JPS62503101A - Methods and catalysts for the conversion of methane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Methods and catalysts for the conversion of methane Background of the invention 1. Field of invention The present invention converts methane into hydrogen in the presence of oxygen and comparatively containing ethane and ethylene. The present invention relates to methods and catalysts for converting higher hydrocarbons.

2. Description of conventional literature Methane is an abundant hydrocarbon feedstock obtained primarily from natural gas.

The natural gas content ranges from 60 to 99%, with other components being ethane, propane, Butane, carbon dioxide and nitrogen. The world's storage capacity is approximately 2.5X 10 I2f The production of chemicals from Yushinaga group methane, which is estimated to be is limited by the lack of a catalytic method that can activate methane.

Currently, methane is either combusted or made of iron or nickel, depending on its value as a heat source. can be reformed over a metal catalyst to produce CO and N2. More CO and N2 When reacted with N2, it becomes methanol and ammonia. However, liquid fuel, plastics, fibers, solvents, and many other materials used in the chemical industry. For example, ethylene or propylene can be used to produce organic compounds. Attractiveness for converting methane directly into more valuable hydrocarbons, such as There is no such method yet. Thus, methane is an underutilized natural resource. It is a resource.

U.S. Sekitsuki No. 4,172,810, No. 4,205,194 and No. 4,239゜65 No. 8 is for converting methane into hydrocarbon products rich in ethylene and benzene. Novel catalysts and methods are disclosed.

The essential components of the catalyst are: (1) Group III noble metal with an atomic number of 45 or more, nickel, or an atom of 47 or more Group Ib precious metals with numbers, (2) a Via group metal oxide that can be further reduced to a lower valence oxide, and (3) Passivated magnesium and strut composited with spinel-coated refractory carrier Carbon composites with rontium or passivated non-zinc containing spinel coated refractory carriers. Illa group metal selected from the group consisting of lucium In this method, the catalyst is brought into contact with methane at high temperature for a short period of time, and then the carbonization produced is It consists of recovering hydrogen. Contained in the catalyst during exposure to methane Some of the metal oxides are reduced and the surface of the catalyst becomes covered with coke, inactivate it. Before reintroducing the methane into the reactor, add oxygen or water to the reactor at an elevated temperature. The catalyst must be regenerated by contacting it with a gas containing

U.S. Pat. No. 4,450,310 describes how methane in the absence of oxygen and water Converts methane to olefins and hydrogen by passing it over a catalyst at temperatures above °C discloses a method for doing so. The catalyst contains Li, Na, K, Rb and Cs. IAI of the periodic table including Be, Mg%Ca%Sr and Group A of the periodic table including Be, Mg%Ca%Sr and Ba and optionally selected from Cu, Re, W%Zr and Rh. It consists of a promoter metal. This when compared with what has been written so far An improvement in the process is a reduction in the amount of coke deposited on the catalyst during the reaction, which thus increasing the reaction time that elapses before the catalyst has to be regenerated. It seems possible.

C0E, Keller and M, Bergin, Journal of Catalysis, Eng. , 9 (1982), pure methane at normal pressure and temperature between 500 and 1000"C. Discloses a method for producing ethylene and ethane from methane by feeding over a catalyst ing. As the methane passes into the reactor, it reacts with the metal oxide catalyst to form ethane. produces ethylene and reduces metal oxides at the same time. After short-term exposure to methane The catalyst must be regenerated and for this purpose switched to a pure oxygen supply and Therefore, the metal oxide is reoxidized. All catalysts were metal oxide supported on Al20). 'f4 was made by The active catalyst is Sn, Pb, Sb, Bi% It is a supported oxide of TI, Cd and Mn. 02 hydrocarbon production of methane These oxides must have good activity and selectivity for conversion to This suggests that it is essential that the Ru. Jones, Leonard and So7ranko convert methane to ethane and ethylene. A series of methods disclosing methods similar to the Keller and Bergin method for producing A patent has been applied for. This reaction is carried out at normal pressure and at a temperature of 500-1000°C. , methane and oxygen are fed separately and cyclically.

The improvements of Jones' method compared to Keller's method include the following: (1) Use of a fluidized bed catalytic reactor instead of a fixed bed catalytic reactor; and (2) A120. instead of supporting active metal oxides on SiO□. Joe Lens, Leonard and Solanco use “reducing agents” as catalysts for this process. Metal oxides that can be used must be used, and they are %Pb, Sn, In and Bi oxides. These oxidations 4,443,644; 4,443,649; 4, respectively. , 443,645; 4.443.647; 4.444,984; 4,44 3.648 and 4,443,646. acid that can be reduced an alkali metal (U.S. Pat. No. 4,499,322) or an alkaline earth Metals (U.S. Pat. No. 4,495 Suga 374) can also be used as cocatalysts; The stability is improved by the presence of phosphorus (PCT Patent Publication WO351008). 04), and other related studies using alkali and alkaline earth metals as cocatalysts. Ru (U.S. Pat. No. 4,489.215) and reducible rare earth oxides. , CeO2 (U.S. Pat. No. 4,499,324) and Pr6O11 (U.S. Pat. No. No. 4,499,323).

Hinsen and Burns [German Patent No. 3,237,079, Chemical Laaira] Ng, 11th Eng., 223 (1983) and Proceeding Or 8th Internac. Journal Congress Ope Catalysis, 3,581 (1984) 1 from methane. A new method for the synthesis of ethylene and ethane is disclosed. the previous method and The improvement of this method when compared is that methane and oxygen are fed simultaneously to the catalytic reactor; The aim is thereby to eliminate the need for cycles between reaction and catalyst regeneration. suitable Oxygen conversion methods include addition from the side of the reactor or recycling of large amounts of hydrocarbon gas. It is an addition to the flow. These oxygenation methods ensure that the partial pressure of oxygen remains low. and thereby maximize the selectivity. Good selectivity is achieved by reaction at 650-750℃ Low 02 partial pressure compared to temperature and methane (PO2-4,05~0.10aj button) It is recognized in For the case of continuous feedstock supply, Burns provides Pb, Reducing oxides of Sb, Sn, Bi, Cd, TI and In are active and selective It was discovered that it is a catalyst. To maintain good selectivity, the acidity of the support should be reduced. It is also essential to Or by using SiO2 carrier instead of A12os, pbO heavy weight By increasing the addition rate to 0.0% or more, and by increasing the catalyst with alkali. This can be achieved by doing so.

U.S. Patent No. 2,020,671 describes alkaline earth metal, aluminum, In the presence of catalysts selected from metal salts of ium and zinc The production of oxygenated acid compounds by reacting tan with steam is disclosed.

U.S. Pat. No. 2,859,258 describes methane in the presence of oxygen-containing metal compounds. discloses the production of ethylene from, for example, aluminum oxide. aluminum, magnesium aluminum silicate, and aluminum magnesium molybdate Metals selected from groups ■, ■, and ■ of the periodic table, such as umum.

3.Object of the present invention The purpose of the present invention is to provide high selectivity and high single pass conversion in the presence of oxygen. Currently, methane is converted to hydrogen, ethylene, ethane and higher hydrocarbons. The goal is to obtain a contact method for understanding the situation.

Another object of the invention is to convert methane into hydrogen, ethylene, ethane and and to provide an active and selective catalyst for synthesizing higher hydrocarbons. It is in.

Another object of the present invention is to avoid intermittent regeneration of the catalyst, thereby removing methane from To achieve continuous synthesis of hydrogen, ethylene, ethane and higher hydrocarbons The process was operated by simultaneous addition of methane and oxygen to the catalytic reactor. be.

These and other objects will become apparent as the description of the invention proceeds.

Anihada@Kagugai Gases containing methane and oxygen, such as Be, MgCa, Sr and Ba, are metal oxides of metals of group IIA of the periodic table; such as Se, Y and La Oxides of metals in group I [lA of the periodic table; for example, Pr, Nd, Sm, Eu, Ce such as Gd%Tb, Dy%Ho%Er%TIII, Yd and Lu metal oxides of the rank-end series except Thus, it is converted into hydrogen, ethylene, ethane and higher hydrocarbon products. It was discovered that it is possible. This catalytic reaction takes place at temperatures between 500 and 1000°C. It is preferable to carry out the reaction at a pressure of 1 to 25 atmospheres.

Some water, CO and C02 are also produced as by-products of the reaction.

The method of the present invention is already for the synthesis of hydrocarbons from methane in the presence of oxygen. Known methods include, for example, MgOlSrO%Y203 and La-0-. , differ in the use of metal oxides that cannot be reduced. these catalysts The second feature is that it is a basic and ionic metal oxide. mosquito Therefore, metal oxides that exhibit basic properties and have no redox potential are Generally, it is a selective catalyst for the synthesis of higher hydrocarbons from mixtures of methane and oxygen.

Furthermore, metal oxides of the lanthanide series excluding IIA, Group IIIA and Ce are as follows: Bottom metal: (a) Group IA metals, which are Li%Na and K; (b) Be%Mg, C11 % Sr and Ba; (c) Sc, Y and La; I [Group IA metal; (d) Ce, Pr5Nd, Ss, Eu%Gd%Tb, Gold of the ranknid series, which are Dy, Ho, Er, Tm, Yb and Lu. (e) metals of group IVB, which are Snn and sols; (r) sb and Bi; selected from metals of group VB; and (H) metals of group IB, which are Cu, AH and Au. It has been found that this can be improved by the addition of one or more promoter oxides. Ta. Promoter oxides can be added in a variety of ways. The addition rate of co-catalyst is 30% by weight, although this can vary from a tactilely effective amount to 50% by weight. Less than is preferred.

The process of the invention differs from already known processes for the synthesis of hydrocarbons from methane by An inert support for the metal oxide is unnecessary and in some cases the overall They are also different in that they can be detrimental to performance.

The method of the invention furthermore combines with already known methods for the synthesis of hydrocarbons from methane. also differs in that methane and oxygen are fed simultaneously to the catalytic reactor. child By using the catalyst described here, the synthesis of hydrocarbons from methane can be It can be carried out in the presence of oxygen without reducing the yield of the hydrogenated product. Wear. Such simultaneous and continuous supply of a mixture of methane and oxygen to the catalytic reactor Feeding eliminates periodic catalyst regeneration, which is the preferred mode of operation of the present invention.

The invention is further illustrated in the following description of preferred embodiments.

Brief description of the drawing Figure 1 shows the conversion of product relative to the conversion of methane (based on the number of moles of methane converted). This is a graph showing the dependence of

FIG. 2 is a graph showing the dependence of product selectivity on operating temperature.

Jaqian Ai Sheng Plate @Ochihada The catalyst may be selected from one or more base metal oxides of Group IIA, Group I[[A and the lanthanide series. can become. These substances can be used as metal oxides or later in the oxide form. It can be supplied as a metal salt that can be decomposed into of suitable metal salts Some examples are acetate, acetylacetonate, carbide, carbonate, hydroxide, Formate, Oxalate, Nitrate, Phosphate, Sulfate, Sulfide, Tartrate, and Habdenides such as chlorides, bromides and iodides.

A particularly suitable catalyst for the process of the invention is La20. ,Y2O,,Pr60++ , Nd, O,, S m 202, Eu2O3, ad20s, Tb0z, DF20 1, l-10203, Er20*, T+, o,, Yb2O3 and Lu20. the package It is a rare earth oxide containing

These oxides are obtained in their pure form or generally from mineral deposits It can be used as a mixture. Where mixtures obtained from ores are used For example, when pastnasite or monazite is used, the Ce content of the ore is It is necessary to reduce the amount to low levels.

Cerium oxide is an acidic solid and can easily cycle between +3 and +4 acid value states. I can do it. As a result, CeO converts methane, ethylene, and ethane in the presence of oxygen. CO and CO2 rather than carbon and higher hydrocarbons.

In another embodiment of the invention, the catalyst comprises the base metal oxide and IA, nA, cocatalytic acids, such as nlA, i, VB, IB group and lanthanide series metal oxides; It can consist of a mixture with a chemical compound. Preferred forms of catalysts in the mixture are IA, II Co-catalyst amounts of Group A, IVB, VB or IB elements may also be deposited on the rare earth oxide. It is. Another preferred form of the catalyst is It is deposited on alkaline earth oxides of elements of the tanide series.

Group IA, IIA, In, VB or IB elements can be subjected to rare earth oxidation by various methods. Can be deposited on objects. IA, IIIA, I on alkaline earth oxides The same method is applied for the deposition of elements of the VB, VB, l or lanthanide series. do. Suitable methods are adsorption, incipient impregnation, precipitation, co-precipitation and dry mixing.

After the elements are deposited on one of the above groups, they are treated at high temperature in an atmosphere of oxygen. It is converted into its oxide form by treatment. Promoter metal oxide deposition The weight addition rate of the material can vary between 0 and 50%, but less than 10% is preferred. be.

The above metal oxides can be deposited on conventional supports such as Sio and A1□03. It can also be deposited. These supports are not an essential part of the catalyst formulation, but Catalytic pellets with improved geometry and/or improved medical strength and durability It can be used to give. When using ordinary carriers, their acidic It is important to reduce the carbon acid content from methane and oxygen, otherwise the carrier It may become a catalyst for the formation of chemical compounds. The acidity of the support is determined by e.g. The use of high weight loadings of oxides, the use of alkali metal loading prior to metal oxide deposition reduced by various means, such as body doping, or the use of low porosity carriers. can be done.

Suitable methods for preparing unsupported catalysts include, for example, those from Group IA or IIA. Cocatalyst metal salts such as are deposited on rare earth oxides by incipient wet impregnation. That's true. Metal salts are dissolved in water and other solvents and then mixed with rare earth oxides An aqueous solution of a metal salt is preferable, as long as it wets the surface of the oxide. , in which case water-soluble salts are used. solution to facilitate dissolution of metal salts. An acid and/or base can be added to. Wetting the tJ earth oxide with a salt solution After that, the oxide is dried in an oven. Finally, for use during the process In order to prepare a solid, the metal or metal salt should be added to the oxide form of 4. You can bake it at high temperature for a long time. For example, it is possible to circulate air. The catalyst is placed in a kiln or tube that can be heated several times at a high temperature, preferably about 500 to 1000°C. Heat for an hour.

Unsupported metal oxides used as catalysts are prepared in various pellet shapes and sizes. Its shape and size create good contact between the gas and the solid surface of the catalyst. Determined by the needs. Berrett is known to specialists in this field of technology. It can be prepared in a conventional manner using methods. For example, catalyst pellets are gold It can be prepared by extrusion of souffles of genus oxides. In this way the shape The formed beret is then dried and then fired at a high temperature. For example, the periodic table Cocatalyst ft group oxides to base metal oxides, such as those from Groups IA or IIA. Addition should be done before or after forming the base metal oxide into a pellet shape. Can be done.

The method of preparing the catalyst is further illustrated in the Examples below.

The catalyst described above is loaded into a reactor and exposed to gas containing methane and oxygen at high temperature. and make contact. Hydrocarbon feedstocks to this process include methane, ethane, and Natural gas containing bread and other light hydrocarbons. The methane content of the gas is 60-100 volume percent, preferably 90-100 volume percent.

natural gas to give a hydrocarbon to oxygen ratio of 1 to 50, preferably 2 to 15; The mixture is then mixed with an oxygen-containing air stream. The oxygen-containing stream can be, for example, nitrogen or argon. It can contain an inert diluent side, such as. However, the diluent Requires a large reactor size and removes the product from the process stream to purify it. Therefore, it is preferable to use substantially pure oxygen.

The optimum ratio of hydrocarbon to oxygen fed to the reactor is ethylene, ethane and Furthermore, the yield of higher hydrocarbons is selected to be the highest. This choice depends on the composition of the catalyst, Depends on many factors, such as reaction temperature and pressure, and desired hydrocarbon product distribution. is controlled. As the oxygen partial pressure relative to the methane partial pressure is increased, methane conversion increases. However, the yields of ethylene and ethane are At elementary partial pressures, the production of carbon dioxide increases relative to the desired hydrocarbon products. It does not increase proportionately. This relationship was demonstrated for the catalyst described in Example 18. 1 using an integrated fixed bed reactor. In this figure, the selection rate (transfer methane conversion (based on the number of moles of methane converted) and the methane-to-oxygen feed ratio. A prosplot is shown. For ethylene, ethane and higher hydrocarbons The combined selectivity for Cn is shown in the figure as total Cn. These data are Temperature of 700°C, pressure of 1 atm, GHSV of 8X10'hr = (NTP) and 1 Obtained at 0% by volume 02 feed.

Argon diluent was used in this experiment to maintain a constant space velocity.

The operating temperature for contacting methane and oxygen with the catalyst is 500-1000°C, preferably Preferably, the temperature is 550 to 850°C. The optimal choice of reaction temperature depends, for example, on the composition of the catalyst. , the partial pressures of hydrocarbons and oxidants, and the distribution of desired hydrocarbon products. depends on factors. The dependence of hydrocarbon selectivity on operating temperature is described in Example 6. The catalyst shown in FIG. These data are based on 37,5000hr” (NT GHSV of P), methane partial pressure of 0.30 atm, oxygen partial pressure of 0.05 atm, and 0 ．． Acquired at an argon partial pressure of 65 atmospheres. For all temperatures tested in Figure 1 The oxygen conversion rate was 100%. The data in Figure 2 are for relatively high-grade hydrocarbons. shows that the highest selectivity for There is. The highest selectivity for ethylene was found at 850°C, the highest temperature tested. It is recognized that

The operating pressure for contacting the methane and oxygen mixture with the catalyst is not critical. death However, the higher the pressure, the lower the selectivity to relatively higher hydrocarbons. The overall system pressure affects catalyst performance. The effect of system pressure depends on the composition of the catalyst used. It's different. The preferred operating pressure is 1 to 50 atmospheres, more preferably 1 to 20 atmospheres. Ru.

Conversion of methane to ethylene, ethane and higher hydrocarbons in a catalytic reactor A variety of different contact conditions can be used to maximize conversion. suitable In one example, the reactor contains a fixed bed of catalyst and a hydrocarbon and oxygen stream. are mixed and fed to the reactor. In a second preferred embodiment, the reactor is containing a fixed bed, supplying the hydrocarbon feedstock to one end of the reactor, and supplying oxygen to one end of the reactor. Feed through several inlets evenly spaced along the length. Catalyst in fluidized bed, boiling Using other contact methods, such as suspension in a milling bed, moving bed, or entrained bed. Although it is possible to contact solid oxides with methane and oxygen-containing gases, For this purpose, fixed bed catalysts are particularly suitable. Fixed bed catalysts are used in the process Depending on the desired yield and throughput for the hydrocarbons required, series or Can be operated in parallel.

In addition to producing ethylene, ethane, and higher hydrocarbons, this catalytic reaction is used in many It also produces a large amount of hydrogen. Hydrogen is not only valuable as a fuel, but also uses a lot of water. It is a desirable reactant in refineries where elementary consuming reactions are carried out.

Having described the basic aspects of the invention, the following examples illustrate specific embodiments of the invention. An illustrative example. The conversion rate and selectivity described in the examples are based on the number of moles of methane. Based on. − XA garden - 1st grade These examples illustrate the production of pure oxide catalysts according to the present invention.

Pure metal oxides of groups I[A and ll1A, and metals of the lanthanide series] The oxides were obtained and calcined in a kiln at 900°C for 4 hours. After compressing the body into pellets and crushing them, sieve them to a size of 20 to 32 sieves. It was. These oxides are shown in Table 1.

X-saraho-11 This example describes a test procedure for the evaluation of a catalyst and also presents the results.

The metal oxide pellets from Examples 1-11 were each placed in the catalyst bed of a plow at 25.4°C. A quartz tube (inner diameter 4I) was packed to give it height.Then, this quartz tube was It was immersed in a sand bath heater and reacted for 2 hours under a 50ee/min argon flow. The mixture was heated to the appropriate temperature. When the reaction temperature is reached, the feed is replaced with methane (0.30 atm) , switch to a mixture of oxygen (0,05 atm) and argon (0,65 atm) to Set the speed to GHSV (gas space velocity per hour) of 37 = 500 hr-' (NTP). The effluent from the 0 reactor was determined by on-line gas chromatography. It was analyzed periodically. The reaction was carried out for 4 to 12 hours, during which time the contact inactivation occurred rarely or never. The first results for several metal oxides tested are shown below. In these tests, the reaction temperatures given in the table give the highest yields of hydrocarbon products. The catalyst bed inlet temperatures corresponding to this optimum result, selected to match the above conditions, are shown in Table 1.

The combined selectivity of ethylene, ethane, and higher hydrocarbons is expressed as total Cn in the table. and the last column shows the moles of hydrogen relative to ethylene and ethane in the reaction effluent. Show the ratio. The balance of oxygenated carbon material was close to ±5%.

From the data shown in Table 1, all of the pure metal oxide catalysts are ethylene, ethane and The high selectivity towards higher hydrocarbons and higher hydrocarbons is evident. in the product It is assumed that the molar ratio of H2 to C2H and C2H varies between 0.4 and 1.7. It is also clear that in such a conjugation, large amounts of hydrogen are produced along with the hydrocarbons.

This hydrogen can be used as a fuel or in refinery combinations where many hydrogen-consuming reactions take place. Can be used in nato. Particularly high selectivity for hydrocarbon products is , MgO1S r O, Y 203, La2O3, Nd2O,, Sm2O3, E Obtained by u2O, and Gd2O.

Although the SrO catalyst exhibits the highest selectivity, this advantage is limited by the low per-pass offset by high oxygen and methane addition rates. Among the above oxides, Y2O1, Contains La20=, Nd2O,, 5L6203, Eu2O3 and G d 203 , rare earth oxides have a selectivity of about 60% to higher hydrocarbons, per pass. 100% 02 addition rate and relatively low operation to achieve the highest hydrocarbon yield. operating temperature (750-800°C), providing the best overall performance.

Surashikoku - Volume 1 This example illustrates the preparation of a mixture of oxide catalysts according to the present invention.

Prepare a solution of lithium salt by dissolving L+NOs in distilled water The lanthanum oxide was then initially moistened by this LiNO3 solution. Impregnated with The mixture was dried in a vacuum oven at 110°C for 12 hours.

The dried solid was then smoked in air at 600°C for 4 hours.

Sufficient lithium to give a final loading of 1.0 wt% Li2O is present when La= Deposited on 03.

X These examples illustrate the preparation of different mixtures of oxide catalysts according to the present invention.

1.0% by weight on either La, O, or MgO according to the procedure of Example 13. Catalysts with various metal oxides were prepared. Catalysts made from W4 are shown in Tables 2 and 3. vinegar.

X blood-11 This example describes a test procedure for the evaluation of mixed oxide catalysts and presents the results. .

Each of the catalysts of Examples 13 to 28 was sieved into pellets with a size of 20 to 32 sieve openings. After being pressed into a sheet shape, it was filled into a quartz reactor and the exposed to reaction conditions. The experimental results for these catalyst samples are shown in Tables 2 and 3. show.

Otomi = = Tomoe = Two = True True = -N ~ ~ ~ N ~ ~ A comparison of the data in Tables 2 and 3 shows that base metal oxides, in this case La20* or is the selection of MgO, fli, Zhou Mi's IA, IIA, I[IA, rl, VB and can be enhanced by impregnating them with other metal oxides of group IB. A particularly preferred catalyst is an alkali metal oxide promoted L a203, with La20-1 and LiO2 promoted with alkaline earth oxides It appears to be enhanced MgO.

Suo Akira-1 Tate 233 This example illustrates the use of different amounts of cocatalyst oxide on base metal oxide.

Follow the procedure of Example 13, but use 5r(No, )2 instead of L+NO* Then, La20. With a weight conversion of SrO of 0.25-10.0 wt% above A catalyst was prepared. The prepared catalysts are shown in Table 4.

Inuo Plate - Main± This example demonstrates the strontium oxide enhanced oxidation prepared in Examples 30-33. The test method for evaluating lanthanum is described and the results are presented.

Each of the catalysts of Examples 30 to 34 was shaped into a pellet with 20 to 32 sieve meshes. After pressing and filling a quartz reactor, the reaction conditions were as described in Example 12 above. exposed the matter. Test results for these catalyst samples are shown in Table 4.

A comparison of the data in Table 4 shows that the weight conversion of cocatalyst oxide is not important. are doing. By depositing SrO on La20*, the weight of strontium oxide 10 percent, regardless of whether the addition rate is 0.25% or 10.0% An increase in selectivity to higher hydrocarbons of the order of magnitude is achieved.

X Arashi 1Σ21 Shadow This example demonstrates rare earth oxides as catalysts for the oxidative coupling of methane. Illustrating the use of a mixture, where the mixture has a portion of the cerium removed. Obtained from ore.

Pastonasite was obtained and dissolved in an acidic solution. By extraction from this solution This Langund concentrate was then treated with rare earth carbonate with different proportions of cerium removed. It was converted to salt, filtered and dried. The carbonate was then baked at 750°C for 4 hours. By doing so, it was decomposed into oxides.

Pure cerium oxide was also obtained for comparison with the rare earth oxide mixture.

The prepared catalysts are shown in Table 5, and the La20. , CeO2 and The amounts of other rare earth oxides (RezO3) are shown in the table.

Rattan ■-11 This example describes the evaluation of rare earth oxide mixtures prepared in Examples 35-38. We describe the test procedures and present the results.

Each of the catalysts of Examples 35 to 38 was placed in a bed with a mesh size of 20 to 32 sieves. After pressing into a pellet shape and filling a quartz reactor, the reactor was heated as described in Example 12. exposed to suitable conditions. Experimental results for these catalyst samples are shown in Table 5.

A comparison of the data in Table 5 shows that as the CeO2 content of rare earth oxides increases , indicating a decrease in selectivity towards higher hydrocarbons.

Mixtures containing up to 10% by weight of CeO2 give good results in acceptance. . However, at higher concentrations of cerium, the selectivity drops to lower values. However, in pure CeO□, almost all of the methane is converted to carbon oxides.

ni Arashi-1 more This example combines two catalysts according to the invention with a conventional catalyst consisting of lead oxide supported on silica. Compare with the catalyst of

Lead oxide catalysts on silica include W, Hinsen, W, Bitin and M, Burns-Blossie. Deing, 8th International Combres of Catalyst, 3- 1581 (1984). Cab-()Sil H 85 silica was impregnated to incipient wetness with a solution of lead acetate dissolved in distilled water. . The mixture was dried for 12 hours at 120° C. in a vacuum dryer. dry solid The bodies were then baked in air at 800°C for 4 hours. 11.2% by weight of PbO Sufficient lead was deposited on the Sin to give the final dosing rate.

This supported lead oxide catalyst is pressed into a pellet shape with a size of 20 to 32 sieves, A quartz reactor was charged and subjected to reaction conditions as described in Example 12. This touch Experimental results for the catalysts and catalysts of Examples 6 and 18 are shown in Table 6.

The conventional catalyst of 11.2% PbO/SiO2 is the same as the catalyst disclosed in this invention. However, the activity of conventional catalysts is For a reaction temperature of 900°C, 50% of the oxygen is converted in one pass. only. On the other hand, for La20= and SrO/La20= catalyst At temperatures as low as , 600° C., 100% of the oxygen is converted per pass. No. A comparison of the data shown in Table 6 shows that the amount of hydrogen produced by pbO/S i O2 The amount of phase N is higher than that produced by either La2O5 or SrO/La20. It also shows that there are very few. Thus, the catalyst disclosed in the present invention is sensitive to the presence of oxygen. superior to conventional catalysts for the synthesis of hydrocarbons from methane.

The above detailed description is for illustrative purposes only and may not depart from the spirit of the invention. Obviously, many changes can be made.

FIG, l CH410,, ttbrto 10 20 30 40 S.

FIG.2 Touch t4 loaf entrance 5 return (°C) international search report

Claims (38)

[Claims] 1. By contacting a gas containing a mixture of methane and oxygen with a catalyst, To convert tane into hydrogen, ethylene, ethane and higher hydrocarbon products In the method of a Group IIA metal of the periodic table; (b) a metal of Group III of the periodic table, which is Sc, Y or La; Group A metal; (c) Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, T m, Yb or Lu; and (d) metals of the lanthanide series, excluding Ce; mixture of the use of one or more metal oxides selected from the group consisting of the following metals: Featured improvements. 2. The catalyst is I selected from the group consisting of Be, Mg, Ca, Sr and Ba. 2. The method of claim 1, wherein the metal oxide is a Group IA metal. 3. 3. The method of claim 2, wherein the catalyst is MgO. 4. 3. The method according to claim 2, wherein the supporting medium is SrO. 5. The catalyst is gold, a group IIIA metal selected from the group consisting of Sc, Y and La. 2. The method according to claim 1, wherein the oxide is an oxide of the genus. 6. 6. The method of claim 5, wherein the metal oxide is Y2O3. 7. 6. The method of claim 5, wherein the metal oxide is La2O3. 8. Catalysts include Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y of the lanthanide series selected from the group consisting of b, Lu and mixtures thereof. 2. The method of claim 1, wherein the oxide is a metal oxide of a metal. 9. Metal oxides occur in rare earth minerals, except for a portion of CeO2. 2. The method of claim 1, wherein the rare earth oxide is a mixture of intact rare earth oxides. 10. Gas containing methane and oxygen is catalyzed at a temperature of 500 to 1000℃. 2. A method according to claim 1, wherein the method comprises contacting. 11. Claim 1, wherein the pressure of the gas in the contact zone is between 1 and 50 atmospheres. Method. 12. The molar ratio of methane to oxygen fed to the reactor is between 0.5 and 50. The method described in item 1 of the scope of the request. 13. A gas containing methane and oxygen is brought into contact with a catalyst at a temperature of 550 to 850°C. , the pressure of the gas in the contact zone is 1 to 20 atm, and the methane fed to the reactor is 2. A method according to claim 1, wherein the molar ratio of is to oxygen is from 2 to 20. 14. The oxygen supply comprises 20 to 100 volume percent oxygen. The method described in Section 1. 15. 15. The method of claim 14, wherein the oxygen feed is essentially pure oxygen. 16. The methane feed is claimed to consist of 60 to 100 volume percent methane. The method described in box 1. 17. 17. The methane feed is essentially pure methane. Method. 18. The catalyst includes a catalyst according to claim 1 as a first base metal oxide. And they also contain metal (a) Group IA metals, which are Li, Na and K; (b) Be, Mg, Ca, Sr and Ba, Group IIA metals; (c) Group IIIA metals, which are Sc, Y and La; Metal; (d) Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, metals of the lanthanide series, which are Tm, Yb and Lu; (e) Sn and Pb; Metals of group IVB (f) Metals of group VB, which are Sb and Bi; (g) Cu, Ag and and (h) mixtures thereof. A second promoter metal oxide selected from the group consisting of: The method described in paragraph 1. 19. The second cocatalyst oxide is present in a catalytically effective amount of 50 percent by weight of the mixture. 19. The method of claim 18, wherein the method is present in an amount up to 10%. 20. The base metal oxide is MgO, CaO or SrO and the promoter oxide is Li 19. The method of claim 18, wherein 2O. 21. The base metal oxide is Y2O3 and the promoter oxide is Li2O, BeO, M gO, CaO, SrO, BaO, tin oxide, lead oxide, antimony oxide, bis oxide 19. The method of claim 18, wherein the oxide is copper oxide, silver oxide or gold oxide. 22. The base metal oxide is La2O3 and the promoter oxide is Li2O, BeO, MgO, CaO, SrO, BaO, tin oxide, lead oxide, antimony oxide, vinyl oxide 19. The method of claim 18, wherein the oxide is smut, copper oxide, silver oxide or gold oxide. 23. Base metal oxides do not occur in rare earth minerals, except for a portion of CeO2. It is a mixture of rare earth oxides as it is, and the promoter oxides are Li2O, Be O, MgO, CaO, SrO, BaO, tin oxide, lead oxide, antimony oxide, acid The method according to claim 18, which is bismuth oxide, copper oxide, silver oxide or gold oxide. . 24. A gas containing methane and oxygen is brought into contact with a catalyst at a temperature of 500 to 1000°C. 19. The method of claim 18. 25. Claim 18, wherein the pressure of the gas in the contact zone is between 1 and 50 atmospheres. the method of. 26. The molar ratio of methane to oxygen fed to the reactor is between 0.5 and 50. The method according to item 18. 27. A gas containing methane and oxygen is brought into contact with a catalyst at a temperature of 550 to 850°C. , the pressure of the gas in the contact zone is 1 to 20 atm, and the methane fed to the reactor is 19. The method of claim 18, wherein the molar ratio of is to oxygen is from 2 to 20. 28. Claims wherein the supply of oxygen consists of 20 to 100 volume percent oxygen The method according to paragraph 18. 29. 29. The method of claim 28, wherein the oxygen supply is essentially pure oxygen. Law. 30. The methane feed is claimed to consist of 60 to 100 volume percent methane. The method according to paragraph 18. 31. 31. The method of claim 30, wherein the methane feed is essentially pure methane. . 32. (1) Metal (a) Group IIA metals of the periodic table, which are Be, Mg, Ca, Sr and Ba; (b) (c) Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yh and Lu, excluding Ce metals of the lanthanide series; and (d) mixtures thereof. a first base metal metal oxide selected from the group consisting of; and (2) a metal; (a) Group IA metals of the periodic table, which are Li, Na and K; (b) Be, Mg, Ca , Sr and Ba, Group IIA metals of the periodic table; (c) Sc, Y and La; , Group IIIA metals of the periodic table; (d) Ce, Pr, Nd, Sm, Eu, Gd, Tb , Dy, Ho, Er, Tm, Yb and Lu; (e ) IVB metals of the periodic table, which are Sn and Pb; (f) periodic metals, which are Sb and Bi; metals of group VB of the periodic table; (g) metals of group IB of the periodic table, which are Cu, Ag and Au; and and (h) mixtures thereof. the presence of oxygen containing a second promoter metal oxide selected from the group consisting of Catalyst for converting methane to higher hydrocarbon products in. 33. The cocatalyst oxide is present in an amount up to 50% by weight of the mixture. Catalyst according to Range 32. 34. The promoter oxide is present in an amount up to 10% by weight of the mixture. Catalyst according to Range 33. 35. The base metal oxide is MgO, CaO or SrO, and the promoter oxide is Li2 33. The catalyst of claim 32, which is O. 36. The base metal oxide is Y2O3, and the promoter oxides are Li2O, BeO, Mg O, CaO, SrO, BaO, tin oxide, lead oxide, antimony oxide, bisma oxide 33. The catalyst according to claim 32, which is copper oxide, silver oxide or gold oxide. 37. The base metal oxide is La2O3 and the promoter oxide is Li2O, BeO, MgO, Ca0, SrO, BaO, tin oxide, lead oxide, antimony oxide, vinyl oxide 33. The catalyst of claim 32, which is smuth, copper oxide, silver oxide, or gold oxide. 38. Base metal oxides are present in rare earth minerals, except for a portion of CeO2. As-produced, a mixture of rare earth oxides and cocatalyst oxides include Li2O, B eO, MgO, CaO, SrO, BaO, tin oxide, lead oxide, antimony oxide, The catalyst according to claim 32, which is bismuth oxide, copper oxide, silver oxide or gold oxide. Medium.