KR20180081659A - Dehydrogenation catalysts and preparation method thereof - Google Patents

Abstract

The present invention relates to a dehydrogenation catalyst in which platinum as an active metal, and lanthanum (La) and tin (Sn) as an active auxiliary metal are supported on an alumina (Al_2O_3) support having a mesopore of 5 to 50 nm and a macropore of 50 nm to 20 μm, wherein a weight ratio of the auxiliary metal components La and Sn to the platinum component is 0.01 to 50.0 wt%/m^2, a volume amount of the macropore per unit weight of the support is 0.05 to 0.4 cc/g, and a volume amount of the mesopore is 0.2 to 0.8 cc/g. According to the present invention, the dehydrogenation catalyst enhances dispersibility of platinum metal and increases interaction between the support and platinum as the active metal by bimodal pore properties of the support and an effect of the auxiliary metal dispersed in alumina. Therefore, the dehydrogenation catalyst not only improves efficiency of dehydrogenation process and increases stability and lifetime of the catalyst by enabling an operation to be performed under severe conditions, but also can improve process basic unit by increasing selectivity.

Description

[0001] DEHYDROGENATION CATALYST AND PREPARATION METHOD THEREOF [0002]

The present invention relates to a dehydrogenation catalyst, and more particularly, to a dehydrogenation catalyst which can be operated under severe conditions and can increase the lifetime of the catalyst while improving process efficiency, and a process for producing the dehydrogenation catalyst.

In general, in the case of hydrocarbon gas, especially propane, a process for producing propylene from propane using a noble metal such as platinum or an oxide-based dehydrogenation catalyst such as chromium has been widely practiced industrially. However, since propane dehydrogenation reaction is an endothermic reaction, the reaction temperature of the adiabatic reaction apparatus decreases with the progress of the reaction. Therefore, in order to increase the production amount of propylene, additional reaction heat must be supplied constantly. Also, the propane dehydrogenation reaction is difficult to obtain a high conversion rate because it is an equilibrium reaction by the reversible reaction in which the yield of the maximum propylene is thermodynamically limited.

In the field of catalyst dehydrogenation of hydrocarbons, efforts are being made to develop improved catalysts with high activity and selectivity and high stability during use. The stability of the catalyst means the rate of catalyst deactivation when in use. The rate of deactivation of the catalyst affects the useful life, and in general, the catalyst is required to be highly stable, in order to extend its lifetime and increase the yield of the product under high severity process conditions.

Alumina, silica, zeolite, and the like are used as a carrier of the catalyst used in the dehydrogenation reaction of hydrocarbons. The characteristics required for such a dehydrogenation catalyst should include the content of the active component, the type of promoter, the dispersity of the active component, the type of carrier, the pore characteristics of the carrier, and the acidity of the carrier. However, existing catalysts are inactivated rapidly and there is room for improvement in terms of reaction stability.

In addition, dehydrogenation can improve the yield at a very high temperature, low hydrogen concentration and high pressure. However, since the stability of the catalyst is deteriorated under such a severe condition, development of a catalyst capable of maintaining stability even in harsh conditions is urgently required Is required.

It is an object of the present invention to solve the problems of the prior art as described above, and it is an object of the present invention to provide a catalyst capable of maintaining the stability of the catalyst under harsh conditions, Catalyst.

Another object of the present invention is to provide a method for producing a dehydrogenation catalyst.

It is another object of the present invention to provide an improved dehydrogenation process using the dehydrogenation catalyst of the present invention.

Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments.

According to one aspect of the present invention, there is provided an alumina (Al ₂ O ₃ ) carrier having mesopores of 5 to 50 nm and macropores of 50 nm to 20 탆, Wherein the weight ratio of the lanthanum and the tin auxiliary metal component to the platinum component is 0.01 to 50.0 wt% / m 2, and the macropore volume per carrier unit weight is 0.05 cc / / g to 0.4 cc / g, and the mesopore volume is 0.2 cc / g to 0.8 cc / g.

According to another aspect of the present invention,

The macropore volume per carrier unit weight is in the range of 0.05 cc / g to 0.4 cc / g, the mesopore volume is in the range of 0.2 cc / g to 0.2 cc / g, Preparing alumina having bimodal pore characteristics of 0.8 cc / g;

Preparing a lanthanum / alumina (La / Al ₂ O ₃ ) catalyst by sequentially impregnating, drying and firing lanthanum (La) on the alumina support;

Preparing a lanthanum / alumina _{(Sn-La / Al 2 O} 3) catalyst, said lanthanum / alumina impregnated with the tin catalyst in order to, by drying and firing, platinum; And

(Pt-Sn-La / Al ₂ O ₃ ) catalyst by sequentially impregnating the tin-lanthanum / alumina catalyst with platinum, drying and calcining the tin-lanthanum / alumina catalyst. And a method for producing the catalyst.

Another aspect of the present invention relates to a dehydrogenation process comprising contacting a dehydrogenatable hydrocarbon with a dehydrogenation catalyst of the present invention under dehydrogenation conditions and obtaining a dehydrogenation product.

According to the dehydrogenation catalyst of the present invention, an appropriate amount of lanthanum is supported on alumina to increase the dispersibility of the platinum metal, and the interaction between the support and the active metal, platinum, can be increased to enable operation under harsh conditions So that the production amount can be increased.

Also, according to the present invention, catalyst stability and lifetime can be increased to increase the catalyst reaction-regeneration cycle.

In addition, according to the present invention, it is possible to improve the process unit level and the productivity by increasing the selectivity.

Hereinafter, the present invention will be described in more detail.

One aspect of the present invention is to provide an alumina (Al ₂ O ₃ ) carrier having mesopores of 5 to 50 nm and macropores of 50 nm to 20 μm as platinum as an active metal and lanthanum (La) and tin Sn) -supported dehydrogenation catalyst, wherein the weight ratio of the lanthanum and the tin auxiliary metal component to the platinum component is 0.01 to 50.0 wt% / m 2, the macropore volume per carrier unit weight is 0.05 cc / g to 0.4 cc / g , And the mesopore volume is from 0.2 cc / g to 0.8 cc / g.

The dehydrogenation catalyst of the present invention can improve the selectivity, stability and lifetime by supporting platinum as an active metal and tin and lanthanum as an auxiliary metal on alumina whose pore characteristics are controlled so that the carrier has pore characteristics, It can be maintained at a high selection for a long period of time.

The carrier of the dehydrogenation catalyst according to the present invention is alumina suitable, and the crystallinity of alumina is preferably 90% or more as a factor for determining the degree of formation of coke. In a preferred embodiment, in the present invention, the crystalline form of the carrier may be alumina in which two crystalline forms of theta or shea and gamma coexist. However, when the theta phase is less than 90% and coexists with the alpha crystal phase, it is difficult to maintain the bimodal pore structure.

Mesopores and macropores are pores that act as a channel for reactants and products. The ratio of the mesopores to the macropores is determined in consideration of the dispersibility of the catalyst and the mass transfer rate. The mesopores are preferably larger than the macropores. For example, the ratio of the mesopores and the macropores is in the range of 8: 2 To 6: 4. As the ratio of mesopores increases, the dispersibility improves. As the ratio of macropores increases, mass transfer becomes faster.

The pore volume and pore size of the carrier are the main factors that determine the mass transfer coefficient of the reactants and the product. In the case of the high chemical reaction rate, the diffusion resistance of the material determines the overall reaction rate. It is advantageous to keep the activity of the catalyst high. Therefore, the use of a carrier having a large pore size becomes insensitive to the accumulation of coke, and the high mass transfer rate results in a high reaction activity even when the liquid hourly space velocity (LHSV) is increased.

On the other hand, when the catalytic reaction is activated and proceeds rapidly, more reactants are supplied from the outside to the catalytic active sites. If the movement of the reactant increases abruptly, the flow will be resisted. This state is called a mass diffusion limited region. In actual catalytic reactors, most of them are used in the region of mass transfer control. Therefore, in order to overcome the mass transfer dominant region, it is desirable to adjust meso and macropores in the above-mentioned ratio in the catalyst.

The carrier of the present invention is a substance having a crystal form, and the size distribution, the total volume, the uniform distribution thereof, the mesopore size distribution present in the macropore structure, and the total volume thereof are important in the unit carrier weight. In the present invention, the macropore volume is in the range of 0.05 cc / g to 0.4 cc / g, and the mesopore volume is in the range of 0.2 cc / g to 0.8 cc / g. And has a bimodal distribution with a pore distribution.

In order to prevent weakening of the strength due to macropores, plastic deformation at a high temperature of 900 ° C to 1,200 ° C for 1 to 24 hours results in a particle crushing strength of not less than 3.0 kgf. The surface area of the final catalyst has a nitrogen adsorption specific surface area of 50 m < 2 > / g to 170 mm < 2 > / g or less. If the specific surface area of the support is less than 50 m < 2 > / g, the dispersibility of the metal active component is lowered. If it exceeds 170 m < 2 > / g, the gamma crystallinity of alumina is maintained high,

The alumina having the bimodal pore characteristics of the present invention is determined during the preparation of the carrier material and is commercially available and applicable as a catalyst. Such an alumina support is obtained through a molding process in various organoaluminum slurries, preferably using organoaluminum having 4 to 14 carbon atoms. Alumina is required to be heat treated so as to have an appropriate strength and pore distribution for industrial application. In the present invention, a gas hourly space velocity (GHSV) of 300 to 5,000 hr ^-1 in an oxygen or nitrogen gas atmosphere is 900 to 1,200 hr to ^-1 and processing the carrier to be applied in the present invention by a high-temperature calcination process of about 0.5 ~ 20 hr ^-1.

The alumina support having bimodal pore characteristics according to the present invention may be produced by controlling the kind and amount of the acid used in the production process. The acid component is combined with the aluminum element of the alumina carrier to attenuate the characteristics of the Lewis acid possessed by the alumina itself, thereby facilitating desorption of the product and inhibiting the formation of coke. In addition, the effect of decreasing the acid point inherent in the crystallinity of alumina itself is exhibited by the modification of the property of gamma to the property of theta or alpha.

The introduction of lanthanum is performed, for example, by impregnating La (NO ₃ ) ₃ 6H ₂ O (lanthanum nitrate hexahydrate) as a precursor of lanthanum in the above alloy carrier, drying it at 60 to 120 ° C for 12 to 36 hours in a dryer, Lt; 0 > C for 2 to 4 hours in the presence of firing and hydrogen.

In the present invention, platinum is supported so as to serve as an active site of a dehydrogenation catalyst. Tin is a catalyst for promoting catalytic activity as a cocatalyst for preventing the activity of platinum, which is an active metal, from being easily inactivated at high temperature, Thereby reducing the deactivation rate of the catalyst and increasing the stability of the catalyst, thereby suppressing hydrocracking, oligomerization, and coke formation on the catalyst surface, which are dehydrogenation side reactions.

According to the present invention, when platinum and tin are introduced at an optimum content into a lanthanum / alumina (La / Al ₂ O ₃ ) catalyst which is introduced at an optimal content on the basis of an alumina support, coking formation is suppressed even in a high- The target product can be produced at a high yield and the inactivation can be suppressed for a long period of time. For this purpose, the content of platinum is preferably 0.1 to 5 parts by weight based on 100 parts by weight of alumina, more preferably 0.1 to 2 parts by weight More preferably from 0.5 to 1.5 parts by weight. Further, in the case of tin, it is preferably introduced in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of alumina, more preferably 1 to 5 parts by weight, most preferably 2 to 4 parts by weight .

In the present invention, the weight ratio of the lanthanum and the tin auxiliary metal component to the platinum component is 0.01 to 50.0 wt% / m 2. If the weight ratio of the auxiliary metal component to the platinum component is less than 0.01 wt% / m 2, the selectivity of propylene is lowered due to cracking reaction of hydrocarbons by platinum. If the weight ratio of the auxiliary metal component exceeds 50.0 wt% / m 2, The reaction activity becomes low.

The introduction of platinum for example as platinum precursor _{H 2 PtCl 6 6H 2 O (} chloroplatinic acid hexahydrate) the lanthanum / impregnated on alumina catalyst in the presence of oxygen, after drying for 12 to 36 hours 60 ~ 120 ℃ conditions of the dryer 500 to Lanthanum / alumina (Pt-La / Al ₂ O 3) catalyst in the presence of barium and hydrogen at 600 ° C for 2 to 4 hours, and the introduction of tin can be performed, for example, The tin-acetylacetonate is impregnated with the platinum-lanthanum / alumina catalyst, dried in a drier at 60-120 ° C for 12-36 hours, calcined at 500-600 ° C in the presence of oxygen, (Sn-Pt-La / Al ₂ O ₃ ) catalyst in the presence of a catalyst.

In the present invention, the introduction of the active metal and the active auxiliary metal preferably proceeds in the order of lanthanum, tin and platinum, as described above. In other words, it was confirmed that the degree of improvement of yield was not remarkable when the order of lanthanum, tin, and platinum was introduced in the order of the order.

The dehydrogenation catalyst according to the present invention has a high degree of dispersion when the active ingredient is supported, and the development of mesopores and macropores has an effect of increasing the mass transfer rate. When the size of the pores existing in the catalyst is large, it is insensitive to the reduction of the activity due to the coke generated on the catalyst, and high reaction activity is exhibited even when the liquid space velocity is increased due to the high mass transfer rate.

The catalysts prepared according to the present invention provide improved performance that is different from conventional catalysts, namely, high hydrocarbon conversion and selectivity and performance stability as well as resistance to improved caulking and ease of removal of coke, as the dehydrogenation reaction conditions are severer do. The catalyst of the present invention is used in a severe process condition (H2 / C3 ratio = 0 to 1.0, high temperature = 550 to 700 ° C, high pressure = 0.0 to 5.0 kgf / cm ² Etc.) is possible.

The dehydrogenation catalyst of the present invention can have a great many uses. Thus, in particular, it can be used, for example, for the dehydrogenation of hydrocarbons or other organic compounds, in particular the dehydrogenation of C2 to C5 linear hydrocarbons. The saturated hydrocarbons in the present invention are mainly reactants of ethane, propane, butane, isobutane, pentane, and olefins having a carbon skeleton corresponding to saturated hydrocarbons used as reactants by dehydrogenation, that is, ethylene, propylene, 1- or 2- -Butylene, isobutylene, and pentene.

The catalysts of the present invention may also be used in combination with other catalysts such as hydrosulfuration, hydrodenitrification, desulfurization, hydrodesulfurization, dehydrohalogenation, reforming, steam reforming, cracking, hydrocracking, hydrogenation, dehydrogenation, isomerization, Can be used as catalysts for various reactions such as dismutation, oxychlorination and dehydrocyclization, oxidation and / or reduction reactions, Claus reaction.

Another aspect of the present invention relates to a method for producing a dehydrogenation catalyst, which will be described in detail below.

The method of the present invention has a mesopore of 5 to 50 nm and macropores of 50 nm to 20 탆, wherein the macropore volume per carrier unit weight is 0.05 cc / g to 0.4 cc / g, and the mesopore volume is Alumina (La / Al ₂ O) is prepared by impregnating, drying and firing lanthanum (La) sequentially on the alumina support to produce alumina having bimodal pore characteristics of 0.2 cc / g to 0.8 cc / ₃ ) Prepare the catalyst. Then, platinum-lanthanum / alumina (Sn-La / Al ₂ O ₃ ) catalyst was prepared by impregnating the lanthanum / alumina catalyst with tin in sequence, followed by drying and firing, Platinum-tin-lanthanum / alumina (Pt-Sn-La / Al ₂ O ₃ ) catalyst is prepared by impregnation, drying and firing.

The alumina may be alumina in which a theta crystal phase or a theta crystal phase and a gamma crystal phase coexist.

As the precursor of the metal used in the lanthanum supporting step, any of the commonly used precursors can be used. Generally, metal precursors such as metal chloride, nitrate, bromide, oxide, it is preferable to use at least one selected from a hydroxide and an acetate precursor, and it is particularly preferable to use metal nitrate. The amount of the metal precursor used is not particularly limited, but the content of the lanthanum is preferably 0.2-5 wt%, more preferably 0.5 wt%, based on the total weight of the final platinum-tin-lanthanum-alumina catalyst However, addition of more than 5% by weight of lanthanum is not preferable because it can block the active sites of platinum during the preparation of the catalyst, and when less than 0.2% by weight is added, I do not.

Each solvent used in the metal impregnation system may be selected from water or an alcohol, and water is preferred, but is not limited thereto.

The lanthanum-supported heat treatment is performed for the purpose of forming lanthanum-alumina. The lanthanum is heat treated at a temperature of 350 to 1000 ° C, preferably 500 to 800 ° C for 1 to 12 hours, preferably 3 to 6 hours . When the heat treatment temperature is less than 350 ° C. or the heat treatment time is less than 1 hour, formation of lanthanum-alumina is not sufficient, and when the heat treatment temperature exceeds 1000 ° C. or the heat treatment time exceeds 12 hours, lanthanum- Is undesirably deformed.

The tin precursor used in the tin deposition step may be any of the commonly used precursors. Generally, tin precursors include chlorides, nitrides, bromides, oxides, and acetates Acetate precursor, it is particularly preferable to use tin chloride (Tin (II) Chloride). The amount of the tin precursor to be used is not particularly limited, but it is preferable that the tin content is 0.5 to 10 wt% based on the total weight of the final platinum-tin-lanthanum-alumina catalyst in order to maintain high activity for a long time and stably, The addition of tin in an amount of more than 10% by weight is not preferable because the amount of the active site of platinum is reduced during the preparation of the catalyst and the activity is reduced. On the other hand, when less than 0.5% by weight is added The tin prevents the sintering of the platinum particles and keeps the particle size of the platinum small, thereby improving the dispersion degree, thereby failing to suppress the carbon deposition.

In the preparation of the tin precursor solution, an acid is used. The acid solution which can be used is an acid present in a liquid state at room temperature and may be selected from a group consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid and phosphoric acid. But is not limited to.

The tin is impregnated and the thermal drying is performed to remove the remaining moisture. The drying temperature and the drying time can be limited according to general moisture drying conditions. For example, the drying temperature is 50 to 200 ° C, preferably 70 To 120 캜, and the drying time is 3 to 24 hours, preferably 6 to 12 hours. Further, the heat treatment is carried out for the purpose of forming tin-lanthanum-alumina, and is carried out at a temperature range of 350 to 1000 캜, preferably 500 to 800 캜, for 1 to 12 hours, preferably 3 to 6 hours . If the heat treatment temperature is less than 350 ° C. or the heat treatment time is less than 1 hour, formation of tin-lanthanum-alumina is not sufficient. If the heat treatment temperature is more than 1000 ° C. or the heat treatment time is more than 12 hours Tin-lanthanum-alumina phase may be denatured.

As the platinum precursor used in the platinum carrying step, any of the commonly used precursors can be used. Generally, the platinum precursor includes chloroplatinic acid, platinum oxide, platinum chloride, It is preferable to use at least one selected from platinum bromide precursors, and it is particularly preferable to use chloroplatinic acid. The amount of the platinum precursor to be used is not particularly limited, but it is preferable that the content of platinum is 0.5 to 10 wt% based on the total weight of the final platinum-tin-lanthanum-alumina catalyst. , It is difficult to obtain a high degree of dispersion of platinum during the preparation of the catalyst and it is not preferable to use a large amount of expensive platinum. On the other hand, when less than 0.5% by weight is added, the active site of platinum which is the active metal of the dehydrogenation reaction is not sufficiently formed And it is difficult to produce the product with high selectivity and yield.

After impregnation with platinum, thermal drying and heat treatment are performed. Since the purpose of thermal drying is to remove residual moisture after impregnation with platinum, drying temperature and drying time can be limited according to general moisture drying conditions. The drying temperature may be set at 50 to 200 ° C, preferably 70 to 120 ° C, and the drying time may be set to 3 to 24 hours, preferably 6 to 12 hours. The heat treatment may be performed at a temperature ranging from 400 to 800 ° C for 1 to 12 hours and preferably at a temperature of 500 to 700 ° C for 3 to 6 hours to obtain a platinum-tin-lanthanum-alumina catalyst .

The method of impregnating the carrier with the metal active component or the auxiliary metal component may be an incipient wetness method or any other impregnation method. As the precipitation method, a coprecipitation method, a homogeneous precipitation method, or a sequential precipitation method can be used. In the preparation of the catalyst powder by the precipitation method, the active material and the support are simultaneously precipitated to obtain a powdery catalyst, the ratio of the active material can be freely adjusted, and the mutual binding force between the active material and the support is strengthened, It is possible to produce an excellent catalyst powder.

Another aspect of the present invention is directed to an improved dehydrogenation process using the dehydrogenation catalyst of the present invention.

In the method for producing propylene from propane according to the present invention, a mixed gas containing propane, hydrogen and oxygen is reacted at a reaction temperature of 600 to 1000 占 폚, preferably 600 to 800 占 폚, 0.1 to 5.0 kgf / high pressure, H2 / C3 ratio of ㎠ is 0 to 1.0, the mixed gas and a liquid space velocity of 0.1 ~ 30 hr ^-1 and a catalyst, preferably 2 ~ 20 hr ^-1 to gas phase reaction in the oxidation reaction conditions dehydrogenase To produce propylene from propane.

The process for producing propylene from propane according to the present invention is effective for producing propylene even under severe high temperature conditions. When the dehydrogenation catalyst according to the present invention is applied, the production of propylene and the reduction in catalytic activity are low. That is, the propylene production method of the present invention can utilize the heat of reaction generated by the oxidation reaction of oxygen, and exhibits a high propane conversion rate by overcoming the reaction equilibrium. In addition, even when the reaction conditions are severer, the performance of the catalyst is decreased, and even when the deactivation is intensified, the effect is improved in terms of long-term use stability. In addition, the secondary effect of the present invention also has the function of removing the coke on the catalyst during the reaction, thereby improving the activity of the catalyst.

Hereinafter, the present invention will be described in more detail with reference to examples. It should be noted, however, that this is for the purpose of illustrating the present invention and should not be construed as limiting the scope of protection of the present invention.

Example  1: Preparation of dehydrogenation catalyst

A spherical commercial alumina having a gamma crystallinity and an average diameter of 1.65 mm and a packing density of 0.56 g / ml was purchased from the carrier used for the catalyst synthesis and thermally deformed at a temperature of 1050 ° C for 2 hours in an air atmosphere Phase. After that _{La (NO 3) 3 · 6H} 2 O (99.99%, Sigma) with hydrochloric acid compared to alumina support weight (HCl> 35%, Daejung chem ) 0.4% by weight, nitric acid (HNO3, 70%, Daejung chem ) carrier weight ratio 0.3% by weight, and 1.5 times the volume of the distilled water carrier. The mixture is stirred for 3 hours and then carried on a rotary evaporator at 80 ° C and 25 rpm for 4 hours, followed by evaporation under reduced pressure. After that, it was heat-treated at 1100 ° C for 2 hours in a firing furnace, and then dried at 230 ° C for 24 hours. Then, tin, platinum and potassium were successively carried on the alumina support. First, tin chloride (SnCl ₂ ,> 98%, Sigma) was added in an amount of 0.5 wt% based on alumina, 5 wt% based on the weight of hydrochloric acid (HCl,> 35%, Daejung chem) carrier, nitric acid (HNO ₃ , 60%, Daejung chem) 2% by weight based on the weight of the distilled water carrier was dissolved in 2 times the weight of the carrier, and 15 g of sulfuric acid-pretreated alumina was added thereto. The supported liquid was stirred at 25 rpm for 3 hours at 80 ° C using a rotary evaporator, and then dried by rotating at 25 rpm for 1.5 hours under reduced pressure at 80 ° C. After that, it was heat-treated at 600 ° C for 2 hours and then dried in a 230 ° C heating furnace for 24 hours. Thereafter, 15 g of tin-supported alumina was added to 0.6 wt% of alumina with chloroplatinic acid (H ₂ PtCl ₆ .6H ₂ O, 99.95%, Aldrich), 0.5 wt% with respect to the hydrochloric acid carrier and 0.3 wt% And was carried in distilled water. The supported liquid was stirred at 25 rpm for 3 hours at 80 ° C using a rotary evaporator, and then dried by rotating at 25 rpm for 1.5 hours under reduced pressure at 80 ° C. Thereafter, it was heat-treated at 550 ° C for 2 hours and dried at 230 ° C for 24 hours.

Thereafter, 15 g of alumina bearing tin and platinum was loaded in distilled water twice as much as the carrier, 0.9% by weight of potassium nitrate (KNO ₃ ,> 99%, Sigma-Aldrich) carrier and 0.5% by weight of hydrochloric acid carrier. The supported liquid was stirred at 25 rpm for 3 hours at 80 ° C using a rotary evaporator, and then dried by rotating at 25 rpm for 1.5 hours under reduced pressure at 80 ° C. After the heat treatment at 600 ° C for 2 hours, the catalyst was dried in a 230 ° C heating furnace for 24 hours to prepare a dehydrogenation catalyst.

Comparative Example  One

A potassium-tin-platinum / alumina (K-Pt-Sn / Al ₂ O ₃ ) catalyst was prepared in the same manner as in Example 1 except that lanthanum was not supported in Example 1.

Test Example  One

In order to confirm the performance of the dehydrogenation catalyst according to the present invention, the following experiment was conducted. 1.5 g of the catalyst prepared in the above Examples and Comparative Examples were packed in a quartz reactor having a volume of 7 ml, respectively, and oxidative dehydrogenation reaction was carried out by supplying a mixed gas of propane, hydrogen and oxygen. The ratio of hydrogen to propane was 1: 1, the ratio of propane to oxygen was 30: 1, the reaction temperature was 650 ° C, the pressure was 1.5 kgf / cm 2, the H2 / Was maintained at 15 hr < ^-1 > and an oxidative dehydrogenation reaction was carried out. The gas composition after the reaction was analyzed by gas chromatography connected to the reactor to determine the propane conversion, the propylene selectivity in the product after the reaction, and the propylene yield. The results are shown in Table 1 below.

Performance (mol%) [Reaction time (1 hr)] Performance (mol%) [Reaction time (5 hr)] Conversion Rate Selectivity yield Conversion Rate Selectivity yield Example 1 40.3 92.2 37.1 37.5 94.1 35.2 Comparative Example 1 37.6 92.3 35.4 35.9 93.5 33.9

Referring to the results of Table 1, it can be seen that the dispersibility of the platinum metal is increased and the interaction between the support and the platinum as the active metal is increased as in the present invention, thereby improving the conversion, selectivity and yield.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. this

It will be obvious.

Claims (9)

A dehydrogenation catalyst in which platinum as active metal and lanthanum (La) and tin (Sn) as active auxiliary metals are supported on an alumina (Al ₂ O ₃ ) carrier having mesopores of 5 to 50 nm and macropores of 50 nm to 20 μm Wherein the weight ratio of the lanthanum and the tin auxiliary metal component to the platinum component is 0.01 to 50.0 wt% / m 2, the macropore volume per carrier unit weight is 0.05 cc / g to 0.4 cc / g, Lt; RTI ID = 0.0 > cc / g < / RTI > to 0.8 cc / g.
The dehydrogenation catalyst according to claim 1, wherein the alumina is alumina (Al ₂ O ₃ ) having a crystallinity of 90% or more.
The dehydrogenation catalyst according to claim 1, wherein the hydrocarbon is a C2 to C5 linear hydrocarbon.
The macropore volume per carrier unit weight is in the range of 0.05 cc / g to 0.4 cc / g, the mesopore volume is in the range of 0.2 cc / g to 0.2 cc / g, Preparing alumina having bimodal pore characteristics of 0.8 cc / g;
Preparing a lanthanum / alumina (La / Al ₂ O ₃ ) catalyst by sequentially impregnating, drying and firing lanthanum (La) on the alumina support;
Preparing a lanthanum / alumina _{(Sn-La / Al 2 O} 3) catalyst, said lanthanum / alumina impregnated with the tin catalyst in order to, by drying and firing, platinum; And
(d) preparing platinum-tin-lanthanum / alumina (Pt-Sn-La / Al ₂ O ₃ ) catalyst by sequentially impregnating the tin-lanthanum / alumina catalyst with platinum, followed by drying and firing By weight based on the total weight of the dehydrogenation catalyst.
5. The process for producing a dehydrogenation catalyst according to claim 4, wherein the alumina is alumina in which a theta crystal phase or a gamma crystal phase coexists with a theta crystal phase.
5. The method of claim 4, wherein the calcination temperature at the time of lanthanum loading is about 500 to 1050 ° C.
5. The method of claim 4, wherein the ratio of Al ₂ O ₃ : La at the time of lanthanum loading is 0.001 to 1.0 molar ratio.
Contacting the dehydrogenatable hydrocarbon with the catalyst according to any one of claims 1 to 3 under dehydrogenation conditions and obtaining the dehydrogenation product.
The process according to claim 8, wherein the mixed gas containing propane, hydrogen and oxygen is heated at a reaction temperature of 600 to 1000 ° C, at a pressure of 0.1 to 5.0 kgf / cm < 2 >, using a dehydrogenation catalyst of any one of claims 1 to 3, And the H2 / C3 ratio is in the range of 0 to 1.0, thereby producing propylene from propane.