KR102113122B1 - Method of preparing dehydrogenation catalysts - Google Patents

Abstract

In the present invention, in preparing a dehydrogenation catalyst having a form in which platinum, auxiliary metals, alkali metals, or alkaline earth metals are supported on a carrier, reacting the carrier with an aqueous sulfuric acid solution and drying and drying the carrier treated with sulfuric acid after washing with water. Relates to a method for preparing a dehydrogenation catalyst, the dehydrogenation catalyst prepared by the method of the present invention can increase the size and volume of pores on a carrier to decrease the material diffusion resistance of the reaction to improve catalytic activity.

Description

METHOD OF PREPARING DEHYDROGENATION CATALYSTS

The present invention relates to a method for producing a dehydrogenation catalyst, and more particularly, to a method for producing a dehydrogenation catalyst capable of improving catalyst activity by increasing the size and volume of pores of a carrier.

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

In the field of catalytic 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 deactivation rate of the catalyst affects the useful life, and in order to prolong the life and increase the yield of the product under severe process conditions, it is generally required that the catalyst is highly stable.

In general, platinum, which acts as an active point of a dehydrogenation catalyst, is easily deactivated at a high temperature, and there is a problem in that activity is easily reduced by carbon deposition. In order to suppress the deactivation of the platinum catalyst and improve selectivity and performance, tin, zinc, magnesium, and manganese are used, and when dehydrogenation at a high temperature, alkali metals such as lithium, sodium, and potassium are used. Contents on increasing thermal stability have already been studied. In addition, studies have been conducted on the possibility of increasing the catalyst performance by improving the dispersion degree of platinum by adding an earth metal such as lanthanum and cerium as an activity enhancer to increase the interaction between the active metal and the catalyst carrier (support). come.

However, although the catalysts prepared by simply adding and replacing auxiliary metals as described above have improved in terms of activity and selectivity of the catalyst in the dehydrogenation reaction, the deactivation of the catalyst proceeds rapidly, so it is not satisfactory in terms of reaction stability, so the limitation of development is limited. have.

The present invention is to solve the problems of the prior art as described above, one object of the present invention is to increase the volume and size of the pores on the carrier by pre-treating the carrier of the dehydrogenation catalyst with sulfuric acid, to select the conversion rate, conversion of the dehydrogenation catalyst It is to provide a method for producing a dehydrogenation catalyst that can improve the degree and yield.

Another object of the present invention is to provide an improved dehydrogenation process using a dehydrogenation catalyst prepared by the method 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.

One aspect of the present invention for achieving the above object,

In preparing a dehydrogenation catalyst having a form in which platinum, auxiliary metals, alkali metals or alkaline earth metals are supported on a carrier, reacting the carrier with an aqueous sulfuric acid solution and drying and drying the carrier treated with sulfuric acid after washing with water. It relates to a manufacturing method.

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

In the dehydrogenation catalyst prepared by the method of the present invention, since the carrier is etched with sulfuric acid to increase the size and volume of the pores of the carrier, the material diffusion resistance is reduced, so that mass transfer of reactants and products is easy, and catalytic activity It can provide an improved effect. In addition, the dehydrogenation catalyst prepared by the method of the present invention has an effect of delaying deactivation due to coke generation, and has high coke regeneration, so that initial activity can be maintained for a long time after regeneration.

In addition, according to the present invention, it is possible to increase the catalytic reaction-regeneration cycle by increasing catalyst stability and lifetime, and improve process unit and productivity by increasing selectivity.

1 is a schematic view illustrating a process in which a catalyst carrier is modified by sulfuric acid pretreatment by a method for preparing a dehydrogenation catalyst according to an embodiment of the present invention.

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

In one aspect of the present invention, in preparing a dehydrogenation catalyst having a form in which platinum, auxiliary metals, alkali metals or alkaline earth metals are supported on a carrier, the carrier is reacted with an aqueous sulfuric acid solution, and the carrier treated with sulfuric acid is washed and dried. It relates to a method for producing a dehydrogenation catalyst comprising a step.

In the present invention, platinum (Pt) is supported to act as an active point of a dehydrogenation catalyst, and tin is catalytically active as a co-catalyst to prevent the active metal, platinum from being easily deactivated at high temperatures and easily degraded by carbon deposition. Serving as an enhancer, it is supported to reduce the deactivation rate of the catalyst and increase the stability of the catalyst to suppress dehydrogenation side reactions such as hydrocracking, oligomerization, and coke formation on the catalyst surface.

The dehydrogenation catalyst prepared by the method of the present invention is insensitive to the accumulation of coke when the size and volume of the pores of the carrier are expanded by sulfuric acid pretreatment, and the mass transfer rate is high, resulting in a liquid hourly space velocity (HSV). ), It shows a high reaction activity.

In the present invention, when the dehydrogenation catalyst is prepared, the carrier is wet-etched with sulfuric acid to control the pore characteristics of the carrier, and then the active metal and the auxiliary metal are supported.

The dehydrogenation catalyst carrier is allowed to react with an aqueous sulfuric acid solution and is contacted with an aqueous sulfuric acid solution of H ₂ SO ₄ / H ₂ O = 1/20 to 1/2000 during such time at an effective temperature of 500 ° C. or higher. Generally speaking, the dehydrogenation catalyst preparation method of the present invention can be most conveniently performed by suspending the dehydrogenation catalyst carrier in a suitable liquid medium in which sulfuric acid is dissolved. The suspension can be treated at a suitable temperature for the desired reaction period, preferably while stirring or mixing in other ways.

Water may be used alone, but one or more water miscible organic solvents such as lower aliphatic alcohols or tetrahydrofuran may also be present. For example, in wet etching, reactants with alumina carriers include sulfuric acid, water, acetonitrile, dimethyl formamide, formamide, diethyl sulfoxide, hexamethyl phosphoric triamide, dimethyl acetamide, methyl alcohol, A mixed solution with one or more substances selected from the group consisting of ethyl alcohol and isopropyl alcohol can be used.

As mentioned above, the type of acid selected for use affects the reaction conditions needed to etch the catalytic performance to the desired degree. Suitable concentrations of sulfuric acid may generally range from 0.005 M to 0.05 M, suitable reaction temperatures may range from 50 ° C to 100 ° C, and suitable reaction times may range from 1 hour to 1 day.

After contact with sulfuric acid, water is washed with any suitable means to remove unreacted (excess) sulfuric acid. For this, it is preferable to wash unreacted sulfuric acid from the catalyst using a water-miscible organic solvent such as water (distilled water), alcohol, or a mixture of water and a water-soluble organic solvent.

After washing with water, the sulfuric acid-pretreated catalyst is dried and calcined, and dried and calcined at a high temperature of 500 ° C to 1000 ° C for 1 to 24 hours to prevent weakening of strength by sulfuric acid treatment. At this time, the drying speed may be accelerated by applying a vacuum.

 As the carrier, alumina, silica and mixed components thereof may be used, preferably alumina is suitable. The theta phase crystallinity of alumina is preferably 90% or more. In the case of gamma-alumina, the side reaction property due to the acid point of the alumina itself is large, the alumina crystallinity changes during the reaction, and the structural properties of the specific surface area decrease. In the case of alpha-alumina, it exhibits low catalytic activity by lowering the dispersibility of the noble metal and reducing the total active area of the noble metal due to its low specific surface area.

The carrier has a specific surface area of 70 to 170 m 2 / g, meso pores of 5 to 50 nm, and macro pores of 50 to 20 μm. If the specific surface area of the carrier is less than 70 m 2 / g, the dispersibility of the metal active component decreases, and when it exceeds 170 m 2 / g, the gamma crystallinity of alumina is maintained to increase side reaction. The volume of the pores of the carrier and the size of the pores are the main factors that determine the mass transfer coefficient of the reactants and products, and the diffusion resistance of the material determines the overall reaction rate in a situation where the chemical reaction rate is high, so a structure with a large pore size is a catalyst. It is advantageous to maintain the activity of high. In addition, the use of a carrier having a large pore size is insensitive to the accumulation of coke, which is advantageous for maintaining catalytic activity.

The dehydrogenation catalyst according to the present invention is highly active by having pores of a size and volume controlled by sulfuric acid treatment, has a high activity density of the catalyst of the unit surface area, is easy to transfer mass of reactants and products, and according to coke production It has an effect of delaying inactivation, high coke regeneration, no change in initial activity even after regeneration, high strength, strong external shock, and no structural changes due to heat or changes in properties of the active material.

The platinum is used as an active metal, and the auxiliary metal is selected from the group consisting of tin, germanium, gallium, indium, zinc and manganese, and tin is particularly preferred. The alkali metal or alkaline earth metal may be selected from the group consisting of calcium, potassium, sodium, magnesium, lithium, strontium, barium, radium, and beryllium.

In the present invention, the weight ratio of the auxiliary metal component to the platinum component is 0.01 to 50.0 wt% / m 2. When 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 by the cracking reaction of hydrocarbons with platinum, and when the weight ratio of the auxiliary metal component exceeds 50.0 wt% / m 2, dehydrogenation The reaction activity becomes low.

The dehydrogenation catalyst according to the present invention has a volume density of 0.5 to 0.8 g / cc, and preferably has a strength of 15 to 70 N, so as to increase the strength so that it has less stiffness with less debris even during regeneration or catalyst circulation. If the strength of the catalyst is less than 15N, it is easily broken and difficult to apply to a continuous reaction system. The dehydrogenation catalyst is accompanied by coke formation, and after a certain reaction, the coke is burned and regenerated through an oxidation reaction, and thermal cracking occurs during the process. In addition, friction or impact is applied during transport under conditions of circulating the catalyst. In the case of using a catalyst that is weak to impact, having a high strength has a great advantage in process operation because it hinders the product flow and increases the pressure in the reactor to lower the conversion rate of the catalyst. In the present invention, the concentration of sulfuric acid, which is a pretreatment material, is adjusted to prevent weakening of strength by pretreatment with sulfuric acid, and plastic residue is removed at a high temperature of 500 ° C to 1000 ° C for 1 to 24 hours after sulfuric acid pretreatment to remove residual materials.

The dehydrogenation catalyst in the present invention can be prepared by various methods. Hereinafter, a platinum-tin-potassium / alumina (Pt-Sn-K / Al ₂ O ₃ ) catalyst will be described as an example. First, an alumina pretreated with sulfuric acid is prepared, and a potassium / alumina (K / Al ₂ O ₃ ) catalyst is prepared by sequentially impregnating, drying, and calcining an auxiliary metal (eg, potassium (K)) in the sulfuric acid pretreated alumina carrier, Subsequently, the potassium / alumina catalyst was sequentially impregnated with tin, dried and calcined to prepare a platinum-potassium / alumina (Sn-K / Al ₂ O ₃ ) catalyst, and then platinum was sequentially applied to the tin-potassium / alumina catalyst. Impregnation, drying and calcination can be used to prepare platinum-tin-potassium / alumina (Pt-Sn-K / Al ₂ O ₃ ) catalysts.

In the present invention, a method of impregnating a carrier with a metal active component or an auxiliary metal component may use an incipient wetness method, or other impregnation methods. As the precipitation method, a coprecipitation method, a homogeneous precipitation method, or a sequential precipitation method can be used. When the catalyst powder is prepared by the precipitation method, the active material and the carrier, which are the components, are simultaneously immersed to obtain a powdered catalyst, and the ratio of the active material can be freely controlled, and stability is improved by strengthening the mutual bonding force between the active material and the carrier. It is possible to produce excellent catalyst powder.

The introduction of auxiliary metals such as potassium and tin is impregnated with KNO ₃ in the alloy carrier as a precursor of potassium, dried in a dryer at 60 to 120 ° C. for 12 to 36 hours, followed by calcination and hydrogen at 500 to 600 ° C. in the presence of oxygen. It can be carried out by reducing for 2-4 hours in the presence.

According to the present invention, when platinum and tin are introduced into the potassium / alumina (K / Al ₂ O ₃ ) catalyst introduced at the optimum content as described above based on the alumina carrier pretreated with sulfuric acid, coking is generated even in the high temperature reaction region. This is suppressed to produce the target product with a high yield, and it is possible to suppress inactivation for a long time. To this end, platinum is preferably introduced in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of alumina, and 0.1 to 2 parts by weight It is more preferably introduced in an amount of parts, and most preferably introduced in an amount of 0.5 to 1.5 parts by weight. In addition, tin is preferably introduced at a content of 0.1 to 10 parts by weight with respect to 100 parts by weight of alumina, more preferably 1 to 5 parts by weight, and most preferably 2 to 4 parts by weight. .

Any precursor may be used as the precursor of the metal used in the potassium-supporting step, in general, metal chloride, nitrate, bromide, oxide, hydroxide It is preferable to use at least one selected from (hydroxide) or acetate precursors, and metal nitrate is particularly preferable. The amount of the metal precursor is not particularly limited, but based on the total weight of the final platinum-tin-potassium-alumina catalyst, the potassium content is preferably 0.2 to 5% by weight, more preferably 0.5% by weight However, when more than 5% by weight of potassium is added, it is not preferable because it can prevent the active point of platinum during catalyst preparation, and when less than 0.2% by weight is added, the amount is very small, so it is not desirable to see the effect of increasing the reaction activity. Does not.

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

In addition, the heat treatment after potassium support is carried out for the purpose of forming potassium-alumina, preferably in the temperature range of 350 to 1000 ° C, preferably 500 to 800 ° C for 1 to 12 hours, preferably 3 to 6 hours. It is desirable to do. When the heat treatment temperature is less than 350 ° C or the heat treatment time is less than 1 hour, it is not preferable because the formation of potassium-alumina is not sufficient, and when the heat treatment temperature exceeds 1000 ° C or the heat treatment time exceeds 12 hours, potassium-alumina It is not preferable because there is a fear of denaturation of the phase.

The tin precursor used in the tin-carrying step may be any precursor as long as it is a commonly used precursor. In general, the precursor of tin may be chloride, nitride, bromide, oxide or acetate ( Acetate) It is preferable to use at least one selected from precursors, and tin chloride (Tin (II) Chloride) is particularly preferred. The amount of the tin precursor is not particularly limited, but in order to maintain high activity stably for a long time, based on the total weight of the final platinum-tin-potassium-alumina catalyst, the tin content is preferably 0.5 to 10% by weight, 1% by weight is more preferable, but when adding more than 10% by weight of tin, it is not preferable because there is a problem in that the activity of the platinum decreases due to a decrease in the amount of the platinum active point during catalyst preparation, whereas when adding less than 0.5% by weight It is undesirable because tin prevents the role of suppressing carbon deposition by preventing the sintering of platinum particles and improving the dispersion degree by keeping the particle size of platinum small.

An acid is used in the preparation of a tin precursor solution, and the acid solution that can be used is an acid that exists in a liquid (solution) state at room temperature, and may be selected from one or more groups consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid. It is not limited.

After impregnating with tin, thermal drying is performed to remove the remaining moisture. The drying temperature and drying time may be limited according to general moisture drying conditions. For example, the drying temperature is 50 to 200 ° C, preferably 70 ~ 120 ℃, the drying time can be set to 3 to 24 hours, preferably 6 to 12 hours. In addition, the heat treatment is performed for the purpose of forming tin-potassium-alumina, which is performed at a temperature range of 350 to 1000 ° C, preferably 500 to 800 ° C for 1 to 12 hours, preferably 3 to 6 hours. It is preferred. This is not preferable because the formation of tin-potassium-alumina is insufficient when the heat treatment temperature is less than 350 ° C or the heat treatment time is less than 1 hour, and when the heat treatment temperature exceeds 1000 ° C or the heat treatment time exceeds 12 hours. It is not preferable because the phase of tin-potassium-alumina may be denatured.

The platinum precursor used in the platinum supporting step may be any precursor as long as it is a commonly used precursor. In general, the platinum precursor may be chloroplatinic acid, platinum oxide, platinum chloride, or the like. It is preferable to use at least one selected from platinum bromide precursors, and chloroplatinic acid is particularly preferred. The amount of the platinum precursor is not particularly limited, but based on the total weight of the final platinum-tin-potassium-alumina catalyst, it is preferable that the content of platinum is 0.5 to 10% by weight, adding more than 10% by weight of platinum In the case of catalyst preparation, it is difficult to obtain a high degree of dispersion of platinum, and it is not preferable to use expensive platinum. On the other hand, when less than 0.5% by weight is added, the active point of platinum, which is the active metal of the dehydrogenation reaction, is not sufficiently formed. Therefore, it is difficult to produce a product with high selectivity and yield, which is undesirable.

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

As an alternative, the introduction of platinum is, for example, H ₂ PtCl ₆ · 6H ₂ O (chloroplatinic acid hexahydrate) as a precursor of platinum, impregnated with the potassium / alumina catalyst, dried in a dryer at 60 to 120 ° C. for 12 to 36 hours, and oxygen is present. It can be carried out as a platinum-potassium / alumina (Pt-K / Al ₂ O3) catalyst preparation by calcination under conditions of 500 to 600 ° C. and reduction for 2 to 4 hours in the presence of hydrogen, and the introduction of tin is, for example, a precursor of tin. Tin-acetylacetonate was impregnated with the platinum-potassium / alumina catalyst, dried in a dryer at 60-120 ° C for 12-36 hours, then calcined under oxygen and at 500-600 ° C in the presence of hydrogen. Reduction for 2-4 hours can be performed as a tin-platinum-potassium / alumina (Sn-Pt-K / Al ₂ O ₃ ) catalyst preparation.

The catalyst prepared by the present invention provides improved performance that is more differentiated than the catalyst by the conventional method, as the dehydrogenation reaction conditions are more severe, that is, high hydrocarbon conversion and selectivity and performance stability, improved resistance to coking and ease of coke removal. do. The catalyst of the present invention can be operated under severe process conditions (H2 / C3 ratio = 0 to 1.0, high temperature = 550 to 700 ° C, high pressure = 0.0 to 5.0 kgf / cm 2, etc.) due to increased stability.

The dehydrogenation catalyst produced by the process of the present invention can have a very large number of uses. Therefore, it can be used in particular for dehydrogenation of, for example, hydrocarbons or other organic compounds, especially for C2 to C5 linear hydrocarbons. The saturated hydrocarbon in the present invention is the main target reactant of ethane, propane, butane, isobutane, and pentane. The olefin having a carbon skeleton corresponding to the saturated hydrocarbon used as a reactant by dehydrogenation reaction, that is, ethylene, propylene, 1- or 2 -Converted to butylene, isobutylene, and pentene.

The dehydrogenation catalyst prepared by the production method of the present invention is hydrosulfuration, hydrodenitrification, desulfurization, hydrodesulfurization, dehydrohalogenation, reforming, steam reforming, cracking, hydrocracking, hydrogenation, It can be used as a catalyst for various reactions such as dehydrogenation, isomerization, dismutation, oxychlorination and dehydrocyclization, oxidation and / or reduction reactions, and claus reactions.

Another aspect of the invention relates to an improved dehydrogenation method using a dehydrogenation catalyst prepared by the method of the invention.

In the method for producing propylene from propane according to the present invention, a mixed gas containing propane, hydrogen, and oxygen is used at a reaction temperature of 600 to 1000 ° C, preferably 600 to 800 ° C, 0.1 to High pressure of 5.0 kgf / cm 2, H2 / C3 ratio of 0 to 1.0, liquid space velocity between the mixed gas and the catalyst is 0.1 to 30 hr ^-1 , preferably 2 to 20 hr ^-1 by gas phase reaction under the conditions of gas phase reaction to oxidative dehydrogenation Propylene is produced from propane by reaction.

The method for producing propylene from propane according to the present invention is a method for producing effective propylene even under severe high temperature conditions. When the dehydrogenation catalyst according to the present invention is applied, an increase in propylene production and a decrease in catalyst activity are low. That is, the propylene production method of the present invention can utilize the reaction heat 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 severe, the performance of the catalyst is small, and even when deactivation is severe, it shows an improved effect in terms of long-term stability. In addition, as a side effect of the present invention, there is also a function of removing coke on the catalyst during the reaction, thereby improving activity.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, this is for explaining the present invention, and should not be interpreted as limiting the protection scope of the present invention.

Example 1: Preparation of dehydrogenation catalyst

Alumina having a spherical gamma crystallinity was purchased from Sasol, Germany, and a tubular electric furnace (Korea Electric Furnace) was used for 1 to 6 hours at a temperature of 1050 ° C. over 300 ml / min of air flow. It was thermally deformed and used as a catalyst synthesis carrier. As a result of measuring the crystallinity of alumina using an X-ray analysis method, it had a theta crystallinity of 90% or more.

The heat-modified alumina carrier was put in a sulfuric acid aqueous solution having a molar ratio of H ₂ SO ₄ / H ₂ O = 1/20 and contacted at 80 ° C. for 2 hours, washed with distilled water and dried and calcined at 800 ° C.

Subsequently, tin, platinum, and potassium were sequentially supported on the sulfuric acid-pretreated alumina carrier. First, tin chloride (SnCl ₂ ,> 98%, Sigma) 0.5% by weight compared to alumina, hydrochloric acid (HCl,> 35%, Daejung chem) carrier weight 5% by weight, nitric acid (HNO ₃ , 60%, Daejung chem) carrier After 2% by weight of 0% by weight compared to the weight of the distilled water carrier was dissolved and dissolved, 15 g of sulfuric acid-pretreated alumina was added and supported. The supported liquid was stirred at 80 rpm for 3 hours at 80 ° C. using a rotary evaporator, and then dried by rotating at 25 rpm for 1.5 hours at 80 ° C. under reduced pressure. After heat treatment for 2 hours at 600 ℃ and dried for 24 hours at a heating furnace at 230 ℃. Subsequently, 15 g of tin-supported alumina was compared with 0.6% by weight of chloroplatinic acid (H ₂ PtCl ₆ · 6H ₂ O, 99.95%, Aldrich) alumina, 0.5% by weight of a hydrochloric acid carrier, and 0.3% by weight of a nitric acid carrier compared to a distilled water carrier. It was put in distilled water of a ship and supported. The supported liquid was stirred at 80 rpm for 3 hours at 80 ° C. using a rotary evaporator, and then dried by rotating at 25 rpm for 1.5 hours at 80 ° C. under reduced pressure. After heat treatment for 2 hours between 550 ℃ and dried for 24 hours in a 230 ℃ furnace. Thereafter, 15 g of tin and platinum-supported alumina were added in 0.9% by weight compared to a potassium nitrate (KNO ₃ ,> 99%, Sigma-Aldrich) carrier and 0.5% by weight compared to a hydrochloric acid carrier in distilled water twice as much as the carrier. The supported liquid was stirred at 80 rpm for 3 hours at 80 ° C. using a rotary evaporator, and then dried by rotating at 25 rpm for 1.5 hours at 80 ° C. under reduced pressure. Thereafter, a heat treatment was performed between 600 ° C. for 2 hours, followed by drying in a heating furnace at 230 ° C. for 24 hours to prepare a dehydrogenation catalyst.

Comparative example  One

A platinum-tin-potassium / alumina (Pt-Sn-K / Al ₂ O ₃ ) catalyst was prepared in the same manner as in Example 1, except that in Example 1, an alumina carrier not pretreated with sulfuric acid was used. Did.

Comparative example  2

A platinum-tin-potassium / alumina (Pt-Sn-K / Al ₂ O ₃ ) catalyst was prepared in the same manner as in Example 1, except that the carrier was pretreated with an aqueous hydrochloric acid solution instead of the sulfuric acid aqueous solution in Example 1 Did.

Test example  1- Performance test of dehydrogenation catalyst

In order to confirm the performance of the dehydrogenation catalyst according to the present invention, the following experiment was performed. After 1.5 g of the catalyst prepared in Example 1 and Comparative Examples 1 to 2 were filled in a quartz reactor having a volume of 7 ml, propane, hydrogen, and an oxygen mixed gas were supplied to each to perform an oxidative dehydrogenation reaction. At this time, the ratio of hydrogen and propane was 1: 1, and the ratio of propane and oxygen was fixed at 30: 1, the reaction temperature was 650 ° C, the pressure was 1.5 kgf / cm 2 high pressure, the H2 / C3 ratio was 0.5, and the liquid space velocity. Was carried out while maintaining the oxidative dehydrogenation reaction at 15 hr ⁻¹ . The gas composition after the reaction was analyzed by gas chromatography connected to the reaction apparatus to obtain propane conversion, propylene selectivity in the product after the reaction, and propylene yield, and the results are shown in Table 1 below.

Performance (mol%) [Reaction time (1hr)] Performance (mol%) [Reaction time (5hr)] Conversion rate Selectivity yield Conversion rate Selectivity yield Example 1 38.7 94.9 36.8 37.2 95.0 35.3 Comparative Example 1 37.6 94.8 35.8 35.8 94.9 34.0 Comparative Example 2 37.9 95.7 35.1 36.4 96.9 33.6

As can be seen through the results of Table 1, it can be seen that when the alumina carrier pre-treated with sulfuric acid by the method of the present invention is used, conversion and selectivity are improved. In addition, it can be confirmed that the catalyst dehydrogenation long life test was conducted using the dehydrogenation catalyst prepared by the method of the present invention to maintain long-term activity in an equivalent yield.

The present invention has been described in detail with reference to preferred embodiments of the present invention, but the present invention is not limited to the above-described embodiments, and many modifications by those skilled in the art to which the present invention pertains are within the scope of the technical spirit of the present invention. This possibility will be obvious.

Claims (10)

In preparing a dehydrogenation catalyst having a form in which platinum, auxiliary metal, alkali metal or alkaline earth metal is supported on a carrier , the catalyst carrier is an aqueous solution of sulfuric acid having H ₂ SO ₄ / H ₂ O = 1/20 to 1/2000 and 70 ° C. Method for producing a dehydrogenation catalyst comprising the step of contacting with sulfuric acid for 100 to 100 ° C. for 1 hour to 1 day, and drying and drying the carrier treated with sulfuric acid at a high temperature of 500 ° C. to 1000 ° C. for 1 to 24 hours.
delete delete The method according to claim 1, wherein the carrier is selected from the group consisting of alumina, silica and mixed components thereof.
[6] The method of claim 1, wherein the auxiliary metal is one selected from the group consisting of tin, germanium, gallium, indium, zinc and manganese.
The method according to claim 1, wherein the alkali metal or alkaline earth metal is one selected from the group consisting of calcium, potassium, sodium, magnesium, lithium, strontium, barium, radium, and beryllium.
The method of claim 1, wherein the carrier has a specific surface area of 70 to 170 m 2 / g, and has a meso pore of 5 to 50 nm and a macro pore of 50 to 20 μm.
The method according to claim 1, wherein the catalyst has a volume density of 0.5 to 0.8 g / cc, and a strength of 15 to 70 N.
Dehydration comprising contacting a dehydrogenable hydrocarbon with a dehydrogenation catalyst modified by the method of any one of claims 1 and 4 to 8 under dehydrogenation conditions and obtaining a dehydrogenation product. Method of digestion.
10. The method of claim 9, wherein the dehydrogenation method comprises a mixture gas containing propane, hydrogen, and oxygen using a dehydrogenation catalyst modified by the method according to any one of claims 1 and 4 to 8. A dehydrogenation method characterized by producing propylene from propane by reacting in a gas phase under a reaction temperature of 600 to 1000 ° C, a high pressure of 0.1 to 5.0 kgf / cm 2, and a H2 / C3 ratio of 0 to 1.0.

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