KR20180079178A - Composite catalyst support, dehydrogenation catalysts and preparation method thereof - Google Patents

Abstract

The present invention relates to a composite catalyst carrier in which a cerium compound is doped on a carrier and content of a cerium compound is from 0.02 to 2.0 wt% based on 100 wt% of a composition of the carrier; a dehydrogenation catalyst; and a preparation method thereof. The dehydrogenation catalyst prepared using the composite catalyst carrier of the present invention can be operated under severe conditions so that efficiency of a dehydrogenation process is improved and stability and lifetime of the catalyst are increased, and a cost per process can be improved by increasing selectivity.

Description

TECHNICAL FIELD [0001] The present invention relates to a composite catalyst support, a dehydrogenation catalyst,

The present invention relates to a composite catalyst carrier, a dehydrogenation catalyst, and a production method thereof, and more particularly, to a composite catalyst carrier, a dehydrogenation catalyst, and a production method thereof, which can operate under harsh conditions, ≪ / RTI >

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.

DISCLOSURE Technical Problem The present invention has been made to solve the problems of the prior art as described above, and one object of the present invention is to provide a composite catalyst carrier which can maintain the stability of the catalyst under harsh conditions.

Another object of the present invention is to provide a dehydrogenation catalyst having excellent selectivity and conversion rate which can increase the productivity of products and reduce the unit cost.

It is still another object of the present invention 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 an aspect of the present invention,

Wherein the carrier is doped with a cerium compound and the content of the cerium compound is 0.02 to 2.0% by weight based on 100% by weight of the carrier composition.

The carrier may be alumina, silica, or a mixture thereof, preferably alumina (Al ₂ O ₃ ) having a crystallinity of 90% or more.

According to another aspect of the present invention,

1. A dehydrogenation catalyst having a carrier in which a transition metal active component, an auxiliary metal, an alkali metal or an alkaline earth metal is supported, wherein the carrier is doped with a cerium compound on a carrier and the content of the cerium compound is in the range of 0.02 - 2.0% by weight of the dehydrogenation catalyst.

According to another aspect of the present invention,

A cerium precursor solution is doped on the carrier and then dried and fired to obtain a composite catalyst carrier having a cerium content of 0.02 to 2.0% by weight, impregnating the resulting composite catalyst carrier with a transition metal active component and an auxiliary metal, The present invention relates to a process for producing a dehydrogenation catalyst.

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

According to the carrier and the hydrocarbon dehydrogenation catalyst containing the cerium compound doped on the carrier according to the present invention and having a cerium compound content of 0.02 to 2.0 wt% based on 100 wt% of the carrier composition, Operation is possible and 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.

According to the present invention, it is possible to improve the process unit level and increase the productivity by increasing the selectivity.

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

One aspect of the present invention relates to a composite catalyst carrier characterized in that a carrier is doped with a cerium compound and the content of the cerium compound is from 0.02 to 2.0% by weight based on 100% by weight of the carrier composition.

If the content of the cerium compound in the present invention is less than 0.02% by weight, the catalyst stability, lifetime and productivity increase effect can not be sufficiently obtained. On the contrary, when the cerium compound content exceeds 2.0% by weight, The catalytic metal is encapsulated and the active site is blocked to lower the activity of the catalyst.

The composite catalyst carrier of the present invention is a composite catalyst carrier capable of improving the selectivity, stability, and lifetime of the dehydrogenation catalyst by doping cerium onto the carrier.

In the composite catalyst carrier according to the present invention, alumina, silica and a mixed component thereof may be used as the carrier, preferably alumina. The crystallinity of the alumina is a factor for determining the degree of formation of coke, preferably 90% or more. In a preferred embodiment, the crystalline form of the carrier may be alumina in which two crystalline forms of theta or shea and gamma coexist.

As the cerium compound used in the present invention, at least one selected from the group consisting of cerium oxide, cerium hydroxide, cerium carbonate, cerium nitrate, cerium chloride, and a mixture thereof can be used.

A dehydrogenation catalyst according to another aspect of the present invention is a dehydrogenation catalyst having a carrier in which a transition metal active component, an auxiliary metal, an alkali metal or an alkaline earth metal is supported, wherein the carrier is doped with a cerium compound on a carrier, The content of the cerium compound is 0.02 to 2.0% by weight.

The dehydrogenation catalysts of the present invention provide improved performance that is different from conventional catalysts, namely, high hydrocarbon conversion and selectivity and performance stability, and resistance to improved caulking and ease of removal of coke as the dehydrogenation reaction conditions are severer. The catalyst of the present invention can be 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 kg _f / cm ² Etc.) is possible.

In the present invention, the transition metal active component may be at least one selected from the group consisting of platinum (Pt), palladium (Pd), nickel (Ni), cobalt (Co), ruthenium (Ru), rhenium (Re), rhodium (Rh), osmium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu) or zinc (Zn). These may be used singly or in the form of an alloy.

In the dehydrogenation catalyst of the present invention, the auxiliary metal may be at least one selected from the group consisting of magnesium, calcium, titanium, zirconium, vanadium, niobium, chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, iridium, At least one oxide or compound selected from the group consisting of zinc, boron, aluminum, gallium, indium, silicon, germanium, tin, phosphorus, antimony, bismuth, lanthanum, praseodymium, neodymium and samarium .

The cerium-doped dehydrogenation catalyst of the present invention can have a variety of uses. Thus, it can be used, for example, for dehydrogenation of hydrocarbons or other organic compounds, in particular for 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 a variety of other processes 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 uses platinum as an active ingredient.

In the method of the present invention, a cerium precursor solution is doped onto a support in the form of alumina, silica, or a mixture thereof, followed by dry calcination to obtain a composite catalyst carrier having a cerium content of 0.02 to 2.0 wt% The transition metal active component and the auxiliary metal are impregnated and then fired to prepare a dehydrogenation catalyst.

The carrier may be alumina, silica or a mixed carrier thereof. Preferably, the alumina having a crystallite of theta or co-existing with the crystallite of theta and gamma crystal phase may be alumina having a crystallinity of 90% or more.

The cerium precursor may be at least one selected from the group consisting of cerium chloride, cerium nitrate, cerium bromide, cerium oxide, cerium hydroxide, and cerium acetate precursor.

In preparing the cerium precursor, the cerium precursor is suspended in at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.

In the present invention, the transition metal active component refers to a substance capable of electronically, physically, and chemically influencing the dehydrogenation reaction of saturated hydrocarbons, and widely includes a carrier material and finally contains metal fine particles, oxides, chlorides, sulfides, hydrides Form, halogen salt, oxychloride, carrier material, or a combination of the other ingredients.

For example, as a raw material of the platinum component, chloroplatinic acid, ammonium chloroplatinic acid, bromoplatinic acid, platinum chloride hydrate, platinum carbonyl salt or acid, nitroplated platinum salt or acid may be used, preferably chloroplatinic acid (H ₂ PtCl ₆ ) is supported on the cerium-doped mixed catalyst carrier prepared above by a known impregnation method (adsorption method) together with hydrochloric acid.

The impregnation of the transition metal active component with the cerium-doped composite catalyst carrier may be carried out by using an incipient wetness method, or by 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 substance and the carrier, which are constituent elements, are simultaneously sedimented to obtain a powdery catalyst, the ratio of the active substance can be freely controlled and the mutual binding force between the active substance and the carrier is strengthened, It is possible to produce this excellent catalyst powder.

On the other hand, the impregnation of the solution containing the transition metal active ingredient is carried out by applying hydrochloric acid at a concentration of 30% of about 1% by weight of the carrier to the aqueous solution after final preparation of the carrier material, Lt; 0 > C for 0.5-60 hours. After drying at 100 to 700 ° C. for about 0.5 to 60 hours, the gas hourly space velocity (GHSV) is 100 to 5,000 at a temperature of 500 to 700 ° C. for 0.5 to 20 hours under a drying and firing process. hr < ^-1 > is advantageous for preventing condensation at high temperatures of the transition metal active ingredient metal microparticles and for removing excess residual chlorine.

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

In the dehydrogenation process according to the present invention, the mixed gas containing propane, hydrogen and oxygen is heated at a reaction temperature of 600 to 1000 ° C, preferably 600 to 800 ° C, at a reaction temperature of 0.1 The gas phase reaction is carried out under the conditions of an atmospheric pressure of 10 kgf / cm 2, an H2 / C3 ratio of 0 to 1.0, and a liquid space velocity of the mixed gas and the catalyst of 0.1 to 30 hr ^-1 , preferably 2 to 20 hr ^-1 Propylene is produced from propane by a dehydrogenation reaction.

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 obtained as the carrier used in the catalyst synthesis. After that, a solution of cerium nitrate (CeN ₃ O ₉ .6H ₂ O) was prepared by dissolving 0.4% hydrochloric acid (HCl,> 35%) based on the weight of carrier and 0.15% nitric acid and distilled water After stirring for 3 hours, the mixture was supported on a rotary evaporator at 80 DEG C and 25 rpm for 3 hours and then evaporated under reduced pressure. Thereafter, it was heat-treated at 1050 ° C for 2 hours in a firing furnace, and then dried at 230 ° C for 24 hours.

Subsequently, tin, platinum and potassium were sequentially carried on the Ce-doped alumina support. Tin chloride _{(SnCl 2,> 99%,} Sigma) with 0.3% carrier weight, hydrochloric acid (HCl,> 35%, JUNSEI ) 0.5%, nitric acid _{(HNO 3, 70%, Yakuri} ) 2 times with 0.1% carrier weight ratio After put in distilled water, 15 g of the carrier prepared above was added and carried.

 The supported liquid was dried using a rotary evaporator, stirred at 25 rpm for 3 hours at 80 ° C, and then rotated at 25 rpm for 1.5 hours under reduced pressure at 80 ° C. Then, it was baked at 600 ° C for 2 hours in a heating furnace and dried at 230 ° C for 24 hours.

Thereafter, 15 g of tin-supported alumina was carried in distilled water twice as much as the carrier in which 0.5% of hydrochloric acid, 0.5% of hydrochloric acid and 0.3% of nitric acid was dissolved in a platinum chloride (H ₂ PtCl ₆ .6H ₂ O, 99.95%, Aldrich) carrier . The supported liquid was dried using a rotary evaporator, stirred at 25 rpm for 3 hours at 80 ° C, and then rotated at 25 rpm for 1.5 hours under reduced pressure at 80 ° C. Then, it was baked at 550 캜 for 2 hours in a heating furnace and dried at 230 캜 for 24 hours.

Then, 15 g of alumina bearing tin and platinum was loaded in distilled water twice as much as the carrier in which 1% of potassium nitrate (KNO ₃ ,> 99%, Sigma) carrier and 0.5% of hydrochloric acid were dissolved. The supported liquid was dried using a rotary evaporator, stirred at 25 rpm for 3 hours at 80 ° C, and then rotated at 25 rpm for 1.5 hours under reduced pressure at 80 ° C. Then, it was baked at 600 ° C for 2 hours in a heating furnace and dried at 230 ° C for 24 hours.

Example  2 to 5

The procedure of Example 1 was repeated, except that the content of cerium compound was adjusted as shown in Table 1, and platinum-tin-potassium / alumina catalyst (Pt-Sn-K / Al 2 O 3) was prepared.

Comparative Example  One

A platinum-tin-potassium / alumina catalyst (Pt-Sn-K / Al ₂ O ₃ ) was prepared in the same manner as in Example 1 except that alumina without cerium doping was used in Example 1.

Comparative Example  2

Tin-potassium / alumina catalyst was prepared by sequentially carrying out tin, platinum and potassium on a cerium-doped alumina support in the same manner as in Example 1 except that the cerium compound content was adjusted to 2.1 wt% (Pt-Sn-K / Al ₂ O ₃ ).

Test 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 conducted. As shown in Table 1, 1.5 g of the catalyst prepared in Example 1 and Comparative Example 1 were filled in a quartz reactor having a volume of 7 ml, respectively, at different concentrations of the cerium compound, and then propane, hydrogen, And the dehydrogenation reaction was carried out respectively. At this time, the ratio of hydrogen to propane was fixed to 1: 1, the ratio of propane to oxygen was set to 30: 1, the reaction temperature was maintained at 650 ° C., the pressure was maintained at 1.5 absolute pressure and the liquid space velocity was maintained at 15 hr ^-1 . Respectively. The gas composition after the reaction was analyzed by gas chromatography connected to the reaction apparatus to determine the propane conversion, the propylene selectivity in the product after the reaction, and the propylene yield, and the results are shown in Table 1 below.

　
　 Performance ( wt% ) [Reaction time ( 1hr ) Performance ( wt% ) [Reaction time ( 5hr )
　 Cerium compound
content Conversion Rate Selectivity yield Conversion Rate Selectivity yield Comparative Example 1 0 wt%  37.5   93.1  34.9   35.1   94.4  33.1 Comparative Example 2 2.1 wt%  36.3   93.0  33.8   34.8   94.1  32.7 Example 1 0.02 wt%  38.0   93.2  35.4   35.8   94.8  33.9 Example 2 0.1 wt%  39.5   93.2  36.8   37.4   94.8  35.5 Example 3 0.5 wt%  39.7   93.5  37.1   37.7   95.2  35.9 Example 4 1.0 wt%  38.3   93.3  35.7   36.4   94.7  34.5 Example 5 2.0 wt%  37.8   93.2  35.2   35.8   94.5  33.8

As shown in Table 1, the cerium-doped catalyst according to the present invention had a propane conversion of 37.8% to 39.7%, a propylene selectivity of 93.2% to 93.5% and a propylene yield of 35.2 to 37.1% Catalyst activity. It was also confirmed that the catalyst activity was maintained high as the reaction time increased. On the other hand, the catalyst of Comparative Example 1 composed of only general alumina not doped with cerium, and the catalyst whose range of the cerium compound is out of the range of the present invention (Comparative Example 2), has higher stability than the catalyst of the present invention (Examples 1 to 5) Although similar, we can see that the initial activity is different.

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 will be obvious. Accordingly, the true scope of protection of the present invention should be defined in the appended claims and their equivalents.

Claims (17)

Wherein the carrier is doped with a cerium compound and the content of the cerium compound is from 0.02 to 2.0% by weight based on 100% by weight of the carrier composition.
The composite catalyst carrier according to claim 1, wherein the cerium compound is at least one selected from the group consisting of cerium oxide, cerium hydroxide, cerium carbonate, cerium nitrate, cerium chloride, and mixtures thereof.
The composite catalyst carrier according to claim 1, wherein the support is alumina (Al ₂ O ₃ ) in which a theta crystal phase or a theta crystal phase and a gamma crystal phase coexist with each other in which the theta crystal phase is 90% or more.
1. A dehydrogenation catalyst having a carrier in which a transition metal active component, an auxiliary metal, an alkali metal or an alkaline earth metal is supported, wherein the carrier is doped with a cerium compound on a carrier and the content of the cerium compound is in the range of 0.02 - 2.0% by weight based on the total weight of the hydrocarbon dehydrogenation catalyst.
The hydrocarbon dehydrogenation catalyst according to claim 1, wherein the cerium compound is at least one selected from the group consisting of cerium oxide, cerium hydroxide, cerium carbonate, cerium nitrate, cerium chloride, and a mixture thereof.
The hydrocarbon dehydrogenation catalyst according to claim 1, wherein the carrier is alumina (Al ₂ O ₃ ) in which a theta crystal phase or a theta crystal phase and a gamma crystal phase coexist with each other in which the theta crystal phase is 90% or more.
The method of claim 4, wherein the transition metal active component is selected from the group consisting of platinum (Pt), palladium (Pd), nickel (Ni), cobalt (Co), ruthenium (Ru), rhenium (Re), rhodium ), Titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn) .
The method of claim 4, wherein the auxiliary metal is selected from the group consisting of magnesium, calcium, titanium, zirconium, vanadium, niobium, chromium, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, iridium, nickel, 0.001 to 5.0% by weight of at least one oxide or compound selected from the group consisting of zinc, boron, aluminum, gallium, indium, silicon, germanium, tin, phosphorus, antimony, bismuth, lanthanum, praseodymium, neodymium, Wherein the hydrocarbon dehydrogenation catalyst is a hydrocarbon dehydrogenation catalyst.
The method of claim 4, wherein the catalyst is Pt-Sn-K / Ce- Al 2 O ₃ as the catalyst, a hydrocarbon dehydrogenation catalyst, characterized in that the content of the cerium compound in the alumina support is 0.02 to 2.0% by weight.
The hydrocarbon dehydrogenation catalyst according to claim 4, wherein the hydrocarbon is a C2 to C5 linear hydrocarbon.
A cerium precursor solution is doped on the carrier, followed by drying and firing to obtain a composite catalyst carrier having a cerium content of 0.02 to 2.0 wt%, impregnating the resulting composite catalyst carrier with a transition metal active component and an auxiliary metal, and then firing Wherein the dehydrogenation catalyst is produced by a method comprising the steps of:
The process for producing a dehydrogenation catalyst according to claim 11, wherein the carrier is alumina in which a theta crystal phase or a crystallite phase and a gamma crystal phase coexist, wherein alumina having 90% or more crystallinity of theta is used.
The process for producing a dehydrogenation catalyst according to claim 11, wherein the cerium precursor is at least one selected from cerium chloride, cerium nitrate, cerium bromide, cerium oxide, cerium hydroxide, and cerium acetate precursor .
14. The method of claim 13, wherein the cerium precursor is adsorbed on at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, hydrofluoric acid, and phosphoric acid.
12. The method according to claim 11, wherein the calcination of the support after cerium doping is performed at 700 ° C to 1200 ° C.
Contacting the dehydrogenatable hydrocarbon with the catalyst according to any one of claims 4 to 10 under dehydrogenation conditions and obtaining a dehydrogenation product.
The method of claim 16, wherein the mixed gas containing propane, hydrogen, and oxygen is heated at a reaction temperature of 600 to 1000 占 폚, 0.1 to 10 kgf / cm < 2 >, using a dehydrogenation catalyst of any one of claims 4 to 10, Wherein the propane is subjected to a gas phase reaction under a condition that the gas pressure and the H2 / C3 ratio are 0 to 1.0 and the liquid space velocity (LHSV) of the mixed gas and the catalyst is 0.1 to 30 hr ^-1 , Way.