DE2328064C3 - Hydrocarbon steam reforming catalyst - Google Patents

Description

The invention relates to a hydrocarbon steam reforming catalyst. At present, hydrocarbon steam reforming processes are used in the production of hydrogen gas, fuel or different synthesis gases predominate. The steam reforming of hydrocarbons is usually by passing the hydrocarbons, especially paraffin hydrocarbons, in gaseous form Condition together with steam through catalysts filled in a heat-resistant cylinder carried out at a temperature of 400 to 800 "C and a pressure of 1 to 30 at.

The steam reforming response can be expressed by the following equations if one Hydrocarbons of the formula CmHn supplies:

CmHn + ITiH ₂ O> mCO +

CmHn + 2mH ₂ O - »mCO ₂ + 6m

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

CH ₄ + H ₂ Oi
CO + H ₂ O.

CO + 3H ₂ (3)

? CO, + H ₂ (4)

The equilibrium composition of the gas produced depends on the temperature, pressure and proportions of the substances supplied (steam-carbon ratio: ratio of the steam moles per gram atom of carbon of the supplied hydrocarbon (s), hereinafter referred to as "H ₂ O / 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 "CO 2} / C"), and therefore the desired gas, e.g. B. hydrogen gas, fuel gas or various synthesis gases can be obtained.

The main problem with using the

Steam reforming catalyst is that of carbon deposition on the catalyst, although it is from the conditions when hydrocarbons react with steam.

The main reactions that lead to carbon deposition are represented by the following equations reproduced:

CmHn> C + Cm'Hn '+ H, (5)

2CO> C + CO,

The carbon deposition on the catalyst causes a decrease in the activity of the catalyst, but the problems are even more serious Powdering and the decomposition of the catalyst due to the carbon deposition as well as the inevitable subsequent interruption of operations due to gas pipeline clogging.

In order to prevent this carbon deposition, H ₂ O / C is usually increased. An increase in the H ₂ 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 the increase in the H ₂ O / C is uneconomical.

As known catalysts having a suppressing effect on carbon deposition

Up to now there have been catalysts available that use nickel as Main ingredient and potassium as a catalysis promoter on a refractory oxide support have (US-PS 33 34 055, US-PS 33 94086). These catalysts prevent deposition of the Reforming the hydrocarbons formed active carbon as stable carbon. Well tends Potassium to migrate through the catalyst and to evaporate due to its low boiling point. As a result, the catalyst condenses

4S evaporated potassium and is deposited on low-temperature parts downstream of the steam reforming plant, whereby it unfavorably clogs the pipe system.
In addition, there have already been catalysts which contain nickel and uranium on a heat-resistant oxide carrier (Jap. Pat. Publ. 7708/68, 4454/71, 25366/71, 25367/71). These catalysts promote the reaction of the active carbon deposited on the catalyst during reforming with water with the formation of hydrogen gas and carbon monoxide. However, their use is limited because the uranium, which acts as a catalytic promoter, is a radioactive element.
Hydrocarbon steam reforming

f'o catalysts made from a heat-resistant oxide carrier with nickel as a major catalytically active ingredient and 2 to 49 wt% silver as Catalysis demand agent known, which is heated by firing a shaped mixture of the powdery egg

(> s stable oxide carrier with nickel and silver compounds are available (GB-PS 10 32 754). When using them, the H ₂ O / C ratio is at least 1.3, and the catalyst should preferably

Sators still contain an alkali metal, which brings the disadvantages mentioned.

A similar catalyst with 1 to 10 wt% nickel and 0.01 to 10 wt% silver on a porous Carrier is also known for hydrocracking (US Pat. No. 2,926,130).

The most important requirement of the steam reforming catalyst is that it can prevent carbon deposition on the catalyst with the lowest possible H ₂ O / C ratio. In addition, it is very desirable that the steam reforming catalyst should perform this function with different types of hydrocarbons, i.e. both paraffin and olefin hydrocarbons! can meet. Furthermore, such a catalyst should have excellent activity in a wide range of temperatures and pressures. In addition, the steam reforming catalyst should have high heat resistance and mechanical strength, so that it can withstand higher temperatures and pressures.

The invention is therefore based on the object of providing a hydrocarbon vapor formic catalyst indicate which meets all these requirements better than the known catalysts.

The invention, with which this object is achieved, is a hydrocarbon vapor formic catalyst made of a help-resistant oxide support with nickel as a main catalytic active ingredient and silver as a catalysis promoter, obtainable by firing a shaped Mixture of the powdery, hot-coated oxide carrier with nickel and silver compounds, with the Indicates that the catalyst has a lower amount, calculated as NiO, of 10 to 30% by weight, at least 2 mg atoms of silver per KX) g of catalyst and at least one oxide element in an atomic ratio of the earth element or elements to silver from 0.2 to 2.0.

The raw materials for nickel, which in the case of the catalyst according to the invention are mainly catalytic active ingredient is used include, inter alia. Nickel oxide, nickel nitrate, nickel carbonate, nickel oxalate, Nickel formate.

The raw materials for silver that is used in the invention Steam reforming catalyst serving as a catalyst support means include, inter alia. Silver oxide, nitrate and carbonate.

As rare elements that are used in the invention Catalysts serve as additional catalysis requirements, lanthanum, Ccr, yttrium, praseodymium, Use neodymium, etc. Taking into account availability and cost, lanthanum, cerium and yttrium preferred. Mixtures of rare earth elements can also be used which one obtains from monazite, xenolim, bastnaesite, etc. As raw materials for these rare earth elements, they too are to be borne by the hilzebesländigen oxide, especially oxides, nitrates, carbonals, Use hydroxides and oxalates.

The refractory oxides used in the steam reforming catalyst of the present invention include the oxides of aluminum. Silicon, magnesium, titanium, zirconium, beryllium, thorium. The heat-resistant Oxide can be in any form, e.g. B. spherical, cylindrical, slice-shaped or be powdery. In general, carbon separates when acidic oxides such. B. alumina.

Silica, etc. are used as a carrier, but it has been found that the analyzer composition in accordance with the invention, the carbon deposition will then also be considerably halted can when these acidic oxides are used as carriers.

If silver is present in an amount of less than 2 mgAtomcn per KX) g of the catalyst, is the suppressive effect on carbon deposition unsatisfactory, and the rate of carbon deposition exceeds 40 mg / h at the usual feed rate of the hydrocarbons, unless the ratio H, CKC is set higher than 3. As a result, the Operation of the steam reforming plant disrupted. The syllable iigc can be increased by far more than 2 mg Alome (per KM) catalyst) as long as the main catalyst component Nickel can be kept above its lower (iren / e.

The reasons for the effect of silver as a catalyst requirement in the sense of suppressing the Carbon sequestration has not yet been elucidated, but when silver is combined, silver can be used are supported by a help-resistant oxide, evidently the reactivity between the active carbon and improve steam.

Furthermore, the earth elements are alkaline substances and have a good affinity for acidic metal oxides, such as B. alumina and silicon imide. Therefore, the cutting member can sufficiently adhere to alumina or silica and the surface of the aluminum or silicon oxides to convert to an alkaline demise, which apparently the negative effect on carbon deposition is improved. In addition, the oxides of the cores have good heat resistance, and it appears that the alkaline elements improve the heat resistant wedge of the catalyst and prevent its deterioration by heat.

The manufacture of the foundational steam formic catalyst takes place as follows: Fine mixture of water-soluble compounds of the Nickels, silver, and stainless steel. which are mixed with each other in the above ranges is mixed with powders of hilly land oxides in a dry or muddy state, and the obtained mixture is processed into its intended shape and fired, whereby the desired catalyst is obtained. No differences in behavior are observed of the catalyst, whether you use the silver compound and the sellenerd element content at the same time or one after the other or gradually mixes.

The catalyst obtained in this way can be used for steam reforming for a wide range of hydrocarbons including methane and exhaust gases from various hydrocarbon materials. Liquefied natural gas, hydrocarbons with higher molecular weights, are used as hydrocarbons than that of methane, like liquid hydrocarbons, liquefied petroleum gas. Butane. Hexane. Light petroleum distillates and naphtha are used.

Di, - amount of hydrocarbons is / equals mil Steam passed over the catalyst and can be in a temperature range of 350 to 000 C. and in a pressure range from I to 50 ku cnr refor-

If hydrocarbons with more than 1 "." The amount of steam formed over the molded catalyst is Carbon dioxide separation only 2 mg II or less, even if in each case the ratio of H, O / C only 0.75. If an exhaust gas from the Peirolcuinindustric when using hydrocarbons as raw material over the conventional catalytic converter dam pfreformierl is, the exhaust gas must first be passed over a hydrogenation catalyst are to convert the olefinic hydrocarbons into paraffinic hydrocarbons to convert and thus prevent excessive carbon separation. If that Feed gas passed over the hydrogenation catalyst the temperature of this gas rises due to the hydrogenation reaction. and the activity of the A significant amount of hydrogenation catalyst is lost. So there has been a mandatory limit up to now for the content of olefin hydrocarbons !! in the feed gas.

With the catalyst according to the invention, on the other hand, a feed gas with a content of about 15 vol- ⁰ oo olefinic hydrocarbons can be directly steam reformed without the occurrence of any disturbances, without the gas first being passed over the otherwise customary hydrogenation catalyst layer. In this way, the construction costs of the reforming plant can be reduced and its operation can be made considerably easier.

At a ratio of H ₂ O / C of 3.0, the carbon deposition can be reduced to 5 mg / h or less despite the said content of olefin hydrocarbons.

When the catalyst activity in proportion to the feed rate of carbon, d. H. as the number of gram atoms of carbon per unit of volume of the catalyst is expressed per unit time of supplied hydrocarbon, can the proportion of unreacted hydrocarbon z. B. in the case of η-butane at 55 g atoms of carbon each Maintain 0.01% or less per hour and liter of catalyst. Therefore, the invention Catalyst 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 gases for methanol synthesis, oxo synthesis, etc. and can be used directly for the steam reforming of a starting gas containing olefins. Furthermore, the catalyst according to the invention can also be used at a low H ₂ O / C ratio and can therefore be used to generate gas for ore reduction. In addition, the catalyst of the present invention has a good suppressive effect on carbon deposition and can therefore be arranged on a plant part where carbon tends to be deposited in the steam reforming plant, that is, usually at the inlet part.

The invention will now be based on exemplary embodiments with reference to the drawing be explained; in it shows

F i g. 1 is a diagram for explaining the relationships between HjO / C ratios and the Carbon deposition if, according to one embodiment, η-butane above that according to the invention The catalyst is steam reformed,

F i g. Fig. 2 is a diagram for explaining the relationship between the ratio La / Ag and the Carbon deposition. if, according to another exemplary embodiment, n-Bulan above the crfmdungsgcommcn Catalyst is oxo-reformed, and

F i g. 3 is a diagram for explaining the relationships between ethylene concentrations and the Carbon deposition. if, according to a further embodiment, ethylene containing ethane over steam reformed with the refined catalyst will.

at

spat

Catalysts according to the invention and comparison catalysts were prepared in the following manner:

Catalyst A (inventive catalyst)

75.0 g nickel nitrate hexahydrate, 9.3 g lanthanum nitrate hexahydral and 3.67 g of silver silver were separately dissolved in water, and the three obtained aqueous ones Solutions were mixed with each other to make a total volume of 70 ml. 100 g of spherical active alumina support material with grain sizes of 1.68 to 2.82 mm impregnated with the resulting mixed solution and dried at 110 ° C. for 3 hours and then be Fired at 900 C for 2 hours.

The catalyst obtained contained 15.4 weight ⁰ Zc nickel as NiO and 17.2 mgAtomc lanthanum per 100 t catalyst (21,6mgAtome lanthanum per 100 g de "carrier material) and had a Atomverhällnis Lan than to silver of 1.0 to .

Catalyst B (comparative analyzer)

75.0 g of nickel nitrate hexahydral and 7.34 g of silver nitrate were separately dissolved in water, and the two aqueous solutions obtained were mixed together until a total volume of 70 ml , 82 mm were impregnated with the mixed solution obtained, ^{dried at 110 °} C. for ^{3 hours and fired at 900 °} C. for 2 hours.

The catalyst obtained contained 15.5 weight ⁰ / nickel as NiO and 34.7 mgAtome silver per 100 g de · catalyst.

Catalyst C (comparative catalyst)

75.0 g of nickel nitrate hexahydrate and 18.7 g of lanthanum nitrate hexahydrate were separately dissolved in water, and the two aqueous solutions obtained were mixed with each other to make a total volume of 70 ml. 100 g of spherical active alumina carrier material with grain sizes voi 1.68 to 2.82 mm were impregnated with solution of the obtained compound, getrockne 3 hours at 110 ⁰ C and then baked for 7 hours at 900 ° C.

The catalyst obtained contained 16.2% by weight Nickel as NiO.

Catalyst D (comparative catalyst)

75.0 grams of nickel nitrate hexahydrate and 18.7 grams of lanthanum nitrate hexahydrate were dissolved separately in water, and the two aqueous solutions obtained were mixed together to make a total volume of 70 ml. 100 g of ball shaped active aluminum oxide carrier material with grain sizes from 1.68 to 2.82 mm were used with de impregnated mixed solution obtained, dried at 110 ° C for 3 hours and calcined at 900 ° C for 2 hours

The catalyst obtained was 15.3% by weight Nickel as NiO and 34.2 mg Alome I.aiillian per 100 g Catalyst.

25 ml of each of the prepared catalysts were each in a reaction tube with an inner diameter of 15 mm, the catalytic converter was 1 tempera door on the run to 6 (K) C or more and increased to 800 C or more at the exit. Hydrogen was released through this reaction tube at a flow rate of about 300 ml / min together with steam for 1 to 2 hours through gelcilcl 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 temperature of the catalyst layer at certain values, and adjusting the rate of injection of η-butane, steam and carbon dioxide so that the ratios of H ₂ O / C and CO ₂ IC defined values ingested, and the starting materials passed through the reaction tube after passing a Vorhilztcils, the reaction being triggered over the catalyst. The reaction product gas was passed through a condenser and a trap to an analyzer, and a total analysis of the reaction product gas for its constituents other than water was carried out by means of gas chromatography.

The amount of carbon deposits was determined determined by looking after the completion of the experimental reaction the Kalalysatorschichl supplied oxygen to so the deposited carbon in To convert carbon dioxide. The carbon dioxide obtained was then measured quantitatively.

If tests were to be carried out over the same catalyst while changing the ratios of H ₂ O / C and CO ₁ IC , the catalyst was reduced again and then used for the further tests.

The relationships between the H ₂ O / C ratio and the carbon cutoff in the steam reforming of n-bulane under atmospheric pressure for each of the named catalysts A to D are illustrated in FIG. 1 were the following:

Initial temperature of the

Catalysts 730 to 8 (X) C

Analyzer volume 25 ml

Response time I hour

Test pressure atmospheric pressure

In the following table 1 are the test data and results, including data, given when elevated pressure was applied.

Table 1 - Colil- H ₂ O C CO, C pressure KaUiIy- Keaklionpriiduclgas / usa »Ι CO co. inimensel / ung coal loading slotT- merkuni! <0.001 KaUiIy sloff- salary (VoI.- "' Ah- <0.001 sator / uführ- layer- CjH IO divorce <0.001 quick win initial H ₂ CH ₄ <0.0ΘΙ digkeil ·) tempe- 15.9 12.1 <0.001 ralur 3.4 19.7 (mg h) <0.001 (kg enr) I Cl 3.9 19.5 <0.001 1.2 55.1 3.07 0.0 1.0 830 71.1 6.1 64.9 0.91 <0.001 1.5 A. 54.4 3.06 0.0 1.0 508 57.6 13.9 11.0 19.3 <0.001 32.5 3.01 0.0 15th 595 47.3 23.0 44.8 29.3 <0.001 32.5 3.01 2.95 15th 590 15.5 19.6 6.3 13.5 <0.001 56.7 3.00 0.0 15th 785 71.0 34.5 22.5 4.3 <0.001 56.7 3.00 2.35 15th 744 29.5 16.5 11.5 2.7 <0.001 32.4 1.18 0.0 15th 820 59.6 3.7 20.3 14.5 <0.001 7.5 32.4 1.20 1.20 15th 800 35.3 2.7 17.4 4.7 <0.001 9.1 56.2 2.89 0.0 1.0 842 71.8 13.7 11.2 0.12 <0.001 B. 59.0 3.00 0.0 1.0 535 59.5 23.1 45.9 16.5 0.175 32.6 3.01 0.0 15th 557 46.7 20.7 5.7 31.2 0.023 57.0 2.97 0.0 15th 784 70.9 35.2 22.0 4.2 0.036 56.8 2.99 2.93 15th 743 29.7 17.5 10.6 1.3 0.004 32.7 1.19 0.0 15th 815 59.9 3.88 20.0 13.7 0.011 32.3 1.19 1.22 15th 803 38.7 2.70 18.8 4.1 <0.001 110.9 0.2 kg **) 59.2 2.89 0.0 1.0 840 71.8 6.80 65.7 0.06 0.003 127.2 0.5 cm ² C. 56.1 2.92 0.0 1.0 570 58.3 13.8 11.2 17.7 32.5 3.02 0.0 15th 599 49.0 23.1 45.7 29.5 32.5 3.02 3.06 15 · 591 15.8 20.3 5.8 11.7 56.5 3.05 0.0 15th 790 71.4 35.1 22.1 3.6 56.5 3.05 3.01 15th 741 29.6 1.65 32.5 1.19 0.0 15th 515 60.0 13.9 32.4 1.20 1.23 15th 799 38.5 4.31

* | gAiomcC./hl catalyst. ** l Pressure difference between upstream and downstream of the catalyst layer.

ίο

Fortsel / ιιημ

Killuly charcoal II »() C CO ₂ ('Diuck Kalaly- KeiiklionspriHlukliMs / usiimmcnsel / ung charcoal

sailor stuff- sillor- (VnI .- "ii | sloff- ηκιΐιιημ

feed layer; ib-

gcschwin- output- llj (O ( ¹ Oj ( ¹ IIj C ₄ II III separation

tliykeit * 1 lempe-

ratiir

(kji cnr) (Ci (mg, h)

55.6 2.99 0.0 1.0 335 72.2 16.1 11.7 0.05 0.027 58.9 2.83 0.0 1.0 533 58.5 2.91 20.7 17.6 0.397 32.5 2.99 0.0 15th 576 44.7 2, (K) 19.3 33.9 0.057 32.5 2.99 3.09 15th 578 14.3 5.40 67.4 12.7 0.186 57.6 2.99 0.0 15th 789 70.9 13.6 11.5 4.07 0, (K) 8 57.6 2.99 2, H6 15th 762 29.9 22.9 44.9 2.16 0.036 32.6 1.20 0.0 15th 798 58.2 19.2 0.70 15.8 0.017 39.6 32.6 1.18 i: i9 15th 785 36.5 33.2 23.9 6.42 0.049 101.1

*) üAtonic (hl Katnlysalor.

It follows from the test data in Table I, that the catalysts B, C and I) (comparative catalysts) have a slightly higher concentration Residual butane result and thus a somewhat lower catalytic ^ activity than the catalyst according to of the invention. The catalyst Λ delivers a low concentration of residual butane, whereby the reaction product gas has a composition almost identical to that of the equilibrium composition which means that the catalyst has good catalytic activity over a range of temperatures having.

Furthermore, the catalyst according to the invention shows a noticeably lower carbon deposition than the catalysts B, C and D (comparative analyzers) and therefore a good suppressive effect on the cabbage separation. One foresees this mainly from the test results at atmospheric pressure in I- 'i and I.

Example 2

Catalysts were prepared in a manner similar to Example I, the atomic ratio being was changed from lanthanum to silver and there were the oppressing effects on carbon deposition animal addiction.

Namely, the molar ratios of Lanlhan nitrate were to silver nitrate to 100: 0 (catalyst D), 95: 5, 80:20, 65:35, 50:50 (catalyst Λ), 35:65, 20:80, 5:95 and 0: 100 (catalyst B) set, but the total of gAtomcn lanthanum and Silver per 100 g of carrier material was kept constant at 43.2 mg of atoms.

An Oxoreformierrcktion of n-butane with 25 ml of catalyst material each with an initial temperature of the catalyst of 785 to 825''C, a pressure of 15 kg / cm ² and with ratios of HiO / C and CO ₂ / C of about 1, 2 carried out in a manner similar to that in Example 1, and the carbon deposits were determined. The reaction time was 1 hour, and the KoIilen.Moffzuiuhr-

(C) speed was 32 to 33 gAtom C "/ h · I catalyst. The results are summarized in F i and 2.

If the atomic ratio of lanthanum to silver / u becomes large and one approaches the catalyst with the composition nickel-lanthanum-aluminum oxide, ie D, the suppressing effect on the carbon deposit decreases, and the catalyst activity also decreases. Therefore, the catalysts should be manufactured and assembled according to the invention in such a way that the Alomverhälnis of the rare earth element content to silver is in a range from 0.2 to 2.0.

B e i s ρ i e 1 3

Aluminum nitrate nonahydrate, nickel nitrate hexahydrate, Lanthanum chloride hexahydrate and silver nitrate became weights as shown in Table 2 weighed and separately dissolved in water. The four aqueous solutions obtained were mixed with each other mixed to make a total volume of 2 liters and then added dropwise with ammonia water offset to precipitate precipitation. After settling, the supernatant liquid was through Decant away. Then 2 l of distilled water were added to the precipitated residue, which Mixture was stirred and decanted. This step was repeated twice, and

(> o Then the solid residue was distilled off. The residue was then dried and pulverized at 110 ° C. for 10 hours. The powders obtained were mixed with 2 wt .-% polyvinyl alcohol and then mixed into tablets with a diameter of 10 mm and

i> 5 molded to a thickness of 5 mm under a pressure of 500 kg / cm ² . The tablets obtained were calcined at 900 ° C. for 2 hours and used as catalysts.

Table 2

Kalalysalor Aluminum- Nicki-Iniliai I anlhan- Silhmiiiral NiO iiilnil nili.il

ΛΙ, ο,

I .ι

Au (ιημ.Λΐηιικ HKIu KaIaU-

s.llllll

563.1 75.0 0.48 0.19 19.3 S0.4 561.0 75.0 0.95 0.37 19.3 80.1 556.8 75.0 I, X (p 0.73 19.3 79.5 521.9 75.0 9.35 3.67 19.3 74.5 478.4 75.0 18.70 7.34 19.3 68.3 391.5 75.0 37.91 14.68 19.3 55.9

4.3
21.6
43.2
86.4

U -) ι

4.3 21.f. 43.2 36.7

The cutaneous salor activity and carbon sequestration became similar for these Catalysts I through .1 as measured in Example 1, and the final amounts of the amounts of lanthanum and silver as a calcium analyte were examined. The results are given in Table 3.

Table 3

Kalaly- carbon sliilT-

/ uführ-μι-schwin iliiiku-it ·)

II.OC ti), C Drmk KaIaIy- Ucakliiiiisprodukluas / iisaniniL-iisi-I / iiiiu | \ ol .- ".. i Knhlcn

sahn- slnll.ili-

schichi- W ₂ (O (O. <II, (, 11 III slIicuIiiii

allsgangslcnipcrat in

Ί 32.6 1.21 1.23 Ikp curl ι (Ί 36.5 32.0 25.1 6.4 0.005 Imu I i ·: 32.4 1.18 1.20 15th 803 36.9 33.1 24.9 5.1 <(UK) I 31.6 F. 32.4 ! .18 1.21 15th 801 37.2 33.6 24.3 4.9 <(). (K) I 7.5 G 32.5 1.20 1.17 15th 805 36.8 32.5 25.0 5.7 <0.001 3.6 II 32.4 1.19 1.24 1.5 796 37.2 33.3 24.3 5.2 <0.001 1.2 I. 32.6 1.20 1.27 15th 800 36.5 31.2 26.0 6.3 <0.001 1.8 .1 uAlnmc Ch- I Kalalysnior. 15th 789 1.9

As Table 3 shows, the reactive product gas composition is almost identical to the equilibrium composition, and accordingly good catalyst activity was achieved. The amount of Carbon deposition decreases with an increase in the content of lanthanum and silver, and it does so it is necessary that at least 2 mg atoms of silver are present per KK) g of catalyst. It is also desirable that at least 2 mg of lanthanum atoms per K) Og of catalyst are present, so that you can see the good The effect of the lanthanum stops.

Example 4

The reforming of methane containing olefin hydrocarbons was carried out using catalysts A to D according to Example 1 in order to make further comparisons of the behavior of the catalysts. The test gas which was processed here was a gas mixture of methane, ethylene and hydrogen, in which the ethylene concentration was varied in a range from 0 to 1.7% by volume, while the hydrogen partial pressure was fixed at 15% by volume and the remainder each consisted of methane. The test gas was passed over the catalyst together with steam at an H ₂ O / C ratio of 3.0, and the reaction was carried out with each

4s 25 ml of the catalysts Λ to I) under the following Reaction conditions similar to Example 1 are carried out:

Pressure 8 kg cnr

Catalyst shell inlet

temperalur 500 ('

Ka'.alysatorschichtauslaU-

temperature 750 C

Response time 1 hour

Carbon supply

wind speed 30 gAloine

ChI catalyst

The relationships between the ethylene concentration and the carbon separation were determined and the results are shown in FIG. 3 illustrates.

F i g. 3 shows that the amount of carbon separation increases with an increase in the concentration of ethylene in the case of catalysts B, C and D (comparable catalysts) grows and evidently from the Ethylene concentration is influenced, while in the case of the catalyst A according to the invention practically no influence of the ethylene concentration can be determined. Therefore, if the ingenious Gas reforming catalyst is used

Oil-filled coal storage with higher concentration containing starting gas of a Dainpfrcformieranlage without any pretreatment in a hydrogenation reactor.

Example 5

Incompatible catalysts were made as follows hergeslelli:

Catalyst K

75.0 g of nickel nitrate hexahydrate. 3.67 g of silver mineral and 5.S g of a mixture of stone earth elements. obtained from monazite sand were separately dissolved in water, and the obtained three aqueous solutions were mixed together to make a total volume of 70 ml. 100 g of spherical active alumina carrier material of 1.68 to 2.82 mm in size was impregnated with the resulting mixed solution. Dried for 2 hours at 9 (Xl C fired for 3 hours at 110 C.

The catalyst obtained contained 5.5% by weight Nickel as NiO. 17.2 mg atoms silver per KX) g catalyst (21.6 mg Alomc silver per KX) g of the carrier material and 6.8 mgAtomc lanthanum. 10.8 mgAtome (he 2.9 mgAlome Neodymium and a small amount of praseodymium. Samarium etc. per 100 g of catalyst.

'label 4

Catalyst L

The catalyst was prepared in the same way as the catalyst K with the exception that the s basic mixture of catalyst K through 9.38 g of t'crnilrathexahydral was replaced.

The catalyst obtained contained 15.4% by weight of nickel as NiO, 17.2 mg of atomic silver per 100 g of catalyst (21.6 mgAtomc silver per 100 g of the carrier material) and 17.2 mgAtomc ('er per 100 g catalyst.

Catalyst M

The catalyst was processed in the same way as the

is catalyst K with the exception that the

Incremental mixture of the catalyst K through

8.27 g of yttrium nitrate hexahydral was replaced. the

The catalyst obtained contained 15.4% by weight of nickel

as NiO, 17.2 mg Alome silver per 100 g catalyst

zo (21.6 mg Alome silver per 100 g carrier material) and

17.2 mgAtome Yttrium per 100 g of the catalyst

(21.6 mgAtomc yttrium per 100 g of the carrier crystal).

The amount of carbon separation was determined for

the catalysts K., L and M according to the

; s game I explained procedure intended to

their carbon deposition suppressing effects

check gcn. The results are shown in Table 4

specified.

K.n.iK coal ■, .um slnfT-

/ ufiilii-

ui-sdiwtn-

ciiükeit'l

IU) C CO, C Pressure Kalah- KeaktinnspriHluklgas / usiimmensct / iing (Vol.- "») Kohlcn-

salor- slolTah-

Schichl- II, CO CO ₂ CH ₄ C ₄ H IO separation

Ausüangslcmperalur

1.20 0.0 (kg cm-) I C) 58.1 19.3 6.7 15.9 0.001 (mg 32.5 1.22 1.25 15.0 801 36.6 32.8 24.2 6.4 <0.002 3.5 32.4 1.19 0.0 15.0 785 58.0 19.4 6.9 15.7 <0.001 7.1 32.4 1.18 L19 15.0 793 36.3 32.7 24.1 6.9 <0.002 1.8 32.6 1.19 0.0 15.0 788 58.5 19.4 7.0 15.1 0.001 3.9 32.3 1.20 1.21 15.0 800 36.5 33.3 23.7 6.5 0.001 5.1 32.5 15.0 791 4.7

* l μΛίοπκ · Ch-I Kalalysalor.

It can be seen from Table 4 that the catalysts if they are not only lanthanum, but also (er. yttrium or a mixture of rare elements contained as a catalysis promoter together with the silver on the carrier material, a have good catalytic activity and a good carbon deposition suppressing effect. It should also be noted that a good carbon deposition suppressing effect can also be achieved lets, if one of Monaziten, Xenotimen, Bastnacsi-5.S The last component mixture obtained as a separate component is used.

For this purpose 3 sheets of drawings

Claims (2)

Patent claims: 1. Hydrocarbon steam reforming catalyst made from a heat-resistant oxide carrier with Nickel as a major catalytically active ingredient and silver as a catalytic promoter, obtainable by firing a molded mixture of the powdery egg heat-resistant Oxide support with nickel and silver compounds, characterized in that the catalyst contains an amount of nickel, calculated as NiO, from 10 to 30% by weight, at least 2 mg atoms of silver per 100 g of catalyst and at least one rare earth element in an atomic ratio of the rare earth element or elements to silver contains from 0.2 to 2.0. 2. Use of a catalyst according to claim I for hydrocarbon steam reforming.