KR100915840B1 - Cu/Co/SiO2-BASED COMPOSITE CATALYST USED FOR THE DEHYDROGENATION OF DIETHYLENEGLYCOL - Google Patents

Abstract

The present invention is a catalyst capable of continuously producing p-dioxanone from diethylene glycol for a long period of time with high selectivity and high yield by a gas phase process in a fixed bed reactor, and has excellent thermal stability, reaction activity and selectivity, and is represented by Chemical Formula 1 A copper / cobalt / silica based composite catalyst having a composition is provided:

[Formula 1]

CuO (a) CoO (b) M1 (c) M2 (d) M3 (e) SiO ₂ (f)

Where

M 1 represents an oxide of at least one alkaline earth metal selected from magnesium (Mg), calcium (Ca) and barium (Ba);

M2 represents an oxide of at least one metal selected from the group consisting of zinc (Zn), chromium (Cr), manganese (Mn), silver (Ag) and nickel (Ni) as a modifier component;

M 3 represents an oxide of at least one metal selected from the group consisting of tellurium (Te) and selenium (Se);

(a), (b), (c), (d) and (e) are percentages based on the weight of the catalyst, 50 to 87%, 2 to 10%, 0.01 to 5%, 0 to 2%, respectively. , 0.001 to 2% and 10 to 40%.

Diethylene glycol, p-dioxanone, copper / cobalt / silica complex catalyst

Description

Copper / Cobalt / Silica Composite Catalysts for Dehydrogenation of Diethylene Glycol {Cu / Co / SiO2-BASED COMPOSITE CATALYST USED FOR THE DEHYDROGENATION OF DIETHYLENEGLYCOL}

The present invention relates to a catalyst for the dehydrogenation cyclization reaction which is useful for continuously preparing p-dioxanone from diethylene glycol in a gas phase in a fixed bed reactor. Specifically, the present invention relates to p-dioxane from diethylene glycol under mild reaction conditions. The present invention relates to a copper / cobalt / silica based composite catalyst capable of synthesizing rice fields with high selectivity and high yield, and capable of stably synthesizing p-dioxanone over a long period of time without performing a reactivation operation of the catalyst.

p-dioxanone is used as a monomer of biodegradable polymers or morpholinone derivatives and other organic synthetic raw materials. In particular, p-dioxanone is useful as a polymerization raw material of poly (p-dioxanone) which is used as a monofilament type surgical suture having bioabsorption properties, and poly (p-dioxanone) is easily heated under heating. It is attracting attention as a highly recyclable material because it can be decomposed to recover quantitatively the monomer p-dioxanone.

There are several ways to prepare p-dioxanone, but diethyl on the catalyst

Producing directly from lene glycol is said to be the simplest and most economical. As a catalyst used to prepare p-dioxanone by dehydrogenation of diethylene glycol in the gas phase, US Pat. No. 2,900,395 discloses a copper-chromium catalyst system; U.S. Patent 3,119,840 discloses a copper / pumice based catalyst; U. S. Patent No. 5,310, 845 discloses a catalyst system in which alumina supports alkaline components such as copper, zinc and potassium; Japanese Patent Application Laid-Open No. 1998-120675 discloses a catalyst in which copper is supported on a carrier which defines a total amount of acid point where the acid strength (Ho) is stronger than 1.5; In addition, Japanese Patent Application Laid-Open No. 2000-351775 proposes a catalyst whose maximum particle diameter of supported copper is adjusted to 0.5 µm or less based on the catalyst according to Japanese Patent Application Laid-Open No. 1998-120675.

However, a common problem of the above known catalysts, including supported catalysts, is that the catalyst life is very short, for example, Japanese Patent Laid-Open No. 2000-351775 discloses diethylene glycol in a catalyst system in which copper, zinc and potassium components are supported on alumina. The initial conversion rate to p-dioxanone is 100%, but the conversion rate is 88% after 12 hours of reaction, and the conversion rate drops to 22% after 100 hours of continuous reaction. As an industrial catalyst for continuous process operation in a fixed bed reactor, There is a problem that is not suitable for use.

Such rapid conversion decreases because the catalyst is easily deactivated due to sintering of the catalytically active component, carbon caulking, or the like. The reaction for producing p-dioxanone by dehydrogenation of diethylene glycol in the gas phase is generally performed at 250 to 350 ° C., whereas the sintering temperature of the microcopper particles is about 180 ° C. (Refer to Topics in Catalysis 8 ( 1999) 259), deactivation by sintering of catalytically active particles whose main component is copper is inevitable.

In addition, p-dioxanone, which is a catalytic reaction product, is characterized by being easily polymerized in the presence of a compound having a hydroxy group such as diethylene glycol, which is a reactant (or unreacted product) (which serves as a polymerization initiator). Due to the formation of coke, there is a problem that the deterioration of the catalyst proceeds rapidly. To delay this, the reaction must be run under high conversion conditions, which is one cause of poor reaction selectivity.

On the other hand, a method of adding hydrogen gas together with diethylene glycol has been proposed for the purpose of alleviating carbon coking on a catalyst (US Patent No. 3,119,840, US Patent No. 5,310,945, Japanese Patent Application Laid-Open No. 1998-120675, Japanese Patent Application Laid-Open No. 2000-351775). number). However, U.S. Patent No. 5,310,945 illustrates the conversion rate reduction after 140 hours, and Japanese Patent Laid-Open No. 2000-351775 also illustrates the conversion rate reduction after 100 hours, and thus requires frequent reactivation operations during continuous process operation. The use of conventionally known dehydrogenated cyclization catalysts as an industrial catalyst for this is problematic.

On the other hand, the present inventors have developed an efficient catalyst having improved characteristics and a method for preparing such a catalyst, in order to compensate for such a problem, the production of p-dioxanone from "diethylene glycol capable of continuous operation in the gas phase catalyst process (Korean Patent No. 0558576) and "Method for preparing a copper / silica-based nanocomposite catalyst used for dehydrogenation of diethylene glycol" (Korean Patent Application No. 2006-34776). . However, although the catalyst according to the present invention has increased the utility as an industrial catalyst due to the dramatic improvement in activity and thermal stability, there is no room for improvement. For example, when copper, which is the main component of catalytic activity, was improved to cobalt or nickel, it was found that catalytic activity and reaction stability were more enhanced. However, 2-methoxyethanol and dimethoxysanol were synthesized in the process of synthesizing p-dioxanone from diethylene glycol. In the present invention, cobalt or nickel may be used as an optional ingredient because the production of the same by-products is increased and the selectivity of p-dioxanone is decreased, or the amount of use thereof is in the range of 0.001-5%, preferably 0.001-2%. Inevitably limited to, there was a lack in securing long-term reaction stability in spite of high activity and selectivity. In particular, the by-product of 2-methoxyethanol was more markedly increased when improved to the nickel component than the cobalt component.

Therefore, the inventors of the present invention have steadily studied to develop a more industrially useful catalyst for continuously producing p-dioxanone from diethylene glycol in a gas phase process in a fixed bed reactor. Increasing by-products of 2-methoxyethanol, which is inevitably generated when improving a cocatalyst with a significant amount of cobalt, can be significantly suppressed when adding a component such as tellurium (Te) or selenium (Se). Finally, the inventors have found that the activity and lifetime of the catalyst can be improved while maintaining the selectivity of p-dioxanone.

Accordingly, an object of the present invention is to provide a high-efficiency and high yield of dehydrogenation cyclization catalyst which can continuously produce p-dioxanone from diethylene glycol for a long time in a gas phase process in a fixed bed reactor. It is to provide a copper / cobalt / silica composite catalyst having excellent activity, selectivity and long-term reaction stability.

In order to achieve the above object, the present invention provides a catalyst having a composition represented by the following formula (1):

[Formula 1]

CuO (a) CoO (b) M1 (c) M2 (d) M3 (e) SiO ₂ (f)

Where

M 1 represents an oxide of at least one alkaline earth metal selected from magnesium (Mg), calcium (Ca) and barium (Ba);

M2 represents an oxide of at least one metal selected from the group consisting of zinc (Zn), chromium (Cr), manganese (Mn), silver (Ag) and nickel (Ni) as a modifier component;

M 3 represents an oxide of at least one metal selected from the group consisting of tellurium (Te) and selenium (Se);

(a), (b), (c), (d) and (e) are percentages based on the weight of the catalyst, 50 to 87%, 2 to 10%, 0.01 to 5%, 0 to 2%, respectively. , 0.001 to 2% and 10 to 40%.

As described above, the catalyst according to the present invention is useful for continuously preparing p-dioxanone from diethylene glycol by a gas phase process in a fixed-bed reactor, and the p-dioxanone from diethylene glycol under mild reaction conditions. It can be synthesized with high selectivity and high yield, and further improved utilization of P-dioxanone for long-term stability without performing catalyst reactivation operation due to improved catalyst performance and durability. .

Hereinafter, the present invention will be described in detail.

In the catalyst having the composition represented by Formula 1 according to the present invention, the copper component is a main component for driving the dehydrogenation reaction of the reactant diethylene glycol, and its content is 50 to 87% as a percentage based on the weight of the catalyst, preferably It consists of 60 to 85%. When the copper content is small, the activity per catalyst weight (or volume) is low, and when too much, the thermal stability of the fine copper particles cannot be secured. Silica (SiO ₂ ) can suppress sintering of copper particles by complexing nano-sized silica particles with nano-sized fine copper particles as a main component for enhancing thermal stability of the fine copper particles. Accordingly, the silica used should be used having a particle size of 4 to 50 nm, preferably 25 nm or less, the content is used in the range of 10 to 40% as a percentage based on the weight of the catalyst. When the silica content is less than this, there is no effect, and in many cases, the catalytic activity is low because the shielding effect of the active ingredient by the silica component is large.

The Cu-SiO ₂ catalyst in the above composition range by the silica component is useful as a dehydrogenation catalyst, but the product p-dioxanone is easily ring-opened polymerized as in the reaction of the present invention, and further, the reactant (unreacted product after the reaction) When ethylene glycol served as a polymerization initiator, the reaction characteristics showed a different aspect from that in the general catalytic reaction.

 In a typical catalytic reaction, the catalyst activity tends to be gradually deactivated according to the elapsed time of the reaction, but the reaction of the present invention shows a gradual decrease in activity up to a certain time and then a sharp decrease in conversion at some point. Indicates. This is due to the rapid deterioration of the catalytic activity due to the accelerated carbon adhesion of the polymer on the catalyst under conditions in which the catalyst is inactivated to some extent and does not sufficiently digest the diethylene glycol (that is, in a reaction atmosphere in which an excessive polymerization initiator is present). Judging. For these reasons, existing catalyst reactions have to be operated under high conversion conditions-preferably over 99% conversion-in order to maintain unreacted diethylene glycol at the lowest possible concentration. The life is also shortened.

 Therefore, in order to be utilized as an industrial catalyst for the gas phase reaction of a fixed-bed reactor, the catalyst activity is increased inherently, and the carbon deposition on the catalyst is suppressed by the polymer, or the fast depolymerization of the polymer in which the linking group is an ester group. There is a need for a technique that maintains the long-term reaction stability of the catalyst by not linking it through to carbon deposition.

Therefore, in the present invention, the above object can be achieved by improving the Cu—SiO ₂ based catalyst to an appropriate amount of cobalt (Co) component. As described above, the reaction stability of the catalyst was enhanced due to the improvement of the cobalt component and showed high activity resilience against the temporary decrease in conversion caused during the operation of the reaction process. The amount of the cobalt component added is 2 to 10%, preferably 2.5 to 8%, based on the weight of the catalyst, and the lower the amount of the cobalt component, the lower the effect of the cobalt component. Increasing activity lowered, and the selectivity decrease of p-dioxanone was also large.

On the other hand, the improvement by the cobalt component has the above-described advantages, but there is a problem that the selectivity to p-dioxanone is lowered, in particular, by-products of 2-methoxyethanol in the by-products is significantly increased. In the process of synthesizing p-dioxanone, it is 2-hydroxyethoxy acetaldehyde (HOCH ₂ CH ₂ OCH ₂ CHO) which is an intermediate, or 2-hydroxy, which is a successive product of p-dioxanone which is a product. This is due to the promotion of decarbonylation or decarboxylation reactions from ethoxy acetic acid (HOCH ₂ CH ₂ OCH ₂ CO ₂ H), and by-products of this 2-methoxyethanol are tellurium (Te) or selenium ( It could be alleviated by modification by Se) component. The addition amount of the tellurium (Te) or selenium (Se) component is 0.001 to 2%, preferably 0.005 to 0.5% as a percentage based on the weight of the catalyst. The degradation is a big feature. Since the tellurium and selenium are easily alloyed with many metals, most of the metal catalysts are catalyst poisons, and the catalysts of the present invention need to be extremely limited in order not to degrade the catalytic activity. there was.

The effect of the cobalt component is apparent even when the nickel (Ni) component is improved, but byproduct modification of 2-methoxyethanol cannot be suppressed only by component modifications such as tellurium and selenium without lowering the catalytic activity. Therefore, the nickel component is one of the optional components of M2 in the formula (1) according to the present invention, and other, such as zinc (Zn), chromium (Cr), manganese (Mn) and silver (Ag), etc. to improve the characteristics of copper (Cu) Although well known for the materials, the catalyst of the present invention is preferably in the range limited to 0 to 2% as a percentage based on the weight of the catalyst. When used in excess of 2%, the catalytic activity and long-term reaction stability were lowered.

M1 component in the formula (1) of the present invention is one or more alkaline earth metal oxide selected from magnesium (Mg), calcium (Ca) and barium (Ba), by controlling the acid and base properties of the catalyst to suppress side reactions and carbon deposition As a component, the amount used is preferably 0.01 to 5%, preferably 0.05 to 3%, as a percentage based on the weight of the catalyst. If the amount of use is smaller than this, it is not effective, and in the case of excessive use, the decrease in catalytic activity is large, which is not preferable.

The catalyst of the present invention of Chemical Formula 1 prepared under the above composition and composition ratio showed high activity, selectivity, and reaction stability, and thus showed a result of improving catalyst life, thereby increasing utility as an industrial catalyst. there was.

Catalysts useful for the dehydrogenation of diethylene glycol having a composition represented by Formula 1 according to the present invention can be prepared by any method under the condition that the particle size of the copper oxide which is the main component of the catalyst is controlled to 50 nm or less. In order to achieve the object of the present invention, homogeneity between components of multiple components must be maintained, and in particular, it is preferable to prepare by coprecipitation because uniform complexing of copper particles and silica particles is important.

Copper, cobalt, M2 oxide and silica components in the formula (1) is co-precipitated in the aqueous solution (A, B) containing each component, using a sodium hydroxide aqueous solution as a co-precipitation, and the resulting slurry is hydrothermally aged and washed Is manufactured. Here, the copper, cobalt and M2 components may use water-soluble salts such as nitrates, hydrochlorides and sulfates, but preferably nitrates (aqueous solution A), and silica is used colloidal silica stabilized with sodium ions (aqueous solution B). ). At this time, the copper oxide crystals are prepared in the shape of a rod, and a shape adjusting agent may be used to control the particle size or shape.

Since the M1 and M3 component oxides in Formula 1 have solubility in water, the M1 and M3 component aqueous solutions are mixed in a slurry containing copper, cobalt, M2 oxide, and silica components, which are not simultaneously prepared by coprecipitation. And spray drying. In this case, the M1 component may be nitrate or acetate, but preferably acetate is used, and the M3 component is an ammonium salt or an acid compound [eg, ammonium tellurate, ammonium selenate, terurium acid, selenious acid). Etc.].

The dried catalyst powder can be molded by conventional molding methods-extrusion method, tableting method, and supporting method, but the catalyst type is formed into a hollow cylinder type because it is preferable to minimize the pressure load of the catalyst layer due to the reaction characteristics. Good to do. Thereafter, the formed catalyst is calcined at 300 to 1000 ° C, preferably 400 to 900 ° C under an air atmosphere.

 Basically, the catalyst of the present invention can be prepared according to the method described in Korean Patent No. 0558576 and Korean Patent Application No. 2006-34776.

The catalyst according to the present invention can be usefully used to produce p-dioxanone by dehydrogenating diethylene glycol in gaseous state under the flow of nitrogen gas or hydrogen-containing nitrogen gas.

The reaction is performed by first charging the catalyst in the oxide state of Formula 1 to a fixed bed reactor, and then activating at 150 ° C. to 300 ° C. for about 1 to 20 hours using a hydrogen gas or a hydrogen-containing gas. Performing a dehydrogenation cyclization reaction of diethylene glycol under the prepared catalyst, and p-dioxanone can be prepared by such a reaction. At this time, the diethylene glycol is supplied to the reactor in a gaseous state in the range of LHSV (liquid hourly space velocity = liquid space velocity) of 0.05 to 5.0 hr ^-1 , preferably 0.1 to 2.0 hr ^-1 , and the dehydrogenation cyclization reaction is 200 to 400 ° C., preferably 250 to 350 ° C., and under pressure conditions ranging from 0 (atmospheric pressure) to 5 atmospheres, preferably 0 (atmospheric pressure) to 1 atmosphere.

In the above reaction, the dehydrogenation reaction of diethylene glycol having a high boiling point is endothermic and the product p-dioxanone has a polymerization property, and when the reaction pressure is high, the reactant and the product are condensed in the catalyst layer to promote the formation of the polymer. Deactivation of may proceed. Therefore, the reaction pressure is advantageously as low as possible at 1 atm (absolute pressure) or less. In addition, it is preferable to include hydrogen in nitrogen used as a carrier gas to suppress carbon deposition on the catalyst. However, when the hydrogen concentration is high, the product of p-dioxanone, which is a reverse reaction in the presence of a catalyst, is a hydrogenolysis reaction (ie, hydrogenation of p-dioxanone) may proceed, resulting in lower conversion and lower reaction selectivity. Therefore, the hydrogen content of the hydrogen-containing nitrogen gas is suitably 0.1 to 50% by volume, preferably 0.1 to 30% by volume of the carrier gas used.

Hereinafter, the present invention will be described in detail by way of examples.

However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited to the following examples.

Hereinafter, the content of each component of the catalyst means "% by weight" based on the total weight of the catalyst.

EXAMPLE

Example 1

CuO (72.8) CoO (5.2) CaO (0.23) MgO (0.25) ZnO (0.2) TeO ₂ (0.02) SiO ₂ (21.3)

<Catalyst preparation>

3,500 g of copper nitrate [Cu (NO ₃ ) ₂ · 3H ₂ O] in 10 L of deionized water, 319.7 g of cobalt nitrate [Co (NO ₃ ) ₂ · 6H ₂ O], zinc nitrate [Zn (NO ₃ ) ₂ · 6H ₂ O] Dissolve 11.57 g and prepare solution A. Sodium hydroxide solution was added to 4 L of deionized water to adjust the pH to 9.2. Prepare Solution B in which 965.6 g of colloidal silica Ludox SM-30 (manufactured by Grace Davison) was prepared, and 1,250 g of sodium hydroxide was dissolved in 10 L of deionized water. Prepare. 47.5 g of Aerosil 300 (manufactured by Degussa) was dispersed in 2L of deionized water using a homogenizer in a 50L reactor equipped with a stirrer, and 8L of deionized water was further added thereto, followed by stirring. Simultaneously adding to the coprecipitation process was carried out at 20 ℃ or less. At this time, the pH of the solution C was adjusted to adjust the pH, and after completion of coprecipitation, the final pH of the slurry solution was adjusted to 9.3. 300 g of 0.5% by weight polyvinylpyrrolidone aqueous solution having an average molecular weight of 10,000 was added thereto, and hydrothermally aged at 85 ° C. for 6 hours, confirming that the pH of the resulting solution was 7, and the resulting slurry solution was sufficiently washed with deionized water. After filtering, the precipitate was recovered.

The precipitate obtained was dispersed in deionized water, followed by 11.44 g of calcium acetate [Ca (OAc) ₂ .H ₂ O], 21.06 g of magnesium acetate [Mg (OAc) ₂ .4H ₂ O], and tellurium [Te ( OH) ₆ ] 0.46 g of the aqueous solution dissolved in deionized water was mixed and then dried first by spray drying.

 The dried powder was dried at 120 ° C. for 12 hours, first calcined at 300 ° C., and 5% by weight of graphite powder was mixed with a tableting aid and hollow cylinder type (OD ==) in an automatic tablet press. 8.2 mm, H = 3.2 mm, internal diameter = 3 mm) and calcined at 650 ° C. for 6 hours under air flow to obtain an oxide catalyst.

The copper oxide particle size of the catalyst was 5 nm as measured by the XRD line broadening method.

<Reaction>

240 ml of the catalyst was charged in a 1 × X120 cm tubular reactor in which the fruit was circulated outside the reactor, and slowly heated up to 300 ° C. while flowing 5% H ₂ containing N ₂ gas to activate the catalyst. Subsequently, diethylene glycol was vaporized in a vaporizer under a mixed gas flow of 20% by volume hydrogen and 80% by volume nitrogen (LHSV = 0.5hr ^-1 ), and the operation was started at a reaction temperature of 275 ° C and an atmospheric pressure of 99%. It confirmed that the above conversion rate was shown. After that, the operation was performed under the conditions showing the conversion rate of 98% or more, and when the conversion rate was decreased, the dehydrogenation cyclization reaction was performed while maintaining the other conditions and increasing the reaction temperature. The product was analyzed by gas chromatography.

 The reaction results are shown in Table 1.

Comparative Example 1

CuO (72.8) CoO (1.2) CaO (0.25) MgO (0.25) ZnO (0.3) SiO ₂ (25.2)

Prepare Solution A by dissolving 3,500 g of copper nitrate, 73.8 g of cobalt nitrate, and 17.35 g of zinc nitrate in 10 L of deionized water. Sodium hydroxide solution was added to 4 L of deionized water to adjust the pH to 9.2, and Solution B was prepared by dissolving 1,065.8 g of colloidal silica Ludox SM-30. Prepare solution C by dissolving 1,184 g of sodium hydroxide in 10 L of deionized water. To a 50L reactor equipped with a stirrer, 79.1g of Aerosil 300 was dispersed in 2L of deionized water using a homogenizer, and 8L of deionized water was further added thereto, followed by stirring and simultaneously adding the solutions A, B, and C to 20 ° C. Coprecipitation process was performed below. The subsequent procedure was performed in the same manner as in Example 1.

 Copper oxide particle size was 4.7 nm in the prepared catalyst.

 The catalyst was charged to a 1 "x 120 cm reactor and the catalyst was activated in the same manner as in Example 1, followed by dehydrogenation of diethylene glycol.

 The reaction results are shown in Table 1.

division Reaction time (hr) Reaction temperature (℃) % Conversion p-dioxanone selectivity (%) Example 1 500 275 99.5 96.0 1,000 275 99.5 96.1 2,000 277 99.6 96.6 2,500 282 99.6 97.2 3,500 290 99.0 95.7 Comparative Example 1 500 280 99.5 95.8 1,000 285 99.7 96.0 1,500 285 99.6 96.7 2,200 290 99.3 97.0 2,400 295 98.2 95.8 2,600 295 94.9 95.0

As shown in Table 1, cobalt in the copper-silica component Increasing the component content and modifying the tellurium component showed a marked improvement in long-term reaction stability. During operation, the selectivity of 2-methoxyethanol was 0.5 ~ 0.95% at the beginning of the reaction (less than 500 hours), after which the selectivity was less than 0.5%.

Comparative Example 2

A catalyst of CuO (72.8) CoO (5.2) CaO (0.25MgO (0.25) ZnO (001) SiO ₂ (21.3) without the tellurium component in the composition catalyst of Example 1 was prepared in the same manner based on 50 g of copper nitrate The powder after primary baking was shape | molded by the press, it was crushed and screened by -20-+40 mesh, and it baked at 650 degreeC.

1.0 g of the catalyst was charged in a micro reactor, activated, and diethylin glycol was flowed at a rate of 0.02 ml / min (WHSV = 1.2 hr ^-1 ) under a flow of 7 ml / min hydrogen and ²⁸ ml / min nitrogen. Reaction was performed at 270 degreeC and normal pressure, sending. The result of continuous reaction for 150 hours was 99.5% conversion, 94.2% p-dioxanone selectivity, and 2.8% selectivity of 2-methoxyethanol.

Example 2

The catalyst of Example 1 was crushed and screened to a size of -20 to +40 mesh, 1.0 g of this catalyst was charged to a microreactor, and the reaction was carried out under the same conditions as in Comparative Example 2. After 125 hours, the conversion was 99.3%, 96.4% selectivity, and 0.7% selectivity of 2-methoxyethanol. Thereafter, over night, an operation trouble occurred in which the outlet of the reactor was clogged by the coagulation of the product p-dioxanone having a melting point of about 24 ° C. Immediately after the operation trouble was solved, the reactivity of the catalyst under the same conditions showed a conversion of 59.3% and a selectivity of 86.9%. After 24 hours in the continuous reaction, the catalytic reactivity showed 96.9% conversion and 97.8% selectivity.

 The above results show that the catalyst modified with an appropriate amount of cobalt component has excellent activity resilience and reaction stability against temporary deactivation of the catalyst due to abnormal operation.

Example 3

CuO (73.8) CoO (3.5) CaO (0.23) MgO (0.25) Ag ₂ O (0.2) SeO ₂ (0.02) SiO ₂ (22)

Slurry of the composition catalyst was prepared in the same manner as in Example 1.

A catalyst composed of silver (manufactured using silver nitrate) as the M 2 component and selenium (manufactured using selenium acid) as the M 3 component was prepared based on 50 g of copper nitrate. Calcium, magnesium and selenium components were prepared by the slurry mixing method, and the subsequent workup and reaction were carried out in the same manner as in Comparative Example 2. The catalyst reacted at 270 ° C. for 120 hours had a conversion of 99.7% and a selectivity of 96.8%, and a selectivity of 2-methoxyethanol was 0.65%.

Claims (7)

A catalyst for dehydrogenation of diethylene glycol represented by Chemical Formula 1 below: [Formula 1] CuO (a) CoO (b) M1 (c) M2 (d) M3 (e) SiO ₂ (f), Where M 1 represents an oxide of at least one alkaline earth metal selected from magnesium (Mg), calcium (Ca) and barium (Ba); M2 represents an oxide of at least one metal selected from the group consisting of zinc (Zn), chromium (Cr), manganese (Mn), silver (Ag) and nickel (Ni) as a modifier component; M 3 represents an oxide of at least one metal selected from the group consisting of tellurium (Te) and selenium (Se); (a), (b), (c), (d) and (e) are percentages based on the weight of the catalyst, 50 to 87%, 2 to 10%, 0.01 to 5%, 0 to 2%, respectively. , 0.001 to 2% and 10 to 40%. The catalyst according to claim 1, wherein the dehydrogenation-ring reaction is carried out in a gas phase process in a fixed bed reactor. The catalyst according to claim 1, wherein the copper oxide (a) is contained in the range of 60 to 85% by weight of the total weight of the catalyst. The catalyst according to claim 1, which contains cobalt oxide (b) in the range of 2.5 to 8% by weight. The catalyst according to claim 1, wherein the M1 component is contained in the range of 0.05 to 3% by weight of the total weight of the catalyst. The catalyst according to claim 1, wherein the M3 component is contained in the range of 0.005 to 0.5% by weight of the total weight of the catalyst. The catalyst according to any one of claims 1 to 6, wherein the catalyst is shaped into a tubular or hollow cylinder type.