JP3618003B2 - Method for producing alkali metal-supported samarium oxide catalyst - Google Patents

Description

【００２６】
なお、比較例として、触媒活性，耐久性を比較するためＬｉＦ／Ｓｍ_２Ｏ_３触媒を用いたが、その調製は次のように行なった。
フッ化リチウム（９８％以上）の粉末１．０４ｇ に水を加え加熱溶解したものに、酸化サマリウム（９９．９％以上）の粉末１３．９５ｇを加えて懸濁液とし、１５０℃で攪拌しながら加熱、蒸発乾固した。
次にこれを空気中で、４００℃で２時間焼成し、更に７５０℃で２時間焼成して加圧成形した後、粉砕し粒度１６〜４２メッシュに分級したものを触媒として用いた。
【００２７】
表１において、実施例Ｎｏ．１〜８ は比較例であり、フッ化リチウムの水溶液に酸化サマリウムの粉末を加えて混練し、蒸発乾固した後加熱焼成、粉砕したものである。また実施例Ｎｏ．１１〜１８は本発明方法により調製されたものであり、リチウムメトキシドのアルコール溶液と酢酸サマリウム溶液との混合液を蒸発乾固し、加熱焼成後粉砕したものを用いている。そして比較例の場合は３０％ＬｉＦのものと５０％ＬｉＦのもの、本発明例の場合は３０％Ｌｉのものと５０％Ｌｉのものとを示している。
【００２８】
これらの結果を解析するに、比較例，本発明例ともにＬｉＦを３０％担持させたものと５０％担持させたものとの間での有意差は認められなかった。そしてまたいずれの場合も反応温度が６００℃から７５０℃まで上昇するにつれてメタン転化率，Ｃ_２ 選択率およびＣ_２ 収率ともに上昇していき、Ｃ_２ 選択率はおよそ７００℃でピーク的な値を示し、Ｃ_２ 収率はおよそ７５０℃でピーク的な値を示すことも明らかとなった。
【００２９】
そのような傾向にあって、比較例と本発明例とを比較すると、メタン転化率およびＣ_２ 選択率ともに、本発明例は比較例との全く遜色なく、したがってＣ_２ 収率も比較例と有意差が認められず、同等の性能が確認された。
上記触媒２ｇをアルミナ製の反応管に充填し、７５０℃で大気圧でＣＨ_４：Ｏ_２：Ｎ_２ ＝２：１：４の混合ガスを７リットル／ｈの流速で流し耐久試験を行なった。
耐久試験による触媒の性能は、反応生成物を反応管出口に取り付けられた捕集器によって捕集し、ガスクロマトグラフによって分析した。
【００３０】
分析結果は、反応したメタン，酸素の割合を表したメタン転化率，酸素転化率，反応生成物におけるＣ_２ 成分（Ｃ_２Ｈ_４とＣ_２Ｈ_６）の合計の選択率、反応したメタンから得られたＣ_２ 成分の合計の収率で表し評価した。
結果は、次の表２に示す。また図５に本発明例（リチウムメトキシドのアルコール溶液と酢酸サマリウム溶液との混合液を蒸発乾固し加熱焼成後粉砕してなる触媒を用いた例：実施例Ｎｏ．１８）をグラフとして示した。
【００３１】
【表２】

【００３２】
この表２においては、比較例として２つ（ＬｉＦ担持量３０モル％の実施例Ｎｏ．４とＬｉＦ担持量５０モル％の実施例Ｎｏ．８）、本発明例としてＬｉ担持量５０モル％の実施例Ｎｏ．１８ （リチウムメトキシドと酢酸サマリウムとにより調整された触媒を用いたもの）を示している。いずれの場合も反応温度は７５０℃である。
【００３３】
その結果、一般にはＣ_２ 収率が１６％程度以上であればまだ使える状態にあると判断されるが、比較例としての実施例Ｎｏ．４ のもの（ＬｉＦ担持量３０モル％）はおよそ４０時間（ｈｒ）で使用に耐え得なくなり、実施例Ｎｏ．８ のもの（ＬｉＦ担持量５０モル％）はおよそ７０時間で使用に耐え得なくなるものであるのに対し、本発明例としての実施例Ｎｏ．１８ のもの（Ｌｉ担持量５０モル％）は２００時間以上にわたって高いＣ_２ 収率が得られることが明らかとなった。
【００３４】
その理由としてはいろいろと考えられるが、特に本発明に係る製造方法によれば、触媒の組成物であるリチウム（Ｌｉ）と酸化サマリウム（Ｓｍ_２Ｏ_３）とが均質に混合されていて、活性成分であるリチウム（Ｌｉ）が揮散しにくい状態となっており、従来の製造方法の触媒では表面のフッ化リチウムが反応系に飛翔すれば最早触媒反応に寄与しなくなるのが、本発明方法による触媒では内部の酸化リチウムがじわじわと触媒反応に寄与し続けることに因るものと思われる。
【００３５】
そしてこの表２には示していないが、本発明例の場合、リチウムメトキシド溶液と酢酸サマリウム溶液とを用いてＬｉ担持量３０モル％に調製した触媒についても同様の効果が得られた。また酢酸サマリウムでなくサマリウムアセチルアセトナートを用いて調製した触媒についても同様の効果が期待されるものである。
【００３６】
以上表１および表２に示した実験結果および図２〜図５に示したグラフからもわかるように、本発明例によれば、Ｃ_２ 収率が従来の製法のものと同等以上の遜色ないものであることはもとより、長時間の使用にも耐え得るものであり、連続的な酸化カップリング反応によるエタン・エチレンの製造には好適なものと言える。そしてまたこの触媒中には腐食成分であるハロゲンが含まれないため、反応装置がその触媒からの揮散成分によって腐食されるといったことも回避されるものである。
【００３７】
尚、本発明は上記実施例の触媒に何ら限定されるものではなく、本発明の趣旨を逸脱しない範囲で各種の触媒を提示できるものである。たとえば本発明の触媒原料であるアルカリ金属アルコキシドとしては、上記のリチウムメトキシドに限らずナトリウム（Ｎａ），カリウム（Ｋ）等の他のアルカリ金属のアルコキシドの適用も考えられ、またアルコキシドとしてもメトキシドのほかエトキシドなども適応できるものである。
【００３８】
【発明の効果】
以上説明したことから明かなように本発明方法により製造されたアルカリ金属酸化物担持酸化サマリウム系触媒によれば、メタンから炭素数の１つ多いエタン・エチレン等の炭化水素を酸化カップリング反応により製造するに際し、Ｃ_２ 選択率、Ｃ_２ 収率を高めることができるばかりか、触媒寿命も際立って長いために、持続的な触媒反応によりメタンからエタン・エチレン製造を生産性良く行なうことができるものである。しかもこの触媒中にハロゲン等の腐食成分が含まれないため反応装置の腐食回避による恒久的使用も達成される。したがって天然ガス中のメタンを原料とする合成化学産業の発展に大いに寄与するものである。
【図面の簡単な説明】
【図１】３０モル％ＬｉＯＣＨ_３／Ｓｍ（ＣＨ_３ＣＯＯ）_３ 触媒を用いた活性試験における反応温度とＣＨ_４転化率，Ｃ_２収率，Ｃ_２選択率との関係を示した図である。
【図２】５０モル％ＬｉＯＣＨ_３／Ｓｍ（ＣＨ_３ＣＯＯ）_３ 触媒を用いた活性試験における反応温度とＣＨ_４ 転化率，Ｃ_２ 収率，Ｃ_２ 選択率との関係を示した図である。
【図３】３０モル％ＬｉＯＣＨ_３／Ｓｍ（Ｃ_５Ｈ_７Ｏ_２）_３ 触媒を用いた活性試験における反応温度とＣＨ_４ 転化率，Ｃ_２ 収率，Ｃ_２ 選択率との関係を示した図である。
【図４】５０モル％ＬｉＯＣＨ_３／Ｓｍ（Ｃ_５Ｈ_７Ｏ_２）_３ 触媒を用いた活性試験における反応温度とＣＨ_４ 転化率，Ｃ_２ 収率，Ｃ_２ 選択率との関係を示した図である。
【図５】５０モル％ＬｉＯＣＨ_３／Ｓｍ（ＣＨ_３ＣＯＯ）_３ 触媒を用いた耐久試験（７５０℃）における試験経過時間とＣＨ_４ 転化率，Ｃ_２ 収率，Ｃ_２ 選択率との関係を示した図である。[0001]
[Industrial application fields]
The present invention particularly relates to a method for producing an alkali metal-supported samarium oxide catalyst as a catalyst used to produce hydrocarbons having one carbon such as ethane and ethylene by oxidative coupling reaction using methane as a raw material. is there.
[0002]
[Prior art]
In recent years, synthetic chemistry has been developed that uses methane (CH ₄ ) in natural gas as a raw material and produces hydrocarbons with one carbon number such as ethylene (C ₂ H ₄ ) and ethane (C ₂ H ₆ ). .
One of these methods is a so-called oxidative coupling reaction, in which bimolecular condensation of methane (CH ₄ ) is carried out in the presence of an oxidizing agent such as oxygen (O ₂ ) using a catalyst, and ethylene ( C 2 _{H 4)} and ethane (C 2 _{H 6)} or the like, which lies C ₂ compounds of and one, the methane partial oxidation in what is referred to as the so-called partial oxidation of methanol, such as oxygen-containing compounds To get.
[0003]
Meanwhile, according to the former oxidative coupling reaction, ethylene _(C 2 _{H 4)} and ethane _(C 2 _{H 6)} methane (CH ₄₎ than obtaining a _{C 2} compounds such as the via carbon monoxide (CO) dioxide There is a problem in that it is difficult to selectively obtain the C ₂ compound (C ₂ H ₄ , C ₂ H ₆ ) because the reaction that is oxidized to carbon (CO ₂ ) is more dominant.
[0004]
Therefore, various catalysts have been proposed to solve this problem. For example, a catalyst in which an alkali metal halide (for example, lithium chloride, lithium bromide, etc.) is supported on an oxide (for example, samarium oxide) is disclosed in JP-A-62-25036. The catalyst shown here increases the methane conversion rate (the rate at which methane in the raw material is changed to another) and suppresses the complete oxidation reaction in which methane is oxidized to CO ₂ through CO, and the oxidative coupling reaction (ethane occupied in the reaction product, split phase ethylene) relative dominance in to C ₂ selectivity of progression to enhance it is to be effective.
[0005]
[Problems to be solved by the invention]
However, such a generally known catalyst (a catalyst in which an alkali metal halide is supported on a basic oxide) is prepared and manufactured as follows.
That is, a basic oxide powder is added to an aqueous solution of an alkali metal halide and kneaded, and this is evaporated to dryness while heating at a temperature of 100 to 200 ° C. Then, this is heated and fired at several 100 ° C., and pulverized into a desired powder diameter (approximately 10 to 50 mesh) is used as a catalyst.
[0006]
According to this type of catalyst, alkali metal salts (halides, carbonates, etc.) generally have a low melting point (except for fluorides, most of them have a melting point of 800 ° C. or lower), and at the reaction temperature of oxidative coupling. When exposed to a high temperature of 700 to 800 ° C., there was a drawback that the supported component was volatilized in a short time and lost its activity.
[0007]
Therefore, according to such a catalyst, the selectivity of C ₂ compounds such as ethane and ethylene drops rapidly with time, and as a result, the C ₂ yield (= methane conversion × C ₂ selectivity) is low. In addition, there is a problem that the continuous reaction of the C ₂ compound generation cannot be maintained because the catalyst life is short.
Further, for example, among alkali metal salts, the halide most effective for improving the C ₂ yield is not only the loss of the activity of the catalyst when volatilized during the reaction, but the halogen is a metal material in the latter stage of the reactor. There was also a problem of corrosion.
[0008]
The present invention has been made to solve such problems, and its object is to produce hydrocarbons having one carbon number such as ethane and ethylene from methane by oxidative coupling reaction. It is to provide a catalyst having a high C ₂ selectivity, and hence a high C ₂ yield (= methane conversion × C ₂ selectivity) and a longer catalyst life.
Another object of the present invention is also to provide a catalyst that enables the permanent use of the apparatus with little influence of corrosion on the reaction apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve this object, the present invention provides an alkali metal-supported samarium oxide-based catalyst, and in producing the catalyst, a mixed liquid of an alkali metal alkoxide and samarium acetylacetonate or samarium acetate is heated. The gist is that it is evaporated to dryness and fired and ground.
[0010]
In this case, the alkali metal alkoxide is preferably lithium methoxide. The catalyst obtained by supporting lithium oxide, which is the resulting catalyst, on samarium oxide is expected to have a better C ₂ selectivity than the catalyst produced by the conventional method and to improve the C ₂ yield accordingly. Further, since the catalyst does not contain halogen, corrosion of the reactor can be prevented.
[0011]
【Example】
Examples of the present invention will be described in detail below.
First, a method for producing a catalyst according to the present invention will be described.
[0012]
(Catalyst preparation method 1)
Alcohol or water is added to samarium acetylacetonate (Sm (C ₅ H ₇ O ₂ ) ₃ ) or samarium acetate (Sm (CH ₃ COO) ₃ ), dissolved in ethylene glycol, and stirred while heating.
Next, lithium methoxide (LiOCH ₃ ) dissolved in alcohol and a small amount of nitric acid are added and mixed, and stirring is continued while heating.
Water is added to this, heated to 80 ° C., and left for 3 to 24 hours.
The mixed solution is heated to 100 to 200 ° C. with stirring to evaporate to dryness, and is baked in air at 400 to 750 ° C. for 4 to 24 hours, whereby lithium is added to samarium oxide (Sm ₂ O ₃ ). A supported catalyst is obtained.
[0013]
Specifically, the following two types of catalysts were prepared. One is the case where samarium acetylacetonate (Sm (C ₅ H ₇ O ₂ ) ₃ ) is used, and the other is the case where samarium acetate (Sm (CH ₃ COO) ₃ ) is used. . To explain each,
[0014]
(1) Catalyst preparation method using samarium acetylacetonate Add a small amount of alcohol to 17.91 g of samarium acetylacetonate (99.5% or more), dissolve in ethylene glycol, and stir while heating at 80 ° C. .
Next, 0.76 g of lithium methoxide (99.5% or more) dissolved in alcohol is mixed with a small amount of nitric acid, and stirring is continued while heating at 80 ° C.
Water is added to this, heated at 80 ° C., and left for 3 to 24 hours.
The mixture is heated to 150 ° C. with stirring to evaporate to dryness. The mixture is calcined in air at 400 ° C. for 2 hours, further calcined at 750 ° C. for 2 hours, pressure-molded, pulverized and granulated. What was classified into 16-42 mesh was used as a catalyst.
[0015]
(2) Catalyst preparation method using samarium acetate A small amount of water is added to 15.98 g of samarium acetate (99.9% or more), dissolved in ethylene glycol, and stirred while heating at 80 ° C.
Next, lithium methoxide (99.5% or more) 0.76 g dissolved in alcohol and a small amount of nitric acid are added and mixed, and stirring is continued while heating at 80 ° C.
Water is added thereto, and the mixture is allowed to stand at 80 ° C. for 3 to 24 hours.
The mixture is heated to 150 ° C. with stirring to evaporate to dryness. The mixture is calcined in air at 400 ° C. for 2 hours, further calcined at 750 ° C. for 2 hours, pressure-molded, pulverized and granulated. What was classified into 16-42 mesh was used as a catalyst.
[0016]
In addition to the above-described catalyst preparation method, a method using a rotary evaporator is also included. This will be described as the following catalyst preparation method 2.
[0017]
(Catalyst preparation method 2)
Alcohol or water is added to samarium acetylacetonate (Sm (C ₅ H ₇ O ₂ ) ₃ ) or samarium acetate (Sm (CH ₃ COO) ₃ ) and dissolved with ethylene glycol. This is transferred to a rotary evaporator eggplant-shaped flask and stirred while heating.
Next, lithium methoxide (LiOCH ₃ ) dissolved in alcohol and a small amount of nitric acid are added to a rotary evaporator eggplant type flask, and stirring is continued while heating.
Water is added thereto, heated to 80 ° C., and left for 3 to 4 hours.
The mixed solution is heated under reduced pressure at 80 to 100 ° C. with stirring to evaporate to dryness, and is calcined in air at 400 to 750 ° C. for 4 to 24 hours to samarium oxide (Sm ₂ O ₃ ). Is obtained.
Also in the case of the production method using this rotary evaporator, the following (1) example of samarium acetylacetonate (Sm (C ₅ H ₇ O ₂ ) ₃ ) and ( ₂ ) samarium acetate (Sm (CH ₃ COO) ₃ ) Each example is specifically shown.
[0018]
(1) Catalyst preparation method using samarium acetylacetonate Add a small amount of alcohol to 17.91 g of samarium acetylacetonate (99.5% or more) and dissolve with ethylene glycol. This is transferred to an eggplant type flask of a rotary evaporator and stirred while heating at 80 ° C.
Next, what melt | dissolved 0.76g of lithium methoxide (99.5% or more) with alcohol is added to the eggplant type flask of a rotary evaporator, and stirring is continued, heating at 80 degreeC.
Water is added thereto, and the mixture is allowed to stand at 80 ° C. for 3 to 24 hours.
This mixed solution is heated under reduced pressure at 90 ° C. with stirring to evaporate to dryness. This is baked in air at 400 ° C. for 2 hours, further baked at 750 ° C. for 2 hours, pressure-molded, and then pulverized. What was classified into particle size 16-42 mesh was used as a catalyst.
[0019]
(2) Catalyst preparation method using samarium acetate A small amount of water is added to 15.98 g of samarium acetate (99.9% or more) and dissolved in ethylene glycol. This is transferred to a rotary evaporator eggplant type flask and stirred while heating at 80 ° C.
Next, what melt | dissolved 0.76g of lithium methoxide (99.5% or more) with alcohol is added to the eggplant type flask of a rotary evaporator, and stirring is continued, heating at 80 degreeC.
Water is added thereto, and the mixture is allowed to stand at 80 ° C. for 3 to 24 hours.
This mixed solution is heated under reduced pressure at 90 ° C. with stirring to evaporate to dryness. This is baked in air at 400 ° C. for 2 hours, further baked at 750 ° C. for 2 hours, pressure-molded, and then pulverized. What was classified into particle size 16-42 mesh was used as a catalyst.
[0020]
Thus, the experiment of the reaction which actually produces | generates ethane and ethylene from a methane gas by oxidative coupling reaction using the catalyst manufactured in this way was conducted, and the result is demonstrated below.
[0021]
(1) Reactive gas As the methane used in the oxidation coupling reaction, methane in natural gas (including hydrocarbons of ethane or higher) can be used in addition to pure methane.
As the oxygen used for the oxidative coupling reaction, oxygen in the air can be used in addition to pure oxygen.
Methane and oxygen are present in the reaction system at CH ₄ / O ₂ (molar ratio) = 1 to 10 and are not particularly limited, but other inert gases such as nitrogen, helium, and argon may be present. Good.
[0022]
(2) Reaction pressure The reaction is usually carried out under atmospheric pressure, but it can also be carried out under reduced pressure or under pressure as necessary.
(3) Reaction temperature The reaction temperature is usually 600 to 850 ° C, preferably 700 to 800 ° C.
(4) Specific reaction conditions 2 g of the above catalyst was packed in an alumina reaction tube, and a mixed gas of CH ₄ : O ₂ : N ₂ = 2: 1: 4 at 600 to 750 ° C. and atmospheric pressure was 7 liter / h. The reaction was carried out at a flow rate of.
[0023]
The reaction product obtained by the above operation was collected by a collector attached to the reaction tube outlet and analyzed by a gas chromatograph.
The analysis results are as follows: methane conversion rate representing the proportion of reacted methane and oxygen, oxygen conversion rate, selectivity of each component of CO, CO ₂ , C ₂ H ₄ , C ₂ H _{6 in} the reaction product and C ₂ component Selectivity, the ratio of C ₂ H ₄ and C ₂ H _{6 in} the C ₂ component (ethylene / ethane ratio), the total of C ₂ H ₄ and C ₂ H ₆ and C ₂ component obtained from reacted methane It was expressed in the yield.
[0024]
The results are shown in Table 1 below. Various experimental data including the experimental results shown in Table 1 are shown as graphs in FIGS.
The prepared catalyst is expected to be an oxide due to decomposition of the organic components by calcination, but in order to avoid confusion, the indication of the catalyst in the table is indicated by the name of the raw material used for convenience, and samarium oxide It was expressed as a metal atomic weight% of lithium amount.
[0025]
[Table 1]

[0026]
As a comparative example, a LiF / Sm ₂ O ₃ catalyst was used in order to compare the catalyst activity and durability, but the preparation was performed as follows.
To 1.04 g of powder of lithium fluoride (98% or more) dissolved in water and heated, 13.95 g of samarium oxide (99.9% or more) powder was added to form a suspension and stirred at 150 ° C. While heating, evaporate to dryness.
Next, this was calcined in air at 400 ° C. for 2 hours, further calcined at 750 ° C. for 2 hours and pressure-molded, and then pulverized and classified to a particle size of 16 to 42 mesh was used as a catalyst.
[0027]
In Table 1, Example No. Nos. 1 to 8 are comparative examples in which samarium oxide powder was added to an aqueous solution of lithium fluoride, kneaded, evaporated to dryness, heated and fired, and pulverized. In addition, Example No. Nos. 11 to 18 are prepared by the method of the present invention, and a mixture of an alcohol solution of lithium methoxide and a samarium acetate solution is evaporated to dryness, heated and baked, and used. In the case of the comparative example, those of 30% LiF and 50% LiF are shown, and in the case of the present invention, those of 30% Li and 50% Li are shown.
[0028]
When these results were analyzed, no significant difference was observed between those in which 30% LiF was supported and those in which 50% was supported in both the comparative example and the inventive example. In both cases, as the reaction temperature increases from 600 ° C. to 750 ° C., the methane conversion rate, C ₂ selectivity and C ₂ yield all increase, and the C ₂ selectivity reaches a peak value at about 700 ° C. It was also revealed that the C ₂ yield shows a peak value at about 750 ° C.
[0029]
In such a tendency, when the comparative example and the inventive example are compared, both the methane conversion rate and the C ₂ selectivity are the same as the comparative example, and therefore the C ₂ yield is also the same as the comparative example. No significant difference was observed, and equivalent performance was confirmed.
2 g of the catalyst was filled in an alumina reaction tube, and a durability test was performed by flowing a mixed gas of CH ₄ : O ₂ : N ₂ = 2: 1: 4 at 750 ° C. and atmospheric pressure at a flow rate of 7 liter / h. .
The performance of the catalyst by the durability test was collected by a collector attached to the outlet of the reaction tube and analyzed by a gas chromatograph.
[0030]
The analysis results are as follows: reacted methane, methane conversion rate representing oxygen ratio, oxygen conversion rate, total selectivity of C ₂ components (C ₂ H ₄ and C ₂ H ₆ ) in the reaction product, reacted methane the resulting expressed evaluated in a total yield of C ₂ components.
The results are shown in Table 2 below. FIG. 5 is a graph showing an example of the present invention (an example using a catalyst obtained by evaporating and drying a mixed solution of an alcohol solution of lithium methoxide and a samarium acetate solution, heating and firing and then pulverizing: Example No. 18). It was.
[0031]
[Table 2]

[0032]
In Table 2, two comparative examples (Example No. 4 with a LiF loading of 30 mol% and Example No. 8 with a LiF loading of 50 mol%) and an example of the present invention with a Li loading of 50 mol% are shown. Example No. 18 (using a catalyst prepared by lithium methoxide and samarium acetate). In either case, the reaction temperature is 750 ° C.
[0033]
As a result, it is generally judged that the C ₂ yield is still usable if the C ₂ yield is about 16% or more. No. 4 (LiF loading 30 mol%) cannot be used in about 40 hours (hr). 8 (LiF loading 50 mol%) cannot be used in about 70 hours, whereas Example No. as an example of the present invention. It was revealed that 18 (Li supported amount 50 mol%) can obtain a high C ₂ yield over 200 hours or more.
[0034]
There are various reasons for this. In particular, according to the production method of the present invention, lithium (Li), which is a composition of the catalyst, and samarium oxide (Sm ₂ O ₃ ) are homogeneously mixed and activated. According to the method of the present invention, lithium (Li) as a component is hardly volatilized, and the catalyst of the conventional production method no longer contributes to the catalytic reaction if the surface lithium fluoride flies into the reaction system. In the catalyst, it seems that the internal lithium oxide gradually contributes to the catalytic reaction.
[0035]
Although not shown in Table 2, in the case of the present invention example, the same effect was obtained with a catalyst prepared using a lithium methoxide solution and a samarium acetate solution to a Li loading of 30 mol%. A similar effect is expected for a catalyst prepared using samarium acetylacetonate instead of samarium acetate.
[0036]
As can be seen from the experimental results shown in Tables 1 and 2 and the graphs shown in FIGS. 2 to 5, according to the example of the present invention, the C ₂ yield is comparable to or higher than that of the conventional manufacturing method. It can withstand long-time use as well as being suitable for production of ethane / ethylene by continuous oxidative coupling reaction. In addition, since the halogen which is a corrosive component is not contained in the catalyst, it is possible to avoid the reaction apparatus being corroded by the volatilizing component from the catalyst.
[0037]
In addition, this invention is not limited to the catalyst of the said Example at all, A various catalyst can be shown in the range which does not deviate from the meaning of this invention. For example, the alkali metal alkoxide that is a catalyst raw material of the present invention is not limited to the above lithium methoxide, and other alkali metal alkoxides such as sodium (Na) and potassium (K) can be used. Besides these, ethoxide can also be applied.
[0038]
【The invention's effect】
As is clear from the above description, according to the alkali metal oxide-supported samarium oxide catalyst produced by the method of the present invention, hydrocarbons such as ethane / ethylene having one carbon number higher than methane are oxidized by an oxidative coupling reaction. In the production, not only can the C ₂ selectivity and C ₂ yield be increased, but also the catalyst life is remarkably long, so that ethane / ethylene production from methane can be carried out with high productivity by continuous catalytic reaction. Is. In addition, since the catalyst does not contain corrosive components such as halogen, permanent use by avoiding corrosion of the reactor can be achieved. Therefore, it greatly contributes to the development of the synthetic chemical industry using methane in natural gas as a raw material.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between reaction temperature, CH ₄ conversion, C ₂ yield, and C ₂ selectivity in an activity test using a 30 mol% LiOCH ₃ / Sm (CH ₃ COO) ₃ catalyst. .
FIG. 2 is a graph showing the relationship between reaction temperature and CH ₄ conversion, C ₂ yield, and C ₂ selectivity in an activity test using 50 mol% LiOCH ₃ / Sm (CH ₃ COO) ₃ catalyst. .
FIG. 3 shows the relationship between reaction temperature and CH ₄ conversion, C ₂ yield, and C ₂ selectivity in an activity test using 30 mol% LiOCH ₃ / Sm (C ₅ H ₇ O ₂ ) ₃ catalyst. FIG.
FIG. 4 shows the relationship between reaction temperature and CH ₄ conversion, C ₂ yield, and C ₂ selectivity in an activity test using 50 mol% LiOCH ₃ / Sm (C ₅ H ₇ O ₂ ) ₃ catalyst. FIG.
FIG. 5 shows the relationship between test elapsed time and CH ₄ conversion, C ₂ yield, and C ₂ selectivity in an endurance test (750 ° C.) using 50 mol% LiOCH ₃ / Sm (CH ₃ COO) ₃ catalyst. FIG.

Claims (2)

A method for producing an alkali metal-supported samarium oxide catalyst, which comprises heating and evaporating a mixed liquid of an alkali metal alkoxide and samarium acetate or samarium acetylacetonate, followed by firing and pulverization. 2. The method for producing an alkali metal-supported samarium oxide catalyst according to claim 1, wherein the alkali metal alkoxide is lithium methoxide .

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