MOLDED CATALYST, PRODUCTION METHOD FOR SAME, AND METHOD FOR PRODUCING CYCLIC KETONE USING SAME

Abstract

A catalyst molded body, a production method thereof and a method for preparing cyclic ketone using the same, including: (a) producing a mixed powder including a catalyst powder and a binder; (b) producing a slurry by mixing an aqueous alkali hydroxide solution with the mixed powder; and obtaining a catalyst molded body by molding and heat-treating the slurry.

Claims

1. A method for producing a catalyst molded body, the method comprising: (a) producing a mixed powder comprising a catalyst powder and a binder; (b) producing a slurry by mixing a first aqueous solution with the mixed powder; and (c) obtaining a catalyst molded body by molding and heat-treating the slurry.

2. The method of claim 1, wherein the catalyst is at least one oxide selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, nickel, copper and zinc.

3. The method of claim 2, wherein the catalyst has a molar ratio (Ma/Al) of magnesium and aluminum of 1.0 to 5.0.

4. The method of claim 1, wherein the binder comprises an inorganic binder in an amount of 1 to 20 parts by weight based on 100 parts by weight of the catalyst molded body.

5. The method of claim 1, wherein the binder comprises an organic binder in an amount of 0.1 to 4.5 parts by weight based on 100 parts by weight of the catalyst molded body.

6. The method of claim 1, wherein the first aqueous solution comprises alkali hydroxide in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the catalyst molded body.

7. A catalyst molded body produced according to claim 1.

8. The catalyst molded body of claim 7, wherein the catalyst molded body has a compressive strength of 10 N or more.

9. The catalyst molded body of claim 7, wherein the catalyst molded body has a diameter of 1.0 to 10.0 mm.

10. A method for producing cyclic ketone, the method comprising: (i) preparing a reactant comprising non-cyclic ketone; and (ii) reacting the reactant with the catalyst molded body according to claim 7 in a reactor.

11. The method of 10, wherein Step (ii) is performed by a batch-type or continuous-type process.

12. The method of claim 10, after Step (ii), further comprising: (iii) isolating cyclic ketone from the product in Step (ii).

13. The method of claim 12, wherein the raw material isolated in Step (iii) is recycled by the reactant in Step (i).

Description

DESCRIPTION OF DRAWINGS

[0024] FIG. 1 illustrates an example of a catalyst molded body according to the present specification;

[0025] FIG. 2 illustrates a schematic view of an example of a reactor to which the catalyst molded body according to the present specification is applied;

[0026] FIG. 3 illustrates the experimental results confirming the long-term stability of the catalyst molded body according to the present specification; and

[0027] FIG. 4 illustrates the experimental results confirming the stability of the catalyst molded body according to the present specification in the presence of impurities.

MODES OF THE INVENTION

[0028] Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention can be realized in various different forms, and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention, portions that are not related to the description are omitted in the drawings, and like reference numerals are added to like portions throughout the specification.

[0029] Throughout the specification, when one part is “connected” to another part, this includes not only a case where they are “directly connected to each other”, but also a case where they are “indirectly connected to each other” with another member interposed therebetween. Further, when one part “includes” one constituent element, unless otherwise specifically described, this does not mean that another constituent element is excluded, but means that another constituent element may be further included.

[0030] When a range of numerical values is described in the present specification, the value has the precision of significant figures provided according to the standard rules in chemistry for significant figures, unless a specific range thereof is stated otherwise. For example, 10 includes a range of 5.0 to 14.9, and the number 10.0 includes a range of 9.50 to 10.49.

[0031] Hereinafter, the Examples of the present invention will be described in detail with reference to the accompanying drawings.

[0032] Method for Producing Catalyst Molded Body

[0033] A method for producing a catalyst molded body according to an aspect of the present specification may include: (a) producing a mixed powder including a catalyst powder and a binder; (b) producing a slurry by mixing a first aqueous solution with the mixed powder; and (c) obtaining a catalyst molded body by molding and heat-treating the slurry.

[0034] Step (a) may be a step of producing a mixed powder by mixing a binder with a catalyst powder having activity for producing a molded body having excellent mechanical strength, which can also be applied to a continuous-type process.

[0035] The catalyst may be at least one oxide selected from the group consisting of magnesium, aluminum, manganese, iron, cobalt, nickel, copper and zinc. For example, the catalyst may include magnesium and aluminum in a range of molar ratio (Mg/Al) of 1.0 to 5.0, for example, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.5, 5.0 or between two values thereof, but the range is not limited thereto. For example, when the Mg/A1 molar ratio falls within a range of 1.0 to 3.0, the selectivity of cyclic ketone may be 60% or more. Examples of such catalysts include at least one of metal oxides or metal hydroxides such as hydrotalcite, quintinite, and fougerite.

[0036] The binder may include an inorganic binder in a range of 1 to 20 parts by weight, for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight or between two values thereof, based on 100 parts by weight of the catalyst molded body. The inorganic binder may be at least one selected from, for example, calcium oxide (CaO), aluminum oxide (Al.sub.2O.sub.3), and boehmite (AlOOH), but is not limited thereto.

[0037] The binder may include an organic binder in a range of 0.1 to 4.5 parts by weight, for example, 0.1 part by weight, 0.2 part by weight, 0.3 part by weight, 0.4 part by weight, 0.5 part by weight, 0.6 part by weight, 0.7 part by weight, 0.8 part by weight, 0.9 part by weight, 1.0 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2.0 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3.0 parts by weight, 3.1 parts by weight, 3.2 parts by weight, 3.3 parts by weight, 3.4 parts by weight, 3.5 parts by weight, 3.6 parts by weight, 3.7 parts by weight, 3.8 parts by weight, 3.9 parts by weight, 4.0 parts by weight, 4.1 parts by weight, 4.2 parts by weight, 4.3 parts by weight, 4.4 parts by weight, 4.5 parts by weight or between two values thereof, based on 100 parts by weight of the catalyst molded body. The organic binder may be at least one selected from, for example, hydroxy methyl cellulose (MC), carboxy methyl cellulose sodium salt, and acetic acid, but is not limited thereto.

[0038] The binder may include an inorganic binder and an organic binder having the above-described contents, respectively.

[0039] According to the composition and content of the catalyst and binder described above, the mechanical properties of the catalyst molded body and the yield and selectivity of the cyclic ketone can be improved, and simultaneously, the by-product yield can be reduced.

[0040] Step (b) may produce a slurry form in which each component is easily dispersed and molded by mixing a first aqueous solution with the mixed powder.

[0041] The first aqueous solution may include alkali hydroxide in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the catalyst molded body, and the content of the alkali hydroxide may be in a range of, for example, 0.1 part by weight, 0.2 part by weight, 0.3 part by weight, 0.4 part by weight, 0.5 part by weight, 0.6 part by weight, 0.7 part by weight, 0.8 part by weight, 0.9 part by weight, 1.0 part by weight or between two values thereof.

[0042] The alkali hydroxide is an enhancer, and can improve the selectivity of the catalyst for cyclic ketone and reduce the yield of by-products.

[0043] Step (c) may include: (c1) pressure-molding the slurry; (c2) primarily drying the pressure-molded slurry at 15 to 35° C. for 1 to 48 hours; (c3) secondarily drying the pressure-molded slurry at 90 to 120° C. for 1 to 24 hours; and (c4) firing the pressure-molded slurry at 350 to 650° C. for 1 to 10 hours.

[0044] Step (c1) is a step of forming the catalyst molded body in a predetermined form, and the compressive strength of the molded body may be improved by pressurization. The pressure molding may be performed by an extruder, a roller press, and the like.

[0045] Step (c2) may remove moisture by primarily performing drying at room temperature, and may be performed for, for example, 1 hour, 6 hours, 12 hours, 18 hours, 24 hours, 30 hours, 36 hours, 42 hours, 48 hours, or hours in a range between two values thereof.

[0046] Step (c3) performs secondary drying under high temperature conditions, and may be performed at 90° C., 95° C., 100° C., 105° C., 110° C., 115° C., 120° C. or a temperature in a range between two values thereof for 1 hour, 4 hours, 8 hours, 12 hours, 16 hours, 20 hours, 24 hours or hours in a range between two values thereof.

[0047] Step (c4) may remove moisture and the organic binder by performing firing at 350° C., 375° C., 400° C., 425° C., 450° C., 475° C., 500° C., 525° C., 550° C., 575° C., 600° C., 625° C., 650° C. or a temperature in a range between two values thereof for 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours or hours in a range between two values thereof.

[0048] When the catalyst molded body 7 is dried and fired step by step under different temperature conditions as described in (c2) to (c4), the removal rate of moisture and the like may be adjusted to improve the mechanical strength of the catalyst molded body and maximize an area where catalysis is possible.

[0049] Catalyst Molded Body

[0050] The catalyst molded body according to another aspect of the present specification may be produced by the above-described method for producing a catalyst-molded body. FIG. 1 illustrates an example of a catalyst molded body according to an exemplary embodiment of the present specification.

[0051] The catalyst molded body may have a compressive strength of 10 N or more. The compressive strength may be, for example, 10 N, 11 N, 12 N, 13 N, 14 N, 15 N, 16 N, 17 N, 18 N, 19 N, 20 N, 21 N, 22 N, 23 N, 24 N, 25 N, 26 N, 27 N, 28 N, 29 N, 30 N, 31 N, 32 N, 33 N, 34 N, 35 N, 36 N, 37 N, 38 N, 39 N, 40 N, 41 N, 42 N, 43 N, 44 N, 45 N, 46 N, 47 N, 48 N, 49 N, 50 N, 51 N, 52 N, 53 N, 54 N, 55 N, 56 N, 57 N, 58 N, 59 N, 60 N, 61 N, 62 N, 63 N, 64 N, 65 N, 66 N, 67 N, 68 N, 69 N, 70 N, 71 N, 72 N, 73 N, 74 N, 75 N, 76 N, 77 N, 78 N, 79 N, 80 N, 81 N, 82 N, 83 N, 84 N, 85 N, 86 N, 87 N, 88 N, 89 N, 90 N, 91 N, 92 N, 93 N, 94 N, 95 N, 96 N, 97 N, 98 N, 99 N, 100 N or in a range between two values thereof. The catalyst molded body may have excellent mechanical strength due to the combination with the binder, the enhancer, and the drying process.

[0052] The catalyst molded body may have a diameter of 1.0 to 10.0 mm, for example, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm, 7.0 mm, 7.5 mm, 8.0 mm, 8.5 mm, 9.0 mm, 9.5 mm, 10.0 mm or in a range between two values thereof.

[0053] Since the catalyst molded body may improve the rate of the aldol condensation reaction, and also has sufficient mechanical strength and stability, the catalyst molded body may be applied to a fixed-bed catalyst reactor.

[0054] In addition, the catalyst molded body has excellent stability even at a high temperature of 200 to 350° C. and even though the reaction is performed for a long time, the activity is maintained, and thus the catalyst molded body may be suitably applied to a continuous-type reactor.

[0055] Method for Producing Cyclic Ketone

[0056] The method for producing cyclic ketone according to another aspect of the present specification may include: (i) preparing a reactant including non-cyclic ketone; and (ii) reacting the reactant with the above-described catalyst molded body in a reactor.

[0057] FIG. 2 illustrates an example of a reactor to which the method for producing cyclic ketone is applied.

[0058] Referring to FIG. 2, Step (i) may mix a reactant including non-cyclic ketone in a mixer, and then heat the reactant in a pre-heater.

[0059] The reaction in Step (ii) is a heterogeneous catalytic reaction and may be performed by a batch-type or continuous-type process. A method for producing cyclic ketone in the related art has a problem in that it is difficult to perform the method by a continuous-type process because the stability and mechanical strength of the catalyst are insufficient, so a homogeneous catalytic process, in which a reactant and a catalyst are mixed and introduced into a batch-type reactor, and then neutralization and filtration processes are performed, was used. When the catalyst molded body having excellent service life is used, both a batch-type process using a slurry reactor and a continuous-type process using a fixed-bed reactor can be applied.

[0060] When the reaction in Step (ii) is performed by a batch-type process, the reactant prepared in Step (i) is mixed with the above-described catalyst molded body, and then an aldol condensation reaction is performed in a batch-type reactor, the catalyst molded body is recovered, and the product may be obtained by distillation.

[0061] When the reaction in Step (ii) is performed by a continuous-type process, the reactant prepared in Step (i) may be introduced into a reactor packed with the above-described catalyst molded body, and the reactor may perform a reaction at 200 to 350° C., for example, 200° C., 210° C., 220° C., 230° C., 240° C., 250° C., 260° C., 270° C., 280° C., 290° C., 300° C., 310° C., 320° C., 330° C., 340° C., 350° C. or a temperature in a range between two values thereof. The reactor may be packed with a catalyst molded body so as to satisfy a liquid hourly space velocity (LHSV) condition of 0.15 to 1.50 h−1, for example, 0.15 h.sup.−1, 0.20 h.sup.−1, 0.25 h.sup.−1, 0.30 h.sup.−1, 0.35 h.sup.−1, 0.40 h.sup.−1, 0.45 h.sup.−1, 0.50 l/h, 0.55 h.sup.−1, 0.60 h.sup.−1, 0.65 h.sup.−1, 0.70 h.sup.−1, 0.75 h.sup.−1, 0.80 h.sup.−1, 0.85 h.sup.−1, 0.90 h.sup.−1, 0.95 h.sup.−1, 1.00 h.sup.−1, 1.05 h.sup.−1, 1.10 h.sup.−1, 1.15 h.sup.−1, 1.20 h.sup.−1, 1.25 h.sup.−1, 1.30 h.sup.−1, 1.35 h.sup.−1, 1.40 h.sup.−1, 1.45 h.sup.−1, 1.50 h.sup.−1 or in a range between two values thereof. When the liquid hourly space velocity is excessively low, the selectivity of a target product may be reduced, and when the liquid hourly space velocity is excessively high, the reaction is insufficiently performed, and thus, the step may be uneconomical due to a low process conversion rate. When the liquid hourly space velocity satisfy the conditions of 0.20 to 0.80 h.sup.1, a cyclic ketone selectivity of 60% or more and a by-product yield less than 10% may be simultaneously satisfied, but the values are not limited thereto.

[0062] When the reaction in Step (ii) is performed by a continuous-type process, the product yield is relatively increased, and the process cost may be reduced compared to a batch-type process which requires a filtration process for increasing the temperature, cooling the reactor and recovering the catalyst at each batch. When a catalyst in the related art is used, stability is insufficient when the catalyst is used under high temperature conditions or for a long time, so it is difficult to apply a continuous-type process, but the difficulty can be solved using the catalyst molded body.

[0063] After Step (ii), it is possible to further include isolating cyclic ketone from the product in Step (iii). The isolation may isolate cyclic ketone, recycled raw materials and by-products by combining known various methods, for example, various methods such as filtration, distillation, concentration under reduced pressure, layer separation, adsorption, absorption, and extraction.

[0064] The raw material isolated in Step (iii) may be used in mixture with the reactant in Step (i) and recycled.

[0065] For example, Step (iii) may remove water by layer separating the product and isolate cyclic ketone, recycled raw materials and by-products by distillation. Since the catalyst molded body has sufficient stability even when distilled recycled raw materials including impurities are used, cyclic ketone may be produced by applying a recirculation flow as described above.

[0066] Hereinafter, the examples of the present invention will be described in more detail. However, the following experimental results describe only representative experimental results among the above-mentioned examples, and the scope and contents of the present invention should not be interpreted as being reduced or limited by the examples, and the like. The effects of each of various embodiments of the present invention, which are not explicitly set forth below, will be described in detail in a corresponding section.

Preparation Example

[0067] A mixed powder was produced by mixing a magnesium-aluminum oxide catalyst powder, an inorganic binder and an organic binder. An aqueous solution of the mixed powder mixed with an enhancer and distilled water was added thereto, extruded, and then primarily dried at 25° C. for 24 hours. After secondary drying was performed at 105° C. for 12 hours, a catalyst molded body was produced by firing the resulting product at 500° C. for 4 hours to remove water and the organic binder.

Example 1

[0068] During the production of isophorone using acetone by producing the catalyst powder by a known co-precipitation method, characteristics of the catalyst molded body according to the magnesium-aluminum molar ratio (Mg/Al) were confirmed, and the results are shown in the following Table 1. All the remaining conditions were equally maintained.

TABLE-US-00001 TABLE 1 Example Example Example Example Classification 1-1 1-2 1-3 1-4 Mg/Al molar 1.0 2.5 3.0 3.5 ratio Acetone 28.4 23.7 30.9 21.3 conversion rate (%) IPH selectivity 64.2 65.8 68.4 57.5 (%) IPH + MO 75.4 77.8 75.0 82.5 selectivity (%) By-product 24.6 22.2 25.0 17.5 selectivity (%) IPH yield (%) 18.2 15.6 21.1 12.3 IPH + MO yield 21.4 18.5 23.2 17.6 (%) By-product 7.0 5.3 7.7 3.7 yield (%)

[0069] Referring to Table 1, the catalyst molded body had a 2 to 4-fold higher IPH yield compared to the by-product yield, and thus minimized the production of by-products, and could produce cyclic ketone. It can be confirmed that Examples 1-1 to 1-3 satisfying a Mg/Al molar ratio of 1.0 to 3.0 have an IPH selectivity of 60% or more, which is excellent, and both the acetone conversion rate and the IPH selectivity are sharply reduced around a molar ratio of 3.0 to 3.5.

Example 2

[0070] The characteristics of the catalyst molded body were confirmed while varying the type, content and molding equipment of the inorganic binder, and the results are shown in the following Tables 2 and 3. All the remaining conditions were equally maintained.

TABLE-US-00002 TABLE 2 Comparative Comparative Example Example Example Example Classification Example 2-1 Example 2-2 2-1 2-2 2-3 2-4 Inorganic — 5 wt % of 2 wt % of 5 wt % of 10 wt % of 5 wt % of binder MgO CaO CaO CaO Al.sub.2O.sub.3 Acetone 44.7 40 52.9 41.6 48.9 50.1 conversion rate (%) IPH 64.8 64.1 56.9 65.5 56.3 59.1 selectivity (%) IPH + MO 68.4 68.7 59.8 69.5 60 61.4 selectivity (%) By-product 31.6 31.3 40.2 30.5 40 38.6 selectivity (%) IPH yield 29 25.6 30.2 27.3 27.6 29.6 (%) IPH + MO 30.6 27.5 31.7 29 29.4 30.8 yield (%) By-product 14.2 13.5 21.3 12.7 19.6 19.3 yield (%) Compressive — — 15 10 65 40 strength (N)

[0071] Referring to Table 2, Comparative Example 2-1 including no inorganic binder or Comparative Example 2-2 including magnesium oxide as the inorganic binder had an insufficient compressive strength due to the insufficient binding force between mixed powders, but Examples 2-1 to 2-4 including potassium oxide or aluminum oxide as the inorganic binder had a high compressive strength of 10 N or more, and thus can be applied to a fixed-bed catalyst reactor. In particular, Example 2-2 in which 5 wt % of calcium oxide was added had high IPH selectivity while having a low by-product yield.

TABLE-US-00003 TABLE 3 Comparative Example Example Example Example Example Classification Example 2-1 2-2 2-5 2-6 2-7 2-8 Binder/process — 5 wt % of 5 wt % of 5 wt % of 5 wt % of 5 wt % of CaO CaO/press CaO/firing CaO + 5 CaO + 10 wt % of wt % of Al.sub.2O.sub.3 Al.sub.2O.sub.3 Acetone 44.7 41.6 49.9 53.8 50.2 46 conversion rate (%) IPH selectivity 64.8 65.5 61.5 55.5 61.1 62.3 (%) IPH + MO 68.4 69.5 64 58.4 63.7 65.8 selectivity (%) By-product 31.6 30.5 36 41.6 36.3 34.2 selectivity (%) IPH yield (%) 29 27.3 30.7 29.9 30.7 28.6 IPH + MO 30.6 29 31.9 31.4 32 30.2 yield (%) By-product 14.2 12.7 18 22.4 18.2 15.7 yield (%) Compressive — 10 26 18 33 33 strength (N)

[0072] Referring to Table 3, Examples 2-5 and 2-6, in which the inorganic binder was included and pressure molding was performed by a roller press or a firing process was applied, had a remarkably improved compressive strength and an increased IPH yield compared to Example 2-2. In addition, Examples 2-7 and 2-8, in which calcium oxide and aluminum oxide were combined as an inorganic binder, were excellent in IPH yield and compressive strength, and simultaneously could minimize an increase in by-product yield.

Example 3

[0073] The characteristics of the catalyst molded body were confirmed while varying the type and content of the organic binder, and the results are shown in the following Table 4. All the remaining conditions were equally maintained.

TABLE-US-00004 TABLE 4 Comparative Classification Example 3-1 Example 3-1 Example 3-2 Example 3-3 Example 3-4 Organic 5 wt % of 1 wt % of 3 wt % of 1 wt % of 1 wt % of binder MC MC MC CMC AA Acetone — 46 44.5 46 51.5 conversion rate (%) IPH — 62.3 63.5 62.8 58.7 selectivity (%) IPH + MO — 65.8 67.4 66.5 61.4 selectivity (%) By-product — 34.2 32.6 33.5 38.6 selectivity (%) IPH yield — 28.6 28.2 28.9 30.2 (%) IPH + MO — 30.2 30 30.6 31.6 yield (%) By-product — 15.7 14.5 15.4 19.9 yield (%) Compressive 17 33 26 33 32 strength (N) MC: hydroxymethyl cellulose, CMC: carboxymethyl cellulose sodium salt, AA: acetic acid

[0074] Referring to Table 4, it was difficult to apply Comparative Example 3-1 in which the content of the organic binder was 5 wt % because the compressive strength was significantly reduced and the organic binder was not sufficiently removed from the catalyst molded body, but Examples 3-1 to 3-4, in which 1 to 3 wt % of the organic binder was included, could improve the IPH yield and compressive strength.

Example 4

[0075] The characteristics of the catalyst molded body were confirmed while varying the type and content of the enhancer and distilled water, and the results are shown in the following Table 5. All the remaining conditions were equally maintained.

TABLE-US-00005 TABLE 5 Example Example Example Example Example Classification 4-1 4-2 4-3 4-4 4-5 Enhancer — 0.25 wt % 0.5 wt % 1.0 wt % 0.25 wt % of NaOH of NaOH of NaOH of KOH Acetone 46 42 41.1 34.2 44.7 conversion rate (%) IPH 62.8 63.1 62.3 61.7 63.1 selectivity (%) IPH + MO 66.5 67.6 67 69.8 66.7 selectivity (%) By-product 33.5 32.4 33 30.2 33.3 selectivity (%) IPH yield 28.9 26.5 25.6 21.1 28.2 (%) IPH + MO 30.6 28.4 27.5 23.9 29.8 yield (%) By-product 15.4 13.6 13.5 10.3 14.9 yield (%) Compressive 33 39 39 35 50 strength (N)

[0076] Referring to Table 5, Examples 4-2 to 4-5, in which sodium hydroxide or calcium hydroxide was included as an enhancer, had a reduced by-product yield and an improved compressive strength.

Example 5

[0077] The stability of the catalyst molded body during a continuous-type reaction in a fixed-bed catalyst reactor was confirmed. A schematic view of the fixed-bed catalyst reactor is illustrated in FIG. 2.

[0078] The catalyst molded body was reacted by introducing only pure acetone under conditions of a reaction temperature of 285° C., a reaction pressure of 1 barg, and a LHSV of 0.20/h, and the results are illustrated in FIG. 3.

[0079] In addition, in order to confirm stability during the application by recirculating acetone and mesityl oxide through a distillation column in the reactor, the effect of the catalyst molded body on impurities was confirmed by introducing acetone 96%, mesityl oxide 1.6%, tertiary-methylbenzene 0.1% and water 1.3%, and the results are shown in FIG. 4.

[0080] Referring to FIG. 3, it could be confirmed that the catalyst molded body had excellent stability because the IPH yield was not reduced even when the reaction was performed for 1,500 hours or more. Furthermore, referring to FIG. 4, the catalyst molded body is excellent in stability even in the presence of impurities, so the activity was not significantly reduced even though acetone was recirculated.

[0081] The above-described description of the present invention is provided for illustrative purposes, and a person skilled in the art to which the present invention pertains will understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are only illustrative in all aspects and not restrictive. For example, each constituent element which is described as a singular form may be implemented in a distributed form, and similarly, constituent elements which are described as being distributed may be implemented in a combined form.

[0082] The scope of the present invention is represented by the claims to be described below, and it should be interpreted that the meaning and scope of the claims and all the changes or modified forms derived from the equivalent concepts thereto fall within the scope of the present invention.