 220 ^° C., for example 170 ^° C. So that the process can be carried out continuously for a long time, the batches must be desulfurized in such a way that their sulfur content is well below 0.0005 wt .- ^ is, which can conveniently be achieved with the method according to British patent specification 902 148. The process is also suitable for the gasification of methanol alone or in conjunction with hydrocarbon batches.

The invention is explained in more detail below with reference to exemplary embodiments.

example 1 Representation of the catalyst mass

A mixture of Niekelnitrat hexahydrate (1344 g) and w aluminum nitrate nonahydrate (192 g) was heated to 70 ⁰ C, so that a concentrated solution of the two salts was obtained in their Kristalllsationswasser. Then 522 g of cylindrical tablets (cookies) made of xon earth and with a diameter of 4.8 mm (the alumina previously ^{calcined at 145O 0} C) were kept in the hot salt solution for 30 minutes and then drained, dried and calcined at 700 ⁰ C for 4 hours · The weight of the cookies was now 609 g. They were held in the brine, drained, dried and calcined two more times in the same manner, so that their weight was finally 755 g. They were then kept in a weak potassium hydroxide solution (1.7 g KOH per 100 ral solution) 30 minutes and then drained, dried and oalciniert 3 hours at 700 ⁰ C.

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The amounts of the starting materials were chosen so that the Catalyst mass had the following composition: HiO 29 wt .- #; KgO 0.3 wt .- ^, alumina (introduced as ITitrate) 2.2 wt. #; Remainder of the earth (introduced as a cookie).

Use in steam reforming processes

The experiments were carried out in a small, externally heated, tubular reaction vessel which contained 335 ml of catalyst. Before the start of the steam reforming Kaphthacharge has been reduced, the catalyst mass by dilute hydrogen atm with steam through the catalyst bed at a bed outlet temperature of 700 ⁰ G and a pressure of about 29 was passed therethrough · As batch was entschv / efelte M
turns.

clear naphtha with a boiling range from 30 to 170 ⁰ C

The process was initially carried out at a bed outlet temperature of about 63O ⁰ C (bed inlet temperature about 400 ⁰ C) and a steam ratio of 2 to 3. First (Experiment I) the inflow of steam and naphtha was chosen so that the hourly liquid space velocity of the naphtha Was 2.15. This could be increased to 3.08 (experiment II) before oil breakthrough could be detected.

The procedure (Experiment III) was then carried out uniformly under similar conditions for 84 hours. Man could not detect any reduction in the catalyst activity and no carbon formation.

The results of these tests are shown in the table below can be seen from which it can be seen that the process is suitable for the production of medium-rich motor gas. It would therefore be expected that the process is suitable for the production of synthesis gas, for which correspondingly higher Steam conditions and temperatures than those described are necessary would be.

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mm J (J · »

!Tabel

Experiment no * I II III

Hourly liquid space velocity, steam ratio, bed inlet temp. ⁰ C Bed outlet temp- ⁰ O outlet pressure atü Exhaust gas volume l / h Outgoing rock oil volume l / h Operating time h G-as composition Vol ~ $:

CO ₂

CH.
4th

fc In a similar experiment, but in which an alkali-free Catalyst was used, the minimum vapor ratio for carbon-free operation was found to be 2.5 up to 3.0.

Example 2

Example 1 was repeated, with the difference that in this experiment the catalyst was diluted with biscuits from "Ciment Pondu" (e.Wz,) to the extent of 2133 times its own volume by the reading volume and the surface / volume ratio to imitate a catalytic converter _? which is in the shape of rings about 16 mm long and high and 7 mm thick,

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2.15 3.08 4.9 2.86 2.16 2.29 21.8 2.28 374-417 396-410 34.5 390-410 628-631 635-637 38.8 626-630 28 28 28 1213 1790 1660 0 0.003 0 6th 4th 84 5.0 4.9 22.0 22.1 36.6 36.5 36.4 36.5

as they are used in large-scale production in pipes with a diameter of, for example, about 8 to 15 cm. At a space velocity of 1.2 and an outlet bed temperature of 63O ⁰ O, essentially the entire batch was reformed.

In an experiment under similar conditions with the only difference that the initial bed temperature 75O ⁰ O and the space velocity was 1.6, the entire batch was again transformed, but there was a slow carbon deposition on the catalyst, so that the pressure drop of 0.07 atm or less was increased to 1.4 atm in 6 hours. | Thus, this catalyst does not receive enough alkali "is a a carbon free operation at a bed outlet temperature of 75O ⁰ C to enable.

Example 3

The preparation of the catalyst according to Example 1 was repeated, with the difference that thorium nitrate was used instead of aluminum nitrate. The amounts of the starting materials were chosen so that the composition of the catalyst was as follows: NiO 29 wt, - #; KgO 0.3 wt. -? S; ThO ₂ 11.4 wt. # J remainder of alumina. It was tested as in Example 2 with an exit bed temperature of 63O ^{0 O.} (

At a vapor ratio of 2.2, $ 45 of the naphtha was not converted when the liquid hourly space velocity was 1.2, and about $ 2.5> was not converted at a space velocity of 0.9. After several hours of operation, no carbon deposits could be found on the catalyst «

Example 4

Using the same preformed alumina carrier as in Example 1, a catalyst was prepared by "that

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the support was first impregnated with a mixture of Hickelnitrat and calcium nitrate, followed by calcining the whole at 45O ⁰ C for 4 hours to give the took convert to oxides, after which the carrier with palladium nitrate impregnated and the whole again for 4 hours at 45O ⁰ C ealcined. The amounts of the starting materials were chosen so that the catalyst had the following composition: NiO 8 wt .- #; CaO 5 wt. #; Pd 0.5 wt. Yes; Rest of clay.

The catalyst was diluted with cookies from "Ciment Fondu" in a ratio of 70:30 and tested using the naphtha charge and apparatus according to Example 1. At a pressure of 28 atm, a Bettausgangsstemperatur of 75O ⁰ C and an hourly Plüssigkeitsraumgeschwindigkeit of 1.0 was the minimal steam ratio is 2.5.

Example 5

The same alumina carrier with a small surface area as in the previous examples was impregnated with a mixture of chloroplatinic acid and aluminum nitrate, so that a catalyst with a platinum content of 2.0 % and an alumina content of 1.5% was obtained. He was tested in a diluted bed at a bed outlet temperature of 75O ° C as in the previous examples, W. It was found that it was possible to work with space velocities of up to 1.6 without oil breakthrough. At a space velocity of 1.2 the minimum vapor ratio was about 1.5.

Example 6

A catalyst «produced by impregnating the same alumina carrier small surface with magnesium nitrate, calcination, Impregnation with rhodium nitrate and repeated calcination was shown, had the following composition: Rh 0.46 #, MgO 0.64 #t remainder of alumina. It was in a dilute bed as in the previous examples in a

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Bed outlet temperature of 75O ⁰ O and a vapor ratio • yon tested 5.0 and it resulted a substantially complete transformation induced (total aromatic hydrocarbons 3330 mg / m ^, C-Hg 1.0 vol #). At this steam ratio and also at a steam ratio of 3 * 5, carbon was slowly deposited.

Example 7

Catalyst A with a 0.45 # rhodium content and a 0.2 # calcium oxide content on alumina as a carrier was represented as follows:

500 g of 4.76 mm pellets made of clay which had previously been ^{calcined at 1400 °} C. were impregnated with 700 ml of an aqueous solution which contained 38.5 g of calcium nitrate. The imprängierte alumina was drained, dried and calcined for 6 hours at 700 ⁰ C. The cookies were then soaked with 190 ml of an aqueous solution containing 2.46 g of rhodium nitrate.

The cookies were then drained, dried and ^{calcined at 450 °} C. for 6 hours.

Catalyst B with a 1, perpetual rhodium content and a 0.5% impregnated alumina content on a preformed alumina carrier was represented as follows:

There were 500 g of 4.76 mm clay cookies, which were in front of |

was calcined at 1400 ^° C., impregnated with 350 ml of an aqueous solution which contained 35 g of Al (NO -) -. 9H ₂ O. The impregnated clay pellets were drained, dried and ^{calcined at 700 °} C. for 6 hours. The cookies were then impregnated with 173 ml of an aqueous solution containing 8.8 g of rhodium nitrate. The cookies were then drained, dried and calcined at 450 ° C. for 6 hours.

Catalyst C (shown for comparison purposes) with a 1, 4 # rhodium strength was prepared in the same calcined alumina as follows:

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For example, 500 g of the clay are immediately mixed with 173 ml of one impregnated aqueous solution containing 7.09 g of rhodium nitrate. The catalyst was drained, dried and calcined as with the previous catalysts.

The catalysts were used in the steam reforming of naphtha, the process being carried out in a small externally heated tubular reaction vessel containing 334 ml of catalyst. Before the start of the steam reforming Naphthacharge the catalyst mass was in each case reduced by being passed through atm of diluted with steam ^ hydrogen at a bed outlet temperature of 75O ⁰ O and a pressure of 29 *. 4 The boiling range of desulfurized Naphthacharge was 30-120 ⁰ O.

The steam reforming took place at a bed outlet temperature of 750 ⁰ O (bed inlet temperature 400 ⁰ C) and a steam ratio of 3. The pressure was 28 atm. The flow rate of the steam and the naphtha were set differently so that the liquid hourly space velocity of the naphtha varied from 1.2 to 1.8. The naphtha was completely converted into gaseous products, and the concentration of unconverted aromatic hydrocarbons and ethane in the exhaust gas was regarded as a hatred of catalyst activity. (The lower the concentration of these compounds, the higher the catalyst activity).

The results shown in the table below show that both Catalyst A and Catalyst B are one have greater activity than Catalyst C. No carbon deposit was found.

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- 21! Table

Hourly liquid room velocity

speed 1.2 1.4 1.6 1.8

Exhaust gas exhaust gas exhaust gas

total C ₉ H ₆ sat. O ₉ H ₆ gas. O ₂ Hg. total 0 «ed

aroma * aroma. * aroma. aroma.

Walk / walk / walk / walk /

mg / m * 70I5S mg / m * Yol? i mg / m ^ vol? £ mg / m * V0I5Ä

catalyst A. 645 catalyst B. <100 catalyst σ 695

0.1 950 0.2 1980 0.6 3500 0.9 0.0 225 0.1 195 0.2 2250 0.5 0.2 1220 0.5 3530 0.9 8430 8.9

• f total aromatic content »benzene + toluene

Claims 1

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Claims (8)

Claims 1 · Continuous process for the transformation of a normally liquid hydrocarbon feed with a boiling point below 33O ⁰ C by steam ,, characterized in that a catalyst is used "which consists of a preformed support, a metal or oxide having a catalytic action for the transformation of Hydrocarbons by steam and at least one compound of beryllium or magnesium or an element of groups III to TII of the table of the periodic table with an atomic number of at most 90 which acts as a promoter. 2. The method according to claim 1 _r, characterized in that the carrier material of the catalyst has an average pore radius of over 500, in particular over 1000 pounds. 3. The method according to claim 1 or 2, characterized in that the carrier material of the catalyst consists of alumina. 4 * Method according to one of the preceding claims, characterized in that aluminum oxide is selected as the promoter will. 5. - The method according to any one of the preceding claims, characterized in that the concentration of nickel or cobalt in the material to be applied to the preformed catalyst support is over 20 #,. is preferably over 50 Jt, in particular 70-98 #, expressed as monozyd, or the concentration of a metal of the platinum group in the material to be applied to the preformed catalyst support is in the range from 3 to 90%, in particular from 10 to 80 % . 109824/1839 6. The method according to any one of the preceding claims, characterized in that it is at a steam ratio of 1.3 to 5.5, a temperature of 550 to 750 ⁰ O and a pressure of at least 7 atm (where the steam ratio, the temperature and the Pressure, taking into account other variables, such as the system and catalyst dimensions and the space velocity, can be selected in such a way that the equivalent methane content of the grass produced is at least 10 vol- #) and, compatible with these variables, at such a low space velocity chosen it is carried out that at least 92 VoI- ^ of the hydrocarbon charge is reformed. 7. Catalyst, characterized in that it consists of nickel, at least one compound serving as a promoter of an element from groups III to V of the table of the periodic table and a preformed carrier which is less than 65 $> silica or at a silica content above 65 i * less ice contains 12 pounds of clay and has an average pore radius of over 500, especially over 1000 pounds « 8. A method for producing a catalyst for use in a method according to any one of claims 1 to 7 or a pre-mass reducible to such a catalyst, the catalyst or the pre-mass being a metal of the piatin group contains, characterized in that a preformed carrier material initially with a serving as a promoter Compound is impregnated and the so treated carrier then with a metal of the platinum group or with one to a such metal reducible mass is impregnated. PATHfTANWXLTS WWHe.H.FINCKE, DIPL-INQ. 110 » M. 109824/1839