KR100837377B1 - Preparation methods for liquid hydrocarbons from syngas by using the zirconia-aluminum oxide-based fischer-tropsch catalysts - Google Patents

Abstract

A cobalt/zirconia-alumina catalyst in which small pores and large pores coexist by supporting cobalt as an active component on a zirconia-alumina support which comprises ZrO2 and Al2O3 and has a specific surface area by a coprecipitation process, thereby containing the cobalt in the support is provided, and a method for producing liquid hydrocarbons from syngas using the catalyst is provided. In a catalyst for Fischer-Tropsch reaction in which cobalt as an active component is supported on a support, the catalyst for Fischer-Tropsch reaction is characterized in that the catalyst is a catalyst in which cobalt as an active component is supported on a mixed support of zirconia and alumina containing Al2O3 and ZrO2, bimodal structures in which small pores(PS1) with a relatively small pore size and large pores(PS2) with a relatively large pore size coexist are formed in the catalyst, the small pores(PS1) ranges from 2 to 10 nm and the large pores(PS2) ranges from 10 to 200 nm, the ZrO2 is contained in the amount of 1 to 30 wt.% relative to the Al2O3, and the cobalt is contained in the amount of 5 to 40 wt.% relative to the total support. A method for producing liquid hydrocarbons from syngas comprises subjecting syngas to Fischer-Tropsch reaction in the presence of the catalyst for Fischer-Tropsch reaction to produce liquid hydrocarbons. Further, a specific surface of the carrier is 150 to 400 m^2/g and a specific surface of the catalyst is 100 to 300 m^2/g.

Description

Preparation methods for liquid hydrocarbons from syngas by using the zirconia-aluminum oxide-based Fischer-Tropsch catalysts using a catalyst for Fischer-Tropsch reaction using a mixed carrier of zirconia and alumina

1 is 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst prepared in Example 1 according to the present invention and 20 wt% Co / 80 wt% Al prepared in Comparative Example 1 After Fischer-Tropsch is performed using a ₂ O ₃ catalyst, the conversion rate of carbon monoxide according to reaction time is shown.

FIG. 2 shows 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst of Example 1, 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ of Example 3 according to the invention The pore distribution of the O ₃ catalyst, 20 wt% Co / Al ₂ O ₃ catalyst of Comparative Example 1 and 0.5 wt% Ru / 20 wt% Co / 5 wt% Zr / Al ₂ O ₃ catalyst of Comparative Example 2 is shown.

Figure 3 shows an electron micrograph of the 0.5% by weight Ru / 20% by weight Co / 5% by weight ZrO ₂ -Al ₂ O ₃ catalyst of Example 1 according to the present invention, (a) is 20,000 magnification, (b) Is 100,000 magnification.

The present invention is a mixed carrier of zirconia and alumina prepared by the coprecipitation method, the cobalt is supported as an active ingredient, has a dual pore structure with a relatively different pore size, and maintains a specific pore volume ratio, the catalyst present Fischer-Tropsch reaction of syngas (CO / H ₂ / CO ₂ ) under the present invention relates to a method for producing a high yield of liquid hydrocarbon.
Hereinafter, in the present invention, the mixed carrier of zirconia and alumina is abbreviated as 'zirconia-alumina carrier', and the catalyst in which cobalt is supported as the active ingredient in the mixed carrier of zirconia and alumina is abbreviated as 'cobalt / zirconia-alumina catalyst'.

With the recent rise in international oil prices, the liquefaction of gas (GTL, Gas-) under the situation that the importance of the technology for producing synthetic oil from the syngas produced by the gasification of natural gas, coal or biomass is becoming increasingly important. The technology of producing liquid hydrocarbon by to-Liquid) technology can solve various problems of the existing gas field development method because the final product forms a liquid phase.

(1) The handling of liquids that can be handled easily solves the problem of long distance transportation due to gas transportation, and (2) the existing facilities can be used without the need for a separate transportation, loading and storage facility. 3) By directly producing the product, it has the advantage of being able to sell it immediately and selling clean fuel at a high price. (4) Stranded / remote gas, a small and medium-sized gas resource, far from demand. It is reported that even if only 1 trillion cubic feet of reserve is secured, it can be used economically without the establishment of a separate transportation facility like the LNG system.

The GTL process has been continuously developed since the Fischer-Tropsch (FT) synthesis process was first developed in the 1920s, and the GTL technology based on the FT synthesis technology improves the environment of gas fields. At the same time, it is possible to produce synthetic clean fuel by treating flared gas generated in oil fields. In addition, GTL products, which are clean liquid fuels containing little sulfur, may obtain higher market value than conventional petroleum products produced by refining crude oil. For example, in the US, Europe, and Japan, the sulfur content of diesel fuel for automobiles will be increased to 50 ppm from 500 ppm in 2004 and below 10 ppm in the future.

FT synthetic oil is a fuel that can effectively cope with the strengthening of environmental regulations in advanced countries that are under increasing pressure due to the recent Kyoto Protocol entry into force. According to Sasol's LCA results, GTL synthetic fuel has almost no sulfur and aromatics, so it emits soot and nitrogen oxides. This is reported to be less than 40% compared to existing products. In addition, it has been reported that emissions of particulate matter (PM) can be reduced by more than 40%, and greenhouse gas emissions can be reduced by more than 12% by expanding the spread of diesel fuel cars by F-T synthetic oil and increasing thermal efficiency.

The F-T synthesis method, a key process for GTL technology, was first derived in 1923 by German chemists Fischer and Tropsch developing a technology for producing synthetic fuel from syngas from coal gasification. The GTL process consists of three main processes: (1) reforming reaction of natural gas, (2) FT synthesis reaction of synthesis gas, and (3) reforming reaction of product. The FT reaction carried out using a catalyst at a reaction temperature of 200 to 350 ° C. and a pressure of 10 to 30 atm can be described as four main reactions as follows.

(a) Chain growth in F-T synthesis

CO + 2H ₂ → -CH _2- + H ₂ O ΔH (227 ° C) = -165 kJ / mol

(b) Methanation

CO + 3H ₂ → CH ₄ + H ₂ O ΔH (227 ° C) = -215 kJ / mol

(c) Water gas shift reaction

CO + H ₂ O ↔ CO ₂ + H ₂ ΔH (227 ° C) = -40 kJ / mol

(d) Boudouard reaction

2CO ↔ C + CO ₂ △ H (227 ° C) = -134 kJ / mol

The production mechanism of straight-chain hydrocarbons, the main product, is mainly described by Schulz-Flory's polymerization kinetic scheme, where more than 60% of the FT process has a higher boiling point than diesel. Since it is synthesized primarily, it is further produced through the subsequent process of hydrocracking, and the wax component can be converted into a high quality lubricant base oil through the dewaxing process.

In general, the reforming process for processing atmospheric residue or reduced-pressure residue oil applied to oil refining plant is a technology that has been reliably secured by the improvement of catalyst and process technology. Due to the very different physical properties, further development of suitable hydrocarbon reforming processes is required. Examples of processes for treating the primary product of the FT reaction include hydrocracking, dewaxing, isomerization, allylation, and the like. The main products of the FT reaction are naphtha. Naphtha / gasoline, middle distillate (high centane number, sulfur- and aromatic-free liquid hydrocarbons, α-olefins, Products include oxygenates and waxes.

Catalysts such as iron and cobalt series are mainly used for the FT reaction. Initially, iron catalysts were mainly used, but recently, cobalt catalysts have become the mainstream to increase the production of liquid fuels or waxes and to improve conversion. The characteristics of the iron catalyst are the lowest among the catalysts for the FT reaction, low methane production at high temperatures, high selectivity of olefins in hydrocarbons, and the product can be used as a raw material for the chemical industry as light olefins or alpha olefins as well as fuels. There is a characteristic. In addition, by-products such as alcohols, aldehydes, ketones, etc. other than hydrocarbons are produced, and iron catalysts for low-temperature FT reactions, which are mainly used for producing waxes of Sasol, contain Cu and K as cocatalysts, and SiO ₂ as a binder. It is prepared by the precipitation method. In addition, Sasol's high temperature FT catalyst is manufactured by melting magnetite, K, alumina, MgO and the like.

Cobalt-based catalysts have the disadvantages of being expensive compared to Fe catalysts, but have the advantages of high activity, long life, and low CO ₂ generation, and high yield of liquid paraffinic hydrocarbons. However, there is a problem of producing a large amount of CH ₄ at high temperatures, so it can be used only as a low-temperature catalyst. Since expensive cobalt is used, it is well dispersed and prepared on a high surface area stable support such as alumina, silica, and titania. It is a situation that is used in the form of addition of precious metal promoters, such as Ru, Re.

Four types of FT synthesis reactors developed to date are the circulating fluidized bed reactor, the fluidized bed reactor, the tubular fixed bed reactor, and the slurry-phase reactor. Etc., and the reaction characteristics vary depending on the type of reactor, so it should be appropriately selected according to the composition of the synthesis gas and the type of the final reactant. The FT process parameters depend on the final product, where a high temperature FT process is produced mainly for gasoline and olefins in a fluidized bed reactor, while a low temperature FT process for wax and lube base oil is commercialized in a multi-tube fixed bed reactor (MTFBR) or slurry reactor. It is operating. In the FT synthesis reaction is mainly linear paraffin series form, but the alpha of the combination of the type C _n H _2n in side reactions - made of olefin or alcohol is also a by-product.

On the other hand, as a method generally used to disperse expensive active ingredients, a cobalt component and other activity enhancing materials are added to alumina, silica, titania, etc. as a carrier having a high surface area to prepare a catalyst. Catalysts prepared in one component or mixed form of the above carriers are commercially used to promote acidity. However, when the cobalt particles in the above carriers have similar particle sizes, the FT reaction activity changes depending on the type of carrier. Are reported to be low [Applied Catalysis A 161 (1997) 59]. In contrast, the activity of the F-T reaction is reported to be greatly affected by the dispersibility and particle size of the cobalt component [Journal of American Chemical Society, 128 (2006) 3956]. Therefore, many attempts have been made to enhance the FTS activity and enhance stability by pretreating the surface of the carrier with other metal components to change the surface properties of each carrier.

For example, in the case of using a cobalt-supported alumina carrier, gamma alumina surface properties may be changed to boehmite due to water generated during the reaction, thereby deactivating the catalyst and increasing the rate of oxidation of the cobalt component. There is a possibility that the thermal stability is reduced. In order to solve this problem, a method of enhancing the stability of the catalyst by pretreating the surface of alumina using a silicon precursor has been reported [PCT Publication WO2007 / 009680 A1].

As another method for enhancing the FT catalyst activity, a method of improving catalyst stability by preparing a catalyst having a double porous structure of silica-alumina component and enhancing the mass transfer rate of the high boiling point compound generated during the FT reaction has been reported. US published patent US2005 / 0107479 A1; Applied Catalysis A 292 (2005) 252]. However, the above chambers are prepared using a polymer matrix to form a carrier having a biporous structure, or by simply preparing alumina-silica carrier having a different pore size in advance, and simply mixing the same to prepare a carrier having a biporous structure and using the cobalt. It follows the complex synthesis process which carries active ingredients, such as these.

In addition, when silica is used as a carrier, reduction of cobalt metal and reduction of activity due to strong interaction between cobalt and the carrier are observed due to a strong interaction between the cobalt and the carrier. It has been reported that the method of pretreatment of silica surface using the method is effective [European Patent EP0167215 A2; Journal of Catalysis 185 (1999) 120].

The FT catalysts prepared by the above method show various specific surface areas, but the activity of the FT reaction is known to be closely related to the change in the particle size of the cobalt component, the pore size distribution of the carrier and the reduction of the cobalt component. As a method for enhancing the performance, a method for preparing an FT catalyst by containing a cobalt component in a well-known method on a carrier prepared through a complex synthesis process has been reported.

Accordingly, the present inventors have studied to develop a catalyst suitable for the Fischer-Tropsch reaction by improving heat transfer and mass transfer due to the excellent activity of the catalyst as a method for solving the above problems economically and efficiently. I tried.

As a result, the small pores (PS ₁ ) formed by the dispersion of the zirconia-alumina carrier and cobalt supported on the zirconia-alumina carrier containing ZrO ₂ and Al ₂ O ₃ in a constant ratio and co-precipitated, The coprecipitation method made it possible to prepare a catalyst having a bimodal structure in which large pores (PS ₂ ) formed by uniformly dispersing cobalt in a carrier were present. The catalyst has a specific ratio of large pore and small pore to maintain a specific ratio, the heat transfer and mass transfer is superior to the conventional single pore catalyst as well as the active component as the surface of the alumina is modified by the carrier component zirconia FT reaction under these catalysts is accompanied by an increase in the dispersibility, electron state change, and reducibility of the catalysts, resulting in improved one-pass yield of carbon monoxide and hydrogen and improved long-term performance stability of the catalyst. The present invention has been completed.

Accordingly, the present invention comprises cobalt / cobalt / cobalt / cobalt / cobalt which contains ZrO ₂ and Al ₂ O ₃ and has a specific specific surface area. It is an object of the present invention to provide a method for producing liquid hydrocarbon from a zirconia-alumina catalyst and syngas using the same.

The present invention relates to a catalyst for Fischer-Tropsch reaction in which cobalt is supported as an active ingredient on a carrier, wherein the catalyst is a zirconia-alumina carrier containing Al ₂ O and ZrO ₂ , and cobalt is used as an active ingredient. As a supported cobalt / zirconia-alumina catalyst, a bimodal structure having a relatively small pore size (PS ₁ ) and a large pore (PS ₂ ) is formed at the same time, and the small pore (PS ₁ ) is formed. The pore sizes of and large pores (PS ₂ ) are as follows, wherein ZrO ₂ is contained in an amount of 1 to 30% by weight based on Al ₂ O, and cobalt is contained in an amount of 5 to 40% by weight based on the total carrier. It is characterized by the catalyst for the Fischer-Tropsch reaction.

2 ≤ PS ₁ ≤ 10 nm

10 <PS ₂ ≤ 200 nm

Hereinafter, the present invention will be described in detail.

In general, in the FT reaction for preparing a liquid hydrocarbon using synthesis gas, a cobalt component and other activity enhancing materials are added to alumina, silica, titania, etc. as a high surface area carrier to disperse expensive active ingredients. In the case of using the above carrier alone, there is a disadvantage in that the dispersibility and reducibility of the cobalt component are reduced and the pore blocking phenomenon of the high boiling point compound generated during the reaction occurs, thereby deactivating the catalyst rapidly. In order to overcome this problem, many attempts have been made to enhance Fischer-Tropsch Synthesis (FTS) activity and improve stability by pretreating the carrier with the second component and changing the properties of each carrier.

In the case of the alumina carrier, the surface properties of gamma alumina may be changed to boehmite by water generated during the reaction. Thus, a method of increasing the thermal stability of the alumina as a method of performing pretreatment with another second component is There are various introductions. In addition, when silica is used as a carrier, reduction of cobalt metal and reduction of activity due to strong interaction between cobalt and the carrier are observed due to a strong interaction between the cobalt and the carrier. The method of pretreatment of the silica surface by using is introduced by the existing technology. In particular, as an effective method, many attempts have been made to secure long-term performance stability of catalysts by increasing the mass transfer rate and heat transfer rate of high-boiling compounds produced during the reaction by using a carrier having a double porous structure.

Conventionally, a document having a double pore structure using zirconia and alumina components is known. [Korean Patent Registration No. 10-388310] Such a carrier has a pore distribution in the range of 0.05-1 μm and 1-10 μm. The invention is characterized in that a carrier is prepared by kneading powder of each component, and a catalyst having a wide distribution of pores by a method of supporting the active ingredient therein is produced.

That is, the present invention is a catalyst prepared by supporting an active ingredient on a zirconia-alumina carrier having a double pore distribution, but the present invention is a large pore by supporting cobalt on a single pore zirconia-alumina carrier having a small pore of 10 nm or less Since the invention relates to a catalyst having a double pore structure for forming pores, it is understood that the known invention is a carrier of the double pore, and the present invention is completely different from the catalyst of the double pore. In addition, due to the above differences, these catalysts have completely different pore sizes, specific surface areas, and the like, and thus the use of the catalysts is completely different. Therefore, the known inventions are used for converting hydrocarbons and the present invention is Fischer-Tropsch. There is a difference for the (Fischer-Tropsch) reaction.

Even if the same catalyst is used in the field of catalysts, it is obvious that the effects and the activity of the catalysts are completely different when the field and the active ingredients are different. The present invention and the known literature have similar components, but the structure of the carrier, the size of the carrier pores, the preparation method of the carrier, the active ingredient, the use of the catalyst, etc. are completely different, and these catalysts are completely different.

In conclusion, the present invention is not characterized in the carrier, but using a cobalt / zirconia-alumina catalyst in which cobalt is supported as an active ingredient on the carrier having the fine single pore to form a double pore structure. By performing the Tropsch reaction, no such catalyst has been applied in the art.

The present invention proposes a method for preparing a zirconia-alumina catalyst containing cobalt having a double porous pore structure by introducing a method different from a general method for preparing a F-T catalyst.

That is, the present invention uses a coprecipitation method for preparing a carrier of alumina and zirconia and carrying cobalt as an active ingredient on the carrier to form a catalyst having a double pore structure. Although the co-precipitation is a method generally known in the art, the present invention co-precipitates zirconia and aluminum precursor under the appropriate precipitant and precipitation conditions to form micropores of the carrier and uniformly form only the area of 10 nm or less first. A single microporous zirconia-alumina carrier was prepared, and the cobalt component was secondaryly coprecipitated to prepare a catalyst having a double pore structure and used for the reaction. The method of synthesizing the FT catalyst is not easily changeable by the existing method.

In addition, when the catalyst is prepared by a known coprecipitation method, a carrier having a pore distribution over a wide area is formed, and when using the cobalt component to support the catalyst, there is a disadvantage in that the activity of the catalyst is not excellent. These phenomena reported that the dispersibility of the cobalt component was decreased in the region where the pore distribution of the carrier was too large, thereby decreasing the activity of the catalyst, and that the FT catalyst activity was excellent when the carrier having a pore distribution of 10 nm or less was used [ Journal of Molecular Catalysis A 247 (2006) 206]. In the present invention, a zirconia-alumina carrier having a uniform pore structure of 10 nm or less is first synthesized to co-precipitate the cobalt component to improve the dispersibility of the cobalt component. At the same time, it was possible to prepare a catalyst having a double pore structure in which pore clogging due to the high boiling point compound generated during the reaction can be simultaneously suppressed in the large pores mainly composed of the cobalt active component. Accordingly, in the present invention, a zirconia-alumina carrier having a uniform single pore distribution of 10 nm or less is prepared by the coprecipitation method, and cobalt, which is an active ingredient, is uniformly supported on the carrier of the single pore by the coprecipitation method to activate the catalyst. In the present invention, a method of improving the activity of the FT catalyst on a cobalt / zirconia-alumina catalyst having a double pore structure by simultaneously forming a relatively large pore compared to a carrier composed of a cobalt component is proposed.

In general, the carrier using the alumina component is characterized by having a wide range of pore distribution, and methods such as sol-gel method and precipitation method are mainly used. In this case, a single pore form is distributed in a wide area. In the case of supporting the cobalt, there is a problem in that the particle size is increased while the distribution of particles is not uniform. When the F-T reaction is performed using such a catalyst, pore blocking of small pores may be severe due to the high boiling point compound generated during the reaction, which may cause a sudden decrease in the activity of the catalyst. However, the present invention can secure a high yield of the target liquid hydrocarbon by performing an FT reaction under a cobalt / zirconia-alumina catalyst having a double pore structure in which both small pores and large pores are present by coprecipitation. have.

The zirconia-alumina used as the carrier for the FT reaction catalyst is prepared by coprecipitation and has a specific surface area of 150 to 400 m 2 / g of pores having a pore size of 10 nm or less, and zirconium in a zirconia-alumina carrier The metal is used in the range of 1 to 30% by weight based on the alumina. If the amount is less than 1% by weight, there is a problem in that activity is reduced due to less effect on the dispersibility and reduction of the active ingredient cobalt, and when it exceeds 30% by weight, the specific surface area of the zirconia-alumina carrier is reduced to There may be a problem that the dispersibility decreases, so there is a need to maintain the above area.

The catalyst of the present invention can be prepared by the following two methods.

Firstly, a mixed aqueous solution containing a zirconium precursor and an alumina precursor and a basic precipitant were added to coprecipitate at pH 7 to 8, then aged and calcined at 300 to 900 ° C. to prepare a zirconia-alumina carrier, Aqueous solution containing a zirconia-alumina carrier and a cobalt precursor and a basic precipitant were added to coprecipitate at pH 7-8, and then aged and calcined at 200-700 ° C. to form pores of small pores (PS ₁ ) and large pores (PS ₂ ). The range of sizes is a two-step process for preparing a cobalt / zirconia-alumina catalyst having such a double porous structure.

The second step is a mixed aqueous solution containing a zirconium precursor and an alumina precursor, coprecipitated at pH 7-8 by adding a basic precipitant, and then aged to prepare a slurry-like zirconia-alumina carrier, an aqueous solution containing a cobalt precursor, After coprecipitation at pH 7-8 by adding a basic precipitant, aging to prepare a cobalt slurry, and after mixing the slurry-like zirconia-alumina carrier and cobalt slurry, dried and calcined at 200 ~ 700 ℃ The pore size range of the small pores (PS ₁ ) and the large pores (PS ₂ ) is a method consisting of three steps to prepare a cobalt / zirconia-alumina catalyst having such a double porous structure.

The zirconia-alumina carrier is prepared by the coprecipitation method, the coprecipitation method is carried out using a precipitant in a method generally performed in the art. At this time, the precursor of each metal used as the reaction raw material is not particularly limited to those commonly used in the art, specifically, the alumina precursor is aluminum nitrate (Al (NO ₃ ) ₃ · 9H ₂ O) and aluminum isoprop width As the side (Al [OCH (CH ₃ ) ₂ ] ₃ ), the zirconium precursor, zirconium nitrate (Zr (NO ₃ ) ₂ .2H ₂ O), zirconium chlorooxide (ZrCl ₂ O. 8H ₂ O), etc. may be used. . In order to maintain pH 7-8 during coprecipitation, a basic precipitant is used as a precipitating agent. Specifically, sodium carbonate (Na ₂ CO ₃ ), potassium carbonate (K ₂ CO ₃ ), and ammonium carbonate ((NH ₄ ) ₂ CO ₃ ) And aqueous ammonia can be used.

The alumina and zirconium metal precursors are co-precipitated using the precipitant selected above under an aqueous solution of pH 7 to 8, then aged in a range of 40 to 90 ° C. to filter and wash the precipitate, and the zirconia-alumina carrier. The composition of is prepared to contain 1 to 30% by weight of zirconium oxide and 70 to 99% by weight of Al ₂ O ₃ . When the aging temperature of the prepared carrier is less than 40 ℃, it is difficult to form a zirconia-alumina carrier having a fine single pore structure suitable for the FT reaction, and when the temperature exceeds 90 ℃, the particle size of the carrier increases to decrease the specific surface area Occurs. This maturation is carried out for 0.1 to 15 hours, preferably 0.5 to 10 hours, which is advantageous in the formation of the structure of the catalyst carrier having excellent activity in the region of the given maturation time. If the aging time is less than 0.1 hours, the zirconia-alumina carrier structure is not well developed, which is disadvantageous in terms of reaction, and if it exceeds 15 hours, the particle size increases, the active point decreases, and the synthesis time increases, which is not economical. Can not do it.

The precipitate prepared by the above method is dried in an oven at 100 ° C. or more after a washing process, and then calcined after supporting the cobalt component in the prepared precipitate, which is used for FT reaction, or calcined zirconia-alumina carrier. After the cobalt component can be supported.

Specifically, the specific method of containing the active ingredient cobalt using the prepared zirconia-alumina carrier can be roughly divided into two methods as follows.

First, a slurry solution is prepared using a powdery zirconia-alumina carrier prepared by the above method, and the cobalt precursor is coprecipitated with a coprecipitation agent under an aqueous solution of pH 7-8, and then aged in a range of 40-90 ° C. to precipitate. It is used to filter and wash, the content of the cobalt component is to prepare the FT catalyst to contain 5 to 40% by weight relative to the zirconia-alumina carrier. If the cobalt content is less than 5% by weight, there may be a problem in that the conversion rate and the yield of high-boiling compounds due to the reduction of the active ingredient required for the FT reaction may be reduced. It is preferable to maintain the above range because the dispersibility of the cobalt component decreases as well as the increase in manufacturing cost, which causes a slight increase in activity relative to the amount of cobalt used.

In order to maintain pH 7 to 8 during the coprecipitation, a basic precipitant is used, and the basic precipitant is the same as mentioned above. The aging is carried out at 40 ~ 90 ℃, preferably 50 ~ 80 ℃, if the aging temperature of the prepared catalyst is less than 40 ℃ it is difficult to produce cobalt in the form of uniform particles, so that the support of the cobalt component suitable for FT reaction It is difficult, if it exceeds 90 ℃ cobalt particle size increases due to the aggregation phenomenon, the specific surface area is reduced and the reaction activity is deteriorated. At this time, the aging time is appropriately maintained at 0.1 to 15 hours, preferably 0.5 to 10 hours, which is advantageous in the formation of a zirconia-alumina catalyst containing cobalt having excellent activity in the range of aging time presented. If the aging time is less than 0.1 hours, the dispersibility of cobalt decreases, which is disadvantageous in terms of FT reaction, and if it exceeds 15 hours, the cobalt particle size increases, the active point decreases, and the synthesis time increases, which is not economical. I can't.

The precipitate prepared by the above method is dried after washing for one day in an oven at 100 ° C. or higher, specifically, 100 to 150 ° C., and then the precipitate is directly used for the synthesis of the catalyst for the FT reaction or is a secondary metal catalyst component. It may be calcined and used after supporting.

In addition, the zirconia-alumina catalyst containing cobalt is calcined in the range of 200 to 700 ° C, preferably 300 to 600 ° C. When the firing temperature is less than 200 ° C, no proper interaction between cobalt and the carrier is formed. Particles may become large during the reaction, and if the temperature exceeds 700 ° C., the cobalt component may increase and the dispersibility may decrease, thereby decreasing the activity of the catalyst. have.

In another aspect, the present invention provides a method for producing an FT catalyst using the powdery zirconia-alumina carrier. The cobalt precursor is co-precipitated in an aqueous solution of pH 7-8, and then aged in an area of 40-90 ° C. to precipitate the precipitate. A zirconia-alumina carrier is prepared by firing in the range of &lt; RTI ID = 0.0 &gt;

If the firing temperature is less than 300 ℃ is not suitable for the formation of gamma-alumina, the phase transition of the carrier caused by the water generated during the FT reaction may occur, there is a problem that the activity may decrease, if the temperature exceeds 900 ℃ zirconia-alumina Since the specific surface area of the carrier can be reduced to cause problems in the following cobalt dispersibility, there is a need to maintain the plasticized area.

Thereafter, the cobalt component is supported, and then a cobalt / zirconia-alumina catalyst is prepared. In the coprecipitation, a basic precipitant is used, and the aging time, washing and drying processes of the catalyst are the same as mentioned above.

The cobalt component prepared by the above method is first washed and dried, and then prepared in water or an alcohol solution and then calcined and mixed with the zirconia-alumina carrier prepared by calcining the zirconia-alumina catalyst having the final cobalt. It will be prepared. The precipitate prepared by the above method is dried after being washed for one day in an oven at 100 ° C. or higher after the washing process, and then the prepared precipitate is directly used for FT anti-applied catalyst synthesis or after supporting the precious metal catalyst component in a second manner. It can be baked and used.

The cobalt-containing zirconia-alumina catalyst prepared by the above method has a double porous structure. The final specific surface area is 100 to 300 m 2 / g, and the small pore size of the double porous catalyst is 2 to 10 nm and the large pore is A new catalyst for the FT reaction with a distribution of 10-200 nm is synthesized. In addition, the carrier has a ratio (PV ₁ / PV ₂ ) of a small pore volume (PV ₁ ) in the range of 2 to 10 nm and a large pore volume (PV ₂ ) in the range of 10 to 200 nm. If the ratio of the pore volume (PV ₂ ) is less than 0.5, the specific surface area of the cobalt component may be reduced due to the development of large pores resulting from the cobalt particles, which may cause a problem in that the activity is lowered. In this case, the fine pores of the zirconia-alumina carrier may develop to decrease the dispersibility of the cobalt component, thereby reducing the activity.

In addition, it is possible to use a precious metal component used to increase the reducibility of the cobalt active ingredient and to inhibit the oxidative power against water, specifically, ruthenium, rhenium and platinum precursors may be used in the form of nitrate salts, acetate salts and chloride salts. Can be used. When the noble metal component is used in an amount of 0.05 to 1% by weight based on the zirconium precursor, when the amount is less than 0.05% by weight, the effect is insignificant. Increasing negative problems arise and become ineffective.

The carrier of the present invention facilitates mass transfer of the high-boiling compounds produced during the reaction, as well as cobalt and other substances, as compared to the case where the alumina, titania or silica carriers which are already known are pretreated with various metal components. By further improving the dispersibility and reducing properties of the active ingredient compared to the existing technology, it is possible to obtain the effect of reducing the methane production amount and increasing the selectivity to the liquid hydrocarbon by improving the FT reactivity.

In addition, the present invention is another feature of the method for producing a liquid hydrocarbon by Fischer-Tropsch reaction of the synthesis gas under the catalyst prepared above. The FT reaction is not particularly limited to those commonly used in the art, but the present invention utilizes the catalyst after the catalyst is reduced in a fixed bed, a fluidized bed and a slurry reactor, a temperature range of 200 to 700 ° C., and a hydrogen atmosphere. The reduced FT catalyst is generally performed in the art under the conditions of FT reaction. Specifically, the reaction temperature is 300 to 500 ° C., the reaction pressure is 30 to 60 kg / cm 2, and the space velocity is 1000 to 10000 h ^−1. It is preferable to perform at, but is not limited thereto.

The FT reaction conversion rate of the catalyst prepared by the above method is 10 to 50 mol%, and shows a range of 83 mol% or more of C ₅ or more hydrocarbons, specifically, naphtha, diesel, middle oil, heavy oil and wax.

Hereinafter, the present invention will be described in detail with reference to the following examples, but the present invention is not limited by the following examples.

Example 1

10.8 g of zirconium nitrate (ZrO (NO ₃ ) ₂ .2H ₂ O; Kanto Chem.) As a zirconium precursor and 55.2 g of aluminum nitrate (Al (NO ₃ ) ₃ · 9H ₂ O; Samchun Chem.) As an alumina precursor The solution dissolved in 600 mL of tertiary distilled water and the solution of 71.4 g of potassium carbonate (K ₂ CO ₃ ) as a precipitant in 600 mL of tertiary distilled water are stirred at a temperature of 70 ° C. The pH of the solution was maintained at 7-8 while simultaneously dropping each solution at a rate of 5 mL / min into a 2000 mL flask. The slurry solution was stirred and aged at a temperature of 70 ° C. for about 3 hours, washed with 1800 mL of tertiary distilled water to remove the precipitant, and filtered. Thereafter, the resultant was dried at 100 ° C. for 12 hours and calcined for 5 hours in an air atmosphere at 500 ° C. to prepare a powdery 5% by weight zirconia-alumina carrier. In this case, the prepared carrier was composed only of fine pores of less than 10 nm, the specific surface area was 299 m 2 / g and the pore volume was 0.47 cm ³ / g.

Cobalt precursor solution (8.5 g of cobalt acetate (Co (CH ₃ COO) ₂ 4H ₂ O) was dissolved in 300 mL of tertiary distilled water, and 10.8 g of potassium carbonate (K ₂ CO ₃ ) as a precipitant were added to 300 mL. A dissolved potassium carbonate precursor aqueous solution was prepared. A powdered 5 wt% zirconia-alumina carrier slurry phase was prepared in 200 mL of tertiary distilled water. Next, the solution of cobalt precursor solution, potassium carbonate precursor solution and 5 wt% zirconia-alumina carrier slurry phases were simultaneously dropped at a rate of 5 mL / min into a 2000 mL flask at a temperature of 70 ° C. and stirred. The pH of was maintained at 7-8. The slurry solution was stirred and aged at a temperature of 70 ° C. for about 1 hour, and washed with 1800 mL of tertiary distilled water to remove and filter the precipitant. Thereafter, the mixture was dried at 100 ° C. for at least 12 hours, and calcined at 500 ° C. for 5 hours to prepare a 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst.

Thereafter, ruthenium nitrosylnitrate (Ru (NO) (NO ₃ ) ₃ ) was loaded with 0.5 wt% based on the 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst, followed by distillation. After evaporator, the solution was removed and dried, and calcined under oxygen atmosphere at 400 ° C. for 5 hours to prepare a 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst. The prepared catalyst has a double pore structure, a specific surface area of 245 m ² / g and a pore volume of 0.80 cm ³ / g, in particular the ratio of the pore volume (PV ₁ / PV ₂ ) of small pores to large pores 0.84.

Next, 0.3 g of the prepared 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 2

10.8 g of zirconium nitrate (ZrO (NO ₃ ) ₂ .2H ₂ O; Kanto Chem.) As a zirconium precursor and 55.2 g of aluminum nitrate (Al (NO ₃ ) ₃ · 9H ₂ O; Samchun Chem.) As an alumina precursor The solution dissolved in 600 mL of tertiary distilled water and the solution of 71.4 g of potassium carbonate (K ₂ CO ₃ ) as a precipitant in 600 mL of tertiary distilled water are stirred at a temperature of 70 ° C. The pH of the solution was maintained at 7-8 while simultaneously dropping each solution at a rate of 5 mL / min into a 2000 mL flask. The slurry solution was stirred and aged at a temperature of 70 ° C. for 3 hours, washed with 1800 mL of tertiary distilled water to remove the precipitant, and filtered to prepare a 5 wt% zirconia-alumina precipitate in the form of a cake.

A solution of 8.5 g of cobalt acetate (Co (CH ₃ COO) ₂ 4H ₂ O) as a cobalt precursor in 300 mL of tertiary distilled water and 10.8 g of potassium carbonate (K ₂ CO ₃ ) as a precipitant in 300 mL A precursor aqueous solution was prepared. The pH of the solution was maintained at 7 to 8 while simultaneously dropping each solution at a rate of 5 mL / min into a 2000 mL flask maintained at a temperature of 70 ° C. in 200 mL of tertiary distilled water, the slurry solution being 70 ° C. After stirring and ripening at a temperature of about 1 hour, the mixture was washed with 1800 mL of tertiary distilled water to remove the precipitant and filtered to obtain a cobalt precipitate in the form of a cake.

The zirconia-alumina slurry containing the cobalt was obtained by stirring the zirconia-alumina precipitate and the cobalt precipitate in the form of a cake prepared separately, respectively, at room temperature for 1 hour or more in 200 mL of tertiary distilled water. The prepared slurry was dried in an oven maintained at 100 ° C. for 12 hours or more, and then calcined in an air atmosphere at 500 ° C. for 5 hours to prepare a 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst.

Thereafter, ruthenium nitrosylnitrate (Ru (NO) (NO ₃ ) ₃ ) was loaded with 0.5 wt% based on the 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst, followed by rotary concentration. After evaporator, the solution was removed and dried, and calcined under oxygen atmosphere at 400 ° C. for 5 hours to prepare a 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst. The prepared catalyst has a double pore structure, the specific surface area is 220 m ² / g and the pore volume is 0.62 cm ³ / g, in particular the ratio of the pore volume (PV ₁ / PV ₂ ) of small pores to large pores It was 1.27.

Next, 0.3 g of the prepared 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 3

In the same manner as in Example 2, except that ruthenium was performed to prepare a 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst. The prepared catalyst has a double pore structure, the specific surface area is 238 m ² / g and the pore volume is 0.53 cm ³ / g, in particular the ratio of the pore volume of the small pores to large pores (PV ₁ / PV ₂ ) 1.43.

Next, 0.3 g of the prepared 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 4

The same procedure as in Example 1 was carried out, followed by reduction of the prepared 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst with hydrogen from the outside at 400 ° C. for 12 hours. Sealed and introduced into slurry reactor. The solvent used in the slurry reactor was 300 mL of squalene (squalane), and 5 g of the catalyst was injected and then reduced in a reactor at 220 ° C. for 12 hours or more. The reaction conditions are the reaction temperature 220 ℃ reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr and stirring speed is 2000 rpm, the molar ratio of carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) 28.4 The Fischer-Tropsch reaction was carried out by injection into the reactor at a ratio of 57.3: 9.3: 5. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 5

In the same manner as in Example 4, the Fischer-Tropsch reaction was performed by fixing the temperature of the reaction conditions to 240 ℃. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 6

In the same manner as in Example 1, using cobalt nitrate (Co (NO ₃ ) ₂ · 6H ₂ O) as a cobalt precursor 0.5% by weight Ru / 20% by weight Co / 5% by weight ZrO ₂ -Al ₂ O _Three catalysts were prepared.

Next, 0.3 g of the prepared 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 7

In the same manner as in Example 1, but stirred and aged for about 5 hours on a slurry maintained at a temperature of 70 ℃ of co-precipitating the cobalt component in the carrier 0.5% by weight Ru / 20% by weight Co / 5% by weight ZrO ₂ -Al ₂ O ₃ catalyst was prepared. The prepared catalyst has a double pore structure, the specific surface area is 256 m ² / g and the pore volume is 0.85 cm ³ / g, in particular the ratio of the pore volume (PV ₁ / PV ₂ ) of small pores to large pores 0.95.

Next, 0.3 g of the prepared 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is summarized in the following Table 1, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 8

In the same manner as in Example 1, but stirred and aged for about 10 hours on a slurry maintained at a temperature of 70 ℃ in the process of co-precipitating the cobalt component in the carrier 0.5% by weight Ru / 20% by weight Co / 5% by weight ZrO ₂ -Al ₂ O ₃ catalyst was prepared.

Next, 0.3 g of the 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst prepared above was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 9

In the same manner as in Example 1, 0.5 wt% Ru / 20 wt% Co / 2.5 wt% using zirconium nitrate (ZrO (NO ₃ ) ₂ .2H ₂ O; Kanto Chem.) 5.4 g as a zirconium precursor. A ZrO ₂ -Al ₂ O ₃ catalyst was prepared.

Next, 0.3 g of the 0.5 wt% Ru / 20 wt% Co / 2.5 wt% ZrO ₂ -Al ₂ O ₃ catalyst prepared above was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Example 10

In the same manner as in Example 1, using zirconium nitrate (ZrO (NO ₃ ) ₂ · 2H ₂ O; Kanto Chem.) 21.6 g as a zirconium precursor 0.5% by weight Ru / 20% by weight Co / 10% by weight A ZrO ₂ -Al ₂ O ₃ catalyst was prepared.

Next, 0.3 g of the 00.5 wt% Ru / 20 wt% Co / 10 wt% ZrO ₂ -Al ₂ O ₃ catalyst prepared above was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was charged at 400 ° C. before starting the reaction. 5 vol% H ₂ / He) was subjected to reduction for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Comparative Example 1

In the same manner as in Example 1, a high surface area alumina (specific surface area is 455 m 2 / g) is used as a carrier, cobalt nitrate (Co (NO ₃ ) ₂ · 6H ₂ O) is used as a cobalt precursor After stirring at room temperature for 5 hours or more, rotary evaporator at 70 ° C., dried at 100 ° C. for 12 hours, and calcined at 400 ° C. for 5 hours in an air atmosphere, 20 weights of 20% by weight of cobalt was carried on an alumina carrier. A% Co / Al ₂ O ₃ catalyst was prepared. The prepared catalyst had a single pore structure and had a specific surface area of 227 m ² / g and a pore volume of 0.68 cm ³ / g.

Next, 0.3 g of the prepared 20 wt% Co / Al ₂ O ₃ catalyst was charged to a 1/2 inch stainless steel fixed bed reactor, and then placed under hydrogen (5 vol% H ₂ / He) atmosphere at 400 ° C. before starting the reaction. Time reduction treatment. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Comparative Example 2

In the same manner as in Example 1, zirconium is zirconium oxychloride (ZrCl ₂ O · 8H ₂ O), cobalt nitrate (Co (NO ₃ ) ₂ · 6H ₂ O) and ruthenium nitrosyl nitrate (Ru ( NO) (NO ₃ ) ₃ ), and impregnation method, each component was 0.5 weight% Ru / 20 weight% Co, carrying 0.5 weight% Ru, 20 weight% Co, and 5 weight% Zr with respect to the alumina carrier. A / 5 wt% Zr / Al ₂ O ₃ catalyst was prepared. The prepared catalyst had a single pore structure and had a specific surface area of 187 m ² / g and a pore volume of 0.23 cm ³ / g.

Next, 0.3 g of the 0.5 wt% Ru / 20 wt% Co / 5 wt% Zr / Al ₂ O ₃ catalyst prepared above was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was treated at 400 ° C. (5 ° C.) before starting the reaction. Volumetric reduction was carried out under a volume% H ₂ / He) atmosphere for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 The Fischer-Tropsch reaction was carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

Comparative Example 3

In the same manner as in Example 1, zirconium nitrate (Zr (NO ₃ ) ₂ · 2H ₂ O), cobalt acetate (Co (CH ₃ COO) ₂ · 4H ₂ O) and ruthenium nitrosyl nitrate (Ru (NO) (NO ₃ ) ₃ ), and impregnation method was used to carry 0.5 wt% Ru, 20 wt% Co and 5 wt% Zr to the alumina carrier to carry 0.5 wt% Ru / 20 wt% Co / 5 wt.% Zr / Al ₂ O ₃ catalyst was prepared.

Next, 0.3 g of the 0.5 wt% Ru / 20 wt% Co / 5 wt% Zr / Al ₂ O ₃ catalyst prepared above was charged to a 1/2 inch stainless steel fixed bed reactor, and hydrogen was treated at 400 ° C. (5 ° C.) before starting the reaction. Volumetric reduction was carried out under a volume% H ₂ / He) atmosphere for 12 hours. The molar ratio of reactants carbon monoxide: hydrogen: carbon dioxide: argon (internal standard) at the reaction temperature of 220 ℃, reaction pressure 20 kg / ㎠, space velocity 2000 L / kgcat / hr of 28.4: 57.3: 9.3: 5 Fischer-Tropsch reactions were carried out by injection into the reactor at a fixed rate. The content of the product obtained by the reaction is shown in Table 1 below, the result of which was the average value of 10 hours after the reaction time 60 hours, which is a region in which the activity of the catalyst is stabilized and maintained.

division CO conversion rate (mol% carbon) Carbon selectivity (carbon mole%) BET surface area of the catalyst (㎡ / g) Pore volume ratio of catalyst (PV ₁ / PV ₂ ) C ₁ C ₂ -C ₄ C ₅ or higher Example 1 27.8 7.1 7.6 85.3 245 0.84 Example 2 18.2 6.4 9.6 84.1 220 1.27 Example 3 12.0 6.4 9.4 84.2 238 1.43 Example 4 15.5 5.8 6.4 87.8 245 0.84 Example 5 28.0 5.1 5.3 89.6 245 0.84 Example 6 37.7 8.4 7.1 84.5 - - Example 7 43.3 5.6 6.8 87.6 256 0.95 Example 8 27.2 8.6 7.6 83.8 - - Example 9 25.8 8.3 7.3 84.4 - - Example 10 25.5 7.8 8.5 83.7 - - Comparative Example 1 17.5 11.9 8.5 79.6 227 Single hole Comparative Example 2 22.6 9.2 10.5 80.3 187 Single hole Comparative Example 3 21.5 9.7 11.3 79.0 - -

As shown in Table 1, it was confirmed that the cobalt / zirconia-alumina catalyst prepared according to the present invention has a double pore structure in which both large pores and small pores exist simultaneously.

This is a zirconia-alumina of uniform pore size while increasing the capacity of mass transfer and heat transfer in large pores compared to the catalysts of Comparative Examples 1 and 2 having a single pore structure by using the impregnation method with one conventional component. The use of a carrier makes the dispersibility of cobalt more uniform, reducing the pore blockage caused by the high-boiling compounds produced during the reaction and reducing the selectivity to methane, thereby enabling an efficient Fischer-Tropsch reaction. Could confirm.

In particular, the method of incorporating the cobalt component by the coprecipitation method on the carrier slurry of Example 1 is characterized by the specific surface area and the liquid hydrocarbon of the catalyst prepared by mixing the catalyst prepared independently using the simple coprecipitation method of Example 2 on the slurry. It was confirmed that the selectivity increased.

In addition, it was confirmed that Example 1, which is further loaded with zirconia, to increase the dispersibility and reducibility of cobalt is superior to Example 3, in which the zirconia metal component is excluded. The catalytic performance of this bi-porous structure showed better activity in the slurry reactors of Examples 4 and 5, which confirms that the use of the catalysts presented in the present invention is more advantageous, primarily in the form of reactors that can facilitate mass transfer and heat transfer. Could.

According to the results of the Fischer-Tropsch reaction according to the type of cobalt precursor, the carbon monoxide conversion was increased in the case of Example 6 using cobalt nitrate, compared with the other case using cobalt acetate. The selectivity of was slightly reduced.

In addition, in the experiment confirming the effect of the aging time in the step of containing the cobalt component in the zirconia-alumina carrier, the conversion rate and the selectivity to the liquid hydrocarbon increased in the case of Example 7 which is 5 hours than Example 1, which is 1 hour of aging time. In Example 8, where the aging time was 10 hours, the conversion rate and the selectivity of the liquid hydrocarbon were decreased, but the selectivity of the liquid hydrocarbon was superior to that of Comparative Examples 1, 2, and 3 of the single pore structure. I could confirm it.

Meanwhile, FIG. 1 is 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst prepared in Example 1 and 20 wt% Co / 80 wt prepared in Comparative Example 1 according to the present invention. Fischer-Tropsch was carried out using a% Al ₂ O ₃ catalyst, and the conversion rate of carbon monoxide according to the reaction time was shown. Example 1 shows excellent initial conversion rate and is shown in Table 1 As described above, it was confirmed that the selectivity to liquid hydrocarbons was excellent at similar conversion rates.

FIG. 2 shows 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst of Example 1, 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ of Example 3 according to the invention O ₃ catalyst, and Comparative example 1 20 wt% Co / 80 wt% Al ₂ O ₃ catalyst, and Comparative example 2, 0.5 wt% Ru / 20wt% Co / 5 wt% Zr / 75 wt% Al ₂ O ₃ catalyst of the By showing the pore distribution, it was confirmed that the catalyst prepared in the example had a double pore structure and was excellent in selectivity to liquid hydrocarbons due to excellent heat and mass transfer properties.

3 shows an electron micrograph of 0.5 wt% Ru / 20 wt% Co / 5 wt% ZrO ₂ -Al ₂ O ₃ catalyst of Example 1 prepared according to the present invention, and shows a cobalt in a zirconia-alumina carrier having a plate structure. It can be seen that the component shows a shape in which the particles are evenly dispersed in the form of nano-sized particles.

In conclusion, the cobalt-containing zirconia-alumina catalyst having a bi-porous structure presented in the present invention can improve the stability of the catalyst by improving the mass transfer rate of the high-boiling compound and at the same time, the catalyst proposed in the present invention is an easy method. It was possible to form large pores and to suppress the Fischer-Tropsch reactivity with methane, thereby significantly improving the performance of the catalyst.

In addition, the catalyst of the present invention can be utilized in all reactions for producing liquid hydrocarbons from syngas on fixed bed, fluidized bed reactors and slurry reactors, especially when used in slurry reactors with high material transfer effects. I could confirm that.

In the development of GTL technology, which is in the spotlight as an alternative to cope with the recent rapidly changing oil price problem, the improvement of the catalyst for FT synthesis reaction is directly connected to the improvement of the competitiveness of the GTL technology. Application of zirconia-alumina catalyst can improve the thermal efficiency and carbon utilization efficiency of the GTL process, and also allow the systematic design of the FT reaction process. Therefore, the use of FT reaction catalyst reduces the selectivity to methane and C _5. The increased selectivity to liquid hydrocarbons is expected to be advantageous for the development of competitive GTL process designs with significantly improved furnace carbon efficiency.

Claims (14)

In the catalyst for Fischer-Tropsch reaction in which cobalt is supported as an active ingredient on a carrier, The catalyst is a mixed carrier of zirconia and alumina containing Al ₂ O and ZrO ₂ , and has a cobalt-supported catalyst as an active ingredient, with relatively small pore size (PS ₁ ) and large pores (PS ₂ ) simultaneously. Bimodal present is formed, the pore size of the small pores (PS ₁ ) and large pores (PS ₂ ) is as follows, The ZrO ₂ is 1 to 30% by weight based on Al ₂ O, cobalt is contained in the Fischer-Tropsch reaction catalyst, characterized in that 5 to 40% by weight based on the total carrier. 2 ≤ PS ₁ ≤ 10 nm 10 <PS ₂ ≤ 200 nm The catalyst according to claim 1, wherein the specific surface area of the carrier is 150 to 400 m 2 / g, and the specific surface area of the catalyst is 100 to 300 m 2 / g. The catalyst (PV ₁ / PV ₂ ) of claim 1, wherein the catalyst has a ratio (PV ₁ / PV ₂ ) of a small pore volume (PV ₁ ) in the range of 2 to 10 nm and a large pore volume (PV ₂ ) in the range of 10 to 200 nm. A catalyst characterized by maintaining the range of ˜2.0. The catalyst of claim 1, wherein the catalyst contains a promoter selected from rhenium, ruthenium and platinum in a range of 0.05 to 1 wt% based on the catalyst. 1 step of preparing a mixed carrier of zirconia and alumina by adding a mixed aqueous solution containing a zirconium precursor and an alumina precursor, coprecipitation at pH 7-8 by adding a basic precipitant, and then aging and firing at 300 to 900 ° C. The aqueous solution containing the mixed carrier of zirconia and alumina prepared above and a cobalt precursor and a basic precipitant were added to coprecipitate at pH 7-8, then aged and calcined at 200-700 ° C. to obtain small pores (PS ₁ ) and large pores ( Step 2 to prepare a catalyst having a dual porosity structure in the pore size range of PS ₂ ) Fischer-Tropsch (Fischer-Tropsch) reaction method for producing a catalyst comprising a. 2 ≤ PS ₁ ≤ 10 nm 10 <PS ₂ ≤ 200 nm 1 step of co-precipitation under pH 7-8 by adding a mixed aqueous solution containing a zirconium precursor and an alumina precursor and a basic precipitant, and then aging to prepare a mixed carrier of zirconia and alumina in the form of slurry. Two steps of cobalt slurry prepared by adding an aqueous solution containing a cobalt precursor and a coagulant under a pH of 7 to 8 by adding a basic precipitation agent, and The mixed carrier of the prepared slurry-like zirconia and alumina and the cobalt slurry are mixed, dried and calcined at 200 to 700 ° C., and the pore sizes of the small pores (PS ₁ ) and the large pores (PS ₂ ) are as follows. 3 steps to prepare a catalyst of porous structure Fischer-Tropsch (Fischer-Tropsch) reaction method for producing a catalyst comprising a. 2 ≤ PS ₁ ≤ 10 nm 10 <PS ₂ ≤ 200 nm The method according to claim 5 or 6, wherein the zirconium, alumina and cobalt precursors are one or a mixture of two or more selected from nitrates, halogen salts and acetate salts of the respective metals. The method of claim 5 or 6, wherein the zirconium precursor is used in the range of 1 to 30% by weight based on the alumina precursor. The method of claim 5 or 6, wherein the cobalt precursor is used in the range of 5 to 40% by weight based on the mixed carrier of zirconia and alumina. 7. The process according to claim 5 or 6, wherein the basic precipitant is selected from sodium carbonate, potassium carbonate, ammonium carbonate and ammonia water. The method according to claim 5 or 6, wherein the aging is carried out at 40 to 90 ° C for 0.1 to 15 hours. The method according to claim 5 or 6, wherein after the two-stage treatment, the ruthenium, rhenium and platinum precursors are used in an amount of 0.005 to 1% by weight relative to the zirconium precursor, and then three steps of firing in the range of 100 to 600 ° C are further included. Manufacturing method characterized in that. Under the catalyst of any one of claims 1 to 4, A process for producing a liquid hydrocarbon from syngas, characterized in that to produce a liquid hydrocarbon by Fischer-Tropsch reaction of the syngas. 14. A process according to claim 13 wherein the Fischer-Tropsch reaction is carried out under a reactor selected from a fixed bed, a fluidized bed and a slurry.

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