KR20210024791A - Catalyst for hydrodeoxygenation of guaiacol and method for selective production of hydrocarbon compounds from guaiacol using the same - Google Patents

Abstract

The present invention relates to a catalyst for hydrodeoxygenation of guaiacol and a method for selectively producing a hydrocarbon compound from guaiacol using the same. A NiMo/Al_2O_3-TiO_2 catalyst produced with a specific Ni/Mo composition ratio and reduction temperature by the method according to the present invention shows high guaiacol conversion, HDO conversion and hydrocarbon selectivity, and thus may be useful for the production of cyclohexane, methylcyclohexane and toluene from guaiacol via the HDO reaction.

Description

Catalyst for hydrodeoxygenation of guaiacol and method for selective production of hydrocarbon compounds from guaiacol using the same}

The present invention relates to a catalyst for hydrogenation and deoxidation of guiacol and a method for selectively producing cyclohexane, methylcyclohexane and toluene from guiacol using the same.

Currently, nearly 95% of transportation fuel is fossil fuel-based, and consumes about 30% of the world's energy. In order to solve the problem of depletion of fossil fuels and environmental and economic problems, efforts to produce transport fuels from renewable resources are needed. The conversion of lignocellulosic biomass is one of the most efficient ways to produce biofuels, but lignin-based biocrude usually has a high oxygen content, so it lowers acidity and viscosity and increases low calorific value. It is necessary to remove oxygen in order to improve the characteristics of bio-oil. Hydrodeoxygenation (HDO) is a process of removing oxygen functional groups by using a specific catalyst for the selective decomposition of C-O and C-C bonds in oxygen-containing compounds.

One of the biggest problems in manufacturing biomass-based transportation fuel is to collect carbon while removing oxygen, and development of a suitable catalyst is required to efficiently and inexpensively remove oxygen. The hydrogenation and deoxidation of lignin by a noble metal catalyst that produces a wide range of hydrocarbons has a disadvantage that it is difficult to utilize in an industrial scale due to its high cost. Transition metals such as Ni, Mo, and Co have been widely used as catalysts for hydrogenation and deoxidation due to their high catalytic activity and reasonable cost. In the case of these metals, a single metal species (Ni, Mo, Co, etc.) or a bimetallic species (NiMo, CoMo, NiCo, etc.) may be used as a catalyst for the hydrogenation and deoxidation reaction. The role of activated carbon-supported metal species in the conversion of phenol to HDO has been reported; however, a detailed study of the roles of Ni and Mo species and the Ni/Mo ratio has not been systematically studied.

On the other hand, the impregnation method is a widely used method for producing a catalyst. However, this method has a problem in that it may cause a low density of active sites on the surface of the support, which can reduce the catalytic activity of the catalyst, or a non-uniform distribution of the metal active sites within the support.

Accordingly, the present inventors developed a transition metal-based catalyst, that is, a bimetallic NiMo/Al ₂ O ₃ -TiO ₂ catalyst, by combining a sol-gel method and a continuous flow spray pyrolysis process. The present invention was completed by confirming the effect of the Ni/Mo ratio and the reduction temperature on the HDO conversion rate and product selectivity.

Korean Patent Registration No. 10-1985174

An object of the present invention is to provide a catalyst for hydrodeoxygenation (HDO) reaction of guaiacol.

Another object of the present invention is to provide a method for preparing a hydrocarbon compound from guiacol using the catalyst.

Another object of the present invention is to provide cyclohexane, methylcyclohexane, and toluene prepared by the above method.

To achieve the above object,

The present invention is based on 30 parts by weight of NiMo as a bimetallic catalyst active part; And Al ₂ O ₃ and TiO ₂ 68-72 parts by weight of a support including one or more of; It provides a catalyst for hydrodeoxygenation (HDO) reaction of guaiacol, including.

In addition, the present invention provides a method for preparing a hydrocarbon compound from guiacol, comprising the following steps using the catalyst:

Preheating a solution containing 1-5% by weight of guiacol to 240-260° C. and then supplying the solution to the reactor (Step 1);

Supplying hydrogen (H ₂ ) to the reactor and mixing it with the guiacol-containing vapor of step 1 (step 2); And

A step of reacting the catalyst and the vapor mixed in step 2 inside the reactor under hydrogen pressure of 290-310° C. and 1-3 MPa (step 3).

Furthermore, the present invention provides cyclohexane, methylcyclohexane, and toluene prepared by the above method.

_{The NiMo/Al 2} O ₃ -TiO ₂ catalyst prepared with a specific Ni/Mo composition ratio and reduction temperature by the method according to the present invention shows high guaiacol conversion, HDO conversion, and hydrocarbon selectivity, so that the HDO reaction from guiacol It may be useful for the production of hydrocarbon compounds through.

1 is a schematic diagram showing a catalytic hydrodeoxygenation (HDO) reaction process in a continuous fixed bed reactor.
_{2 is an Al 2} O ₃ -TiO ₂ support prepared by the sol-gel method and spray pyrolysis according to the present invention _{and of the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having different Ni/Mo weight ratios This is an FE-SEM image; (a) Al ₂ O ₃ -TiO ₂ support, (b) 30Mo/Al ₂ O ₃ -TiO ₂ , (c) 5Ni25Mo/Al ₂ O ₃ -TiO ₂ , (d) 10Ni20Mo/Al ₂ O ₃ -TiO ₂ , (e) 15Ni15Mo/Al ₂ O ₃ -TiO ₂ , (f) 20Ni10Mo/Al ₂ O ₃ -TiO ₂ , (g) 25Ni5Mo/Al ₂ O ₃ -TiO ₂ and (h) 30Ni/Al ₂ O _3- TiO ₂ .
3 is a SEM image and EDX dot mapping (Al, Ti, Mo and Ni) of (a) 10Ni20Mo/Al ₂ O ₃ -TiO ₂ and (b) 15Ni15Mo/Al ₂ O ₃ -TiO _{2 catalyst according to the present invention.} This is the image shown.
4 is a spectrum showing the XRD pattern _{of the Al 2} O ₃ -TiO _{2 support and the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having various Ni/Mo weight ratios according to the present invention; (a) Al ₂ O ₃ -TiO ₂ support, (b) 30Mo/Al ₂ O ₃ -TiO ₂ , (c) 5Ni25Mo/Al ₂ O ₃ -TiO ₂ , (d) 10Ni20Mo/Al ₂ O ₃ -TiO ₂ , (e) 15Ni15Mo/Al ₂ O ₃ -TiO ₂ , (f) 25Ni5Mo/Al ₂ O ₃ -TiO ₂ and (g) 30Ni/Al ₂ O ₃ -TiO ₂ .
5 is a spectrum showing the structure characteristics _{of the Al 2} O ₃ -TiO _{2 support and the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having various Ni/Mo weight ratios according to the present invention; (a) N ₂ adsorption-desorption isotherms and (b) pore size distribution.
_{6 is an Al 2} O ₃ -TiO ₂ support calcined by the method according to the present invention _{and NH 3} -TPD _{of the NiMo/Al 2} O ₃ -TiO ₂ catalyst of Examples 1 to 5 and 7 having various Ni/Mo weight ratios It is a spectrum showing the profile.
7 is a spectrum showing the H ₂ -TPR profile of _{the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having various Ni/Mo weight ratios fired by the method according to the present invention.
8 is an XPS spectrum of _{the reduced NiMo/Al 2} O ₃ -TiO ₂ catalyst of Examples 1 to 7 according to the present invention; (a) Mo 3d and (b) Ni 2p.
9 shows the conversion rate, HDO conversion rate, and product distribution of guiacol obtained from the hydrogenation and deoxidation (HDO) reaction for the _{reduced NiMo/Al 2} O ₃ -TiO ₂ catalyst having various Ni/Mo weight ratios according to the present invention. This is the graph shown; Reaction conditions: 0.15 mL/min of liquid guiacol supplied, 60 mL/min of H ₂ supplied, 300° C. 2 MPa, and reaction time of 2 hours.
10 is a diagram showing the HDO conversion reaction path of guaiacol to the reduced NiMo/Al ₂ O ₃ -TiO _{2 catalyst according to the present invention;} HDO: Hydrodeoxygenation, HYD: Hydrogenation.
11 is a graph showing the conversion rate and product distribution _{of guiacol for the reduced 10Ni20Mo/Al 2} O ₃ -TiO ₂ catalyst according to the reduction temperatures of 500, 600 and 700°C.
_{12 is an XPS spectrum of a reduced 10Ni20Mo/Al 2} O ₃ -TiO ₂ catalyst (Example 3) according to a reduction temperature change during HDO reaction; (a) Mo 3d and (b) Ni 2p.
13 is a graph showing the conversion rate and product distribution of guaiacol during the HDO reaction time of 24 hours for _{the 10Ni20Mo/Al 2} O ₃ -TiO ₂ catalyst reduced at 700°C.
14 is an XPS spectrum of a catalyst immediately after reduction (freshyly reduced) and a spent catalyst used in the HDO reaction; (a) Mo 3d and (b) Ni 2p.

Hereinafter, the present invention will be described in detail.

Catalyst for hydrogenation and deoxidation of guiacol

The present invention is based on 30 parts by weight of NiMo as a bimetallic catalyst active part; And Al ₂ O ₃ and TiO ₂ 68-72 parts by weight of a support including one or more of; It provides a catalyst for hydrodeoxygenation (HDO) reaction of guaiacol, including.

In the catalyst for hydrodeoxidation reaction of guiacol according to the present invention, the hydrogenation and deoxidation reaction of guiacol is performed by cyclohexane, methylcyclohexane, and toluene from guiacol. ) May be converted to one or more hydrocarbon compounds selected from the group consisting of, and preferably converted to cyclohexane.

In the catalyst for hydrogenation and deoxidation of guiacol according to the present invention, the NiMo may be a mixture of Ni and Mo in a weight ratio of 7-23:7-23. When Ni or Mo is contained less than the weight ratio, there may be a problem that the guaiacol conversion rate and the HDO conversion rate are lowered.

Preferably, the NiMo may be Ni and Mo mixed in a weight ratio of 9-20:10-21, more preferably, the NiMo is Ni and Mo mixed in a weight ratio of 9-11:19-21 It may have been. When Ni and Mo are mixed in the weight ratio range, the highest guaiacol conversion and HDO conversion may be exhibited, and 100% hydrocarbon selectivity may be exhibited (see Experimental Example 2-1).

According to an embodiment of the present invention, the catalyst for the hydrogenation and deoxidation reaction of guiacol according to the present invention uses bimetallic NiMo as a catalyst, thereby providing more improved catalytic activity than when using a single metal Ni and Mo as a catalyst. There is an effect that can be exerted (see Experimental Examples 1-2 to 1-4 and 2-1).

In the old children hydrogenated de-oxidation catalyst of ahkol according to the invention, the support may be one that contains at least one kind of Al ₂ O ₃ and TiO _2, that contains all of the Al ₂ O ₃ and TiO ₂ It may be, and preferably Al ₂ O ₃ and TiO _{2 may be an Al 2} O ₃ -TiO ₂ composite support mixed in a weight ratio of 75 ~ 85:15 ~ 25, but is not limited thereto.

The catalyst for the hydrogenation and deoxidation reaction of guiacol according to the present invention may be prepared in one-step by combining a sol-gel method and a spray pyrolysis method, and thus Ni and Mo metals serving as catalysts It can be uniformly doped in this support (see Experimental Example 1-1).

Method for producing hydrocarbon compounds from guiacol

In addition, the present invention provides a method for preparing a hydrocarbon compound from guiacol, comprising the following steps using the catalyst:

Preheating a solution containing 1-5% by weight of guiacol to 240-260° C. and then supplying the solution to the reactor (Step 1);

Supplying hydrogen (H ₂ ) to the reactor and mixing it with the guiacol-containing vapor of step 1 (step 2); And

A step of reacting the catalyst and the vapor mixed in step 2 inside the reactor under hydrogen pressure of 290-310° C. and 1-3 MPa (step 3).

In the method for producing a hydrocarbon compound from guiacol according to the present invention, the reactor may be a continuous fix-bed reactor, and the reaction of step 3 is hydrodeoxygenation (HDO). It can be a reaction. The process in which the reaction occurs in a continuous fixed bed reactor is as shown in FIG. 1.

In the method for producing a hydrocarbon compound from guiacol according to the present invention, guiacol and hydrogen mixed in step 2 may be mixed in a molar ratio of 1:90 to 105, preferably 1:95 It may be mixed at a molar ratio of ~100. When mixed outside the molar ratio range, the HDO reaction may not be performed efficiently.

In the method for producing a hydrocarbon compound from guiacol according to the present invention, the catalyst in step 3 may be reduced at 500 to 750°C before the reaction and then used for the reaction, preferably at 690 to 710°C. It may be used for the reaction after reduction. When a catalyst reduced in the above temperature range is used, the catalytic activity for guaiacol conversion, HDO conversion, and hydrocarbon selectivity is greatly improved.In the case of a catalyst reduced to a temperature lower or higher than the above temperature, the catalytic activity may be reduced. In the case of reduction to a high temperature, a lot of energy is required, and thus economical efficiency is also deteriorated (see Experimental Example 2-2).

According to an embodiment of the present invention, the process of reducing the catalyst of step 3 to the temperature includes heating the catalyst from room temperature to 290 to 310°C at a rate of 4 to 6°C/min, and then 290 to 310°C. Heat from 490 to 510°C at a rate of 1 to 3°C/min, hold at 490 to 510°C for 1 to 3 hours, and then, the temperature at 490 to 510°C at a rate of 1 to 3°C/min at 690 Increasing to ~710 ℃, it may be to include a process of holding for 30 minutes to 2 hours at 690 ~ 710 ℃.

In the method for producing a hydrocarbon compound from guiacol according to the present invention, the reaction of step 3 may be preferably reacted for 1 minute to 24 hours, but is not limited thereto, and even if the reaction is performed for 24 hours or more The activity and safety of the catalyst according to the present invention can be maintained (see Experimental Example 2-3).

In the method for producing a hydrocarbon compound from guiacol according to the present invention, the hydrocarbon compound is at least one hydrocarbon compound selected from the group consisting of cyclohexane, methylcyclohexane, and toluene. It may be, preferably, it may be a cyclohexane (cyclohexane).

Furthermore, the present invention provides cyclohexane, methylcyclohexane, and toluene prepared by the above method.

Hereinafter, the present invention will be described in more detail by the following examples. However, the following examples are merely illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

<Example 1-7> NiMo/Al ₂ O ₃ -TiO ₂ Preparation of catalyst

The Al ₂ O ₃ -TiO ₂ composite support and the NiMo/Al ₂ O ₃ -TiO ₂ catalyst were prepared by combining a sol-gel process and a spray pyrolysis method.

Specifically, stable titania sol (0.1M) and boehmite sol (0.2M) were separately prepared through hydrolysis and condensation reactions, and then mixed for 1 hour under stirring conditions. At this time, the amounts of boehmite sol and titania sol were _{fixed to obtain a composite support having a weight ratio of Al 2} O ₃ :TiO ₂ =80:20, and the sol mixture showed a high acidity density.

For loading of the metal catalyst, various amounts of nickel nitrate hexahydrate (Ni(NO ₃ ) ₂ · 6H ₂ O, Sigma Aldrich) and ammonium heptamolybdate with citric acid in the sol mixture under vigorous stirring conditions A mixture containing (ammonium heptamolybdate; (NH ₄ ) ₆ Mo ₇ O ₂₄ ·4H ₂ O, Sigma Aldrich) was added dropwise. The resulting mixture was then used as a precursor solution for spray pyrolysis using a nebulizer having an ultrasonic frequency of 1.7 MHz, and the formed droplets were transferred to a quartz reactor heated to 600° C. by a _{constant flow of N 2 gas.} The obtained spherical particles were precipitated on the bottom of the spray pyrolysis system and collected in a Teflon bag, and then the product sample was fired at 500° C. for 4 hours in a muffle furnace in an atmospheric atmosphere. The calcined catalyst is denoted by xNiyMo, where x and y are the weight percentages of Ni and Mo, respectively, and x+y of the metal loaded in _{Al 2} O ₃ -TiO _{2 is 30 weight percent.}

Nickel nitrate hexahydrate and ammonium heptamolybdate were added dropwise to the sol mixture so that x and y weight percentages of the final catalyst were as shown in Table 1 below.

NiMo/Al ₂ O ₃ -TiO ₂ catalysts
(xNiyMo) x
(Weight percentage of Ni) y
(Weight percentage of Mo) Example 1 30Mo 0 30 Example 2 5Ni25Mo 5 25 Example 3 10Ni20Mo 10 20 Example 4 15Ni15Mo 15 15 Example 5 20Ni10Mo 20 10 Example 6 25Ni5Mo 25 5 Example 7 30Ni 30 0

<Experimental Example 1> Analysis of physical properties of catalyst

1-1. Analysis of catalyst morphology and structure characteristics

The textural properties of the _{Al 2} O ₃ -TiO ₂ support and the NiMo/Al ₂ O ₃ -TiO _{2 catalyst were analyzed using an N 2} porosimetry (TriStar, Micromeritics, USA) at 77K. Prior to analysis, catalyst samples of Examples 1 to 7 were degassed at 150° C. for 12 hours. The specific surface area and N ₂ adsorption-desorption isotherms were determined by the Brunaune-Emmet-Teller (BET) method. The total pore volume was determined by _{N 2} adsorption at a relative pressure of 0.98. The pore size distribution was obtained by the Barrett-Joyner-Halenda (BJH) algorithm. The X-ray diffraction pattern was obtained by a powder X-ray diffractometer (PXRD; MAC-18XHF, Rigaku, Japan) using a Cu Kα radiation source (λ=1.54A). The morphology of the catalyst was analyzed using a field emission scanning electron microscope (FE-SEM; Leo-Supra 55, Carl Zeiss STM, Germany). Each analysis result is shown in FIGS. 2 to 5 and Table 2.

_{2 is an Al 2} O ₃ -TiO ₂ support prepared by the sol-gel method and spray pyrolysis according to the present invention _{and of the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having different Ni/Mo weight ratios This is an FE-SEM image; (a) Al ₂ O ₃ -TiO ₂ support, (b) 30Mo/Al ₂ O ₃ -TiO ₂ , (c) 5Ni25Mo/Al ₂ O ₃ -TiO ₂ , (d) 10Ni20Mo/Al ₂ O ₃ -TiO ₂ , (e) 15Ni15Mo/Al ₂ O ₃ -TiO ₂ , (f) 20Ni10Mo/Al ₂ O ₃ -TiO ₂ , (g) 25Ni5Mo/Al ₂ O ₃ -TiO ₂ and (h) 30Ni/Al ₂ O _3- TiO ₂ .

As shown in FIG. 2, _{since the shape of the catalyst sample did not change even when 30% by weight of metal was doped on the Al 2} O ₃ -TiO ₂ support, all the support and catalyst samples were formed in a spherical shape without agglomeration and ranged from 0.5 to 2 μm. Kept a similar size.

3 is a SEM image and EDX dot mapping (Al, Ti, Mo and Ni) of (a) 10Ni20Mo/Al ₂ O ₃ -TiO ₂ and (b) 15Ni15Mo/Al ₂ O ₃ -TiO _{2 catalyst according to the present invention.} This is the image shown.

EDX dot mappings clearly show that the doped metals Ni and Mo are _{uniformly dispersed throughout the Al 2} O ₃ -TiO _{2 support matrix.} In addition, the Ni/Mo weight ratios of the 10Ni20Mo and 15Ni15Mo samples were analyzed to be approximately 0.45 and 0.9, respectively, which are very close to the calculated values. These results suggest that the spray pyrolysis method used in the present invention is very effective in uniformly doping multi-metal species into the support.

4 is a spectrum showing the XRD pattern _{of the Al 2} O ₃ -TiO _{2 support and the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having various Ni/Mo weight ratios according to the present invention; (a) Al ₂ O ₃ -TiO ₂ support, (b) 30Mo/Al ₂ O ₃ -TiO ₂ , (c) 5Ni25Mo/Al ₂ O ₃ -TiO ₂ , (d) 10Ni20Mo/Al ₂ O ₃ -TiO ₂ , (e) 15Ni15Mo/Al ₂ O ₃ -TiO ₂ , (f) 25Ni5Mo/Al ₂ O ₃ -TiO ₂ and (g) 30Ni/Al ₂ O ₃ -TiO ₂ .

The alumina (Al ₂ O ₃ ) phase is characterized by a set of peaks at 2θ = 37.6, 46.0 and 66.7 ^o (JCPDS card No. 01-080-1385), whereas the characteristic peaks on the _{anatase TiO 2 are 2θ = 25.4} , 37.9, 48.0, 54.3 and 62.8 ^o (JCPDS card No. 03-065-5714). As shown in FIG. 4, _{there is no peak of a molybdenum dopant on the XRD pattern of Mo/Al 2} O ₃ -TiO ₂ , which means that Mo species are well dispersed or dispersed throughout the support. It indicates that it is below the monolayer dispersion amount. On the other hand, in the case of monometallic Ni/Al ₂ O ₃ -TiO ₂ catalyst, the XRD pattern includes peaks at 2θ = 44.6, 51.9, and 76.4 ^o , which is Ni metal (JCPDS card No. 00-004-0850 ), indicating the presence of Ni crystals on the surface of the support. It was confirmed that the XRD peak of bimetallic NiMo/Al ₂ O ₃ -TiO ₂ slightly shifted to a lower 2θ value than the single metal sample due to the formation of the Ni-Mo alloy.

Structure characteristics of the Al ₂ O ₃ -TiO ₂ support and the NiMo/Al ₂ O ₃ -TiO ₂ catalyst are shown in FIGS. 5 and 2.

5 is a spectrum showing the structure characteristics _{of the Al 2} O ₃ -TiO _{2 support and the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having various Ni/Mo weight ratios according to the present invention; (a) N ₂ adsorption-desorption isotherms and (b) pore size distribution.

Catalysts BET, m ² /g Pore volume, cm ³ /g Pore size, nm 80Al ₂ O ₃ -20 TiO ₂ 235 0.22 3.40 30Mo/Al ₂ O ₃ -TiO ₂ 178 0.25 4.22 5Ni25Mo/Al ₂ O ₃ -TiO ₂ 180 0.24 4.04 10Ni20Mo/Al ₂ O ₃ -TiO ₂ 185 0.24 4.06 15Ni-15Mo/Al ₂ O ₃ -TiO ₂ 217 0.27 4.10 20Ni-10Mo/Al ₂ O ₃ -TiO ₂ 225 0.30 4.15 25Ni-5Mo/Al ₂ O ₃ -TiO ₂ 246 0.31 4.04 30Ni/Al ₂ O ₃ -TiO ₂ 257 0.36 4.27

5 and Table 2, the Al ₂ O ₃ -TiO ₂ composite prepared by spray pyrolysis has a specific surface area of 235 m ² /g and a pore volume of ^{0.22 cm 3 /g.} The loading of 30% by weight Mo reduced the ^{specific surface area to 178 m 2} /g due to the pore closure due to the high metal loading. The single metal 30Ni/Al ₂ O ₃ -TiO ₂ had a specific surface area of 257 m ^{2 and a pore volume of 0.36 cm 3} /g, respectively, which was higher than that of the _{original Al 2} O ₃ -TiO _{2 support.} . _{These results may be due to the inhibition of TiO 2} crystal growth by Ni and the generation of pores between the Ni particles and the support. _{The NiMo/Al 2} O ₃ -TiO ₂ catalyst loaded with 30 wt% bimetallic NiMo on the support showed a specific surface area of ^{178-246m 2} /g and a pore volume of ^{0.24-0.31cm 3} /g depending on the metal composition ratio. According to the pore size distribution data (FIG. 5(b)), it was confirmed that the pore size was changed to a larger pore diameter when the metal species were introduced into the support matrix.

1-2. Analysis of ammonia temperature deviation from catalyst

The temperature-programmed desorption of ammonia (NH ₃ -TPD) experiment was performed using a Micromeritics AutoChem II 2920 automatic analyzer equipped with a thermal conductivity detector. _{First, impurities on the surface of the NiMo/Al 2} O ₃ -TiO ₂ catalyst samples of Examples 1 to 7 were removed by pretreatment for 2 hours in a He stream at 400°C. After cooling to 100° C., each sample was saturated with ammonia in a stream of 10% NH ₃ ^{/He at 50 cm 3 /min for 1 hour.} The ammonia desorption step was performed in He at a flow rate of ^{50 cm 3} /min by heating to 700°C at a heating rate of 5°C/min.

_{6 is an Al 2} O ₃ -TiO ₂ support calcined by the method according to the present invention _{and NH 3} -TPD _{of the NiMo/Al 2} O ₃ -TiO ₂ catalyst of Examples 1 to 5 and 7 having various Ni/Mo weight ratios It is a spectrum showing the profile.

Sample Amount of acid site (μmol/g) Total amount of acid sites
(μmol/g) Aciditic density
(μmol/m ² ) Weak
(< 250℃) Moderate
(250-500℃) Strong
(>500℃) Al ₂ O ₃ -TiO ₂ 148.2 205.9 166.1 520.2 2.21 30Mo/Al ₂ O ₃ -TiO ₂ 282.9 129.7 17.4 430.0 2.42 5Ni25Mo/Al ₂ O ₃ -TiO ₂ 269.6 188.2 42.7 500.5 2.78 10Ni20Mo/Al ₂ O ₃ -TiO ₂ 204.7 225.6 59.1 518.2 2.80 15Ni15Mo/Al ₂ O ₃ -TiO ₂ 178.5 279.1 81.7 539.4 2.49 25Ni5Mo/Al ₂ O ₃ -TiO ₂ 128.5 236.4 158.5 523.4 2.12 30Ni/Al ₂ O ₃ -TiO ₂ 182.1 184.7 163.8 530.6 2.06

The acidity of the calcined Al ₂ O ₃ -TiO ₂ support and the NiMo/Al ₂ O ₃ -TiO ₂ catalyst was determined by _{NH 3} -TPD analysis as shown in FIG. 6. As shown in Table 2, the types of acid sites can be classified into weak acid points (<250°C), intermediate acid points (250-500°C), and strong acid points (>500°C) according to the ammonia desorption temperature. The loading of metals in Al ₂ O ₃ -TiO ₂ caused a change in the distribution of the scattered points. The loading of monometallic (Ni or Mo) and bimetallic (NiMo) species resulted in an increase in the weak acid point and a decrease in the strong acid point. The amount of the intermediate acid point was reduced by the loading of monometallic Ni or Mo, but increased when doping bimetals such as 25Ni5Mo and 15Ni15Mo catalysts. In general, the total acid point of the catalyst increased with increasing Ni concentration in the bimetal system. On the other hand, the interaction between the Mo dopant and the support decreased the acid point, and as the amount of Mo increased, the temperature peak slightly shifted to a low temperature (FIG. 6). The acidity density of the bimetallic catalyst of 5Ni25Mo and 10Ni20Mo is higher than that of a single metal catalyst, and the bimetallic catalyst (NiMo/Al ₂ O ₃ -TiO ₂ ) according to the present invention can have a higher catalytic activity than a single metal catalyst. Confirmed that there is.

1-3. Hydrogen heating reduction analysis of catalyst

Temperature-programmed reduction (H _{2 -TPR) of the NiMo/Al 2} O ₃ -TiO ₂ catalyst samples of Examples 1 to 7 was analyzed using a fixed bed reactor. Each calcined catalyst was first pretreated in an Ar stream at 150° C. for 1 hour to remove physisorbed contaminants, and then cooled to room temperature. The reduction process was carried out under a stream of 10 vol% H ₂ ^{/Ar gas mixture at a flow rate of 50 cm 3 /min.} _{The temperature was heated to 900°C at a heating rate of 2°C/min, and H 2} consumption at different temperatures was recorded by gas chromatography (6500GC, YL Instrument, Korea) equipped with a heat conduction detector (GC-TCD). Indicated.

7 is a spectrum showing the H ₂ -TPR profile of _{the NiMo/Al 2} O ₃ -TiO ₂ catalysts of Examples 1 to 7 having various Ni/Mo weight ratios fired by the method according to the present invention.

The 30Ni/Al ₂ O ₃ -TiO ₂ catalyst showed two reduction peaks at 510 and 700°C. The first peak at 510°C is due to a decrease in the dispersed NiO species. The larger peak appeared at high temperature (700°C) is due to the decrease in _{nickel aluminate (NiAl 2} O ₄ ^{), indicating that Ni 2+} is mainly present in the form of a _{NiAl 2} O _{4 spinel structure.} The single metal 30Mo/Al ₂ O ₃ -TiO ₂ catalyst exhibited two main characteristic reduction peaks at 420 and 770°C. ^{The lower reduction peak is associated with the reduction of Mo 6+} in the form of the polymeric octahedral Mo oxide species ^{to Mo 4+} , while the hydrogen consumption signal in the high temperature region (700-900°C) is the reduction of Mo ⁴⁺ to Mo ⁰ . It is due to the 2 reduction step. The loading of bimetallic NiMo in Al ₂ O ₃ -TiO ₂ caused a change in the reduction behavior of the catalyst depending on the composition of the Ni/Mo weight ratio. For example, ^{the reduction of Mo 6+} → Mo ⁴⁺ of the bimetallic catalyst shifted to a lower temperature, and a catalyst sample with a high Ni content assigned to the simultaneous reduction of ^{Mo 4+} → Mo ^{0 and Ni 2+} → Ni ^{0 (} The high temperature reduction peaks of 25Ni5Mo, 20Ni10Mo and 15Ni15Mo) shifted to a lower temperature. It was confirmed that the interaction between Ni and Mo may weaken the interaction between the support and the metal or form a similar phase _{consistent with the NiMoO 4 XRD analysis.}

1-4. XPS measurement of catalyst

XPS measurement was performed using a Thermo Scientific K-Alpha spectrometer instrument to measure the oxide state of the metal dopant (Ni, Mo). The binding energy was adjusted using a carbon C (1s) line as a criterion having a binding energy value at 284.6 eV. The reduced catalyst was passivated with a gas mixture of 3% air/Ar at room temperature for 2 hours and then exposed to air. The chemical states of the Mo and Ni dopants of the fired and reduced samples were confirmed through XPS analysis and are shown in FIG. 8.

8 is an XPS spectrum of _{the reduced NiMo/Al 2} O ₃ -TiO ₂ catalyst of Examples 1 to 7 according to the present invention; (a) Mo 3d and (b) Ni 2p.

As shown in Fig.8(a), the fired 30Mo/Al ₂ O ₃ -TiO ₂ of Mo 3d core-level XPS has _{two of 3d 5/2} (232.8eV) and 3d _3/2 (235.8eV). It shows a clear peak. After reduction, these peaks shifted to a lower binding energy, indicating that the Mo ⁺⁶ species were reduced to a lower oxidation state. Specifically, the deconvolution of the Mo 3d XPS spectrum after reduction ^{showed the coexistence of Mo 5+} (231.4 and 234.5 eV), Mo ⁴⁺ (229.2 and 232.2 eV) and Mo ⁰ (227.8 and 230.8 eV). 8(a), after reduction, the Mo ⁶⁺ percentage of the reduced catalyst decreased from 24% to 15%, whereas when the amount of Ni increased from 0 to 25% by weight, the metallic Mo ⁰ concentration was It increased from 10% to 27%. These results suggest that the reducibility of Mo species increases as the Ni concentration increases in the bimetallic catalyst system.

As shown in FIG. 8(b), Ni 2p core level XPS analysis results, in the case of calcined Ni/Al ₂ O ₃ -TiO ₂ , two peaks at binding energies 855 and 873 eV are Ni 2p ₃ ^{of Ni 2+} _/2 and 2p _1/2 . The presence of broad subpeaks of about 862 and 880 eV is due to the multiple electron excitation of typical Ni ²⁺ _{including NiO, Ni 2} O ₃ , spinel NiAl ₂ O ₄ and NiMoO _4. After reduction, the two separate peaks at the binding energies of 852.2 and 869.4 eV are due to metallic Ni0. It was found that there was no significant difference ^{in the Ni 0} /Ni ²⁺ ratio according to the change in the Ni/Mo weight ratio of the bimetallic composition. This result may be due to the strong interaction between the Ni species and the support, as well as the formation of an amorphous NiMoO ₄ like phase ^{from Mo 6+} and Ni ^{2+ due to oxygen defects.}

<Experimental Example 2> Analysis of catalytic activity of guiacol for HDO reaction

Hydrodeoxygenation (HDO) conversion of guaiacol was performed in a continuous fixed-bed reactor (FIG. 1).

Before the HDO reaction, the calcined catalyst _{was reduced in a mixed gas of H 2} /Ar (60/20 cm ³ /min) to prepare a reduced catalyst. Specifically, 0.1 g of the calcined catalysts of Examples 1 to 7 were first heated from room temperature to 300°C at a rate of 5°C/min, and then heated from 300°C to 500°C at a rate of 2°C/min, and 500 Held at °C for 2 hours. Then, the temperature was increased from 500°C to 700°C at a rate of 2°C/min, maintained at this temperature for 1 hour, and finally cooled to 300°C, which is the temperature for the HDO reaction.

To carry out the HDO reaction, dodecane (>99%, Aldrich) containing 3% by weight of guiacol (99%, Aldrich) was preheated to 250°C in the reactor, and then 0.15 using a high pressure pump. It was fed at a flow rate of mL/min and preheated at 250°C. _{Hydrogen (H 2} ) before the resulting mixture vapor enters the tubular reactor After mixing with flow (60 mL/min), it was supplied to a tubular reactor, and HDO reaction was performed for 2 hours at 300° C. and hydrogen pressure of 2 MPa using each of the reduced catalysts. At this time, guiacol and hydrogen were mixed at a molar ratio of 1:97 ((mol/mol)%) and supplied to the tubular reactor. The vapor product was condensed to a liquid phase at about -10°C using an ethyl-glycol-cooled condenser system.

The liquid product was collected at 20 minute intervals and analyzed by GC-MS (Agilent 7890B, USA) using a capillary column (HP 5MS). The conversion, hydrodeoxygenation degree (X _HDO ) and product distribution of guiacol were calculated by the following equations (1), (2) and (3). In the following formula, C _0GUA is the initial guaiacol concentration (mol/L), C _GUA is the guaiacol concentration at different reaction times (t, h), C _i is the concentration of product i in the HDO product stream, and a _i is Is the number of oxygens in each product i.

(1)

(One)

(2)

(2)

(3)

(3)

2-1. Catalyst activity analysis according to Ni/Mo weight ratio change

The catalytic hydrogenation and deoxidation (catalytic HDO) reaction of guiacol _{for the reduced NiMo/Al 2} O _{3 -TiO 2} catalyst having different Ni/Mo weight ratios in the same manner as described above was carried out at 300° C. and After carrying out at a hydrogen pressure of 2.0 MPa, the HDO conversion rate and product distribution according to the Ni/Mo weight ratio difference are shown in FIG. 9.

9 shows the conversion rate, HDO conversion rate, and product distribution of guiacol obtained from the hydrogenation and deoxidation (HDO) reaction for the _{reduced NiMo/Al 2} O ₃ -TiO ₂ catalyst having various Ni/Mo weight ratios according to the present invention. This is the graph shown; Reaction conditions: 0.15 mL/min liquid guiacol supply, 60 mL/min H ₂ supply, 300°C, 2 MPa, and reaction time of 2 hours.

As shown in FIG. 9, the highest guaiacol conversion of 100% was observed for the _{single metal Ni/Al 2} O ₃ -TiO _{2 catalyst (Example 1), whereas Mo/Al 2} O ₃ -TiO ₂ The guaiacol conversion to the catalyst (Example 7) was only 60%. However, all of these monometallic catalysts had low HDO conversion (<5%). In contrast, HDO conversion was _{much improved with the bimetallic NiMo/Al 2} O ₃ -TiO ₂ catalyst, suggesting that the bimetallic NiMo system promotes the cleavage of CO bonds during catalytic performance. In the bimetallic NiMo system, the HDO conversion rate increased as the Ni concentration increased from 5 to 10% by weight, reaching a peak value of 98%, whereas when the Ni concentration further increased to 15, 20 and 25% by weight, the HDO conversion rate again. Decreased. The reason may be due to the low acidic density of these catalyst samples, as described above. _{Therefore, it was confirmed that the NiMo/Al 2} O ₃ -TiO ₂ catalyst of Example 3 prepared with a Ni concentration of 10% by weight and a Mo concentration of 20% by weight exhibited the highest HDO conversion rate.

Meanwhile, as shown in FIG. 9, the product distribution was also affected by the difference in the weight ratio of Ni/Mo of the catalyst composition. Specifically, Mo/Al ₂ O ₃ -TiO ₂ showed high selectivity of phenol and o-cresol, whereas Ni/Al ₂ O ₃ -TiO ₂ was methylcyclohexanediol. And it had a high selectivity for the product of cyclohexanol (cyclohexanol). In contrast, the use of the NiMo/Al ₂ O ₃ -TiO ₂ catalyst showed high selectivity of cyclohexane and methylcyclohexane. In the case of bimetallic catalysts having 10Ni20Mo, 15Ni15Mo and 20Ni10Mo, the highest hydrocarbon selectivity of 100% (85% cyclohexane, 13% methylcyclohexane and 2% toluene) was shown. The higher catalytic activity of bimetallic NiMo catalysts compared to monometallic Ni or Mo catalysts can be attributed to the influence of NiMo alloy formation. On the other hand, it was confirmed that the Ni-rich (25Ni5Mo) and Mo-rich (5Ni25Mo) catalyst samples had low hydrocarbon selectivity of 31% and 76%, respectively.

As a result, it was confirmed that the 10Ni20Mo/Al ₂ O ₃ -TiO ₂ catalyst exhibited the highest hydrocarbon selectivity of 100% while the HDO conversion rate of guiacol was 98%, and the catalytic activity was the most excellent.

The reaction route for guaiacol conversion using the catalyst according to the present invention can be represented as shown in FIG. 10 based on the product distribution.

10 is a diagram showing the HDO conversion reaction path of guaiacol to the reduced NiMo/Al ₂ O ₃ -TiO _{2 catalyst according to the present invention;} HDO: Hydrodeoxygenation, HYD: Hydrogenation.

Specifically, when Ni-rich catalysts (30Ni/Al ₂ O ₃ -TiO ₂ and 25Ni5Mo/Al ₂ O ₃ -TiO ₂ ) are used, the main products are methylcyclohexanediol and cyclohexanol to be. This is because the methyl group (-CH ₃ ) moves to the benzene ring at the highly hydrogenated Ni site and then hydrogenation of the benzene ring causes 1-methyl-1,2-cyclohexanediol. After generating, cyclohexanone and cyclohexanol were produced by demethylation-dehydration. These compounds were finally converted to cyclohexane through the HDO step. However, in the case of Mo-rich regions, phenol and o-cresol were mainly produced. This is because guiacol can be directly converted to phenol by demethoxylation, followed by methyl substitution to produce o-cresol, followed by hydrogenation and HDO mechanism to toluene, cyclohexane and methyl-cyclohexane. It suggests that it can be converted.

2-2. Analysis of catalytic activity according to HDO reaction temperature change

In order to evaluate the effect of the reduction temperature on the guaiacol conversion rate and product selectivity, the 10Ni20Mo/Al ₂ O ₃ -TiO ₂ catalyst of Example 3 was reduced at different temperatures (500, 600 and 700°C) and then Guiacol. The HDO reaction was carried out.

Specifically, in the process of reducing the catalyst calcined before the HDO reaction, the reduction treatment was performed in the same manner until the step of raising the temperature from 300°C to 500°C and then maintaining it at 500°C for 2 hours, and the subsequent temperature treatment is as follows. Likewise, reduction was performed by differently at 500, 600 and 700°C. The first catalyst (reduction temperature 500℃) was maintained at 500℃ for 3 hours to reduce the reduced catalyst. The second catalyst (reduction temperature 600°C) increased the temperature from 500°C to 600°C at a rate of 2°C/min, and maintained at 600°C for 1 hour to prepare a reduced catalyst, and the last catalyst (reduction temperature 700°C) was used in the HDO experiment by increasing the temperature from 500°C to 700°C at a rate of 2°C, and maintaining the temperature at 700°C for 1 hour in the same manner as the catalyst used in Experimental Example 2-1. .

11 is a graph showing the conversion rate and product distribution _{of guiacol for the reduced 10Ni20Mo/Al 2} O ₃ -TiO ₂ catalyst according to the reduction temperatures of 500, 600 and 700°C.

As shown in Fig. 11, the HDO conversion rate of guiacol increased as the reduction temperature increased. In addition, the product distribution changed with the change of the reduction temperature. Specifically, at a low reduction temperature of 500° C., about 26% of oxygen-containing compounds (phenol and o-cresol) were produced. However, at a reduction temperature of 700° C., no oxygen-containing compounds were produced, and the hydrocarbon selectivity reached a maximum of 100%.

In order to grasp the behavior of these catalysts, the catalysts reduced at different temperatures were analyzed to confirm the oxidation state of the components and their compositions.

_{12 is an XPS spectrum of a reduced 10Ni20Mo/Al 2} O ₃ -TiO ₂ catalyst (Example 3) according to a reduction temperature change during HDO reaction; (a) Mo 3d and (b) Ni 2p.

As shown in FIG. 12, as the reduction temperature increases from 500° C. to 700° C., the ^{concentration of Mo 6+} and Ni ²⁺ decreases, and the concentration of metallic Mo ⁰ and Ni ⁰ increases, so that the reducing temperature of the catalyst increases. It was confirmed that it increased with increasing. In addition, it was confirmed that the HDO conversion rate of guiacol was the highest at a reduction temperature of 700° C. where the metal concentrations (Mo ⁰ and Ni ^{0) were the highest.}

On the other hand, although not shown in FIGS. 11 and 12, when the reduction temperature is further increased to 800° C. or higher, the HDO conversion rate and hydrocarbon selectivity of guiacol begin to decrease, and energy is consumed to maintain a high temperature. In that sense, there may be a problem with poor economics.

Therefore, it was confirmed that the catalytic reduction temperature for the HDO reaction of guiacol is 700°C.

2-3. Catalyst stability analysis

By applying the Ni/Mo weight ratio and reduction temperature confirmed to have the most excellent catalytic activity in Experimental Examples 2-1 and 2-2, the 10Ni20Mo/Al ₂ O ₃ -TiO ₂ sample of Experimental Example 3 was reduced at 700°C. Thereafter, HDO reaction was performed for 24 hours to evaluate catalyst stability.

13 is a graph showing the conversion rate and product distribution of guaiacol during the HDO reaction time of 24 hours for _{the 10Ni20Mo/Al 2} O ₃ -TiO ₂ catalyst reduced at 700°C.

As shown in FIG. 13, the HDO conversion rate was maintained at about 98% during the reaction time of 24 hours. During the reaction, cyclohexane and methylcyclohexane were the main products, and their selectivity was almost unchanged. Methylcyclopentane appeared in the HDO product stream with a selectivity of 2% after 3 hours of reaction time, which appears to be produced from further alkylation of cyclohexane. After 16 hours of reaction, the cyclohexane selectivity slightly decreased by about 4%, and the toluene and dimethyl-benzene selectivity slightly increased, so that the density of the hydrogenation site may decrease slightly as the reaction time increases, but it was confirmed that there was little change. .

The chemical states of Mo and Ni of the spent catalyst were analyzed and compared with the chemical states of the catalyst samples immediately after reduction (FIG. 14).

14 is an XPS spectrum of a catalyst immediately after reduction (freshyly reduced) and a spent catalyst used in the HDO reaction; (a) Mo 3d and (b) Ni 2p.

It can be seen that there was only a small change in the chemical state of these metal dopants after the reaction time of 24 hours, and accordingly, the catalyst prepared by the method according to the present invention has excellent catalytic stability against HDO conversion of guiacol under irradiated conditions. It was confirmed to have.

So far, the present invention has been looked at around its preferred embodiments. Those of ordinary skill in the art to which the present invention pertains will be able to understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Claims (14)

Based on 30 parts by weight of NiMo as an active part of the bimetallic catalyst; And
68-72 parts by weight of a support comprising at least one of Al ₂ O ₃ and TiO ₂ ; including, a catalyst for hydrodeoxygenation (HDO) reaction of guaiacol. The method of claim 1,
The hydrogenation and deoxidation reaction of guiacol is characterized by converting from guiacol to at least one hydrocarbon compound selected from the group consisting of cyclohexane, methylcyclohexane, and toluene. A catalyst for the hydrogenation and deoxidation reaction of guiacol. The method of claim 2,
The hydrogenation and deoxidation reaction of guiacol is characterized in that the conversion from guiacol to cyclohexane (cyclohexane), a catalyst for the hydrogenation and deoxidation of guiacol. The method of claim 1,
The NiMo is a catalyst for hydrogenation and deoxidation of guiacol, characterized in that Ni and Mo are mixed in a weight ratio of 7-23:7-23. The method of claim 4,
The NiMo is a catalyst for hydrogenation and deoxidation of guiacol, characterized in that Ni and Mo are mixed in a weight ratio of 9-20:10-21. The method of claim 5,
The NiMo is a catalyst for hydrogenation and deoxidation of guiacol, characterized in that Ni and Mo are mixed in a weight ratio of 9-11:19-21. A method for preparing a hydrocarbon compound from guiacol, including the following steps, using the catalyst for hydrogenation and deoxidation of guiacol according to claim 1:
Preheating a solution containing 1-5% by weight of guiacol to 240-260° C. and then supplying the solution to the reactor (Step 1);
Supplying hydrogen (H ₂ ) to the reactor and mixing it with the guiacol-containing vapor of step 1 (step 2); And
A step of reacting the catalyst according to claim 1 and the vapor mixed in step 2 inside the reactor under hydrogen pressure of 290-310° C. and 1-3 MPa (step 3). The method of claim 7,
The catalyst of step 3 is a method for producing a hydrocarbon compound from guiacol, characterized in that the catalyst is reduced at 500 to 750°C before the reaction and then used in the reaction. The method of claim 8,
The catalyst of step 3 is a method for producing a hydrocarbon compound from guiacol, characterized in that it is used in the reaction after reduction at 690 to 710°C before the reaction. The method of claim 7,
The hydrocarbon compound is characterized in that at least one hydrocarbon compound selected from the group consisting of cyclohexane, methylcyclohexane, and toluene. The method of claim 10,
The hydrocarbon compound is characterized in that the cyclohexane (cyclohexane), the method for producing a hydrocarbon compound from guiacol. Cyclohexane prepared from guiacol by the method according to claim 7. Methylcyclohexane prepared from guiacol by the method according to claim 7. Toluene prepared from guaiacol by the method according to claim 7.

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