WO2009028907A2

WO2009028907A2 - Method of manufacturing catalyst for propanediol, and method of manufacturing propanediol using the same

Info

Publication number: WO2009028907A2
Application number: PCT/KR2008/005094
Authority: WO
Inventors: Kwang Seop Jung; Jae Hyun Kim; Jung Hee Cho; Sang Chul Chung; Young Sun Jun; Jongheop Yi; Seogil Oh; Nam Dong Kim
Original assignee: Gs Caltex Corporation; Seoul National University Industry Foundation
Priority date: 2007-08-29
Filing date: 2008-08-29
Publication date: 2009-03-05
Also published as: WO2009028907A3; KR100870369B1

Abstract

Disclosed is a method of manufacturing a catalyst for propanediol, the method includes preparing a metal precursor-aqueous solution through dissolving at least one type of metal precursor compound in distilled water, forming precipitation through adjusting pH of the metal precursor-aqueous solution, maturing the precipitation, filtering and drying the matured precipitation, and sintering the dried precipitation. Also, a method of manufacturing propanediol using the catalyst is disclosed.

Description

METHOD QF MANUFACTURING CATALYST FOR PROPANEDIOL, AND METHOD OF MANUFACTURING PROPANEDIOL USING THE SAME

Technical Field The present invention relates to a method of manufacturing a catalyst for propanediol and a method of manufacturing propanediol using the manufactured catalyst, and particularly, to a method of manufacturing a catalyst for manufacturing propanediol in a high yield at a low temperature and pressure and a method of manufacturing propanediol using the catalyst. Background Art

After the industrial revolution, consumption of fossil fuel as an energy resource, such as coal and petroleum, has rapidly risen over the world. It is no exaggeration to say that today's technologies and industries are established and developed based on fossil fuel. However, the rapidly increased consumption of fossil fuel has caused a lot of problems. One of the problems is limited reserves of fossil fuel and the amount of reserves over the world now are revealing its limit. Also, the consumption of the fossil fuel has caused many environmental pollution problems such as an increase of carbon dioxide in the air, and the like. Due to the increase of the environmental pollution, many countries of the world ratified the Kyoto Protocol in 1997 and have been trying to reduce emission of carbon dioxide. Accordingly, much investment and researches have been concentrated on development of alternatives to fossil fuel that are also eco- friendly energy resources.

Biodiesel, one of the eco-friendly energy resources, has been drawing people's attention. Biodiesel is a common name of a fuel that has the same physical characteristic as diesel that is made by processing resources originated from a plant, namely, vegetable oil such as rapeseed oil, soybean oil, used edible oil, and brown rice oil. Since biodiesel has the same physical characteristic with general diesel, it is applicable to an existing diesel engine. Also, since a small amount of pollution is emitted, many countries in the world make an increase in the consumption of biodiesel mandatory and along with the trend, the Republic of Korea also increase the consumption of biodiesel.

Biodiesel is manufactured through a synthesis reaction of fatty acidic methyl- ester by transesterification from the resources originated from the plant. Economical efficiency of the process of manufacturing biodiesel depends on a cost of raw materials and a process of transesterification. That is, economical efficiency may be increased by increasing a yield of biodisel based on improved transesterification or converting a by-product of the process into another high value material.

Glycerol, a main by-product generated from the transesterification, is used in fields such as beauty products, pharmacy, food, and the like. However, since supply is excessively larger than industrial demand, a value of glycerol falls sharply. Accordingly, converting of glycerol, a by-product of biodiesel, into another high vale material was begun in the early 1990s, and currently Dupont in the U.S.A. promotes practical use of a process of converting glycerol into 1,3-propanediol. Also, a necessity of an efficient process of manufacturing 1 ,2-propanediol increases, 1,2- propanediol being used as an intermediate of medical supplies and cosmetics, a synthetic raw material of polyester and unsaturated polyester, and a plasticizer of cellophane. 1 ,2-propanediol, propylene glycol, and C3 dialcohol are widely used in chemical field as an alternative material to an ethylene derivative that is well known to be more toxic than a propylene derivative.

Currently, 1 2-propanediol is manufactured by reacting propylene oxide with a large amount of water to be hydrated. Propylene oxide is manufactured through a process using epichlorohydrin and a process using hydroperoxide. Since both processes use especially toxic material, the process of manufacturing 1 ,2-propanediol has been of interest.

However, the process of manufacturing 1 ,2-propanediol from glycerol has not been disclosed in Korea. The process may be performed by a biological method and a chemical method using a catalyst. The U.S. patent No. 7,049,109 B2 and U.S. patent No. 6,727,088 B2 respectively disclose a process of manufacturing 1, 2-propanediol using a biological method. With respect to the process using the biological method, it is known from the disclosure that, although the process can obtain a high selectivity, a reaction in the process takes a relatively long time and the process has a difficulty in maintaining the process. With respect to the chemical method, not many attempts have been made and catalytic systems and a reaction process are not yet systematized. According to U.S. patent No. 5,616,817, catalyst consisting of Co, Cu, Mn, and Mo is manufactured and glycerol is converted into 1,2-propanediol. Pressure of about 100 atmosphere to 700 atmosphere and temperature of about 180 ^°C to 270 ^°C are suggested as a reaction condition and a pressure of about 200 atmosphere to 325 atmosphere and temperature of about 200 ^°C to 270 ^°C are also suggested as a preferable reaction condition, which is an extreme condition to the manufacturing of propanediol.

Also, according to U.S. publication No. 2005/0244312, a two-step reaction procedure of manufacturing 1 ,2-propanediol from glycerol is suggested. That is, the 1,2-propanediol is manufactured from the glycerol through the two-step reaction, the two-step reaction including a dehydration to manufacture hydroxyacetone from the glycerol and a hydrogenation to manufacture the 1,2-propanediol from the glycerol. However, a catalyst disclosed in the publication is a common catalyst and the publication does not suggest a technique for a catalyst that can be used in manufacturing of propanediol. Also, there is a difficulty in determining an optimum reaction condition that is variable according to specific elements constituting the catalyst, based on the publication. In particular, according to a conventional art, manufacturing of propanediol is possible only under several conditions such as a high temperature and high pressure. Accordingly, development of a catalyst which can improve efficiency of the reaction condition is required.

Disclosure of Invention Technical Goals

An aspect of the present invention provides a method of manufacturing a catalyst which is practical to a reaction process of manufacturing propanediol from hydroxyacetone. Another aspect of the present invention also provides a catalyst for manufacturing propanediol, the catalyst being manufactured based on the above method. Another aspect of the present invention also provides a method of manufacturing propanediol in a high yield under condition of a relatively low temperature and pressure. Technical solutions

According to an aspect of the present invention, there is provided a method of manufacturing a catalyst used in a reaction process of manufacturing propanediol from hydroxyacetone, the method including preparing a metal precursor-aqueous solution through dissolving at least one type of metal precursor compound in distilled water, forming precipitation through adjusting pH of the metal precursor-aqueous solution, maturing the precipitation, filtering and drying the matured precipitation, and sintering the dried precipitation.

The metal is at least one metal selected from a group consisting of Cr, Cu, Ni, Zn and Mn. The metal precursor-aqueous solution is prepared through dissolving a variety of metal compounds containing the metals in the distilled water in different ratio and the pH is adjusted to form the precipitation. The precipitation passes through maturing, filtering, drying, sintering operations to be manufactured as a catalyst, and further passes through reduction operation.

In an aspect of the present invention, a Cu precursor compound and a Cr precursor compound are simultaneously used as a metal precursor compound and a ratio of a number of total Cr atoms to a number of total Cu atoms in the used metal precursor compound is about 2:1.

In an aspect of the present invention, the metal precursor-aqueous solution includes about 40 % to 80 % Cr atoms, about 10 % to 50 % Cu atoms, and at least one metal atom selected from a group consisting of Ni, Zn and Mn as a remaining portion, compared with total atoms of the metal atoms in the metal precursor-aqueous solution. For example, when a number of Cr atoms is about 60 % and a number of Cu atoms is about 30 %, the rest may be occupied by Ni atoms, Zn atoms, and Mn atoms alone or in combination of at least two of them.

In an aspect of the present invention, the adjusting of the pH of the metal precursor-aqueous solution is performed through adding alkali group carbonate or a sodium hydroxide aqueous solution.

Concentration of the alkali group carbonate or sodium hydroxide aqueous solution is about 0.5 mol/L to 3 mol/L and the alkali group carbonate or sodium hydroxide aqueous solution is added at a rate of about 0.1 mL to 10 mL per minute.

The adjusting of the pH of the metal precursor-aqueous solution adjusts pH of the metal precursor-aqueous solution to be about 9 to 13. A precipitation is formed by adding the alkali group carbonate or sodium hydroxide aqueous solution and stirring the same until the pH of the metal precursor-aqueous solution is 9 to 13. The precipitation is matured. The maturing is performed for about 2 hours to 12 hours under a temperature of about 50 "C to 90 ^°C . Also, drying is performed in a temperature range of about 80 ^°C to 200^°C .

In an aspect of the present invention, the method of manufacturing propanediol may further include performing a reduction of the catalyst under hydrogen atmosphere.

The reduction is performed in a temperature range of about 200 °C to 500 ^°C under a gas atmosphere including hydrogen.

The gas atmosphere further includes at least one gas selected from a group consisting of nitrogen, helium, and argon. According to another aspect of the present invention, there is provided a method of manufacturing propanediol, the method including adding hydroxyacetone and a catalyst for propanediol in a reactor, providing hydrogen gas into the reactor while stirring hydroxyacetone and the catalyst to purge hydroxyacetone and the catalyst, and performing hydrogenation reaction where hydroxyacetone reacts with hydrogen. The catalyst for propanediol is manufactured based on the method of manufacturing of the catalyst according to the present invention.

The catalyst included in the reactor is about 1 wt% to 10 wt% compared with hydroxyacetone of 100 wt%.

The purging is performed for about 30 minutes to 60 minutes. The hydrogenation reaction is performed while maintaining a temperature of about 80 "C to 200 ^°C and a pressure of about 30 atmosphere to 150 atmosphere inside of the reactor. Also, the hydrogenation reaction is performed for about 10 hours to 24 hours.

Advantageous Effects

According to embodiments of the present invention, a catalyst for manufacturing propanediol may have appropriate metal content, thereby manufacturing propanediol in a high yield. Also, when propanediol is manufactured from hydroxyacetone through hydrogenation reaction using the catalyst for propanediol, the reaction is effectively performed even at a relatively low pressure and temperature, thereby increasing economical efficiency, efficiency, and safety of the manufacturing process for propanediol. Also, the catalyst can be efficiently manufactured though discovering metal atoms with high activation and an appropriate ratio between metal atoms in manufacturing of the catalyst for propanediol. Specifically, the present invention uses cheap raw materials, thereby reducing manufacturing cost and being applicable to a manufacturing process.

In particular, the method of manufacturing of propanediol according to the present invention can efficiently manufacture propanediol in a high yield at a low pressure and temperature, although the method does not use a great amount of catalyst compared with a conventional method, thereby being applicable to mass production.

Brief Description of Drawings

FIG. 1 is a flowchart illustrating a manufacturing process of a catalyst used for manufacturing propanediol;

FIG. 2 is a graph illustrating an X-ray diffraction analysis result with respect to a catalyst manufactured through Examples 1 to 5. In FIG. 2, (a) indicates a result of a catalyst manufactured through an Example 4, (b) indicates a result of a catalyst manufactured through Example 3, (c) indicates a result of a catalyst manufactured through Example 2, (d) indicates a result of a catalyst manufactured through Example 1 , and (e) indicates a result of a catalyst manufactured based on Example 5. The catalyst is not reduced;

FIG. 3 is a graph illustrating an X-ray diffraction analysis result with respect to a catalyst manufactured through Examples 1 to 5. In FIG. 3, (a) indicates a result of a catalyst manufactured through an Example 4, (b) indicates a result of a catalyst manufactured through Example 3, (c) indicates a result of a catalyst manufactured through Example 2, (d) indicates a result of a catalyst manufactured through Example 1, and (e) indicates a result of a catalyst manufactured through Example 5. The catalyst is reduced;

FIG. 4 illustrates a result of gas chromatography with respect to a final product after performing a conversion of hydroxyacetone to 1 ,2-propanediol through Example l; and

FIG. 5 illustrates a result of gas chromatography with respect to a final product after performing a conversion of hydroxyacetone to 1 ,2-propanediol through Example 2. Best Mode for Carrying Out the Invention

Although a few exemplary embodiments of the present invention have been shown and described, the present invention is not limited to the described exemplary embodiments, wherein like reference numerals refer to the like elements throughout.

FIG. 1 is a flowchart illustrating a manufacturing process of a catalyst used for manufacturing propanediol.

Referring to FIG. 1, a method of manufacturing a catalyst used for manufacturing propanediol includes preparing a metal precursor-aqueous solution in operation SIl, forming precipitation in operation S 12, maturing in operation S 13, filtering and drying in operation S 14, sintering in operation S 15, and performing reduction of in operation S 16.

The metal precursor-aqueous solution is formed by dissolving a variety of metal precursor compounds in operation SIl. The metal may be one of chrome (Cr), copper (Cu), Nickel (Ni), zinc (Zn), Manganese (Mn), and the like or or any combination thereof.

A Cu precursor compound and a Cr precursor compound are simultaneously used as the metal precursor compound, and a ratio of a number of total Cr atoms and a number of total Cu atoms in the used metal precursor compound may be 2:1. Also, the metal precursor-aqueous solution may be composed of about 40 % to 80 % Cr atoms, and 10 % to 50 % Cu atoms, compared with total atoms of the metal atoms, and the rest may be Ni atoms, Zn atoms, or Mn atoms. The Ni, Zn, and Mn atoms may be included in the solution alone or in combination of at least two of them.

When the metal precursor-aqueous solution is prepared, adjusting of pH of the metal precursor-aqueous solution is performed to form precipitation in operation S 12.

The precipitation that is a compound including metal atoms is formed in a specific pH range. The pH of the metal precursor-aqueous solution is adjusted to be about 9 to 13 through adding an alkali group carbonate or a sodium hydroxide aqueous solution. A specific value of the pH may be variable according to a type and content of the metal atoms contained in the metal precursor-aqueous solution. Concentration of the alkali group carbonate or sodium hydroxide aqueous solution is about 0.5 mol/L to 3 mol/L and added at a rate of about 0.1 mL to 10 mL per minute. When the adding rate of the alkali group carbonate or sodium hydroxide aqueous solution is excessively high, a size of a particle of a manufactured catalyst increases, thereby having a problem that activation of the catalyst decreases. Conversely, when the adding rate is excessively low, efficiency of manufacturing of the catalyst decreases. Accordingly, an appropriate adding rate is important and a rate of 0.1 mL to 10 mL per minute is desirable.

In the same manner, when concentration of a pH adjuster such as the alkali group carbonate or sodium hydroxide aqueous solution is excessively high, a size of a particle of the catalyst increases, thereby having a problem that activation of the catalyst decreases. Also, when concentration of the pH adjuster is excessively low, efficiency of manufacturing of the catalyst is decreased. Therefore, adding a pH adjuster with an appropriate concentration is required. The concentration of the pH adjuster used in the present invention is about 0.5 mol/L to 3 mol/L.

When the metal precursor-aqueous solution reaches to a specific value in a pH range of 9 to 13 while the pH adjuster is added in the solution when stirring, the precipitation is matured in operation S 13. The specific pH may be variable according to a type and content of a metal contained in the metal precursor-aqueous solution. The maturing in operation S13 is performed for about 2 hours to 12 hours. During the maturing in operation S 13, a precipitation reaction is sufficiently performed. When a temperature is excessively high or low, since there is difficulty in forming precipitation with a particle size of high activation, the temperature may be about 50^°C to 90 ^"C and desirably be about 60 ^°C to 80 ^°C .

When the forming and maturing of the precipitation is completed, sufficient rinsing with distilled water is required until alkali group carbonate or sodium hydroxide aqueous solution remaining in the precipitation is removed. Subsequently, rinsed precipitation is filtered and dried in operation S 14. The drying is performed in a temperature range of about 80 ^°C to 200 ^°C until the precipitation is sufficiently dried.

To remove an organic compound remaining in the precipitation and to form an alloy phase, sintering in operation Sl 5 after performing the drying in operation S 14 is required. The sintering in operation S 15 is performed in a temperature range of about 400 ^°C to 700 ^°C under an air atmosphere or oxygen atmosphere. A detailed sintering temperature is determined to be a temperature where the alloy phase is formed, the alloy shape representing a high catalytic activity, and is variable according to a kind and content of the metal atoms contained the formed precipitation. However, when the metal atoms of the present invention, such as Cu, Cr, Ni, and the like, are sintered under about 400 ^°C to 700 ^°C , desirably under about 500 ^°C to 600 "C , the alloy shape is appropriately formed.

A catalyst generated after performing the sintering in operation Sl 5 may be formed through establishing a copper chromite (CuCr₂O₄) structure by Cr and Cu, and may further include Ni, Zn, and Mn atoms. When a ratio of the Cr to Cu is 2: 1, the catalyst most highly activates. The catalytic activity according to the ration of Cr to Cu will be described in detail through use of an example. A ratio of a number of atoms of each metal in the catalyst is about 40 % to 80 % Cr atoms, desirably 55 % to 75 %, 10 % to 50 % Cu atoms, desirably 20 % to 40 %, 0 % to 20 % Ni atoms, desirably 5 % to 10 %, 0 % to 20 % Zn, desirably 5 % to 10 %, and 0 % to 20 % Mn, desirably 5 % to 10 %. Subsequently, performing reduction in operation Sl 6 is to reduce the catalyst to increase activity of the manufactured catalyst. The reduction may be performed in a temperature range of about 200 ^°C to 500 ^°C, desirably about 300 ^°C to 400⁰C , while a hydrogen gas is provided at a predetermined rate. The temperature range of about 200 ^°C to 500 ^"C is a temperature where a metal is selectively reduced to perform an optimum catalytic activity.

Reducing in operation S16 may be performed while a nitrogen gas, helium gas, or argon gas is further added, in addition to the hydrogen gas. The nitrogen gas, helium gas, or argon gas may be provided alone or in combination of at least two thereof and may be provided as a mixed gas that mixed with the hydrogen gas. A volume of the hydrogen gas in the mixed gas is about 10 % to 20 %. For example, a volume of a mixed gas provided in performing reduction operation S 16 may be 10 % hydrogen gas and 90 % nitrogen gas (namely, 10 % H₂/N₂).

A manufacturing process of propanediol using a catalyst for manufacturing propanediol is as follows. The catalyst is added together with hydroxyacetone in a batch reactor and the reactor is hermetically sealed. The catalyst include in the reactor is about 1 wt% to 10 wt% compared with hydroxyacetone of 100 wt%. When an amount of the catalyst is small, activation in a reaction is not sufficiently performed. As an amount of the catalyst increases, a higher yield of propanediol is obtained.

However, considering economical efficiency, the catalyst is included in the reactor in about 1 wt% to 10 wt%, desirably 2 wt% to 5 wt%, compared with hydroxyacetone of

100 wt%. Subsequently, purging is performed for about 30 minutes to 60 minutes while stirring is performed in an inside of the reactor. After performing the purging, a hydrogenation reaction is performed through increasing a temperature and pressure inside the reactor, and thus propanediol is manufactured.

The hydroxyacetone, which is a highly reactive compound, may react in the air through a different route, unlike the intention of the present invention to manufacture propanediol. Also, when the air remains inside of the reactor, it may cause decreasing selectivity of the reaction, and thus the purging is required. Although an inert gas, such as Ni, Ar, He, and the like may be used in the purging, it is desirable to use hydrogen which is used in a process for manufacturing propanediol as a reactant gas. However, the present invention is not limited to the above description, the Ni, Ar, and

He gas, as well as hydrogen, may used in the purging, alone or in combination of at least two thereof.

After the purging is completed, the hydrogenation reaction is performed through increasing the temperature and pressure to be in a predetermined range of the temperature and pressure. When a temperature is excessively low in the hydrogenation reaction, efficiency of manufacturing of propanediol decreases.

Accordingly, an efficient temperature is about 80 ^°C to 200 ^°C , desirably 100^°C to 140 ^°C .

When the temperature is lower than 80 ^°C, a conversion rate of hydroxyacetone decreases, and when the temperature is higher than 200 "C, sensitivity decreases and energy efficiency is insufficient. Accordingly, the temperature is maintained in a range of about 80 ^°C to 200 ^°C . The conversion rate and selectivity will be described in Table

1.

Based on the same reason, maintaining the pressure in the hydrogenation reaction at about 30 atmosphere to 150 atmosphere, desirably about 50 atmosphere to 80 atmosphere, is appropriate. The hydrogenation reaction is performed for about 10 hours to 24 hours, desirably about 12 hours to 14 hours, in order to sufficiently perform conversion of hydroxyacetone to propanediol. Propanediol, which is a final product, is ascertained through a gas chromatography.

Hereinafter, although the following Examples will illustrate a method of manufacturing catalyst for propanediol and propanediol according to the present invention in detail, the present invention is not limited thereto. [Example 1] i) manufacturing of a catalyst for propanediol

A metal precursor-aqueous solution, wherein 732 g copper nitrate

[Cu(NO₃)₂-2H₂O] and 26 g chrome nitrate [Cr(NO₃)₂-9H₂O] are dissolved in 400 mL distilled water to include the Cu and Cr in a ratio of 1 :2, was prepared, and then, a sodium hydroxide solution with a concentration of 3 mol/L was added until a pH of the metal precursor-aqueous solution became 12.

Subsequently, temperature of the metal precursor-aqueous solution where precipitation was formed was maintained at about 60 ^°C and a precipitation particle was matured while stirring was performed for six hours. The precipitation was rinsed with distilled water and dried at about 80 ^°C for about 24 hours, and then, the dried powder was grinded, thereby having even particles. Subsequently, the dried precipitation was sintered at about 550 °C under an air atmosphere for six hours. An X-ray diffraction analysis (XRD) result with respect to the sintered catalytic oxide is illustrated in FIG. 2. In FIG. 2, a horizontal axis indicates a diffraction angle (2 theta) and a vertical axis indicates strength of diffraction. A result with respect to the catalyst manufactured in the present embodiment is a second graph (d). From a peak '♦' in (d) of FIG. 2, cooper chromite (CuCr₂O₄) phase is ascertained. ii) reduction of a catalyst for manufacturing propanediol

After 1.5 g of the catalyst was charged with a tube-shaped reactor, a temperature was slowly raised while 10 % H₂/N₂ mixed gas was flowed at 200 mL per minute. When the temperature reached 320 ^°C , the temperature was maintained constant for two hours. An XRD result with respect to the reduced catalytic is illustrated in (d) of FIG. 3. From a peak '♦' in (d) of FIG. 3, it is ascertained that only reduced copper chromite (CuCr₂O₄) remains. iii) manufacturing propanediol

1 g of the catalyst activated through the reduction process was added in a batch reactor together with 5O g hydroxyacetone with a purity of over 90 % and the reactor was hermetically sealed. Subsequently, in order to perform purging, an inside of the reactor was purified through providing 50 mL hydrogen per minute while performing stirring inside the reactor. After the purging was completed, hydrogen was provided through a high pressure, thereby increasing the pressure inside the reactor to 80 atmosphere and also increasing the temperature to 100^°C . Next, hydrogenation reaction was performed for 12 hours, while a final pressure and a final temperature was maintained constant as 80 atmosphere and 100^°C respectively and stirring was intensively performed. A yield of a final product after the hydrogenation is completed is shown in Table 1. [Examples 2 to 5]

Metal precursor-aqueous solutions were prepared and a ratio of Cu to Cr of each solution was 1 :1 (Example 2), 2: 1 (Example 3), 1 :0 (Example 4), and 0:1 (Example 5). Remaining operations, i), ii), and iii), were performed in the same manner as Example 1 , and thus a catalyst and propanediol were manufactured. A yield of a final product through Examples 2 to 5 is shown in Table 1. Also, an XRD result with respect to a catalyst before reduction and a catalyst after reduction, the catalyst being manufactured through Examples 2 to 5, is illustrated in FIGS. 2 and 3.

[Example 6]

A metal precursor-aqueous solution, wherein 5.49 g copper nitrate [Cu(NO₃)₂-2H₂O] and 26 g chrome nitrate [Cr(NO₃)₂-9H₂O] are dissolved in 400 mL distilled water to include the Cu and Cr in a ratio of 1 :1, was prepared. Remaining operations, i), ii), and iii), were performed in the same manner as Example 1, and a yield of a final product through Examples 2 to 5 is shown in Table 1.

[Table 1]

The conversion rate in Table 1 indicates a rate of conversion of hydroxyacetone to another chemical compound through hydrogenation reaction and the selectivity is a rate of propanediol in the converted chemical compound. The yield, which corresponds to a result value of multiplying the conversion rate by the selectivity, indicates a rate of conversion of hydroxyacetone to propanediol. Hereinafter, FIGS. 2 to 5 will be described.

FIG. 2 is a graph illustrating an X-ray diffraction analysis result with respect to a catalyst manufactured through Examples 1 to 5. The catalyst is not reduced. In FIG. 2, (a) indicates a result of a catalyst manufactured through Example 4, (b) indicates a result of a catalyst manufactured through Example 3, (c) indicates a result of a catalyst manufactured through Example 2, (d) indicates a result of a catalyst manufactured through Example 1, and (e) indicates a result of a catalyst manufactured based on Example 5.

(a) in FIG. 2 is the case when a ratio of Cu to Cr is 1:0 and a CuO phase is ascertained from a peak ' D' . When referring to (b) to (c), to (d), and to (e) in FIG. 2, it is recognized that a ratio of Cr increases. It is ascertained that, as a ratio of the Cr increases, strength of the peak 'D' indicating the CuO phase decreases and a CuCr₂O₄ phase is formed, from a peak '♦'. When a ratio of Cu to Cr is 1 :3, remaining Cr after forming the CuCr₂O₄ phase is formed to be Cr₂O₃ phase. As an amount of the Cr increases, a ratio of a Cr₂O₃ phase increases. However, a catalyst including only Cr (Example 5) has insufficient crystallinity and it is ascertained that every metal is formed to be the Cr₂O₃ phase, from a peak ' A ' of (e) in FIG. 2. The yield of the catalyst in Example 5 is zero as shown from Table 1 , and the catalyst may scarcely show catalytic activation. FIG. 3 is a graph illustrating an X-ray diffraction analysis result with respect to a catalyst manufactured through Examples 1 to 5. The catalyst is reduced. In FIG. 3, (a) indicates a result of a catalyst manufactured through an Example 4, (b) indicates a result of a catalyst manufactured through Example 3, (c) indicates a result of a catalyst manufactured through Example 2, (d) indicates a result of a catalyst manufactured through Example 1, and (e) indicates a result of a catalyst manufactured through Example 5.

It is ascertained that all the CuO phases existing before reduction are reduced to Cu phases, from a peak O'. As described in the FIG. 2, when referring to (a) to (b), to (c), to (d), and to (e) in FIG. 3, it is recognized that a ratio of Cr increases. As an amount of Cr, the Cu phases decrease and reduced CuCr₂O₄ phases increases. Specifically, when catalyst including Cu and Cr in a ratio of 1 :2 (Example 1 , (d) of FIG. 3) is used, neither the Cu phases nor Cr₂O₃ phases exist and every metal is reduced to the CuCr₂O₄ phase. However, in the case of using a catalyst including only Cr (Example 5), when comparing (e) of FIG. 2 with (e) of FIG. 3, it is ascertained that a phase is hardly changed.

FIG. 4 illustrates a result of gas chromatography with respect to a final product after performing a conversion of hydroxyacetone to 1 ,2-propanediol through Example 1 and FIG. 5 illustrates a result of gas chromatography with respect to a final product after performing a conversion of hydroxyacetone to 1 ,2-propanediol through Example 2.

As ascertained from FIGS. 4 and 5, peaks excluding peaks corresponding to hydroxyacetone and 1 , 2-propanediol hardly appear, which means the catalyst of the present invention having an extremely high sensitivity effects a reaction. Specifically, a high conversion rate and a result of a reaction experiment obtaining a high yield according to the high conversion rate are ascertained from FIG. 4.

Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Industrial Applicability According to embodiments of the present invention, the catalyst of the present invention, which include optimum ratio of appropriate metal, may efficiently perform hydrogenation process. Also, a high yield may be obtained even with a small amount of the catalyst, thereby being applicable to mass production, and particularly, propanediol is efficiently manufactured at a low pressure and temperature compared with an existing method.

Claims

1. A method of manufacturing a catalyst used in a reaction process of manufacturing propanediol from hydroxyacetone, the method comprising: preparing a metal precursor-aqueous solution through dissolving at least one type of metal precursor compound in distilled water; forming precipitation through adjusting pH of the metal precursor-aqueous solution; maturing the precipitation; filtering and drying the matured precipitation; and sintering the dried precipitation.

2. The method of claim 1, further comprising: performing a reduction of the catalyst under hydrogen atmosphere to activate the catalyst manufactured through the sintering

3. The method of claim 1 , wherein the metal is at least one metal selected from a group consisting of Cr, Cu, Ni, Zn and Mn.

4. The method of claim 1, wherein a Cu precursor compound and a Cr precursor compound are simultaneously used as the metal precursor compound and a ratio of a number of total Cr atoms to a number of total Cu atoms in the used metal precursor compound is about 2: 1.

5. The method of claim 1, wherein the metal precursor-aqueous solution comprises: about 40 % to 80 % Cr atoms; about 10 % to 50 % Cu atoms; and at least one metal atom selected from a group consisting of Ni, Zn and Mn as a remaining portion, compared with total atoms of the metal atoms in the metal precursor- aqueous solution.

6. The method of claim 1 , wherein the adjusting of the pH of the metal precursor- aqueous solution is performed through adding alkali group carbonate or a sodium hydroxide aqueous solution.

7. The method of claim 6, wherein concentration of the alkali group carbonate or sodium hydroxide aqueous solution is about 0.5 mol/L to 3 mol/L.

8. The method of claim 6, wherein the alkali group carbonate or sodium hydroxide aqueous solution is added at a rate of about 0.1 niL to 10 mL per minute.

9. The method of claim 1, wherein the adjusting of the pH of the metal precursor- aqueous solution adjusts pH of the metal precursor-aqueous solution to be about 9 to 13.

10. The method of claim 1, wherein the maturing is performed for about 2 hours to 12 hours under a temperature of about 50 ^°C to 90 ^°C .

11. The method of claim 1 , wherein the drying is performed in a temperature range of about 80 ^°C to 200^°C .

12. The method of claim 1, wherein the sintering is performed in a temperature range of about 400 "C to 700 ^°C .

13. The method of claim 2, wherein the reduction is performed in a temperature range of about 200 °C to 500 ^°C under a gas atmosphere including hydrogen.

14. The method of claim 13, the gas atmosphere further includes at least one gas selected from a group consisting of nitrogen, helium, and argon.

15. A method of manufacturing propanediol, the method comprising: adding hydroxyacetone and a catalyst manufactured through claim 1 in a reactor; providing hydrogen gas into the reactor while stirring hydroxyacetone and the catalyst to purge hydroxyacetone and the catalyst; and performing hydrogenation reaction where hydroxyacetone reacts with hydrogen.

16. The method of claim 15, wherein the catalyst included in the reactor is about 1 wt% to 10 wt% compared with hydroxyacetone of 100 wt%.

17. The method of claim 15, wherein the purging is performed for about 30 minutes to 60 minutes.

18. The method of claim 15, wherein the hydrogenation reaction is performed while maintaining a temperature of about 80 ^°C to 200 ^°C and a pressure of about 30 atmosphere to 150 atmosphere inside of the reactor.

19. The method of claim 15, wherein the hydrogenation reaction is performed for about 10 hours to 24 hours.