KR101085054B1 - Palladium catalyst supported on alumina xerogel support, preparation thereof and ?-butyrolactone production method by hydrogenation of succinic acid using said catalyst - Google Patents

Abstract

The present invention relates to a palladium supported catalyst supported on an alumina control gel, a method for preparing the same, and a method for preparing gamma butyrolactone by hydrogenation of succinic acid using the catalyst, and more specifically, to gamma butyrolactone from succinic acid. In the supported catalyst for preparing, the supported catalyst is an alumina controlled gel (Xerogel) carrier, characterized in that the Pd metal catalyst is supported in a ratio of 1 to 20 parts by weight based on 100 parts by weight of the alumina controlled gel (Xerogel) carrier The present invention relates to a palladium catalyst supported on the same, a method for preparing the same, and a method for preparing gamma butyrolactone by hydrogenation of succinic acid using the catalyst, wherein the succinic acid and succinic anhydride are used in a liquid phase using the catalyst of the present invention. When the hydrogenation of anhydride is carried out, the yield of gamma butyrolactone is higher than that of the conventional commercial alumina supported catalyst. Can, and a regenerated acid by biorefinery process (hereinafter referred to as waste acid) can be prepared butyrolactone without the need for separate purification.

Gamma Butyrolactone, Succinic Acid, Alumina Control Rose, Hydrogenation

Description

Palladium supported catalyst supported on an alumina control gel, a method for preparing the same, and a method for preparing gamma butyrolactone by hydrogenation of succinic acid using the catalyst HYDROGENATION OF SUCCINIC ACID USING SAID CATALYST}

The present invention relates to a palladium supported catalyst supported on an alumina control gel, a method for preparing the same, and a method for preparing gamma butyrolactone by hydrogenation of succinic acid using the catalyst, and more specifically, to gamma butyrolactone from succinic acid. In the supported catalyst for preparing, the supported catalyst is an alumina controlled gel (Xerogel) carrier, characterized in that the Pd metal catalyst is supported in a ratio of 1 to 20 parts by weight based on 100 parts by weight of the alumina controlled gel (Xerogel) carrier The present invention relates to a supported palladium catalyst, a method for producing the same, and a method for producing gamma butyrolactone by hydrogenation of succinic acid using the catalyst.

Succinic acid is attracting attention as a platform compound capable of producing various useful C4 compounds. In particular, succinic acid is a future energy material that can be regenerated in biorefining process of wood waste biomass. Succinic acid can be converted to gamma-butyrolactone through hydrogenation, and gamma-butyrolactone is used in many applications in the pharmaceutical industry, including reaction intermediates, pesticide manufacturing, photochemical etching, capacitor electrolytes and paint solvents. Currently, the market is steadily increasing. Figure 1 shows the reaction paths of gamma butyrolactone production by raw materials known so far, as a process for producing gamma butyrolactone, two commercialized processes such as Reppe Process and Davy McKee Process using copper-based catalysts so far This is known. The Reppe Process, which produces gamma butyrolactone by dehydrogenation of 1,4-butanediol, is the first commercially available process for producing gamma butyrolactone, which is traditionally used in the US and Europe. Although it is a process that is being processed, the economic situation is losing due to the sharp increase in the price of 1,4-butanediol as a raw material, and there is a limitation that 1,4-butanediol is manufactured from formaldehyde, which is a hazardous substance. Since maleic anhydride can be produced at low cost through partial oxidation of n-butane, Davy McKee Process for producing gamma butyrolactone through hydrogenation of maleic anhydride as a raw material in Japan etc. Although it has been commercialized, this also has problems such as increased raw material cost, high temperature and high pressure reaction conditions, environmental pollution due to the generation of various by-products (furan tetrahydrogen, propionic acid, propanol, butanol, butyric acid, etc.).

These problems are due to the fact that the raw materials of the gamma butyrolactone manufacturing process are petrochemical products, and there is an urgent need to develop eco-friendly alternative processes and technologies due to global environmental regulations and rising prices due to oil price fluctuations. Accordingly, succinic acid is attracting attention as a platform compound capable of producing gamma butyrolactone, and as an intermediate that can replace maleic anhydride, the production price has been improved by developing new fermentation strains and developing fermentation process and recovery technology. In addition, prices have been continuously lowered, and price competition with maleic anhydride produced from butane is attained.However, research on the manufacturing technology of gamma butyrolactone based on succinic acid has been only partially conducted as an ancillary to the study of maleic anhydride. The result is inadequate.

The production of gamma butyrolactone based on succinic acid has been studied in part by gas phase flow reaction and batch reaction reaction. Zimmermann, K. Brenner, H-J. Scheiper, W. Sauer, H. Hartmann, US Pat. No. 5,319,111 / J.-A. T. Schwartz, US Patent No. 5,478,952 / G.L. Castiglioni, C. Fumagalli, U. S. Patent No. 6,492, 535] is substantially difficult to apply to the actual commercialization process due to the effects of high viscosity and boiling point of succinic acid or succinic anhydride.

Studies on the batch reaction of succinic acid have proceeded similarly to the hydrogenation of maleic anhydride. Examples of hydrogenation of succinic acid from DuPont using ruthenium-cobalt catalyst [R.M. Deshpande, V.V. Buwa, C.V. Rode, R. V. Chaudhari, P.L. Mills, Catal. Commun., Vol. 3, p. 269 (2002), requires high reaction temperatures and pressures of 250 ° C. and more than 100 bar, requiring sophisticated and expensive installations for practical applications of this process. Example of Hydrogenation of Succinic Anhydride with Palladium Catalysts Studyed in Japan [T. Fuchikami, N. Wakasa, D-H. He, T. Miyake, T. Okada, A. Fujimura, H. Sasakibara, Y. Kanou, T. Saito, U.S. Patent No. 5,502, 217] have achieved a high yield of gamma butyrolactone, but a long reaction time of 16 hours. Required.

On the other hand, the hydrogenation reaction of succinic anhydride using copper-chromium catalyst [U. Herrmann, G. Emig, Ind. Eng. Chem. Res., Vol. 36, p. 2885 (1997), achieved high yields of gamma butyrolactone under mild conditions of 240 ° C and 5 MPa. However, due to heavy metal hazards, the use of chromium catalysts has recently been restricted in Europe and elsewhere. There is a problem that it is difficult to apply to the commercialization process.

As such, the catalysts and conversion processes used in the commercialization process for producing gamma butyrolactone from succinic acid, which can replace maleic anhydride, are very insignificant, so that a high yield of gamma butyrolactone can be obtained under suitable process conditions. Developing catalysts and process systems has important technical and economic significance. In addition, in order to reduce the cost of separation and purification, which accounts for more than 60% of the manufacturing cost of waste succinic acid recycled in the biorefinery process, by-products such as acetic acid without separating and purifying the by-products of the waste succinic acid production and fermentation process separately. The study of producing gamma butyrolactone by direct hydrogenation of succinic acid containing the product also has significant economic significance.

Accordingly, the present inventors have focused their research on excellent carriers capable of maximizing the activity of metal catalyst components as a result of research efforts to overcome the problems of the prior art and to improve economics. The present inventors have already developed a medium pore alumina control gel carrier (Korean Patent No. 919,104 (2009) / Korean Patent No. 833,790 (2008)) having a large specific surface area and excellent physical and chemical properties. As a result, the metal catalyst supported on the alumina control gel has a different surface structure and metal-carrier interaction than the metal catalyst supported on a commercially available carrier, resulting in high dispersion of the catalyst. In addition, the alumina control gel support is not high in crystallinity compared to commercially available alumina supports, not only has a thermally / chemically stable structure, but also has surface properties with medium pores. In addition, the manufacturing process is simpler than that of the alumina airgel carrier manufactured in the supercritical super-dryer, and thus the economic value is high because it is more efficient in mass production of the carrier.

Accordingly, an object of the present invention is to provide a metal catalyst supported in a medium pore alumina control rogel carrier in an optimal combination, and the advantages of the medium pore alumina control rogel carrier having high chemical stability, strong durability and excellent physical properties are utilized. It is to provide a highly dispersed metal supported catalyst for producing gamma butyrolactone and a method for producing the same.

Another object of the present invention is to provide a method for producing a high efficiency batch type gamma butyrolactone by applying the developed supported catalyst to the conversion reaction of waste succinic acid containing impurities into gamma butyrolactone.

In order to achieve the above technical problem, the present invention provides a supported catalyst for preparing gamma butyrolactone from succinic acid, wherein the supported catalyst is 1 to 20 Pd metal catalyst based on 100 parts by weight of an alumina controlled Xerogel carrier. Provided is a palladium catalyst supported on an alumina control gel (Xerogel) carrier, characterized in that supported by the ratio of parts by weight.

In addition, the present invention is an alumina control gel (Xerogel), characterized in that the average pore size of the alumina control gel carrier ranges from 2 nm to 15 nm and the specific surface area is in the range of 100 m ² / g to 300 m ² / g. It provides a palladium catalyst supported on a carrier.

In addition, the present invention comprises the steps of dissolving an aluminum precursor in an alcohol solvent; Ii) forming a sol by performing partial hydration and condensation reaction of the aluminum precursor dissolved in the solution with a mixed solution of water, acid and alcohol solvent; Iii) performing a further hydration and condensation reaction of the sol to form a gel; Iii) aging and drying the gel; Iii) heat-treating the gel at a temperature of 700 to 1,000 ° C. to produce an alumina control rosol carrier; Iii) mixing the alumina control gel carrier and the Pd metal precursor in a dispersion medium and uniformly mixing the same, and supporting the Pd metal catalyst at a ratio of 1 to 20 parts by weight based on 100 parts by weight of the alumina control gel (Xerogel) carrier; Iii) It provides a method for producing a palladium catalyst supported on an alumina control gel (Xerogel) carrier comprising the step of drying and heat treatment the supported catalyst.

In addition, in order to achieve another object of the present invention, the present invention provides a succinic acid or succinic anhydride in the presence of a palladium catalyst supported on an alumina controlled Xerogel carrier in a temperature range of 150 to 400 ℃ and 30 to 200 bar It provides a method for producing gamma butyrolactone by hydrogenation of succinic acid comprising the step of reacting under pressure.

In the present invention, the succinic acid is mixed with acetic acid and succinic acid in the weight ratio range of 1: 5 to 1:10, gamma butyrolactone by the hydrogenation reaction of succinic acid, characterized in that the waste succinic acid is not subjected to separation and purification It provides a manufacturing method.

The palladium supported catalyst supported on the alumina control gel according to the present invention has a higher yield of gamma butyrolactone than the conventional commercially supported alumina supported catalyst when the hydrogenation of succinic acid and succinic anhydride is carried out in the liquid phase. It can be achieved, and gamma butyrolactone can be produced without undergoing a separate purification process of succinic acid (hereinafter referred to as waste succinic acid) regenerated by the biorefinery process.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The palladium-supported catalyst (hereinafter, also referred to as 'palladium / alumina-controlled gel catalyst' in short form) supported on the alumina control gel of the present invention is a simple synthesis with high economic feasibility of an alumina xerogel having medium pores. It is a palladium / alumina-controlled gel catalyst having palladium as an active metal supported on the alumina-controlled gel support, which is usefully improved as a carrier for hydrogenation dehydration by allowing the gamma alumina phase to appear at an appropriate firing temperature after preparation by the route. . Such palladium / alumina controlled gelling catalysts are simpler to manufacture than conventional composite oxide carriers when applied to succinic acid gamma butyrolactone conversion reactions, and are highly dispersed in active metal catalysts to produce gamma butyrolactone. Particularly excellent effect. Until now, there have been no reports of succinic acid gamma butyrolactone conversion reaction using a single metal oxide carrier such as the palladium / alumina controlled gel catalyst of the present invention. Moreover, the catalyst is used to regenerate the biorefinery process. There has also been no case reviewing the productivity of gamma butyrolactone at different temperatures for hydrogenation of waste succinic acid.

In the palladium / alumina control gel catalyst of the present invention, after the alumina control gel support having a pore size in the range of 2 to 15 nm is calcined at a temperature in the range of 700 ° C. to 1000 ° C., preferably 800 ° C. to 900 ° C., the palladium It is supported catalyst. In order for the alumina control gel support to have an excellent effect as a catalyst support, the alumina control gel was calcined in the range of 800 ° C. to 900 ° C., so that the 2θ characteristic peaks of the X-ray diffraction spectrum were 35 ^O to 38 ^O , 45 ^O to 47 ^O , 66 ^O to 68 ^A gamma alumina phase appearing in the range of ^O should be formed. If the firing temperature of the alumina control gel support is less than 700 ° C., the amorphous alumina phase does not show a strong acid characteristic, and the crystallinity is also increased even if it exceeds 1000 ° C. This strong alpha alumina phase exhibits a problem of weakening acid properties, so it is preferable to maintain the above range to form a gamma alumina phase.

Looking at the method for producing a palladium / alumina control gel catalyst according to the present invention in more detail as follows. First, the aluminum precursor is dissolved in an alcohol solvent heated to 50 ° C. to 100 ° C., and then partially hydrated by adding water and an acid to prepare an alumina sol. The aluminum precursor is generally used in the art, but is not particularly limited, and aluminum alkoxide, aluminum acetyl acetate, and alumina sol having an alkoxy group having 1 to 5 carbon atoms may be used. The alcohol solvent is generally used in the art and is not particularly limited. Specifically, alcohols having 1 to 6 carbon atoms may be used. The solvent is used in the range of 1.5 to 2.5 with respect to the aluminum precursor. If the amount is less than 1.5, the solvent is not sufficient to disperse the aluminum precursor. If the solvent exceeds 2.5, the solvent may not be formed smoothly. It is desirable to maintain.

The water and acid used in the reaction are used in the range of 0.3 to 0.5 weight ratio and 0.04 to 0.05 weight ratio, respectively, with respect to the added aluminum, and the amount of the acid and the acid used are appropriate amounts for partially hydrating to prepare an alumina sol. Next, after cooling the prepared alumina sol, water is added to prepare an alumina gel. At this time, the cooling is preferably maintained at room temperature, that is, about 10 ℃ to 30 ℃.

The water is used in the weight ratio range of 1.0 to 1.2 with respect to the added alumina. If the amount is less than 1.0, condensation of the structure occurs during gel formation, and the solvent is evaporated in the pores during the aging process. In this case, it is preferable to maintain the above range because gel formation proceeds too fast to obtain a uniform gel.

Next, the prepared alumina gel is aged and dried. At this time, aging is carried out at room temperature for 2 to 8 days, preferably 3 to 7 days. In addition, drying after aging is dried for 24 to 48 hours at 70 ℃ to 100 ℃, preferably 70 ℃ to 90 ℃.

Next, the dried alumina gel is calcined at a temperature in the range of 700 ° C to 1000 ° C, preferably 800 ° C to 900 ° C, to prepare an alumina control gel.

Next, after impregnating the palladium precursor in the range of 1 to 20 parts by weight based on 100 parts by weight of the prepared alumina control gel, it is dried at 20 ° C. to 200 ° C., preferably 100 ° C. to 150 ° C. for at least 12 hours. After removing all, the mixture was calcined at 300 ° C. to 700 ° C., preferably at 400 ° C. to 500 ° C. for at least 3 hours, to prepare a palladium / alumina controlled gel catalyst. In the present invention, a basic material used as a palladium precursor for preparing a catalyst is palladium nitrate, palladium chloride, palladium acetate, which is well dissolved in water and well decomposed into a metal form by heat reduction. , Amine complex and the like may be used, and preferably, palladium nitrate, which is easily heat-reduced at low temperature, may be used. If the amount of the supported palladium precursor is less than 1 part by weight based on 100 parts by weight of the alumina control gel, the amount of palladium is small to show the required degree of hydrogenation activity. It is preferable to maintain the above range because the activity of the reaction is lowered and the economical efficiency is lowered due to the high price of the palladium precursor.

On the other hand, the present invention provides a method for producing gamma butyrolactone by hydrogenation of succinic acid, characterized in that the hydrogenation reaction is carried out in the presence of the palladium / alumina control rogel supported catalyst. . The process is generally carried out in a batch reaction at a high temperature and pressure range, in particular at a temperature of 150 ℃ to 400 ℃ and a pressure range of 30 bar to 200 bar, the main process conditions are 300 ℃, 100 bar or less It is economically desirable to carry out at a mild temperature and pressure range of. Therefore, in the present invention, the hydrogenation reaction of the waste succinic acid was carried out in the temperature range of 220 ℃ to 260 ℃ and 60 bar pressure, the reaction is possible at a temperature of 200 ℃ or less and a pressure of 40 bar or less, but the reaction rate is slow and high conversion rate It takes a long time to get the reaction, so setting the appropriate temperature, pressure and time is an important factor in controlling the productivity of gamma butyrolactone.

In addition, in the present invention, the process of converting the waste succinic acid to gamma butyrolactone is carried out in consideration of the conversion rate and the reactor volume in the liquid phase, and since it is a liquid phase process that does not overheat, it is easy to regenerate the catalyst because there is no deterioration of catalyst activity due to coke formation. Do. This catalytic reaction process is a heterogeneous reaction using a solid catalyst by dissolving the reactant waste succinic acid in a liquid solvent.The solvent is an aromatic substance such as benzene, toluene and xylene, aliphatic alcohol such as methanol, ethanol, And a wide range of inert solvents, such as tetrahydrofuran, gamma butyrolactone, and dioxane, can be used. In the commercialization process, when the process product, tetrahydrofuran or gamma butyrolactone, is used as a solvent, there is an advantage that separation and solvent removal are not necessary depending on the purpose, but in this process, the productivity of gamma butyrolactone and the byproduct tetrahydrofuran is reduced. 1,4-dioxane was used as the solvent for accurate measurement. Stirring of the reactor was performed using a magnetic driver, and the stirring speed is generally 300 rpm to 1000 rpm, but considering the state of the catalyst and the viscosity of the solvent, the mass transfer at the interface between the hydrogen and the reactants is performed in the region where the mass is maximized. It is preferable.

In an embodiment of the present invention, waste succinic acid is artificially reproduced by mixing succinic acid with acetic acid which is inevitably generated during succinic acid production from the biorefinery process as a reactant. As a by-product of waste succinic acid fermented from glucose in the biorefinery process, it has been reported that the weight ratio of acetic acid and succinic acid can be as high as 1: 7 [C. Du, S.K.C. Lin, A. Koutinas, R. Wang, C. Webb, Appl. Microbiol. Biot., Vol. 76, p. 1263 (2007)], and also, byproducts are a very important issue in the fermentation process, and the proportion of byproducts is expected to decrease further as active research and development proceed. Therefore, the reaction mixture of acetic acid and succinic acid used in the present invention is preferably used in the weight ratio of acetic acid and succinic acid in the range of 1: 5 to 1:10. On the other hand, the amount of the reactants is suitable to more than twice the amount of the catalyst, the specific amount is preferably maintained in a suitable ratio in consideration of the maintenance cost, productivity, catalyst regeneration efficiency, etc. in the actual process.

Hereinafter, the present invention will be described in more detail with reference to Preparation Examples and Examples.

Preparation Example 1 and Comparative Example 1 Preparation of Palladium Supported Catalyst Supported on Medium-Scale Alumina Controlled Gel Carrier and Alumina Controlled Gel Carrier

Medium porosity alumina control gel catalysts were prepared using the sol-gel method. First, 60 ml of ethanol was heated to 80 DEG C while stirring using a magnetic stirrer, and then 7 g of aluminum sec-butoxide (Aldrich), an aluminum precursor, was dissolved in a heated ethanol solvent. Thereafter, while maintaining the solution at 80 ° C., a partial hydration reaction was carried out while gradually adding a ethanol / nitric acid / water (40 ml / 0.1 ml / 0.3 ml) mixed solution to the solution, and in a few minutes, a uniform and transparent alumina sol (sol ) Was prepared. After cooling the obtained sol (Sol) to room temperature, a mixture of ethanol / water (5 ml / 0.6 ml) was slowly injected to obtain an alumina gel through a hydration and condensation reaction, which was aged at room temperature for 5 days. . Thereafter, the aged gel was dried in a drier maintained at 80 ° C. for 36 hours to obtain an alumina xerogel, which was calcined at a temperature of 850 ° C. under an air atmosphere to give an alumina controlled rogel having a gamma alumina phase. The carrier was prepared. The alumina control gel carrier prepared above was described as AX.

The palladium supported catalyst was prepared by supporting palladium on the alumina control gel and the commercially available alumina carrier. Commercial alumina carriers have been described as AC. The supported catalyst using commercial alumina was prepared for performance comparison with the palladium supported catalyst supported on the alumina control gel, and Degussa's product was used. First, palladium nitrate, a precursor of palladium metal, is dissolved in distilled water. At this time, the amount of water was kept at a minimum amount of 0.1 ml per g of catalyst. The prepared alumina control gel was calcined so as to have a weight ratio of palladium: alumina control gel to 0.05: 1, and impregnated with a physical force. At this time, the water was added little by little and the alumina was adjusted to put only the water enough to moisten wet (initial wetness method: incipient wetness method). Through this process, alumina-controlled gel catalyst supporting palladium was prepared. Thereafter, the impregnated palladium / alumina control gel sample was dried at 120 ° C. for at least 24 hours to remove all moisture, and then the catalyst was calcined at 450 ° C. for at least 4 hours at high temperature electric furnace to remove nitrate groups. The catalyst prepared above was described as Pd / AX. The catalyst was prepared by applying the above procedure to commercial alumina for performance comparison according to the carrier, and the catalyst thus prepared was described as Pd / AC. The two catalysts were then subjected to sufficient reduction for 3 hours under 200 ° C. hydrogen atmosphere.

Analyze the physicochemical properties of the palladium supported catalyst (Pd / AC) supported on the commercially available alumina carrier prepared as described above and the palladium supported catalyst (Pd / AX) supported on the alumina control rogel carrier and summarize the results in Table 1 below. The nitrogen adsorption-desorption analysis curves are shown in FIG. 2. On the other hand, Degussa's commercial alumina product is composed of non-porous particles, so it is difficult to carry out nitrogen adsorption and desorption experiments and precise pore volume and pore size are not described.

Palladium content (wt%) Palladium dispersion Specific surface area (m ² / g) Pore Volume (cm ³ / g) Average pore size (nm) AC - - 106 - - AX - - 202 0.33 6.1 Pd / AC 5.2 16.7 99 - - Pd / AX 5.1 24.3 191 0.31 6.1

The nitrogen adsorption-desorption analysis curves of the alumina control gel support (AX) and the palladium supported catalyst (Pd / AX) supported on the alumina control gel support shown in FIG. 2 showed typical Type-IV isotherms and Type-H2 It showed a form of hysteresis. Type-H2 type hysteresis means that ink bottle-shaped medium pores with large pore volume and small pore inlet size were developed in alumina control gel carrier (AX).

On the other hand, as shown in Table 1, the specific surface area of the commercial alumina carrier (AC) is low as about 106 m ² / g, but has a high specific surface area of about 202 m ² / g for the alumina control rogel (AX) carrier. In terms of pore volume, alumina control gel (AX) showed a pore volume of 0.33 cm ³ / g, and a similar pore volume of 0.31 cm ³ / g even after 5 wt.% Of palladium was loaded. In addition, the average pore sizes of the alumina controlled rogel carrier (AX) and the palladium supported catalyst (Pd / AX) catalyst supported on the alumina controlled gel support were calculated to be about 6.1 nm, which were calculated using the BJH model equation. The results indicate that the pores of the alumina control gel carrier (AX) are well maintained even after palladium is supported on the alumina control gel carrier. In FIG. 2, the nitrogen adsorption-desorption analysis curves of the palladium-supported catalyst (Pd / AX) supported on the alumina control gel support (AX) and the alumina control gel support showed similar isotherms and hysteresis. You can explain why.

3 is a palladium supported catalyst (Pd / AC) supported on a commercial alumina carrier (AC) and a commercial alumina carrier, an alumina controlled gel support (AX) and a palladium supported catalyst (Pd / AX) supported on an alumina controlled rose gel carrier X-ray diffraction spectrum is shown. It is confirmed that each of the carriers forms a gamma alumina phase because the 2θ characteristic peak of the X-ray diffraction spectrum is well represented in the range of 35 ^O to 38 ^O , 45 ^O to 47 ^O , 66 ^O to 68 ^O. On the other hand, the palladium supported catalyst (Pd / AC) supported on the commercial alumina carrier and the palladium supported catalyst (Pd / AX) supported on the alumina control gel support showed a characteristic peak of palladium oxide near 2θ = 33 ^O after firing, but after reduction The characteristic peak of palladium oxide disappeared and the inherent metal peak of palladium was observed in the vicinity of 2θ = 40 ^O , confirming that the active point was well developed as a hydrogenation catalyst after the reduction treatment.

FIG. 4 shows a high magnification transmission electron microscope (HR-TEM) image of a palladium supported catalyst (Pd / AC) supported on a commercial alumina carrier and a palladium supported catalyst (Pd / AX) supported on an alumina control gel support. Comparing the two images, the high magnification transmission electron microscope image of the Pd / AC supported catalyst (Pd / AC) supported on the commercial alumina carrier shows that the palladium particles are agglomerated and do not disperse evenly. The image of the palladium supported catalyst (Pd / AX) can visually confirm the form of palladium evenly dispersed in the carrier. In addition, the palladium dispersion degree (described in Table 1), measured by the hydrogen adsorption experiment (H ₂ chemisorption), also shows that the palladium supported catalyst (Pd / AX) supported on the alumina control gel carrier was 24.3%, showing a dispersion degree of 16.7%. It clearly shows that it is evenly dispersed than the palladium supported catalyst (Pd / AC) supported on the alumina carrier.

(Use) Example 2 and Comparative Example 2: By hydrogenation of waste succinic acid on a palladium supported catalyst (Pd / AC) supported on a commercial alumina carrier and a palladium supported catalyst (Pd / AX) supported on an alumina control rogel carrier Preparation of Gamma Butyrolactone

Hydrogenation of waste succinic acid using a palladium supported catalyst (Pd / AC) supported on a commercial alumina carrier prepared in Examples and Comparative Examples 1 and a palladium supported catalyst (Pd / AX) catalyst supported on an alumina control rogel carrier Reaction of gamma butyrolactone by the reaction was carried out for each temperature. The reaction results are shown in FIG. 5 and Table 2. The conversion reaction of waste succinic acid was made in the liquid state and carried out using a batch reactor. For the reaction, an autoclave reactor was charged with 0.4 g of catalyst, 1 g of succinic acid, 0.2 g of acetic acid as a by-product of waste succinic acid with 50 ml of 1,4-dioxane solvent, and then flowed with nitrogen 3,4 times. Remove oxygen from Then, when hydrogen is injected to a pressure of about 20 bar, the reaction temperature is heated to a temperature increase rate of 10 ℃ / min. When the reaction temperature is reached, the pressure is raised to 60 bar again using hydrogen, and this time is used as the reaction start time. The total reaction time was 4 hours, the stirring speed was performed at 500 rpm, the reaction temperature was performed at 220 ℃, 240 ℃, 260 ℃, respectively. After the reaction, the temperature was cooled to room temperature, the pressure was removed, and the catalyst and the liquid product were separated by filtration and analyzed by gas chromatography (GC). By-products mainly produced propionic acid, butyric acid, 1,4-butanediol, and the like.

As shown in Table 2, the palladium supported catalyst (Pd / AX) supported on the alumina control gel support according to the present invention has a higher conversion rate of succinic acid than the palladium supported catalyst (Pd / AC) supported on the commercial alumina carrier at all temperatures. This is because the alumina control gel carrier according to the present invention has excellent physical properties in all aspects such as surface area, surface characteristics and pore characteristics than commercial alumina carriers, leading to high dispersion of the palladium catalyst component. In addition, the yield of gamma butyrolactone according to the high conversion is also excellent on the palladium supported catalyst (Pd / AX) supported on the alumina control rogel carrier, so that the supported catalyst according to the present invention is gamma butyrolactone conversion reaction of waste succinic acid. It can be seen that it acts as a very efficient catalyst.

On the other hand, the gamma butyrolactone yields of the reaction temperature of the palladium supported catalyst (Pd / AX) supported on the alumina control gel support and the palladium supported catalyst (Pd / AC) supported on the commercial alumina carrier shown in FIG. In both catalysts, the yield is almost the same despite the higher conversion of succinic acid. This can be seen that as the temperature increases, the hydrocracking reaction with heat occurs competitively with the hydrogenation reaction, contributing to the decrease in gamma butyrolactone selectivity due to the increase in by-product propionic acid. Therefore, in the present invention, it can be seen that the temperature of 240 ℃ is the most economical condition showing excellent yield.

The embodiments of the present invention described above should not be construed as limiting the technical idea of the present invention. The scope of protection of the present invention is limited only by the matters described in the claims, and those skilled in the art will be able to modify the technical idea of the present invention in various forms. Therefore, such improvements and modifications will fall within the protection scope of the present invention, as will be apparent to those skilled in the art.

1 is a reaction route for preparing gamma butyrolactone for each raw material.

FIG. 2 shows the results of nitrogen adsorption-desorption experiments for analyzing the pore structure and pore characteristics of the alumina controlled gel support (AX) prepared in Example 1 and the palladium supported catalyst (Pd / AX) supported on the alumina controlled gel support.

FIG. 3 shows a commercial alumina carrier (AC) prepared in Comparative Example 1 and a palladium supported catalyst (Pd / AC) supported on a commercial alumina carrier, an alumina controlled rosette carrier (AX) and an alumina controlled roselle prepared in Example 1 X-ray diffraction spectrum of supported palladium supported catalyst (Pd / AX)

4 is a high magnification transmission electron microscope (HR-TEM) image of a palladium supported catalyst (Pd / AC) supported on a commercially available alumina carrier and a palladium supported catalyst (Pd / AX) supported on an alumina controlled gel support.

5 shows the yield of gamma butyrolactone according to the reaction temperature of the palladium supported catalyst (Pd / AX) supported on the alumina control gel support and the palladium supported catalyst (Pd / AC) supported on the commercial alumina carrier.

Claims (5)

In the supported catalyst for producing gamma butyrolactone from succinic acid, The supported catalyst is a palladium catalyst supported on an alumina controlled gel (Xerogel) carrier, characterized in that the Pd metal catalyst is carried in a ratio of 1 to 20 parts by weight based on 100 parts by weight of an alumina controlled gel (Xerogel) carrier. The method of claim 1, The alumina control gel support is a palladium catalyst supported on an alumina control gel (Xerogel) carrier, characterized in that the average pore size is in the range of 100 m ² / g to 300 m ² / g in the range of ² nm to 15 nm . delete In the hydrogenation of succinic acid comprising the step of reacting succinic acid or succinic anhydride at a temperature in the range of 150 to 400 ℃ and pressure in the range of 30 to 200 bar in the presence of a palladium catalyst supported on the alumina controlled Xerogel carrier of claim 1 Gamma butyrolactone production method. 5. The method of claim 4, The succinic acid is gamma butyrolactone production method by hydrogenation of succinic acid, characterized in that the mixed succinic acid and succinic acid in the weight ratio range of 1: 5 to 1:10, the waste succinic acid is not subjected to separation and purification.

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