KR20190012362A - Solid Ni-P Complex Catalyst for Ethylene Oligomerization and Preparation Method thereof - Google Patents

Abstract

Provided in the present disclosure are: a heterogeneous catalyst capable of improving a yield of oligomerization reaction products, especially products of C10 or more while conducting an oligomerization reaction, by supporting a single Ni-P crystal phase of Ni(PO_3)_2, bound with nickel (Ni) and phosphorus (P) on an inorganic oxide support in an active phase; a method of manufacturing the heterogeneous catalyst; and an oligomerization process using the catalyst.

Description

Technical Field [0001] The present invention relates to a nickel-phosphorus complex solid catalyst for producing an ethylene oligomer,

The present disclosure relates to heterogeneous catalysts for oligomerization reactions and methods for their preparation. More particularly, the disclosure provides a method of forming a By supporting a single Ni-P crystal phase of Ni (PO ₃ ) ₂ in which nickel (Ni) and phosphorus (P) are bonded in an active phase, the yield of oligomerization reaction products, And a process for preparing the solid catalyst, and an oligomerization process using the catalyst.

Ethylene is a raw material used as a basic raw material for the chemical industry so that its production and consumption are an indicator of the size of the chemical industry in the country. Typically, ethylene is used as a monomer for producing polymers such as polyethylene, and olefins having a carbon length (or chain) of about C4 to C40 through an oligomerization reaction (specifically alpha-olefins, more specifically linear Alpha-olefins) have been synthesized to produce various chemicals.

On the other hand, linear alpha-olefin (LAO) is a compound that can be used not only for the production of surfactants and synthetic lubricants but also as comonomers for the production of polyolefins. With the recent development of the polyolefin industry, worldwide demand for alpha olefins is rapidly increasing . At present, most of the alpha-olefins are produced by oligomerization of ethylene, so that in the oligomerization reaction, the carbon chain is bonded at the alpha-position by the chain terminal and the double bond.

In this regard, the compositional distribution of the oligomerization reaction product can be varied by controlling the operating conditions of the oligomerization reaction. For example, when the reaction temperature is increased or the reaction time is increased, the proportion of the oligomerization product having a relatively high molecular weight can be increased. On the other hand, when the reaction temperature is lowered or the polymerization time is decreased, the proportion of the oligomerization product in a relatively small size is increased. As such, manufacturers of oligomerization products of ethylene are changing the composition of the oligomerization products in a way that appropriately controls the reaction conditions, taking into consideration the scale of the chemical business derived therefrom. .

The oligomerization product can also be synthesized by various methods, typically a naphtha cracking process in petrochemical processes (IHS CHEMICAL, Light Linear Alpha Olefin Market Study, Special Report Prospectus (2016)). Currently, commercialized oligomerization processes include Axens AlphaButol (R), Axens AlphaHexol (R), and Chevron Phillips (R) 1-hexene production processes. (CHEMSYSTEMS, Developments in linear alpha olefin (LAO)

Conventional oligomerization reactions, specifically oligomerization reactions of ethylene, typically produce linear alpha-olefins and long chain oligomers as liquid phase reactions using homogeneous catalysts. In this case, Cr (II) (Dalton Trans. 44 (2015) 11004-11012), Ni (II) (Angew Chem. Int. IV) (Dalton Trans. 42 (2013) 9129-9138). In addition, oligomerization catalysts using catalysts using zirconium complexes are also known (A. Meiswinkel, A. Wcll, W. Mller, HV Bclt, FM Mosa, A. Al-Hazmi, Oil Gas Eur. , 1030106).

As another method, a process of performing oligomerization reaction of ethylene in a liquid or vapor phase in the presence of a catalyst in which nickel is supported on silica, alumina, silica-alumina or the like as a support is known (for example, Japanese Patent No. 6095808 And 609580, Korean Patent Nos. 1250627 and 1358589, etc.).

In this regard, in the SHOP process (Shell Higher Olefin Process) of Shell, which is a commercial ethylene oligomerization process using a homogeneous catalyst, oligomerization reaction is carried out using nickel as an active metal (Angew. Chem. Int. (2013) 12492-12496). In addition, the homogeneous catalyst is a complex form in which a ligand (PO, NO, etc.) having an ability to support oligomerization reaction is present in the vicinity of Ni (II) and an active metal (for example, -0118275, etc., Japanese Patent Laid-Open Nos. 2015-214540, 2015-209428, 2015-209429, etc. U.S. Patent Nos. 9586982 and 6825148, U.S. Patent Publication No. 2005-0049447 etc.) .

However, when a homogeneous catalyst is used, a complicated separation process such as phase separation is required after preparation of an oligomerization reaction product. Therefore, studies on an ethylene oligomerization reaction using a heterogeneous catalyst are underway.

In this connection, there is known a catalyst in which a metal complex as in the prior art is supported on a support (U.S. Patent Publication No. 2017-0088644 etc.). As another catalyst preparation method, nickel is used as an active metal and a refractory porous support having an acid site such as silica-alumina (domestic patent No. 1358589), zeolite (Appl. Catal. A, 467 (2013) 509- 518) or a material with mesopores (J. Catal. 323 (2015) 76-84)) is also known. However, in the oligomerization process using such a heterogeneous catalyst, the production amount is limited because the selectivity to oligomers having a long carbon chain (C10 or higher oligomers) is low.

On the other hand, it has been reported that a catalyst (Ni ₂ P) prepared by adding nickel (Ni) to an active metal and adding phosphorus (P) in a small amount can be conventionally applied to a hydrogenolysis reaction or a hydrogenolysis reaction. However, almost no examples have been found in the reaction for producing oligomers using ethylene as a reaction raw material, and the Ni ₂ P catalyst has a P / Ni molar ratio adjusted to 2 or less.

As such, the application range of oligomerization reactions of olefins (especially olefins such as ethylene) is continuously expanding. In particular, oligomers with high carbon number (specifically, olefins of C10 or more) (For example, aviation oil, diesel oil, etc.), the related research activities and the competition in the industry are becoming more intense.

Thus, there is a need for development of catalysts with known oligomerization activity and related processes as heterogeneous catalysts, which are not conventionally known catalysts, particularly homogeneous catalysts.

Thus, one embodiment of the present disclosure is a heterogeneous catalyst using an inorganic oxide (especially a porous inorganic oxide) support to alleviate the inefficiency of the process due to the use of conventional homogeneous nickel catalysts, A catalyst having improved oligomerization activity and a process for producing the same.

In another embodiment of the present disclosure, oligomerization products having an increased number of carbon atoms from lower olefins (e.g., ethylene) in the presence of heterogeneous Ni-P supported catalysts having improved catalytic activity, And a process for producing C10 or higher oligomerization products applicable to fuel oil for transportation such as oil, etc. at a high selectivity and a high yield.

According to a first aspect of the present disclosure,

An inorganic oxide support; And

A single Ni-P crystalline phase of Ni (PO ₃ ) ₂ as an active phase supported on the support;

/ RTI >

Here, the content of the Ni (PO ₃ ) ₂ crystal phase is at least 5% by weight based on the total weight of the catalyst, and the oligomerized heterogeneous catalyst is provided.

According to an exemplary embodiment, the inorganic oxide support may be silica, alumina, or silica-alumina.

According to an exemplary embodiment, the inorganic oxide support may be amorphous silica-alumina.

According to a second aspect of the present disclosure,

As a method of producing an oligomerization heterogeneous catalyst,

a) providing an aqueous solution containing a nickel precursor and a phosphorus (P) precursor, respectively;

b) combining said nickel precursor-containing aqueous solution and said phosphorus precursor-containing aqueous solution to prepare an aqueous solution containing nickel (Ni) -phosphorus (P) bonds under controlled pH conditions;

c) contacting the inorganic oxide support with the nickel-phosphorus bond-containing aqueous solution to form a nickel-phosphorus bond-attached inorganic oxide support;

d) heat treating the inorganic oxide support having the nickel-phosphorus bond attached thereto under a calcination atmosphere to form an inorganic oxide support having a single Ni-P crystal phase supported thereon as an active phase and composed of Ni (PO ₃ ) ₂ ;

/ RTI >

Here, the step b) is carried out under the condition that the molar ratio of phosphorus (P) / nickel (Ni) is 0.9 to 6,

Wherein the content of the Ni (PO ₃ ) ₂ crystal phase is at least 5% by weight based on the weight of the catalyst.

According to an exemplary embodiment, said step b)

b1) combining the nickel precursor-containing aqueous solution and the phosphorus precursor-containing aqueous solution to form a nickel (Ni) -phosphorus (P) bond-containing precipitate; And

b2) dissolving the nickel (Ni) -in (P) bond-containing precipitate under a controlled pH condition of 1 to 5 to prepare an aqueous solution containing nickel (Ni) - phosphorus (P) bonds;

. ≪ / RTI >

According to a third aspect of the present disclosure,

Providing an alkene-containing feedstock having from 2 to 6 carbon atoms;

Performing the oligomerization reaction at a temperature of 150 to 350 DEG C and a pressure of 10 to 50 bar under the presence of a heterogeneous catalyst; And

Recovering from the oligomerization product an olefin having an increased carbon number than ethylene;

≪ / RTI >

The heterogeneous catalyst includes:

An inorganic oxide support; And

A single Ni-P crystalline phase of Ni (PO ₃ ) ₂ as an active phase supported on the support;

/ RTI >

Wherein the content of the Ni (PO ₃ ) ₂ crystal phase is at least 5% by weight based on the total weight of the catalyst.

Heterogeneous Ni-P supported catalyst according to embodiments of the present disclosure to control the manufacture of P / Ni mole ratio of the catalyst to the active ingredient or active Ni (PO _{3) 2} alone the Ni-P crystal phase made of an inorganic oxide (Especially, silica-alumina) to provide improved oligomerization activity. In addition, since the heterogeneous catalyst used in the specific examples of the present disclosure can be easily separated from the product after completion of the reaction, problems such as the inefficiency of the separation process in the application of the conventional homogeneous catalyst can be solved, But also to oligomerization processes of ethylene as well as other olefins.

Further, the ethylene-oligomerization product using the catalyst according to the embodiment of the present disclosure can overcome the higher yield and selectivity for C10 or higher olefin, It is expected to be applicable to manufacturing.

FIG. 1 is a graph showing an XRD pattern for a Ni-P based catalyst prepared by varying the molar ratio of P / Ni in the examples; FIG.
FIG. 2 is a graph showing the results of ³¹ P MAS (Magic Angle Spinning) NMR analysis of a catalyst prepared by changing the molar ratio of P / Ni; FIG.
3 is a graph showing the amount of oligomers produced by performing an ethylene oligomerization reaction in the presence of a catalyst (Comparative Example 1 and Examples 1 to 5) calcined (heat-treated under an oxidizing atmosphere) while changing the molar ratio of P / Ni ;
FIG. 4 is a graph comparing the amounts of oligomers produced by performing an ethylene oligomerization reaction in the presence of a catalyst prepared by a reduction treatment and a calcination (oxidation) treatment, respectively; FIG. And
FIG. 5 is a graph showing the results of the measurement of the ethylene oligomerization reaction in the presence of the catalyst prepared by the calcination treatment while fixing the Ni content at 2 wt%, 8 wt% and 16 wt%, respectively, and changing the P / Ni molar ratio A graph comparing the amount of oligomers produced.

The present invention can be all accomplished by the following description. The following description should be understood to describe preferred embodiments of the present invention, but the present invention is not necessarily limited thereto. It is to be understood that the accompanying drawings are included to provide a further understanding of the invention and are not intended to limit the scope of the invention.

The terms used in this specification can be defined as follows.

The term " heterogeneous catalyst " may mean a catalyst that exists in a phase different from the reactants in the catalytic reaction, for example, a catalyst that does not dissolve in the reaction medium. In the case of a heterogeneous catalyst, at least one reactant must diffuse and adsorb to the surface of the heterogeneous catalyst in order for the reaction to take place, and after the reaction, the product must be desorbed from the surface of the heterogeneous catalyst.

&Quot; Support " may refer to a material having a high specific surface area (typically a solid phase material) to which a catalytically active component is attached, and may or may not participate in the catalytic reaction.

The term " crystalline " or " crystalline " may refer to any solid material typically arranged to have a valence lattice structure (e.g., three-dimensional order) Ray diffraction analysis (XRD), nuclear magnetic resonance analysis (NMR), differential scanning calorimetry (DSC), or a combination thereof.

&Quot; Active phase " refers to a component that constitutes a catalyst with other components such as a support as a component that directly contributes to the intended reaction, specifically an oligomerization reaction, more specifically, an oligomerization reaction of ethylene. can do.

The term " oligomerization " may broadly refer to the reaction of forming oligomers and / or polymers, but it is understood that oligomers having an increased number of carbon atoms from lower alkenes such as ethylene, other alkenes or mixtures thereof For example, olefins). ≪ / RTI >

Oligomerization catalyst

As described above, the oligomerization catalyst provided according to one embodiment is a heterogeneous catalyst supported with a single Ni-P crystal phase as an active phase on an inorganic oxide support. The active phase may be a single (pure) or pure crystalline phase of Ni (PO ₃ ) ₂ , a Ni ₂ P crystal phase predominantly contained in the active phase in a conventional hydrorefining or hydrocracking oxygen catalyst, And is distinguished from the mixed Ni-P crystal phase of Ni (PO ₃ ) ₂ and Ni ₂ P produced by the treatment.

According to exemplary embodiments, the inorganic oxide support may specifically be a porous inorganic oxide support. According to a particular embodiment, the inorganic oxide support can be silica, alumina, or silica-alumina, and more specifically amorphous silica-alumina (ASA) materials.

In this connection, silica-alumina is a synthetic material partially containing alumina in a tetrahedral coordination structure in NMR analysis, and contains a site (ionized hydrogen atom) (Bronsted acid) and a site (Lewis acid) And thus different types of acid sites can be distinguished by the manner in which pyridine is attached. At this time, the combination characteristics of Lewis acid and Bronsted acid can be controlled depending on the content of silica.

Illustratively, the molar ratio of silica to alumina in the silica-alumina support can range, for example, up to about 100, specifically about 3 to 50, more specifically about 5 to 30, particularly about 8 to 20 have. As the molar ratio of silica / alumina decreases, the acid point of the catalyst increases, and if too low (linear) the production of alpha-olefins may be reduced or may be inactivated due to coke or the like. On the other hand, if the molar ratio of silica / alumina is too large, stability of the active phase may be lowered. Thus, it may be advantageous to use a silica-alumina support having a suitably selected silica / alumina molar ratio within the ranges described above. It should be understood, however, that such numerical ranges are exemplary.

According to an exemplary embodiment, the specific surface area (BET specific surface area) of the inorganic oxide support is at least about 250 m2 / g, specifically about 300 to 1000 m2 / g, more specifically about 400 to 700 m2 / g Lt; / RTI > Also, the pore volume may range, for example, from about 0.2 to 2 cm 3 / g, specifically from about 0.5 to 1.5 cm 3 / g, and more specifically from about 0.7 to 1.2 cm 3 / g. In addition, the pore size (average diameter) may be in the range of, for example, about 3 to 30 nm, specifically about 5 to 25 nm, more specifically about 7 to 20 nm. It is to be understood that the numerical ranges are for illustrative purposes only.

According to an exemplary embodiment, the acidity of the inorganic oxide support may range, for example, from about 1 to 50 mmol / g, specifically about 5 to 10 mmol / g, It is advantageous to have the above-mentioned range because it affects the productivity and the product fraction in the production of oligomerization products, specifically olefins, more specifically linear alpha-olefins.

In this regard, the inorganic oxide support may be in the form of a powder, but it may optionally be formed into a variety of support forms known in the art, such as granules, pellets, tablets, . For the production of the shaped catalyst, a binder such as alumina, carbon (graphite) and the like may be additionally used. The additional amount of the binder may be, for example, up to about 30% by weight, To about 20% by weight.

On the other hand, according to one embodiment of the present disclosure, the active point or the active ingredient supported on the inorganic oxide support has a single Ni-P crystal phase composed of Ni (PO ₃ ) ₂ . The content of Ni (PO ₃ ) ₂ single crystal phase is at least about 5 wt%, specifically about 8 to 45 wt%, more specifically about 10 to 40 wt%, based on the total weight of the catalyst. In the present embodiment, Ni (PO _{3) 2} crystals present and their content oligomerization (in particular, the oligomerization of ethylene), a significant impact on the active bar, this Ni (PO _{3) 2} a certain level of content of the crystal phase on the Or above, it may contain other crystalline phases that do not improve the oligomerization activity to the desired level or may interfere with the oligomerization reaction. Therefore, a proper amount of the Ni (PO ₃ ) ₂ crystal phase should be supported on the inorganic oxide support.

In this connection, in addition to the Ni-P crystal phase alone of the Ni (PO ₃ ) ₂ crystal phase supported on the inorganic oxide support, Si ₃ (PO ₄ ) ₄ and SiP ₂ O ₅ formed by interaction with the support are added Lt; / RTI > At this time, it should be noted that although the Ni-P crystal phase exists only in the Ni (PO ₃ ) ₂ crystal phase, although additional crystal phases (for example, Si ₃ (PO ₄ ) ₄ and SiP ₂ O ₅ etc. may exist) will be.

According to the exemplary embodiment, Ni-P crystal phase (for example, Ni ₂ P crystal phase) other than the Ni (PO ₃ ) ₂ crystal phase in the Ni-P crystal phase is not contained.

According to one embodiment, the size of the Ni (PO ₃ ) ₂ crystal phase supported on the active phase may be about 10 to 40 nm, specifically about 20 to 30 nm in size.

According to a particular embodiment, an increase in the P / Ni molar ratio in the reactants (e. G., Greater than 5) can be additionally produced by interaction between phosphorus (P) and the silica- The size of the crystal phases Si ₃ (PO ₄ ) ₂ , SiP ₂ O ₇ and the like may be in the range of, for example, about 8 to 45 nm, specifically about 10 to 40 nm. In addition, the content of this additionally produced crystalline phase may be up to about 30 wt.%, Specifically up to about 25 wt.%, More specifically up to about 20 wt.%, Based on the total catalyst.

Preparation of oligomerization catalyst

In one embodiment, the heterogeneous Ni-P containing catalyst comprises a combination of a nickel (Ni) precursor and a phosphorus (P) precursor to form an inorganic oxide, specifically silica, alumina or silica- alumina, more specifically a silica- Followed by calcination (heat treatment in an oxidizing atmosphere).

The nickel precursor is typically a water soluble nickel compound. Examples of the nickel precursor include nickel acetate, nickel nitrate, nickel sulfate, nickel carbonate, nickel hydroxide, nickel halide, nickel acetylacetonate complex and nickel phosphine complex. For example. These nickel precursors can be used alone or in combination. More specifically, nickel nitrate, nickel sulfate, nickel halide, or a combination thereof can be used. More specifically, a hydrate of nickel nitrate, a hydrate of nickel sulfate, a hydrate of nickel halide, or a combination thereof can be used.

(H ₃ PO ₄ ), ammonium phosphate ((NH ₄ ) ₃ PO ₄ ), ammonium hydrogenphosphate (H (NH ₄ ) ₂ ( PO ₄ )) and ammonium hydrogen hydrogen phosphate (H ₂ (NH ₄ ) PO ₄ ), which can be used alone or in combination. Specifically, ammonium hydrogen phosphate can be used.

According to an exemplary embodiment, first, a nickel (Ni) precursor aqueous solution and a phosphorus (P) precursor aqueous solution are separately prepared. In this regard, the concentration of the nickel precursor in the aqueous solution of nickel precursor is, for example, about 2 x 10 ^-4 to 20 x 10 ^-4 mM (specifically about 5 x 10 ^-4 to 18 x 10 ^-4 mM, more specifically, about 8 × 10 ^-4 to 15 × 10 ^-4 mM) may be in the range, and the concentration of the precursor is from about 2 × 10 ^-4 to 60 × 10 ^-4 mM (specifically from about 5 × 10 ^-4 to 55 × 10 ^-4 mM, more specifically about 8 x 10 ^-4 to 50 x 10 ^-4 mM).

Then, a nickel precursor-containing aqueous solution and a phosphorus precursor-containing aqueous solution are combined. Specifically, the phosphor precursor-containing aqueous solution may be added to the nickel precursor-containing aqueous solution slowly (dropwise).

Ni-P precursor binding precipitates can be formed by combining nickel precursors and phosphorus precursors. Illustratively, the combination of the nickel precursor and the phosphorus precursor may be used at a temperature of, for example, about 20 to 40 캜 (specifically about 25 to 30 캜), such as about 0.5 to 2 hours (specifically about 0.5 to 1 hour) And may be carried out under stirring or stirring conditions.

Since it is difficult to directly deposit the Ni-P precipitate on the inorganic oxide support, the pH is adjusted to dissolve the Ni-P precursor precipitate in the aqueous medium in the exemplary embodiment. Here, the pH to be controlled may be in the range of, for example, about 1 to 5, specifically about 1 to about 2.5, and more specifically about 1 to about 2. For this purpose, an acid component may be added by way of example, and examples of such acid components may include nitric acid, hydrochloric acid, sulfuric acid, or a combination thereof. As a result, an aqueous solution containing a nickel-phosphorus (Ni-P) bond can be produced.

By using an aqueous solution containing the nickel-phosphorus precursor bonds thus prepared, it is possible to attach to the inorganic oxide support by a deposition method known in the art, for example, impregnation (specifically, wet impregnation), ion exchange, have.

According to one embodiment, the control of the molar ratio of phosphorus / nickel (P / Ni) in the reactant (or the composition before heat treatment to be described below) has a significant influence on the oligomerization reaction activity of the catalyst, Is a factor that determines the type and amount of the active phase supported on the support of the final catalyst, the size of the crystal phase, and the like. Specifically, when the molar ratio of phosphorus to nickel is small, the size of the Ni-P crystal phase in the subsequent calcination step during the catalyst production process is small enough to be detected by conventional analytical techniques such as XRD, It is judged that even a single Ni-P crystal phase of Ni (PO ₃ ) ₂ is formed. As the proportion of phosphorus (P) increases, a single Ni-P crystal phase of Ni (PO ₃ ) ₂ with a gradually increased size is formed. When the phosphorus content exceeds a certain level, Nickel (P / Ni)) is added as additional crystal phases such as Si ₃ (PO ₄ ) ₄ , SiP ₂ O ₅ and the like are further formed by interaction or reaction between the silica-containing inorganic oxide supports such as silica- The molar ratio needs to be adjusted below a certain value.

In view of the above, in this embodiment, the molar ratio of phosphorus / nickel (P / Ni) in the reactants is adjusted to be in the range of about 0.9 to 6, specifically about 3.5 to 5.5, more specifically about 3.8 to 5. That is, a single Ni-P crystal phase of Ni (PO ₃ ) ₂ starts to be formed when the molar ratio of phosphorus / nickel in the reactant is 0.9 or more, and the single Ni-P crystal phase of Ni (PO ₃ ) ₂ having a detectable crystal size in XRD analysis Only the Ni-P crystal phase is formed. Thereafter, as the molar ratio of phosphorus / nickel exceeds 5, other crystalline phases, such as Si ₃ (PO ₄ ) ₄ and SiP ₂ O ₅ , formed by excessive interaction between phosphorus and support are formed, .

Further, according to exemplary embodiments, the amount of nickel precursor used is in the range of about 2 to 20 wt%, specifically about 5 to 18 wt%, more specifically about 10 to 16 wt%, based on the catalyst weight, . ≪ / RTI >

According to an exemplary embodiment, after forming an inorganic oxide support having a nickel-phosphorus precursor bond attached (immobilized) as described above, the moisture contained in the nickel and phosphorus precursor solution is removed to obtain a solid content. In order to remove moisture, a moisture removing method, evaporation, a filter, and the like known in the art can be used.

Optionally, after removing moisture, a drying step is performed to remove residual moisture and the like in the solid content. The drying temperature may be adjusted within the range of, for example, about 95 to 110 ° C, specifically about 100 to 105 ° C, and the drying time is typically about 6 to 14 hours, To 12 hours. Such drying conditions are to be understood as being exemplary.

Then, in one embodiment, the dried solid is converted to the oxide form of the nickel-phosphorus precursor bond through thermal treatment (calcination) under an oxidizing atmosphere.

At this time, the gas forming the oxidizing atmosphere may be oxygen (specifically, molecular oxygen) alone, a combination of oxygen and inert gas, or an air atmosphere. The inert gas may be helium, nitrogen, argon or a combination thereof. According to an exemplary embodiment, the oxidizing atmosphere can be a mixed gas comprising oxygen and nitrogen, wherein the oxygen content is, for example, about 10 to 50 vol%, specifically about 15 to 40 vol%, more specifically, Can range from about 20 to 30 volume percent.

Further, the heat treatment (calcining) temperature in the oxidizing atmosphere can be selected within the range of, for example, about 500 to 700 ° C, specifically about 520 to 650 ° C, more specifically about 550 to 600 ° C, For example, about 1 to 10 占 폚 / min, specifically about 3 to 5 占 폚 / min. The calcination (oxidation) heat treatment time is not particularly limited, but can be set within a range of, for example, about 1 to 6 hours, specifically about 2 to 5 hours, more specifically about 3 to 4 hours.

In addition, the pressure in the calcining treatment (partial pressure of the oxidizing atmosphere gas) may be in the range of, for example, about 0.1 to 1 bar, specifically about 0.15 to 0.8 bar, more specifically about 0.2 to 0.5 bar. Alternatively, it is also possible to flow (flow) the oxidizing atmosphere gas into the heat treatment apparatus. In this case, the flow rate of the oxidizing atmosphere gas may be about 50 to 300 mL / min, specifically about 100 to 200 mL / min. < / RTI >

The content of the Ni (PO ₃ ) ₂ crystal phase in the oligomerization catalyst prepared above is at least about 5 wt.%, Specifically about 8 to 45 wt.%, More specifically about 10 to 30 wt.%, To 40% by weight.

Oligomerization process

According to one embodiment of the present disclosure, the heterogeneous Ni-P supported catalyst described above is used for oligomerization reactions, specifically oligomerization of C2 to C6 alkenes (specifically C2 to C4 alkenes), more specifically oligomerization of ethylene Can be effectively applied to the reaction.

In one embodiment, the alkene in the feedstock may be, for example, an alkene of 2 to 6 carbon atoms, specifically an alkene of 2 to 4 carbon atoms, more specifically ethylene, and the feedstock may be a mixture of ethylene and other alkene compounds . According to an exemplary embodiment, the content of ethylene in the feedstock may for example be at least about 80 mole%, specifically at least about 90 mole%, more specifically at least about 95 mole%.

In this embodiment, the feedstock is contacted with an oligomerization catalyst to effect an oligomerization reaction, and further, the oligomerization reaction product is reacted with the alkene or other oligomerization product in the feedstock to produce a hydrocarbon having an increased number of carbon atoms, Alpha-olefins, more specifically, linear alpha-olefins, and also various types of olefins may be contained within the oligomerization reaction product.

According to one embodiment, the oligomerization reaction can be carried out in the presence of the above-mentioned heterogeneous Ni-P supported catalyst, and optionally, the co-catalyst can be used together. Such promoter components are known in the art and include, for example, hydrogenated compounds of metals (for example, LiAlH ₄ , CaH ₂ , or NaBH ₄ (sodium borohydride) And the amount of the cocatalyst to be used may be, for example, about 800 to 1200 mol%, specifically about 900 to 1100 mol%, based on the nickel in the main catalyst.

According to an illustrative embodiment, an oligomerization catalyst (or oligomerization catalyst and cocatalyst) is contained in a liquid medium (solvent) in a reaction system and an alkene of 2 to 6 carbon atoms, specifically an ethylene-containing feedstock The gas phase feedstock) is charged into the reaction system or reactor and the reaction is carried out under elevated temperature conditions. In this case, the liquid medium may be a single bond hydrocarbon such as undecane, nonane, heptane, or a mixture thereof, which can be used for a hydrocarbon-based organic solvent, The amount can be adjusted, for example, in the range of about 0.001 to 0.03 g / mL, specifically about 0.002 to 0.02 g / mL, more specifically about 0.005 to 0.01 g / mL.

According to one embodiment, the oligomerization reaction can be carried out, for example, in a temperature range of about 150 to 350 占 폚, specifically about 180 to 300 占 폚, more specifically about 200 to 250 占 폚. In this connection, when the reaction temperature is excessively low or high, it may be advantageous to set within the above-mentioned range because the increase of unreacted materials or the deactivation of the catalyst may be promoted.

The oligomerization reaction pressure can also be adjusted, for example, under a partial pressure condition of the reactants (specifically ethylene) of, for example, about 10 to 50 bar, specifically about 20 to 45 bar, more specifically 30 to 40 bar. The reaction conditions described above are illustrative and can be varied depending on the type and concentration of the alkene in the feedstock.

Illustratively, the feedstock (specifically, the feedstock) can be introduced in a multi-stage manner in the reaction system, for example, selected within about 1 to 20 bar (specifically about 5 to 15 bar) The reaction mixture is heated to the reaction temperature in the state of being filled with pressure, and can be additionally filled up to the set reaction pressure after reaching the reaction temperature. In this way, when the feedstock is injected in a multi-stage manner, the promoter, the main catalyst, and the reactant (olefin) form active species more suitable for the oligomerization reaction during the heating process, .

According to another embodiment, the oligomerization reaction can be carried out in a continuous mode, for example, a fixed bed reactor, a semi-batch reactor, etc., wherein the space velocity is, for example, about 0.1 to 0.9 sec ^-1 , Specifically in the range of about 0.15 to 0.7 sec ^-1 , more specifically in the range of about 0.2 to 0.5 sec ^-1 , but this can be understood in an exemplary sense.

The oligomerization reaction product described above may contain, for example, C4 olefins such as 1-butene, C6 olefins such as 1-hexene, C8 olefins such as 1-octene, C10 or higher olefins and the like. Wherein the C6 olefins and C8 olefins may be predominantly linear alpha-olefins. Further, in the case of C10 or more olefins, it may be a linear and / or branched olefin. In particular, in the case of the oligomerization reaction product of ethylene, oligomers having an almost even number of carbon atoms in the reaction characteristic may be used.

In this regard, according to an exemplary embodiment, the productivity of the oligomer produced by the reaction in the presence of the catalyst described above is, for example, at least about 280 g _{oligo .} g _cat. ^-1 , specifically about 350-450 g _{oligo .} g _{cat .} ^-1 , more specifically about 380 to 430 g _{oligo .} g _{cat .} ^{-1. &} Lt; / RTI >

When the above-mentioned reaction is completed, the oligomer (specifically, the olefin having increased carbon number) can be separated and recovered from the reaction product. This separation process is known in the art and can be performed using, for example, distillation using a boiling point, adsorption, solvent extraction, and the like.

In particular, the heterogeneous Ni-P supported catalyst described above not only increases the yield of the oligomerization product but also increases the fraction of oligomers (olefins) of C10 or higher in oligomerization products of low-carbon alkenes or lower alkenes such as ethylene have. Thus, when the content of C 6 and C 8 oligomers as well as C 10 or higher oligomers is increased in the product to give a well-balanced product distribution, it is possible to obtain an oil applicable for transportation fuel, particularly aviation oil and diesel oil . As an example, in the case of oligomerization of ethylene, the fraction of C6 and C8 oligomers in the product may range, for example, from about 50 to 70 weight percent (specifically about 55 to 65 weight percent) The fraction may range, for example, from about 20 to 40% by weight (specifically about 22 to 30% by weight). In addition, the product content of C4 or less can be, for example, about 40% by weight or less, specifically about 20% by weight or less, more specifically about 16% by weight or less. This is in contrast to the prior art ethylene oligomerization catalyst, which focuses on increasing the yield of C6 or C8 oligomers (e.g., 1-hexene, 1-octene, etc.).

The present invention can be more clearly understood by the following examples, and the following examples are merely illustrative of the present invention and are not intended to limit the scope of the invention.

Example

In the examples, the sample analysis was carried out according to the following procedure.

- XRD analysis

XRD (X-ray diffraction) analysis of the catalysts used in the oligomer reaction was carried out to determine the crystal phase present in the catalyst. At this time, the powder was analyzed using a MiniFlex 600 (Rigaku) analyzer. 2-Theta XRD analysis was performed using X-ray at 40 kV, 15 mA at a rate of 10 ° / min, with the range of 10-80 ° being 0.02 ° step.

- ³¹ P MAS NMR analysis

³¹ P MAS (Magic Angle Spinning) NMR analysis was performed to determine the Ni (PO ₃ ) ₂ and Ni ₂ P crystal phases mixed in the catalyst. At this time, ³¹ P MAS (Magic Angle Spinning) NMR analysis was performed using an AVANCE II 500 instrument, analyzed at 202 MHz frequency, and 95% HPO ₄ was used as an external reference. A 4 mm MAS probe was used and analyzed at a 10 kHz spin rate.

- XRF analysis

The amount of metal present in the catalyst was measured using X-ray fluorescence (XRF) analysis. At this time, analysis was performed using a ZSX PrimusIV (Rigaku) apparatus, and a powder type catalyst was loaded on a boric acid in a pellet form for XRF analysis. Analysis was performed at 6.3 Pa in vacuum.

SIMDIS (simulated distillation) analysis

SIMDIS (Simulated Distillation) analysis was used to deduce the boiling point of the oligomerization product and the fraction of carbon in the product. The analytical conditions were analyzed while raising the temperature from 40 ° C to 400 ° C at 10 K / min.

Comparative Examples 1 to 3

Nonuniform NiO _, / SiO ₂ -Al ₂ O ₃  Catalyst, Ni ₂ P / SiO ₂ -Al ₂ O ₃  Catalyst and Ni ₂ P-Ni (PO ₃ ) ₂ (Ni-P mixed phase) / SiO ₂ -Al ₂ O ₃   Preparation of catalysts (16NiO / ASA, 16Ni17P / ASA R and 16 Ni32P / ASA R)

Of the heterogeneous catalyst used for the oligomerization reaction in a conventional _{NiO / SiO 2 -Al 2 O 3} (16NiO / ASA) catalyst (Comparative Example 1), and _{Ni 2 P / SiO 2 -Al 2} O 3 (16Ni17P / ASA R Catalyst (Comparative Example 2) and Ni ₂ P-Ni (PO ₃ ) ₂ (Ni-P mixed phase) / SiO ₂ -Al ₂ O ₃ (16Ni32P / ASA R) catalyst (Comparative Example 3). At this time, SiO ₂ -Al ₂ O ₃ was used as a support, and the molar ratio of P / Ni was set to 0 (Comparative Example 1), 2.0 (Comparative Example 2) and 3.8 (Comparative Example 3) and supported on a support (wet impregnation) to prepare a catalyst. The catalysts according to Comparative Examples 2 and 3 were heat-treated in a reducing atmosphere using hydrogen gas instead of an oxidizing atmosphere.

Comparative Example 1

The 16NiO / ASA catalyst (Comparative Example 1) was obtained by completely dissolving Ni (NO ₃ ) ₂ .6H ₂ O (purified gold) as a nickel precursor in 10 mL of distilled water as the nickel (Ni) content was fixed to 16 wt% : 6.5 × 10 ^-4 mM) and 2 g of SiO ₂ -Al ₂ O ₃ (Sigma-Aldrich; SiO ₂ / Al ₂ O ₃ molar ratio: 9.8) as a support were added and stirred for 2 hours. Water was evaporated using an evaporator, and the recovered catalyst was dried in an oven set at 105 DEG C for 12 hours. The catalyst was prepared by sintering in a tube furnace at 550 ° C (5 K / min) for 3 hours while flowing 20% oxygen / nitrogen at a flow rate of 100 mL / min.

Comparative Examples 2 and 3

The 6Ni17P / ASA catalyst (Comparative Example 2) and the 16Ni32P / ASA catalyst (Comparative Example 3) were prepared by fixing the nickel (Ni) content to 16% by weight and using Ni (NO ₃ ) ₂ .6H ₂ O Gold thread purification) were completely dissolved in distilled water 10 mL (each of 6 × 10 ^-4 and 15 × 10 ^-4 mM), in accordance with the content of phosphorus that corresponds to the _{(NH 4) 2 HPO 4 (} Sigma-Aldrich , Inc.) 20 mL distilled water ≪ / RTI > The phosphor precursor solution was injected into the nickel precursor solution while dropwise dropwise stirring. When a nickel and phosphorus (Ni-P) precipitated solution was formed, the Ni-P precipitate was completely dissolved by injecting a 10 wt% aqueous solution of HNO ₃ (hydrogen peroxide) dropwise.

2 g of SiO ₂ -Al ₂ O ₃ as a support was added to the metal precursor solution, stirred for 2 hours, and the water was evaporated using an evaporator. The recovered catalyst was dried in an oven set at 105 DEG C for 12 hours. The temperature was raised to 350 ° C. (3.5 K / min) while flowing pure hydrogen gas at a flow rate of 100 mL / min through a tube furnace, and then the temperature was raised again at 600 ° C. (1 K / min) To prepare a catalyst.

Examples 1 to 5

Heterogeneous system Ni (PO ₃ ) ₂ / SiO ₂ -Al ₂ O ₃ Preparation of catalysts (16Ni8P / ASA, 16Ni17P / ASA, 16Ni32P / ASA, 16Ni45P / ASA and 16Ni51P / ASA)

Ni (PO ₃ ) ₂ crystal phase was prepared by controlling the molar ratio of P / Ni with SiO ₂ -Al ₂ O ₃ as a support. Ni (NO ₃ ) ₂ .6H ₂ O was completely dissolved in 10 mL of distilled water as a precursor to adjust the P / Ni molar ratios to 0.9, 2.0, 3.8, 5.3, and 6.0, respectively, based on 16 wt% Ni : 7.2 × 10 ^-4 to 16.5 × 10 ^-4 mM), according to the content of the corresponding P (NH _{4) 2} HPO ₄ were dissolved in distilled water 20 mL (concentration range: 3.4 × 10 ^-4 to 49.9 × 10 ^{- 4} mM). A solution containing Ni-P precipitate was formed in the same manner as in Comparative Example 1, and 10 wt% of HNO ₃ solution was added dropwise to dissolve the precipitate.

2 g of the support SiO ₂ -Al ₂ O ₃ was added to the solution in which the precipitate was dissolved, and the mixture was stirred for 2 hours. Thereafter, water was evaporated using an evaporator, and the recovered solids were dried in an oven set at 105 DEG C for 12 hours. The dried solid material was put into a tube furnace and heat treated (calcined) at 550 ° C (5 K / min) for 3 hours while flowing 20% oxygen / nitrogen gas at a flow rate of 100 mL / min to prepare a catalyst .

- Composition analysis

In the oligomerization catalysts prepared according to Comparative Examples 1 to 3 and Examples 1 to 5, the actual catalyst composition was measured by XRF analysis in addition to the nominal composition, and the results are shown in Table 1 below.

Catalyst name Nominal composition (% by weight) Actual composition (% by weight) Ni P P / Ni molar ratio Ni P P / Ni molar ratio Comparative Example 1 16NiO / ASA 16 0 0 13.5 0 0 Comparative Example 2 16Ni17P / ASA R 16 17 2.0 13.5 14.4 2.0 Comparative Example 3 16Ni32P / ASA R 16 32 3.8 11.5 21.9 3.6 Example 1 16Ni8P / ASA 16 8 0.9 13.3 7.6 1.1 Example 2 16Ni17P / ASA 16 17 2.0 12.9 15.4 2.3 Example 3 16Ni32P / ASA 16 32 3.8 11.7 24.9 4.0 Example 4 16Ni45P / ASA 16 45 5.3 8.7 27.3 5.9 Example 5 16Ni51P / ASA 16 51 6.0 9.5 29.6 5.9

According to the above table, the compositions and contents of nickel and phosphorus were slightly different when the initial metal composition (before the heat treatment) was compared with the metal composition in the finally produced catalyst. This is because phosphorus has a characteristic of volatilizing at high temperature. However, when the final catalyst composition and initial composition were compared, the molar ratio of P / Ni did not greatly differ.

- Crystallographic analysis

The XRD patterns for the calcination catalyst according to Comparative Example 1 and the catalysts prepared by reducing treatment with varying P / Ni molar ratio (Comparative Examples 2 and 3) and the calcined catalysts (Examples 3 to 5) The results are shown in Table 2 and FIG.

Catalyst name Ni content
(wt.%) P content
(wt.%) P / Ni
Mole ratio Crystalline phase Comparative Example 1 16NiO / ASA 16 0 0 NiO Comparative Example 2 16Ni17P / ASA R 16 17 2.0 Ni ₂ P Comparative Example 3 16Ni32P / ASA R 16 32 3.8 Ni ₂ P, Ni (PO ₃ ) ₂ Example 3 16Ni32P / ASA 16 32 3.8 Ni (PO ₃ ) ₂ Example 4 16Ni45P / ASA 16 45 5.3 _{Ni (PO 3) 2, Si} 3 (PO 4) 4, SiP 2 O 5 Example 5 16Ni51P / ASA 16 51 6.0 _{Ni (PO 3) 2, Si} 3 (PO 4) 4, SiP 2 O 5

According to Table 2 and FIG. 1, it was confirmed that the 16NiO / ASA catalyst (Comparative Example 1) containing no phosphorus contained only NiO. When the molar ratio of P / Ni was 2.0 (Comparative Example 2) in 16Ni17P / ASA R and 16Ni32P / ASA R (Comparative Examples 2 and 3) catalysts prepared by reduction treatment while changing the molar ratio of P / ), the crystalline phase is Ni ₂ P was present alone, or when the molar ratio of 3.8 of the P / Ni (Comparative example 3), Ni ₂ P, and Ni (PO _{3) 2} crystal phase is also present a mixture (i.e., mixture Ni- P crystal phase) can be known.

On the other hand, in the case of the 16Ni8P / ASA catalyst (Example 1) and the 16Ni17P / ASA catalyst (Example 2) in which phosphorus was added in a small amount, the content of phosphorus relative to nickel was low and no crystal phase was detected by XRD analysis. However, the addition of a small amount of phosphorus resulted in the formation of Ni (PO ₃ ) ₂ crystal phase during the calcination process, but the size of the Ni (PO ₃ ) ₂ crystal grain was small and uniformly formed.

As a result of XRD analysis, it was confirmed that the Ni (PO ₃ ) ₂ crystal phase was formed as a single phase in the case of the 16Ni32P / ASA catalyst (Example 3) to which phosphorus was added in a sufficient amount. That is, the specific heat treatment conditions (heat treatment under an oxygen atmosphere) in the in / Ni (P / Ni) by adjusting the mole ratio to a specific value (3.8) of pure Ni (PO ₃₎ to the crystal phase in the catalyst can be prepared _two to crystal phase only and the present there was.

In the case of 16Ni45P / ASA catalyst (Example 4) and 16Ni51P / ASA catalyst (Example 5) in which phosphorus was added in excess, phosphorus added in excess with the Ni (PO ₃ ) ₂ crystal phase ), And it was confirmed that Si ₃ (PO ₄ ) ₄ and SiP ₂ O ₅ crystal phases were further formed.

According to the XRD analysis results, PO bond was also present in the 16Ni32P / ASA catalyst (Example 3), similar to the catalyst in which the PO ligand was present in the homogeneous catalyst. That is, it is believed that the PO bond exists around nickel (Ni), which is an active metal, in the Ni (PO ₃ ) ₂ crystal phase, thereby increasing the oligomerization activity of ethylene. On the other hand, P / Ni If the molar ratio is increased to respectively 5.3 (Example 4) and 6.0 (Example 5), Ni-P crystals apparently Ni (PO _{3) 2} crystal phase is one to present alone, a component of the support Si ₃ (PO ₄ ) ₄ and SiP ₂ O ₅ crystal phases in which silicon (Si) and phosphorus (P) are combined are additionally present. This additional crystalline phase can be seen as acting rather than acting as an active phase for the oligomerization reaction.

Based on the results obtained from the XRF analysis and the XRD analysis, the contents of the catalysts according to Comparative Examples 1 to 3 and the crystalline phases in the whole catalyst according to Examples 3 to 5 were calculated and shown in Table 3.

Catalyst name P / Ni
Mole ratio Content of crystal phase (% by weight) NiO Ni ₂ P Ni (PO ₃ ) ₂ Si ₃ (PO ₄ ) ₄ SiP ₂ O ₅ Comparative Example 1 16NiO / ASA 0 13.5 0.0 0.0 0.0 0.0 Comparative Example 2 16Ni17P / ASA R 2.0 0.0 27.9 0.0 0.0 0.0 Comparative Example 3 16Ni32P / ASA R 3.8 0.0 16.3 17.1 0.0 0.0 Example 3 16Ni32P / ASA 3.8 0.0 0.0 36.6 0.0 0.0 Example 4 16Ni45P / ASA 5.3 0.0 0.0 13.6 14.4 8.0 Example 5 16Ni51P / ASA 6.0 0.0 0.0 17.7 12.7 8.7

According to the above table, 27.9 wt% of Ni ₂ P was included in the case of the catalyst 16Ni17P / ASA R (Comparative Example 2), which was prepared through the reduction treatment, and in the case of 16Ni32P / ASA R (Comparative Example 3) Shows that 16.3 wt% of Ni ₂ P and 17.1 wt% of Ni (PO ₃ ) ₂ crystal phases exist in a mixed state.

On the other hand, with respect to the content of the crystalline phase in the catalyst prepared through calcination, it was confirmed that only 36.6 wt% of the Ni (PO ₃ ) ₂ crystal phase alone existed in the case of 16Ni32P / ASA (Example 3) catalyst. In the case of 16Ni45P / ASA catalyst (Example 4) and 16Ni51P / ASA catalyst (Example 5) containing an excess amount of phosphorus (P) is Ni (PO _{3) 2} crystal phase, as well as Si ₃ (PO _{4) 4} and SiP ₂ O ₅ crystal phase was additionally present.

The above results indicate that Ni-P crystal phase composed solely of Ni (PO ₃ ) ₂ crystal phase can be formed as the active phase of the oligomerization reaction by controlling the phosphorus / nickel molar ratio and varying the heat treatment method do.

- ³¹ P MAS (Magic Angle Spinning) NMR analysis

In order to specify the crystal phase of nickel and phosphorus in the reduction catalysts containing Ni-P (Comparative Examples 2 and 3) and the calcination catalysts containing Ni-P (Examples 1 to 3 and 5), ³¹ P MAS Spinning) NMR analysis was performed. The results are shown in Fig.

Referring to FIG. 2, a peak is detected only when Ni ₂ P crystal phase exists in the range of 4500 to 1000 ppm. In the case of the 16Ni17P / ASA R catalyst (Comparative Example 2) and the 16Ni32P / ASA R catalyst (Comparative Example 3), peaks were detected in the range of 4500 to 1000 ppm, which means that the Ni ₂ P crystal phase is present .

In addition, the peak detected in the range of 300 ppm to 700 ppm means the presence of the phosphate bound to P and O, and in the case of the catalysts according to Examples 1 to 3 and 5, the peak is observed in the range of 4500 to 1000 ppm Was not detected. Therefore, it means that there is no Ni ₂ P and only the Ni (PO ₃ ) ₂ crystalline phase exists.

Ethylene oligomerization experiments using heterogeneous catalysts according to Comparative Examples 1 to 3 and heterogeneous catalysts according to Examples 1 to 5

0.25 g of the catalyst prepared according to each of Comparative Examples 1 to 3 and Examples 1 to 5 and 0.3 g of LiAlH ₄ (lithium aluminum hydride) as a co-catalyst were added to 25 mL of undecane as a solvent , Ethylene gas as a reactant was injected and filled up to 10 bar, and then the temperature was raised to 230 ° C. After reaching the reaction temperature of 230 ° C, ethylene gas was further injected and charged to 35 bar to initiate the reaction. At this time, the ethylene pressure was kept constant during the reaction.

After 5 hours of reaction, the product was recovered and analyzed by flame ionized detector (FID) of GC (gas chromatography). For more accurate product analysis, SIMDIS (simulated distillation) technique was used to analyze the boiling point of the oligomerization reaction product to analyze the fraction of the product more accurately. The results of the analysis of the production rate of the oligomer and the product fraction are shown in Table 4 and FIG. 3 (Comparative Example 1 and Examples 1 to 5).

Catalyst name P / Ni
Mole ratio Oligomer production rate
^{_{(g oligo. g cat. -1}} ) Product fraction (wt.%) C ₄ ⁼ C ₆ ⁼ + C ₈ ⁼ C _{10 +} ⁼ Comparative Example 1 16NiO / ASA 0 203.3 23.8 57.9 18.4 Comparative Example 2 16Ni17P / ASA R 2.0 224.6 19.7 57.7 22.6 Comparative Example 3 16Ni32P / ASA R 3.8 418.8 14.8 62.3 22.9 Example 1 16Ni8P / ASA 0.9 298.6 19.6 59.2 21.2 Example 2 16Ni17P / ASA 2.0 289.5 16.8 59.9 23.4 Example 3 16Ni32P / ASA 3.8 416.8 15.2 61.3 23.5 Example 4 16Ni45P / ASA 5.3 426.0 14.8 61.8 23.4 Example 5 16Ni51P / ASA 6.0 352.2 15.9 60.5 23.6

According to Table 4 and FIG. 3, in the case of the 16NiO / ASA catalyst (Comparative Example 1) as the calcined catalyst, the amount of oligomer produced was 203.3 g _{oligo .} g _cat- ¹ . In the product analysis results by GC analysis, C ₄ ⁼ 23.8 wt%, C ₆ ⁼ and C ₈ ⁼ 57.9 wt%, and C ₁₀ ⁼ 18.4 wt% or more.

Also, the amounts of oligomers produced in the presence of 16Ni17P / ASA R catalyst (Comparative Example 2) and 16Ni32P / ASA R catalyst (Comparative Example 3) were 224.6 and 418.8 g _oligo, respectively _. g _{cat .} ^-1 . That is, it can be seen that as the content of phosphorus (P) relative to nickel (Ni) is increased during the production of the catalyst, the amount of oligomer is greatly increased. In addition, the product fraction of ^{_{C 4 = <C 10 + =}} <C 6 = + C 8 = were significantly increased in order of the fraction of C ₁₀ or more even in the oligomer.

On the other hand, the results of oligomerization obtained from the use of the catalyst (16NiO / ASA) according to Comparative Example 1, which is a catalyst produced by the calcination treatment method, are compared with the use of the catalysts according to Examples 1 to 5, And the result was compared with the result of oligomerization.

Referring to Table 4, it can be seen that the oligomer production rate increases as the molar ratio of P / Ni in the calcined catalyst increases. Specifically, in the case of the 16Ni45P / ASA catalyst (Example 4) having a molar ratio of P / Ni of 3.8, the oligomerization yield of ethylene was 426.0 g _{oligo .} g _cat. ^-1 was significantly higher than that of the 16NiO / ASA catalyst (Comparative Example 1) (203.3 g _{oligo .} G _{cat .} ^-1 ). However, as the molar ratio of P / Ni further increased, the amount of oligomer formation decreased (Example 5). This is because the phosphorus content in the catalyst is excessive and the oligomerization activity is lowered due to the crystal phase formed by the bond (reaction) with the support SiO ₂ -Al ₂ O ₃ .

In addition, in the case of the 16NiO / ASA catalyst (Comparative Example 1) in which phosphorus was not added, C ₁₀₊ ⁼ <C ₄ ⁼ <C ₆ ⁼ + C ₈ ^{= the} fraction increases in order. On the other hand, when the molar ratio of P / Ni is 0.9 or more (Examples 1 to 5), it can be seen that the fraction of oligomers C ₁₀ or more increases in the order C ₄ ⁼ <C ₁₀₊ ⁼ <C ₆ ⁼ + C ₈ ⁼ have.

In this way, the addition of phosphorus (P) in the oligomerization catalyst produced by the calcination treatment method significantly affects the improvement of oligomerization reaction activity, in particular, the production of C ₄ olefins is reduced and the amount of C ₁₀ or higher oligomers is increased .

Analysis of effect of catalyst treatment method on oligomerization activity

The composition of the reactants for the preparation of the catalyst remains the same (P / Ni molar ratios are maintained at 0, 0.9, 2, 3.8, 5.3 and 6.0, respectively) The oligomerization reaction was carried out under the same conditions as those of the oligomerization reaction.

It should be noted that the catalyst prepared under an oxidizing atmosphere exhibits an improved oligomerization activity as compared with a catalyst prepared under a reducing atmosphere, even though the P / Ni molar ratio is the same in the catalyst.

Analysis of the effect of nickel (Ni) content on oligomerization activity

An oligomerization catalyst was prepared by a calcination method while varying the molar ratio of P / Ni of the reactants for catalyst preparation, and oligomerization activity was evaluated when the nickel content in the catalyst was fixed to 2 wt%, 8 wt% and 16 wt%, respectively . The results are shown in Fig.

According to the figure, when the nickel content is 2 wt%, the amount of oligomer is gradually increased as the molar ratio of P / Ni is increased, but it is relatively low as compared with other nickel content catalysts. On the other hand, when the nickel content is 8% by weight and 16% by weight, it can be confirmed that the oligomer production amount is remarkably increased by controlling the molar ratio of P / Ni. This suggests that not only controlling the molar ratio of P / Ni in the preparation of the catalyst but also achieving a more desirable oligomerization activity when the content of the Ni (PO ₃ ) ₂ crystal phase in the catalyst is above a certain level.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (18)

An inorganic oxide support; And
A single Ni-P crystalline phase of Ni (PO ₃ ) ₂ as an active phase supported on the support;
/ RTI &gt;
Wherein the content of the Ni (PO ₃ ) ₂ crystal phase is at least 5% by weight based on the total weight of the catalyst. The oligomerization heterogeneous catalyst according to claim 1, wherein the inorganic oxide support is amorphous silica-alumina. The oligomerization heterogeneous catalyst according to claim 2, wherein the molar ratio of silica / alumina in the amorphous silica-alumina ranges from 8 to 20. The oligomerization heterogeneous catalyst according to claim 1, wherein the inorganic oxide support has a BET specific surface area of at least 250 m 2 / g, a pore volume of 0.2 to 2 cm 3 / g, and a pore size of 3 to 30 nm . The oligomerization heterogeneous catalyst according to claim 1, wherein the size of the Ni (PO ₃ ) ₂ crystal phase ranges from 10 to 40 nm. As a method of producing an oligomerization heterogeneous catalyst,
a) providing an aqueous solution containing a nickel precursor and a phosphorus (P) precursor, respectively;
b) combining said nickel precursor-containing aqueous solution and said phosphorus precursor-containing aqueous solution to prepare an aqueous solution containing nickel (Ni) -phosphorus (P) bonds under controlled pH conditions;
c) contacting the inorganic oxide support with the nickel-phosphorus bond-containing aqueous solution to form a nickel-phosphorus bond-attached inorganic oxide support;
d) heat treating the inorganic oxide support having the nickel-phosphorus bond attached thereto under a calcination atmosphere to form an inorganic oxide support having a single Ni-P crystal phase supported thereon as an active phase and composed of Ni (PO ₃ ) ₂ ;
/ RTI &gt;
Here, the step b) is carried out under the condition that the molar ratio of phosphorus (P) / nickel (Ni) is 0.9 to 6,
Wherein the content of the Ni (PO ₃ ) ₂ crystal phase is at least 5% by weight based on the weight of the catalyst. 7. The method of claim 6, wherein step b)
b1) combining the nickel precursor-containing aqueous solution and the phosphorus precursor-containing aqueous solution to form a nickel (Ni) -phosphorus (P) bond-containing precipitate; And
b2) dissolving the nickel (Ni) -in (P) bond-containing precipitate under a controlled pH condition of 1 to 5 to prepare an aqueous solution containing nickel (Ni) - phosphorus (P) bonds;
Based on the weight of the oligomerized heterogeneous catalyst. 7. The method of claim 6, wherein the nickel precursor is used such that the nickel content is in the range of 2 to 20 weight percent based on catalyst weight. The method of claim 6, wherein the nickel precursor is selected from the group consisting of nickel acetate, nickel nitrate, nickel sulfate, nickel carbonate, nickel hydroxide, nickel halide, nickel acetylacetonate complex, nickel phosphine complex and combinations thereof By weight based on the weight of the oligomerized heterogeneous catalyst. The method of claim 6, wherein the precursor is phosphoric acid (H ₃ PO _4), ammonium phosphate _{((NH 4) 3 PO 4} ), dibasic ammonium _{(H (NH 4) 2 (} PO 4)), phosphate 2 hydrogen Ammonium (H ₂ (NH ₄ ) PO ₄ ), and combinations thereof. The method for producing an oligomerization heterogeneous catalyst according to claim 1, 8. The method of claim 7, wherein the controlled pH condition is achieved by adding nitric acid, hydrochloric acid, sulfuric acid, or a combination thereof. 7. The method of claim 6, wherein the gas forming the calcination atmosphere comprises oxygen alone, or a combination of oxygen and an inert gas,
The calcining temperature is in the range of 500 to 700 &lt; 0 &gt; C, and
Wherein the calcining treatment pressure (partial pressure of the oxidizing atmosphere gas) is in the range of 0.2 to 0.5 bar. Providing an alkene-containing feedstock having from 2 to 6 carbon atoms;
Performing the oligomerization reaction at a temperature of 150 to 350 DEG C and a pressure of 10 to 50 bar under the presence of a heterogeneous catalyst; And
Recovering from the oligomerization product an olefin having an increased carbon number than ethylene;
&Lt; / RTI &gt;
The heterogeneous catalyst includes:
An inorganic oxide support; And
A single Ni-P crystalline phase of Ni (PO ₃ ) ₂ as an active phase supported on the support;
/ RTI &gt;
Wherein the content of the Ni (PO ₃ ) ₂ crystal phase is at least 5% by weight based on the total weight of the catalyst. 14. The method of claim 13, wherein the feedstock is an ethylene-containing feedstock. 14. The method of claim 13, wherein the oligomerization reaction is carried out by filling the liquid medium containing the heterogeneous catalyst with the alkene-containing feedstock having 2 to 6 carbon atoms,
Wherein the liquid medium is undecane, nonane, heptane, or a mixture thereof. The oligomerization process according to claim 13, wherein a cocatalyst selected from the group consisting of LiAlH ₄ , CaH ₂ , NaBH ₄ or a combination thereof is used in the range of 800 to 1200 mol% with respect to nickel in the heterogeneous catalyst Way. The oligomerization method according to claim 13, wherein the feedstock is heated to a reaction temperature in the state of filling the feedstock at 1 to 20 bar, and after reaching the reaction temperature, is filled up to the reaction pressure. 14. The process of claim 13, wherein the oligomerization product comprises C4 olefins, C6 olefins, C8 olefins and C10 or greater olefins,
Wherein the oligomerization product has an oligomer fraction of C10 or more in the range of 20 to 40% by weight.

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