Non-noble metal-supported zirconium phosphate catalyst for generating cyclic hydrocarbon, and method for preparing cyclic hydrocarbon by using same

Abstract

This invention relates to a catalyst for preparing a cyclic hydrocarbon, which is a non-noble-metal supported on zirconium phosphate, and to a method of preparing a cyclic hydrocarbon, including preparing a cyclic hydrocarbon from a lignin derivative through hydrodeoxygenation and hydrogenation using the catalyst for preparing a cyclic hydrocarbon.

Claims

1. A method of preparing a cyclic hydrocarbon, comprising preparing a cyclic hydrocarbon from a lignin derivative through hydrodeoxygenation and hydrogenation using a catalyst, wherein the catalyst is a non-noble-metal supported on zirconium phosphate.

2. The method of claim 1, wherein the hydrodeoxygenation and hydrogenation are carried out under conditions of a reaction temperature of 200 to 400 C., a total pressure of 40 to 70 bar, and a reaction time of 1 to 3 hr.

3. The method of claim 1, wherein the lignin derivative is guaiacol, anisole, catechol, phenol or veratrol.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a graph showing the results of guaiacol hydrodeoxygenation conversion and cyclohexane yield of comparative supports;

(2) FIG. 2 is a graph showing the results of guaiacol hydrodeoxygenation conversion and cyclohexane yield of comparative metals;

(3) FIG. 3 is a graph showing the cyclohexane yield and conversion as the results of guaiacol hydrodeoxygenation and hydrogenation depending on the amount of cobalt that is supported; and

(4) FIG. 4 is a graph showing the cyclohexane yield and conversion as the results of guaiacol hydrodeoxygenation and hydrogenation depending on the amount of nickel that is supported.

DETAILED DESCRIPTION

(5) Hereinafter, a detailed description will be given of the present invention.

(6) The present invention addresses a catalyst for preparing a cyclic hydrocarbon, which is a non-noble-metal supported on zirconium phosphate.

(7) The catalyst for preparing a cyclic hydrocarbon according to the present invention is configured such that a non-noble metal is supported on a zirconium phosphate support.

(8) In the present invention, zirconium phosphate, serving as the support, preferably has a P/Zr molar ratio of 1:1 to 1:3.

(9) The non-noble metal preferably includes, but is not necessarily limited to, nickel, cobalt, iron, molybdenum or alloys thereof.

(10) The non-noble metal is preferably supported in an amount of 10 to 40 wt %, and more preferably 20 to 30 wt %, based on the weight of the zirconium phosphate. Within the above amount range, both the metal and the support of the non-noble-metal supported on zirconium phosphate catalyst participate in the reaction. If the amount thereof is less than 10 wt %, active sites of metal may become insufficient. On the other hand, if the amount thereof exceeds 40 wt %, the metal may block the active sites of the support, thus deteriorating the activity of the catalyst.

(11) The catalyst is used for the preparation of a cyclic hydrocarbon from a lignin derivative serving as a reactant.

(12) In addition, the present invention addresses a method of preparing a cyclic hydrocarbon, including preparing a cyclic hydrocarbon from a lignin derivative through hydrodeoxygenation and hydrogenation using the above catalyst.

(13) The lignin derivative is converted into a cyclic hydrocarbon through hydrodeoxygenation and hydrogenation in the above preparation method.

(14) The lignin derivative may include guaiacol, anisole, catechol, phenol or veratrol, and is preferably guaiacol. Here, guaiacol is dissolved in an organic solvent such as n-hexane, n-decane, dodecane, p-xylene, etc.

(15) The cyclic hydrocarbon may include cyclohexane, 1,1-bicyclohexyl, or the like, and is mainly cyclohexane.

(16) In the preparation method according to the present invention, the cyclic hydrocarbon is preferably prepared under conditions of a reaction temperature of 200 to 400 C., a total pressure of 40 to 70 bar and a reaction time of 1 to 3 hr.

(17) In an embodiment of the present invention, a guaiacol reactant and a non-noble-metal supported on zirconium phosphate are placed in a batch-type reactor, and are then allowed to react at a reaction temperature of 200 to 400 C. and a total pressure of 40 to 70 bar for a reaction time of 1 to 3 hr, whereby guaiacol is converted into cyclohexane, or may also be converted into cyclohexanol and methoxycyclohexanol.

MODE FOR INVENTION

(18) A better understanding of the present invention may be obtained via the following examples, which are merely set forth to illustrate but are not to be construed as limiting the scope of the present invention.

Example 1

Preparation of nCo/ZrP (n=20 wt %, 25 wt %, 30 wt %) Catalyst

(19) Zirconium (IV) hydrogen phosphate (P/Zr molar ratio of 1.2, Sigma Aldrich) was heated at a rate of 1 C./min and fired at 400 C. for 4 hr and thus used as a support. The pore volume of the prepared support was measured through nitrogen adsorption-desorption testing, and cobalt was supported using an incipient wetness method.

(20) The fired zirconium phosphate support was added with cobalt (II) nitrate hexahydrate (Sigma Aldrich) in an amount of n wt % (n=20, 25, 30) based on the weight of the support using an incipient wetness method and then dried at 100 C. for 24 hr. Thereafter, the dried catalyst was fired at 450 C. for 5 hr, thus obtaining a solid catalyst in a powder phase.

(21) Subsequently, the catalyst thus obtained was reduced at 510 C. for 3 hr in a hydrogen atmosphere, thereby yielding a cobalt/zirconium phosphate catalyst in a black powder phase.

Example 2

Preparation of nNi/ZrP (n=20 wt %, 25 wt %, 30 wt %) Catalyst

(22) This catalyst was synthesized in the same manner as in Example 1, with the exception that a nickel precursor (nickel (II) nitrate hexahydrate, Sigma Aldrich) was used in lieu of the cobalt precursor.

Comparative Example 1

Preparation of 2 wt % Pt/ZrP Catalyst

(23) This catalyst was synthesized in the same manner as in Example 1, with the exception that a platinum precursor (tetraammineplatinum (II) nitrate, Sigma Aldrich) was used in lieu of the cobalt precursor.

Comparative Example 2

Preparation of 2 wt % Pd/ZrP Catalyst

(24) This catalyst was synthesized in the same manner as in Example 1, with the exception that a palladium precursor (palladium (II) nitrate hydrate, Sigma Aldrich) was used in lieu of the cobalt precursor.

Comparative Example 3

Preparation of 25 wt % Co/ZSM-5 (11.5) Catalyst

(25) ZSM-5 (Si/Al molar ratio of 11.5, Zeolyst), fired at 500 C. for 5 hr, was used as a support, added with a cobalt precursor in an amount of 25 wt % based on the weight of the ZSM-5 support using an incipient wetness method, and then dried at 100 C. for 24 hr. Thereafter, the dried catalyst was fired at 500 C. for 5 hr, thus obtaining a solid catalyst in a powder phase, which was then reduced at 510 C. for 3 hr in a hydrogen atmosphere, thereby yielding a cobalt/ZSM-5 (11.5) catalyst in a black powder phase.

Comparative Example 4

Preparation of 25 wt % Co/SA (40) Catalyst

(26) This catalyst was synthesized in the same manner as in Comparative Example 3, with the exception that silica-alumina SIRAL (40) (Al.sub.2O.sub.3:SiO.sub.2=60:40, Sasol), fired at 500 C. for 5 hr, was used as a support.

Experimental Example 1

Preparation of Cyclohexane through Hydrodeoxygenation and Hydrogenation of Lignin Derivative Guaiacol Using the above Catalyst

(27) 50 ml of a dodecane solvent was added with 0.2 M guaiacol and 0.5 g of the catalyst (nCo/ZrP) of Example 1, and the resulting mixture was placed in a batch-type reactor and heated to 300 C., and the total pressure was maintained at 70 bar using a hydrogen gas, after which the reaction was carried out at 300 rpm for 2 hr 30 min, thus preparing cyclohexane. The temperature was then decreased to room temperature, and a guaiacol conversion and a yield of a final product, namely cyclohexane, were measured. The results are shown in FIG. 3.

(28) The guaiacol conversion and the cyclohexane yield were calculated using Equations 1 and 2 below.

(29) $\begin{array}{cc}{X}_{\mathrm{GUA}}\left(\%\right)=\frac{{n\left(\mathrm{GUA}\right)}_{\mathrm{initial}}-{n\left(\mathrm{GUA}\right)}_{\mathrm{final}}}{{n\left(\mathrm{GUA}\right)}_{\mathrm{initial}}}100& \mathrm{Equation}1\\ Y_{\mathrm{Cyclohexane}}\left(\%\right)=\frac{{n\left(\mathrm{Product}\right)}_{\mathrm{Cyclohexane}}}{{n\left(\mathrm{GUA}\right)}_{\mathrm{initial}}}100& \mathrm{Equation}2\end{array}$

Experimental Example 2

(30) Cyclohexane was prepared in the same manner as in Test Example 1, with the exception that the catalyst (nNi/ZrP) of Example 2 was used. Thereafter, the temperature was decreased to room temperature, and the yield of a final product was measured. The results are shown in FIG. 4.

Comparative Experimental Example 1

(31) Cyclohexane was prepared in the same manner as in Test Example 1, with the exception that the catalyst (2 wt % Pt/ZrP) of Comparative Example 1 was used. Thereafter, the temperature was decreased to room temperature, and the yield of a final product was measured. The results are shown in FIG. 2.

Comparative Experimental Example 2

(32) Cyclohexane was prepared in the same manner as in Test Example 1, with the exception that the catalyst (2 wt % Pt/ZrP) of Comparative Example 2 was used. Thereafter, the temperature was decreased to room temperature, and the yield of a final product was measured. The results are shown in FIG. 2.

Comparative Experimental Example 3

(33) Cyclohexane was prepared in the same manner as in Test Example 1, with the exception that the catalyst (25 wt % Co/ZSMS (11.5)) of Comparative Example 3 was used. Thereafter, the temperature was decreased to room temperature, and the yield of a final product was measured. The results are shown in FIG. 1.

Comparative Experimental Example 4

(34) Cyclohexane was prepared in the same manner as in Test Example 1, with the exception that the catalyst (25 wt % Co/SA (40)) of Comparative Example 4 was used. Thereafter, the temperature was decreased to room temperature, and the yield of a final product was measured. The results are shown in FIG. 1.

(35) Based on the test results, as shown in FIG. 1, when the zirconium phosphate support according to the present invention was used, a rather high cyclohexane yield was obtained compared to when using typical supports having different acid sites, such as SIRAL (40) (Al.sub.2O.sub.3:SiO.sub.2=60:40, Sasol) and ZSM-5 (Si/Al ratio of 11.5, Zeolyst).

(36) As shown in FIG. 2, when the zirconium phosphate support according to the present invention was used, higher cyclohexane yield was obtained in the presence of a non-noble metal such as Ni or Co than in the presence of a noble metal such as Pd or Pt, typically useful for HDO. In particular, the use of Co led to a cyclohexane yield of 88%.

(37) Based on the test results, according to the present invention, a conversion of 99% was achieved in a short reaction time of 2 hr 30 min, and a maximum cyclohexane yield was measured to be 88%.

(38) According to the present invention, the catalyst has no need to treat sulfur that is liable to contaminate a product, and enables the production of cyclohexane at high yield under relatively simple conditions.