DE2328064A1 - HYDROCARBON STEAM REFORMING CATALYST - Google Patents

Description

The invention relates to a hydrocarbon steam reforming catalyst. At present there are hydrocarbon steam reforming processes in the production of hydrogen gas, fuel gas or various synthesis gases predominant. The steam reforming of hydrocarbons is' usually by passing the hydrocarbons, especially paraffinic hydrocarbons, in the gaseous state together with steam by means of catalysts filled in a heat-resistant cylinder a temperature of 400 to 8OO C and a pressure of 1 performed up to 30 at.

The steam reforming reaction can be expressed by the following equations when considering hydrocarbons

3:: - -.51 / IQIl

81- (Item 30 4O9) -Tp-r (7)

Adds the formula CmHn %

CmHn + mH ₂ 0 ► mCO + (m + |) H ₂ (1)

CmHn + 2mH ₂ 0 »■ mC0 ₂ + (2m + j) H ₃ . _o ....... (2)

The reaction process includes in addition to the above given reaction equations thermal decomposition, hydrogenation, etc., and the product obtained exists mainly composed of hydrogen, carbon monoxide, carbon dioxide, methane and water vapor. A relationship between these components can be expressed by the following equilibrium equations reproduce:

CH ₄ + H ₂ O CO + 3H ₂ * .000. <, <,. ". ο. 00. »co .. (3)
CO + HO ^ _ CO + H. . . ο. ο „ο. ο. ο. ο ο ο. ο. ο. (k ),

The equilibrium composition of the gas generated depends on the temperature, pressure and proportions of the substances fed in (steam-carbon ratio; ratio of the molten mols per gram atom of carbon of the hydrocarbon or hydrocarbons fed in, hereinafter included
ⁿ H 0 / C "; carbon dioxide-carbon ratio ratio of the moles of carbon dioxide per gram atom of carbon of the supplied hydrocarbon (s), hereinafter referred to as" COp / C "), and therefore the desired gas, Z ₀ Bo hydrogen gas, Heating gas or can
various synthesis gases can be obtained.

The main problem with the. Application of the steam reforming catalyst is that of carbon deposition on the catalyst, although it depends on the particular conditions when. Hydrocarbons react with steam "

3i -T / 107 / *

The main reactions leading to carbon deposition lead are represented by the following equations?

f ^ &. ^^^ ^^^ ^ j ^^ ^^ ™ ^^^ ^^^ ^^ ~ φ OOOOOOOOOO ö OO Ό ^ 5 OOO -OOOOOO β Ο ^% ^^^ W

This causes carbon deposition on the catalyst a decrease in the activity of the catalyst, but more serious problems are pulverization and fragmentation of the catalyst through the carbon deposition as well as the inevitable subsequent interruption of operations because of the clogging of gas pipes.

To prevent this carbon deposition, H _? O / C increased An increase in the H _? O / C can suppress the carbon deposition on the catalyst, but on the other hand this leads to the consumption of the supplied substances, fuel, etc., and therefore increasing the H 0 / C is uneconomical »·"

In general, olefinic hydrocarbons are more likely to cause carbon deposition than the paraffinic hydrocarbons emerge, and therefore, when considering gaseous or liquid hydrocarbons, those olefinic hydrocarbons contain, used as starting materials, usually a hydrogenation reactor and a desulfurization reactor on the upstream side of the steam reforming plant upstream.

As known catalysts with a suppressing effect on carbon deposition, catalytic converters have hitherto been

3 ü i ..- 5 1/1 0 7 4

lysatoreh available, the nickel as the main component and potassium as the exit catalysis promoter on a heat resistant Have oxide carriers »These catalysts prevent deposition of the 'during reforming the active carbon formed by the hydrocarbons as stable carbon «Well, potassium tends to migrate through the catalyst and because of its low To evaporate boiling point. As a result, condensed the potassium evaporated from the catalyst and precipitates on low-temperature parts downstream of the steam reforming plant from, whereby it unfavorably clogs the pipe system »

In addition, there have already been catalysts that contain nickel and urai on a heat-resistant oxide carrier » These catalysts have one mode of action, the reaction of what is deposited on the catalyst during reforming However, to promote active carbon with water to form hydrogen gas and carbon monoxide Used only to a limited extent as it promotes catalysis acting uranium is a radioactive element.

In addition, these catalysts have a relative good carbon capture control effect on paraffinic hydrocarbons, however, it still does not have a sufficient effect of controlling carbon deposition when using olefinic hydrocarbons be used as starting materials to be reformed.

The most important requirement for the steam reforming catalyst is that one thereby the carbon deposition

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on the catalyst at the lowest possible ratio of H O / C is able to prevent »Besides, it's very desires that the steam reforming catalyst perform this function with different types of hydrocarbons, i.e. both paraffin and olefin hydrocarbons can fulfill »Furthermore, such a catalyst should be a high activity, especially excellent Have activity in a wide range of temperatures and pressures «. In addition, the steam reforming catalyst have high heat resistance and mechanical strength, which means that they have higher temperatures and pressures can withstand.

The invention is therefore based on the object Specify hydrocarbon steam reforming catalyst that meets all these requirements as well as possible »

The invention, with which this object is achieved, is a hydrocarbon steam reforming catalyst made of a heat-resistant oxide carrier with nickel as one main catalytically active ingredient, which is characterized by the fact that it also contains at least 2 mg-atoms of silver each contains 100 g of catalyst as a catalyst promoting agent.

According to an advantageous development of the invention contains the hydrocarbon steam reforming catalyst also at least one rare earth element with an atomic ratio of rare earth elements to silver of 10 or less as a catalyst promoter ο

The raw materials for nickel, which in the case of the catalyst according to of the invention as the main catalytically active ingredient used include nickel oxide, nickel nitrate,

30-851 / 1074

Nickel carbonate, nickel oxalate, nickel formate, etc.

The raw materials for silver used in the invention Steam reforming catalyst serving as a catalysis promoter include silver oxide, nitrate, carbonate, etc.

As rare earth elements, which serve as additional catalysis promotion tools in the case of the catalyst according to the invention can, lanthanum, cerium, yttrium, praseodymium, neodymium, etc. can be used »taking into account availability and cost is preferable to lanthanum, cerium, yttrium, etc. Mixtures of rare earth elements can also be used use, which are obtained from monazite, xenotime, bastnaesite, etc. wins o As raw materials this rare earth element ©, which also to be carried by the heat-resistant oxide, oxides, nitrates, carbonates, hydroxides, Mention oxalates, etc.

In the steam reforming catalyst according to the invention Ixitz-resistant oxides used include the oxides of aluminum, silicon, magnesium, titanium, zirconium, Beryllium, thorium etc. The refractory oxide can have any shape, e.g. spherical, cylindrical, Be lumpy or powdery. In general, carbon separates when acidic oxides, such as. B. aluminum oxide, Silica, etc. are used as a carrier, but it has been found that the catalyst composition according to the invention, the carbon deposition can also hold back considerably when these acidic oxides are used as carriers »

Bie "quantitative proportions of the catalyst components

3 υ a B 5 1/1 0 7 4

according to the invention are given below? nickel is preferably in an amount of at least 3 wt .- $, in particular 10 to 30 wt. $, calculated as NiO, on the basis of the weight of the catalyst present "

When silver in an amount less than 2 mg-atoms per tOO g of the catalyst is the suppression effect on the carbon deposition is unsatisfactory, and the rate of carbon deposition exceeds 40 mg / h at the usual feed rate of hydrocarbons, if not the ratio H "O / C is set higher than 3. As a result, will the operation of the steam reforming plant disrupted. The amount of silver can be well over 2 mg atoms (per 100 g of catalyst) increase as long as the main catalyst component Nikkei can be kept above its lower limit »

Even if the effective catalyst components only Nickel and silver are, the carbon deposition in the steam reforming of paraffin hydrocarbons can be Press down to 10 mg / h or lower for as long Nickel and silver within the specified ranges are present.

In addition, if at least one rare earth element is part of the catalyst, the effect can be achieved the suppression of carbon deposition and heat resistance raise. The rare earth content is in the catalyst with an atomic ratio to silver of 10 or less before. When this atomic ratio exceeds 10, the layers of dispersed silver are microscopic, too far apart, and the suppressive effect on the

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Carbon deposition only takes place locally on
Catalyst instead, so that the desired effect of the silver is not satisfactory »and the carbon deposition is then more than 40 mg / h at the usual hydrocarbon feed rate» The catalyst according to the invention works well without any addition of earth elements, but it has an improved effect the proportion of rare earth elements if the catalyst contains 2 mg atoms or more of silver per 100 g of catalyst.

The reasons for the effect of silver as a catalysis promoter in the sense of suppressing the carbon The divorce has not yet been clarified, but it can Silver when silver salt compounds from a heat-resistant Oxide apparently improve the reactivity between the active carbon and steam.

Furthermore, the rare earth elements are alkaline substances and have a good affinity for acidic metal oxides, such as. B ₁ aluminum oxide and silicon dioxide. Therefore, the rare earth element can sufficiently adhere to alumina or silica and convert the surface of alumina or silica to alkaline behavior, apparently improving the carbon deposition suppressing effect. They also have
Oxides of the rare earth elements have good heat resistance, and it appears that the rare earth elements improve the heat resistance of the catalyst and prevent it from being deteriorated by heat »

The inventors tried steam reforming of

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Hydrocarbons over catalysts containing copper, d. H. from the same group of the periodic table as silver, contained instead of the silver in the catalyst according to the invention, but there was no suppressive effect on carbon deposition.

There is no particular limitation on the method for producing the steam reforming catalyst of the present invention. An example of this is given below? A mixture of water soluble compounds of nickel, silver and possibly rare earth elements, which are related to each other in the above-mentioned ranges are mixed is mixed with powders of refractory oxides in the dry or sludge-like state, and the The resulting mixture is processed into its intended shape and fired, producing the desired catalyst is obtained. No differences are observed in the behavior of the catalyst, whether one uses the silver compound and the rare earth element content simultaneously or sequentially or gradually mixes.

The catalyst obtained in this way can be steam reformed for a wide range of hydrocarbons including methane, exhaust gas from various hydrocarbon materials as a starting gas using process, liquefied natural gas, hydrocarbons with higher molecular weights than that of methane, e.g. liquid hydrocarbons, such as liquefied petroleum gas, Use butane, hexane, light petroleum distillates, naphtha, etc. as raw materials.

The amount of hydrocarbons is simultaneously with steam

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passed over the catalyst and can be with the catalyst in a further temperature range ats the usual, namely in the range from 350 to 900 C, and in a wider pressure range than the usual, namely

contact in the range from 1 to 50 kg / cm «

When hydrocarbons with more than 1 % olefinic hydrocarbons are reformed over the catalyst according to the invention, the carbon deposition is 15 mg / h or less in the case of using the catalyst with only nickel and silver, but only 2 mg / h or less in the case of using the Catalyst with nickel, silver and a proportion of rare earth elements, even if the ratio of ELO / C is only 0.75 in each case. If an exhaust gas from the petroleum industry is steam reformed over the conventional catalyst using hydrocarbons as raw material, the exhaust gas must first be passed over a hydrogenation catalyst in order to convert the olefin hydrocarbons into paraffin hydrocarbons in order to prevent excessive carbon deposition. When the feed gas is passed over the hydrogenation catalyst, the temperature of this gas rises due to the hydrogenation reaction and the activity of the hydrogenation catalyst is noticeably lost. Therefore, up to now there has been a mandatory limit for the G content of olefin hydrocarbons in the feed gas.

According to the invention, on the other hand, a feed gas with a content of about 15 volumes of olefinic hydrocarbons by means of passing over the catalyst according to the invention without the occurrence of any disturbances directly steam-

3098 5 1/10 74

reform without the gas beforehand over the otherwise usual Hydrogenation catalyst layer is passed. So the construction costs of the reforming plant can be reduced and make their operation much easier,

At a ratio of H_O / C of 3> O, the carbon deposition can be reduced to 20 mg / h or less despite the said content of olefin hydrocarbons. In the special case of using the catalyst with nickel, silver and rare earth elements, the carbon deposition can be carried out with an HO / C ratio of an appropriate level even with the stated content of olefinic hydrocarbons bi _; lower s to 5 mg / h or less,

If the catalyst activity is in proportion to the rate of addition of carbon, that is, as the number of gram atoms Carbon of the hydrocarbon supplied per unit volume of the catalyst per unit time is, the proportion of unreacted hydrocarbon z. B. in the case of η-butane at 55 g-atoms of carbon per hour and per liter of catalyst at 0.01 # or hold less. Therefore, the catalyst according to the invention has apparently a practically very satisfactory activity.

The catalyst according to the invention is suitable as a steam reforming catalyst for generating hydrogen gas, methane-rich fuel gas or various synthesis gas en for methanol synthesis, oxo synthesis, etc. and can be used directly for the steam reforming of an olefin containing Using the starting gas «You can also use the

3 0 985 1 / 107A

- .12 -

catalyst according to the invention even at a low Use H O / C ratio and is therefore used to generate. of gas can be used for ore reduction. In addition, the catalyst according to the invention has a good suppressing effect on the carbon deposition and can therefore be arranged on a part of the system where carbon is in the Steam reforming plant tends to deposit, d. H. usually at the inlet part, while the known catalyst can also be used on other parts.

The invention will now be explained in more detail on the basis of exemplary embodiments with reference to the drawing ; show in it s

1 shows a diagram to explain the relationships between H_O / C ratios and carbon deposition, if, according to one embodiment, η-butane above that according to the invention Catalyst is steam reformed;

Fig. 2 is a diagram for explaining the relationship between the ratio La / Ag and the carbon deposition, if according to another embodiment η-butane is oxo-reformed over the catalyst according to the invention; and

3 shows a diagram to explain the relationships between ethylene concentrations and the carbon deposition when, according to a further exemplary embodiment, ethylene-containing ethane is steam reformed over the catalyst according to the invention.

3ü9851 / 10 7

example 1

There were catalysts according to the invention and comparative catalysts made in the following way?

Catalyst A (inventive catalyst)?

75.0 g of nickel nitrate hexahydrate, 9.3 g of lanthanum nitrate hexahydrate and 3.67 silver nitrate were separately dissolved in water, and the three aqueous solutions obtained were mixed with one another to obtain a total volume of 70 ml , 2 "mesh" were impregnated with the resulting mixed solution and at 110 ° C for 3 hours g «
Burned for 2 hours.

Dried at 110 ° C for 3 hours and then at 900 ° C

The catalyst obtained contained 15.4% by weight of nickel as NiO and 17 »2 mg atoms of lanthanum per 100 g of catalyst (21.6 mg-atoms of lanthanum per 100 g of the carrier material) and had an atomic ratio of lanthanum to silver of 1.0.

Catalyst B (inventive catalyst)?

75-0 g of nickel nitrate hexahydrate and 7.34 g of silver nitrate were separately dissolved in water, and the obtained two aqueous solutions were mixed together to make a total volume of 70 ml. 100 g of spherical active alumina carrier material. with grain sizes of 7 to 12 "mesh" were impregnated with the resulting mixed solution, dried at 110 ° C. for 3 hours and fired at 900 ° C. for 2 hours.

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The catalyst obtained contained 15.5% by weight nickel as MiO and 3k.7 mg-atoms of silver per 100 g of the catalyst.

! Catalyst C (comparative catalyst) s

75s0 g nickel nitrate hexahydrate and 18.7 g lanthanum nitrate hexahydrate were separately dissolved in water, and the two aqueous solutions obtained were dissolved to obtain one Total volume of 70 ml mixed together. 1OO g of spherical active alumina carrier material with grain sizes, from 7 to 12 "mesh" were mixed with the obtained mixed solution impregnated, dried at 110 C for 3 hours and then fired at 900 C for 7 hours.

The resulting catalyst contained 16.2 wt _o - $ nickel as NXO.

Catalyst D;

75t O g Nick Eini tra thexahydrat and 18 ", 7 S lanthanum nitrate hexahydrate were dissolved separately in water and the eriialtenen two aqueous solutions were mixed ml together to obtain a total volume of 70. 100 g won. Spherical active alumina carrier material with grain sizes of 7 up to 12" mesh "were impregnated with the resulting mixed solution, dried at 110 ° C. for 3 hours, and baked at 900 ° C. for 2 hours.

The catalyst obtained contained 15 »3 wt .- ^ nickel as MiO land 3h, Z mg atoms of lanthanum per 100 g of catalyst.

25 stL of each made in the manner explained

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Catalyst were each in a reaction tube with an internal diameter given by 15 mm, the catalyst layer temperature was increased so 'that the catalyst layer at the entrance 600 C or more and at the exit 800 C or more could have, and hydrogen was passed through these reaction tubes at a flow rate of about 300 ml / min passed through together with steam for 1 to 2 hours to reduce the catalysts. Then the catalysts were used for the experiments «

The experimental reaction was carried out in each case by keeping the inlet and outlet temperatures of the catalyst layer at certain values, adjusting the feed rates of η-butane, steam and carbon dioxide so that the ratios of H ₂ O / C and CO./C were certain values ingested, and the starting materials passed through the reaction tube after passing through a preheating section, whereby the reaction was initiated above the catalyst. The reaction product gas was sent to an analyzer through a condenser and a trap, and an overall analysis of the reaction product gas for its components except for water was carried out by means of Ga3 chromatography.

The amount of carbon deposits was determined by placing the catalyst layer upon completion of the experimental reaction Oxygen supplied so as to convert the deposited carbon into carbon dioxide, and then the carbon dioxide obtained was measured quantitatively ..

If tests are carried out on the same catalyst under

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If the ratios of H_, O / C and CO ₂ / C were to be changed, the catalyst was reduced again and then used for the further experiments.

In Fig. 1 are the relationships between the H_O / C ratio and the carbon trapping amount in steam reforming η-butane under atmospheric pressure for each of the aforesaid Catalysts A to D is illustrated. The steam reforming conditions of Fig. 1 were as follows

Starting temperature

the catalyst cMcM; 730 to 800 ° G

Amount of catalyst s 25

Response time 1 hour

¥ request pressure: Atmospliäsrendriiclc

In the subsequent table t are the experimental data and results, such as, B ₀ is specified reaction product gas composition, carbon deposition, etc. "including data on the application of increased pressure.

(Table 1, page 1?)

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It results from the test data in Table 1, that the catalysts C and D (comparative catalysts) give a slightly higher concentration of residual butane and thus have a somewhat lower catalytic activity than the catalysts A and B according to the invention, which provide a low concentration of residual butane, the reaction product gas being of almost identical composition how the C balance composition has, which means that the catalyst has good catalytic activity over a wide temperature range.

The catalysts A according to the invention also show and B a noticeably lower carbon deposition than the catalysts C and D (comparative catalysts) and therefore a good suppressive effect on the carbon deposition. This can be seen above all from the test results at atmospheric pressure in FIG. 1.

Example 2

Catalysts were prepared in a manner similar to Example 1, the atomic ratio of lanthanum was changed to silver, and the suppressing effects on carbon deposition were examined.

The molar ratios of lanthanum nitrate to silver nitrate were 100 s 0 (catalyst D), 95 ι 5, 80 s 20, 65:35, 50 ί 50 (catalyst A), 35:65, 20 j 80, 5:95 and 0 5 100 (catalyst B) set, but the total sum of g-atoms of lanthanum and silver per 100 g of support material was kept constant at 43.2 mg-atoms.

31.9851 / 1074

There was an Oxoreformierreaktion of η-butane with 25 ϊπΙ catalyst material at an outlet temperature of the catalyst from -85 to 825 ° C, a pressure of 15 kg / cm and at ratios of ELO / C and CO „/ C of about 1.2 carried out in a manner similar to Example 1, and msn determined the carbon deposits. The reaction time was 1 hour and the carbon feed rate was 32 to 33 g-atoms C / hl of catalyst. The results are summarized in FIG. It can be seen from FIG. 2 that even when silver was used alone as a catalyst promoting agent, the suppressing effect on carbon deposition was very excellent in comparison with the nickel-aluminum oxide catalyst C or the nickel-lanthanum-aluminum oxide catalyst D, that is to say the silver-only catalyst is practically usable «If the rare earth element was added, the carbon deposition suppressing effect was greatly improved, and at the same time, good heat resistance and long life were obtained.

If the atomic ratio of lanthanum to silver becomes too large and you turn to the catalyst of the composition Nikkei -Lan than- aluminum oxide, d. H. D approaches, the suppressive effect decreases on carbon deposition, and catalyst activity also decreases. Therefore should the catalysts are prepared and composed according to the invention in such a way that the atomic ratio of the rare earth element content to silver in a range from 0 to 10, preferably 0.2 to 2.0.

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Example 3

Aluminum extrate nonahydrate, nickel nitrate hexahydrate, Lanthanum nitrate hexalihydrate and silver nitrate were weighed in amounts by weight as shown in Table 2 and separated dissolved in lasser. The four aqueous solutions obtained were mixed together to make a total volume of 2 1, and then ammonia water was added dropwise to precipitate precipitates. To, Upon settling, the supernatant was removed by decantation. Then the precipitated residue 2 liters of distilled water were added, the mixture was stirred and decanted. This process step was repeated twice and then the solid residue was filtered off. The residue was then 10 hours at 110 ° C dried and powdered. The powders obtained were mixed with 2 wt .- ^ polyvinyl alcohol and then into tablets formed with a diameter of 10 mm and a thickness of 5 mm under a pressing pressure of 500 kg / cm. The received Tablets were calcined at 900 ° C. for 2 hours and used as catalysts.

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φ cd RS -P
Λ cd h -P
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The catalyst activity and carbon deposition for those catalysts E to J prepared in the above manner, similarly to Example 1, and the influences of the amounts of the lanthanum and silver as catalysis promoters were examined. The results are given in Table 3.

(Table 3, page 22) 3U9851 / 1074

Table 3

catalyst Carbon-
feeding
dizzy
ability * H ₂ 0/0 oo ₂ / o Printing
kg / cm Catalyst
sohichtaus-
gangs tempe
temperature C Reaction product gas feed
composition (YoI. $) ^H 2 GO \ J \ J Γ * Ν * ιΠι a 6.4
5.1
4.9
5.7
6.5 ' w μ XX / I w V
Carbon-
deposition
mg / h E.
F.
G
Ξ
JL * - = ■
j 52.6
52.4
52.4
52.5
52.4
52.6 1.21
1.18
1.18
1.20
1.19
1.20 I.25
1.20
1.21
1.17
I.24
I.27 in = ε ε = =
τ— 805
801
8-5
796
800
789 56.5
56.9
57.2
56.8
57.2
56.5 52.0
55.I
55.6
52.5
55.5
51.2 25.1
24.9
24.5
25.Ο
24.5
26.0 0.005
<0.001
It
It
II.
0.001 51.6
7.5
5-6
1.2
1.8
1.9

* g-atoms C / h.l catalyst

As Table 3 shows, the reaction product gas composition is almost identical to the equilibrium composition, and accordingly good catalyst activity was achieved Ag atoms of silver are present per 100 g of catalyst. Next is
If lanthanum is also present, it is also desirable that at least 2 mg-atoms of lanthanum per 100 g of catalyst are present, so that the good effect of the lanthanum is achieved.

Example 4

Oxoreforming of naphtha as starting material was carried out using catalysts A to D according to Example 1
carried out.

The experimental procedure was as in Example 1 with the exception that Naptha processes instead of η-butane became. The properties of the raw material processed naphthas are indicated below:

Paraffinic hydrocarbons 94.5 Olefin hydrocarbons 0.2 vol 56 . Naphthenic hydrocarbons 3 »0 vol. 56 Aromatic hydrocarbons 2.3 vol 56

Formula corresponding to the average _{molecular weight: CV k H 1} ^ j ^ Specific weight (15 ° / 4 ^O ) 0.6? 55 Initial boiling temperature 351.4 ° C End boiling temperature 135 »2 ⁰ C

30985 1/1074

Tabel

catalyst Carbon-
feeding
s chwindi ßl · «· ^H 2 o / c 00 ₂ / c Printing
kg / cm Catalyst-
layered
KanÄS t emt) e- 27 Reaction product gas too
composition (Vol <, $) 2 CO CO ₂ 0 ^G 4 ^] Carbon-
separation A. ability * temperature C 27 .1 26.7 45.3 1 ^ O mg / h 31.9 3. 00 2. 98 15.Ο 803 34 .0 24.8 46.9 5 0 2.5 55.8 3. 01 3. 01 It 793 27 .0 34.2 27.7 0 <0 3.7 B. 32.1 1. 50 1. 49 Il 801 26th • 5 26.6 45.1 1 <0 6.5 32.2 3. 02 2. 99 15.0 800 34 .8th 26.4 45.6 5 8.7 55-9 3. 01 3. 03 η 790 27 .2 33-9 28.5 0 15.1 C. 32.1 1. 50 1. 52 Il 8Ο4 26th .1 26.4 45-5 1 0 29.4 32.1 2. 99 3. 01 15.0 798 34 .8th 25.7 46.2 5 0 58.4 55.9 3. 02 .3. 03 It 790 27 .0 33.8 28.5 0 0 57.6 D. 31.9 1. 52 1. 50 It 800 27 .4 26.7 45.I 1 0 596.7 32.1 3. 01 3. 01 15.0 803 33 .0 26.1 45.6 3 0 15.3 56.I 3. 01 3. 02 Il 795 .6 33.7 28.9 ^DH 4 0 19.6 32nd 1. 51 1. 51 H 798 .87 110.9 .20 a / 14 • 75 .001 .83 .001 .25 .001 • 59 .001 .98 "1 • 13 Il , 89 .057 .81 .131 .17 .021 .81 .042 .077 .016

* g atoms C / tul catalyst

OO O CD

It can be seen from Table 4 that catalysts A and B (catalysts according to the invention) lead to a lower concentration of the hexane residue than catalysts C and D (comparative catalysts) and
also have a good suitability for promoting sufficient decomposition and reforming reactions when a starting material is processed which consists of higher hydrocarbons, so that these catalysts A and B have a good catalytic activity.

In addition, the catalysts A and B (according to the invention), particularly the catalyst A, show a considerable suppressing effect on carbon deposition
in comparison with catalysts C and D (comparative catalysts) and can advantageously be used for processing naphtha as a starting material even with an H_O / C ratio as low as 1.5.

Example 5

The reforming of methane containing olefinic hydrocarbons was carried out using catalysts A through D according to
Example 1 carried out to make further comparisons of the behavior of the catalysts. The test gas,
that was processed here was a gas mixture
Methane, ethylene and hydrogen, in which the ethylene concentration varies in a range from 0 to 1.7 vol. $
was, while the hydrogen partial pressure to 15 VoI. ^
was fixed and the rest consisted of methane »
The test gas was passed over the catalyst together with steam at an H _p O / C ratio of 3.0, and the

3ü3851 / 1074

Reaction was carried out with 25 ml each of catalysts A to D under the following reaction conditions similar to Example 1 carried out s

Pressure; 8 kg / cm

Catalyst light inlet temperature s 500 C

Catalyst bed outlet temperature 750 ° C

Response time: 1 hour

Carbon feed rate % 30 g-atoms

C / h.l catalyst

The relationships between the ethylene concentration and the carbon deposition were determined and the results are illustrated in FIG.

Fig. 3 shows that the amount of carbon deposition increases with an increase in the ethylene concentration in the case of Catalysts C and D (comparative catalysts) and is obviously influenced by the ethylene concentration, while in the case of Catalysts A and B (inventive catalysts), particularly in the case of catalyst A, practically no influence of the ethylene concentration can be determined. Therefore, when the gas reforming catalyst according to the invention is used, a starting gas containing olefinic hydrocarbons at a higher concentration can be fed directly to a steam reforming plant without any pretreatment.

Example 6

Catalysts were made as follows:

3U985 1 /

Catalyst K (catalyst according to the invention):

75.0 g of nickel nitrate hexahydrate, 3.67 g of silver nitrate and 5-8 g of a mixture of rare earth elements obtained from monazite sands were separately dissolved in water, and the resulting three aqueous solutions were mixed together to make a total volume of 70% ml to get. 100 g of spherical active aluminum oxide carrier material with sizes from 7 to 12 "mesa" were impregnated with the resulting mixed solution, 3 hours 1
burned,

Dried for hours at 110 ° C and 2 hours at 900 ° C

The catalyst obtained contained 15% by weight of Nikkei as NiO, 17.2 mg atoms of silver per 100 g of catalyst (21.6 mg atoms of silver per 100 g of the support material) and. 6.8 mg-atoms lanthanum, ■ 10.8 mg-atoms Ger 2.9 mg-atoms Neodymium and a small amount of praseodymium, samarium etc. per 100 g of catalyst.

Catalyst L (catalyst according to the invention):

The catalyst became in the same way as the catalyst K produced except that the rare earth element mixture of the catalyst K by 9.38 g of cerium nitrate hexahydrate was replaced.

The catalyst obtained contained 15.4% by weight of nickel as NiO, 17 »2 mg atoms of silver per 100 g of catalyst (21.6 mg atoms of silver per 100 g of the support material) and 17.2 mg atoms of cerium per 100 g of catalyst.

3U985 1/1074

Catalyst M (catalyst according to the invention):

The catalyst was prepared in the same manner with Catalyst K except that the Seltenerdelementmischung of the catalyst by K 8.27 S yttrium nitrate hexahydrate was replaced. The catalyst obtained contained 15.4% by weight of nickel as NiO, 17.2 mg-atoms of silver per 100 g of catalyst (21.6 mg-atoms of silver per 100 g of support material) and 17.2 mg-atoms of yttrium per 100 g of the catalyst (21.6 mg atoms of yttrium per 100 g of the support material) o

The amount of carbon deposition was determined for that Catalysts K, L and M determined according to the procedure explained in Example 1 in order to check their carbon deposition suppression effects. The results are given in Table 5.

(Table 5, page 29) 3U9851 / 1074

Table 5

catalyst Carbon-
feed
dizzy
ability * H ₂ O / C co ₂ / c Printing
kg / cm catalyst
shit
gangs tempe-
temperature C Reaction product gas feed
composition (YoI, $) σο CO ₂ ^CH 4 ° 4 ^{H /} 10 Coal ens.t off -
deposition
mg / h K
L.
M. 52.5
52.4
52.4
52.6
52.5
52.5 1.20
1.22
1.19
1.18
1.19
1.20 0.0
I.25
0.0
1.19
0.0
1.21 15.0
It
15.0
It
15.0
Il 801
785
795
788
800
791 ^H 2 ' 19.5
52.8
19-4
52.7
55-5 6.7
24.2
e.9
24.1
7.0
25.7 15.9
6.4
15.7
6.9
15.1
6.5 0.001
0.002
40.001
0.002
0.001
0.001 5.5
7.1
1.8
5.9
5.1
4.7 VM VJl VM VJl VM VJl
ON OD ON 03 ON OD
Ul Ul VM O ON - »

g-atoms C / h.l catalyst

It can be seen from Table 5 that the catalysts if they are not only considered to be lanthanum, but also cerium, yttrium or a mixture of rare earth elements Catalysis promoters along with the silver on that Contain carrier material, a good catalytic activity and a good suppressive effect on carbon deposition exhibit. It should also be noted that also can obtain a good carbon deposition suppressing effect when one is made of such minerals or ores such as monazites, xenotimes, bastnaesites, etc. obtained rare earth element mixture as the rare earth element fraction according to the invention, d. H. as a catalysis promoter, is used.

0 9 8 5 1/10 7

Claims (8)

Claims 1. Hydrocarbon steam reforming catalyst off
a refractory oxide support with nickel as one
main catalytically active constituent, thereby g ek en α ζ eich η et \ that it also contains at least 2 mg atoms of silver per 100 g of catalyst as a catalyst promoting agent. 2. Catalyst according to claim 1, characterized in that the amount of nickel as NiO is at least 3 wt. - * $> the weight of the catalyst. 3 · Catalyst according to claim 2, characterized in that the amount of nickel as NiO is 10 to 30 wt .- # of the catalyst weight. 4. Catalyst according to claim 1, characterized in that the heat-resistant oxide carrier made of aluminum,
Silicon, magnesium ,. Titanium, zirconium, beryllium or
Thorium oxide consists. 5 * catalyst according to claim 4, characterized in that that the heat-resistant oxide carrier is present in spherical, cylindrical, subdivided or powdery form. 6. Catalyst according to one of claims 1 to 5. » through this characterized in that it also contains at least 1 rare earth element in an atomic ratio of the rare earth element or elements to contain silver of 10 or less. 3U9 8S.1 / 10 7 7 · Catalyst according to claim 6, characterized in that « net that the rare earth element or elements are present in an atomic ratio to silver of 0.2 to 2.0. 8. Catalyst according to claim 6, characterized in that it is ltenerdelemente lanthanum, cerium yttrium,
Contains praseodymium, neodymium or a mixture of rare earth elements obtained from monazites, xenotimes or bastnaesites. 309851/1074