KR20190110958A - Alpha olefin synthesis method and apparatus thereof - Google Patents

Abstract

The present invention relates to an alpha olefin synthesizing method comprising: a first step of preparing a catalyst composition by mixing the catalyst composition including a catalyst and a promoter during 5-20 minutes; a second step of injecting the catalyst composition and ethylene into a reactor; a third step of performing ethylene oligomerization reaction in the reactor; a fourth step of discharging 50-90 wt% of a reaction solution of the reactor during the oligomerization reaction to the reactor; a fifth step of removing heat by passing the reaction solution from the reactor through a heat exchanging device; and a sixth step of mixing the heat-removed reaction solution with the reaction solution in the reactor. The sixth step discharges the heat-removed reaction solution into the reactor through one or more species selected from a group composed of a mixing educator and a spraying unit. The present invention can improve activity of the catalyst.

Description

ALPHA OLEFIN SYNTHESIS METHOD AND APPARATUS THEREOF

The present invention relates to a method and a device for synthesizing alpha olefins, wherein a catalyst and a promoter used for oligomerization of ethylene are mixed in advance for a predetermined time so as to be a uniform mixture, and circulated for heat removal. The present invention relates to a method and an apparatus for synthesizing alpha olefins, in which a solution and ethylene are introduced into the reactor again for reaction.

Linear alpha-olefins are widely used commercially as important materials for comonomers, detergents, lubricants, plasticizers, etc. In particular, 1-hexene and 1-octene are used in the production of linear low density polyethylene (LLDPE). It is often used as a comonomer to control the density.

Conventional manufacturing process of LLDPE (Linear Low-Density Polyethylene) is used to form a branch in the polymer backbone together with ethylene to control density by adjusting the density of density. Copolymerization was performed with comonomers such as 1-hexene and 1-octene.

Therefore, there is a problem that the price of the comonomer takes a large part of the manufacturing cost for the production of LLDPE having a high comonomer content. Various attempts have been made to solve this problem.

In addition, since alpha-olefins have different application fields or market sizes, technology for selectively producing specific olefins is commercially important, and recently, 1-hexene or ethylene oligomerization may be used. There is much research on the chromium catalyst technology for producing 1-octene with high selectivity.

Typically, the reaction raw materials fed to a continuous stirred-tank reactor (CSTR) for the synthesis of linear alpha-olefins are catalyst compositions and olefin monomers comprising ligand compounds, transition metal compounds such as chromium and promoters. In general, it is common to use a stirrer to increase the mass transfer efficiency in the reactor.

However, if the olefin monomer is not uniformly dispersed during the reaction, there is a problem that not only trimerization and tetramerization but also the polymer continues to grow and an undesirable long polymer is formed. In addition, the resulting polymer is often stuck to the stirrer and the mixing efficiency is often lowered, and thus there is a problem that the maintenance of the oligomerization device is expensive.

Accordingly, the present inventors perform the step of pre-mixing the catalyst raw materials such as ligand compound and chromium source and the co-catalyst before inputting the reactor for a certain time, thereby improving the activity of the prepared catalyst composition and controlling the selectivity of the reaction to a certain level or more. And minimization of the production of non-oligomeric polymers from ethylene. In addition, when the reaction solution (catalyst composition and ethylene) which has been circulated for the heat removal is introduced into the reactor again for the reaction, the heat removal and reaction activity in the reactor is increased by using the mixing eductor and / or the injection means. It was confirmed that the present invention was completed.

It is an object of the present invention to provide a method for synthesizing alpha olefins which improves the activity of the catalyst composition used for the synthesis of alpha olefins, and also improves the heat removal and reaction activity of the solution in the reactor.

One embodiment of the present invention comprises a first step of preparing a catalyst composition by mixing a catalyst mixture comprising a catalyst and a promoter for 5 to 20 minutes; Injecting the catalyst composition and ethylene into a reactor; A third step of conducting an ethylene oligomerization reaction in the reactor; A fourth step of discharging 50 to 90% by weight of the reaction solution in the reactor from the reactor during the oligomerization reaction; A fifth step of removing heat by passing the reaction solution from the reactor through a heat exchanger; And a sixth step of mixing the defrosted reaction solution with the reaction solution in the reactor, wherein the sixth step comprises at least one selected from the group consisting of a mixing eductor and spraying means. It provides a method for synthesizing the alpha olefin, which is introduced into the reactor through the defrosted reaction solution.

According to the method for synthesizing alpha olefin of the present invention, the activity of the catalyst is improved by uniformly mixing the ligand compound, the transition metal compound and the co-catalyst constituting the catalyst composition before entering the reactor. This also improves the selectivity and conversion of the reaction and can minimize the production of undesirable long polymers.

In addition, when the reaction solution circulated outside the reactor for heat removal is introduced into the reactor again for the reaction, the mixing efficiency is increased and the effect of mass transfer limitation is increased by using a mixing eductor or a spraying means. Is lowered. That is, heat removal and reaction activity become high in a reactor.

In particular, in the case of using the mixing eductor, a separate agitator may not be used, thereby facilitating the maintenance and repair of the reactor and minimizing the installation cost of the device. In addition, when the sparging nozzle is used as the injection means, when the reaction solution is introduced into the reactor after the circulation by injecting the reaction solution in a fine bubble state, it may affect the reactor by the high linear velocity of the reaction solution. The mechanical load can be lowered.

1 is a flowchart of a method for synthesizing alpha olefin according to an embodiment of the present invention.
2 is a block diagram of an alpha olefin synthesis apparatus according to a first embodiment of the present invention.
3 is a diagram illustrating an operating state of the mixing eductor applied to FIG. 2.
FIG. 4 is a diagram illustrating an operating state of a mixing eductor and an internal reactor applied to FIG. 2.
5 is a block diagram of an alpha olefin synthesis apparatus according to a second embodiment of the present invention.
6 is a perspective view of a sparger applied to FIG. 5.
7 is a block diagram of an alpha olefin synthesis apparatus according to a third embodiment of the present invention.
8 is a plan view illustrating a relationship between a reactor and a sparging nozzle in FIG. 7.
9 is a side view of the sparging nozzle applied to FIGS. 7 and 8.
FIG. 10 is a cross-sectional view taken along the line VV of FIG. 9.
11 is a plan view illustrating a relationship between a reactor and a sparging nozzle in the alpha olefin synthesis apparatus according to the fourth embodiment of the present invention.

Hereinafter, the present invention will be described in more detail to aid in understanding the present invention. The terms or words used in this specification and claims are not to be construed as limiting in their usual or dictionary meanings, and the inventors may appropriately define the concept of terms in order to best describe their invention. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that the present invention.

The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

As used herein, the terms "comprise", "comprise" or "have" are intended to indicate that there is a feature, number, step, component, or combination thereof, that is, one or more other features, It should be understood that it does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

Throughout this specification, "catalyst system", "catalyst composition" or "catalyst system" means a three component comprising a transition metal source, a ligand compound and a promoter, or alternatively, two components of the transition metal compound and a promoter It means a state which can be added simultaneously or in any order to obtain an active catalyst composition. Three or two components of the catalyst composition may be added in the presence or absence of a solvent and a monomer, and the three terms may be used interchangeably.

As used herein, the term 'oligomerization' means that the olefin is small polymerized. Depending on the number of olefins to be polymerized, it is called trimerization and tetramerization, which is collectively called multimerization. In particular, it is meant herein to selectively prepare 1-hexene and 1-octene which are the main comonomers of LLDPE from ethylene.

In the present specification, the hydrocarbyl group refers to all compounds consisting of only carbon and hydrogen, and examples thereof include an alkyl group, an aryl group, an alkenyl group, a cycloalkyl group, and the like. As long as there is no, it can mean both straight and branched chain, it can mean both unsubstituted and substituted. For example, a group which is an alkyl group of C1 to C20 may mean methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, isopentyl group, neopentyl group, and the like. The aryl group of ˜C20 includes, for example, a phenyl group, a naphthyl group, an anthracenyl group, and the like, but is not limited thereto.

In this specification, an alkylaryl group means an aryl group having at least one alkyl group as a substituent, and an arylalkyl group means an alkyl group having at least one aryl group as a substituent.

In the present specification, the hetero element refers to N, O, S, and P, and the heterohydrocarbyl group may mean a hydrocarbyl group including one or more hetero atoms. That is, a heteroalkyl group may mean that any one carbon of the constituent carbons of the alkyl group is substituted with a hetero atom, or a hetero atom is included as a substituent, and the heteroaryl group, like a pyridyl group, any one of the carbons in the aromatic ring is a hetero atom. It may mean substituted. The same may also apply to other heteroarylalkyl groups, heteroalkylaryl groups, heteroalkenylaryl groups, and the like.

Hereinafter, the alpha olefin synthesis method of this invention is explained in full detail.

Synthesis method of alpha olefin

The alpha olefin synthesis method of the present invention comprises the first step of preparing a catalyst composition by mixing a catalyst mixture comprising a catalyst and a promoter for 5 to 20 minutes; Injecting the catalyst composition and ethylene into a reactor; A third step of conducting an ethylene oligomerization reaction in the reactor; A fourth step of discharging 50 to 90% by weight of the reaction solution in the reactor from the reactor during the oligomerization reaction; A fifth step of removing heat by passing the reaction solution from the reactor through a heat exchanger; And a sixth step of mixing the defrosted reaction solution with the reaction solution in the reactor, wherein the sixth step comprises at least one selected from the group consisting of a mixing eductor and spraying means. It is characterized in that the reaction solution is introduced into the reactor through.

1 is a flowchart illustrating a method for synthesizing alpha olefins according to an embodiment of the present invention, and FIGS. 2 and 7 are structural diagrams of an apparatus for synthesizing alpha olefins according to an embodiment of the present invention, respectively.

1, 2 and 7, the alpha olefin synthesis method according to one embodiment prepares a catalyst composition by mixing a catalyst mixture including a catalyst and a promoter using an in-line mixer 1, and prepares the catalyst composition and ethylene. To the reactor (2) to proceed with the ethylene oligomerization (oligomerization) reaction, and then complete the reaction solution is completed in the reactor (2).

The synthesis of the alpha olefin oligomer is a low polymerization reaction using alpha olefins such as ethylene as an exothermic reaction, and thus proceeds while cooling the reactor 2. To this end, the reactor 2 is further provided with a coolant (or refrigerant) jacket 21 on the outside. That is, the cooling water (or refrigerant) jacket 21 cools the reactor 2 in which the exothermic reaction proceeds. And the reactor 2 is provided with a relief valve 22 at the top, it is possible to safely maintain the internal pressure at the set pressure during the synthesis reaction. Optionally, a coil may be included inside the reactor to remove reactor heat (not shown).

For example, the alpha olefin synthesis method may include a first step (ST1) of preparing a catalyst composition by mixing a catalyst mixture including a catalyst and a promoter for 5 to 20 minutes; A second step (ST2) of injecting the catalyst composition and ethylene into the reactor; A third step (ST3) of carrying out an ethylene oligomerization reaction in the reactor; A fourth step (ST4) of discharging 50 to 90% by weight of the reaction solution in the reactor from the reactor during the oligomerization reaction; A fifth step (ST5) of removing heat by passing the reaction solution from the reactor through a heat exchanger; And a sixth step (ST6) of mixing the deoxidized reaction solution with the reaction solution in the reactor.

As an example, the first step ST1 may be performed using the inline mixer 1. In-line mixer is a system that mixes the raw material and the liquid solvent to pass the contents between the minute interval between the stator and the rotor rotating at high speed to reduce the cohesion between molecules and to produce a dispersion and grinding effect. Therefore, the in-line mixer is capable of stable mixing, there is an advantage that the work efficiency is increased because the dispersion, grinding and emulsification proceeds by circulating the contents.

This allows the catalyst and cocatalyst to be uniformly mixed so that the selectivity of the catalyst can remain the same. Therefore, there is an effect that the activity of the catalyst is improved and the production of the polymer other than the oligomer is minimized. In the present invention, a commonly used inline mixer may be used, and the present invention is not particularly limited thereto.

The mixing is characterized in that it is carried out for 5 to 20 minutes, preferably may be carried out for 7 to 15 minutes. If the mixing is performed in less than 5 minutes, chemical bonds such as coordination bonds between the catalyst and the promoter are not well formed, resulting in scale. Can be. In addition, when mixing is performed for more than 20 minutes, deterioration of the catalyst may occur, resulting in a decrease in stability and a decrease in product productivity per catalyst.

In the third step ST3, the injected catalyst composition and ethylene remain in the reactor 2 for a predetermined time to proceed with the ethylene oligomerization reaction.

In the third step (ST3), a homogeneous liquid phase reaction in the presence or absence of an inert solvent using a conventional apparatus and contact technology with the catalyst composition, slurry reaction in which the catalyst composition is not partially or completely dissolved, 2 A phase liquid / liquid reaction, or a bulk phase reaction or a gas phase reaction in which the product olefins act as the main medium, is possible, and a homogeneous liquid phase reaction is preferred.

As an example, the third step ST3 may be performed at a temperature of about 5 ° C. to about 200 ° C., preferably about 30 ° C. to about 150 ° C., and more preferably 45 to 120 ° C.

In addition, the third step ST3 may be performed at a pressure of about 20 bar to about 300 bar, preferably about 20 bar to about 150 bar, and more preferably 45 to 100 bar.

The range of the temperature and pressure conditions may be a condition of the family register to ethylene oligomerization reaction, when performing the ethylene oligomerization reaction within the temperature range and pressure range, the selectivity is excellent for the desired alpha-olefin, The amount of by-products can be reduced, increasing efficiency and reducing costs in process operation.

In addition, the third step (ST3) is the ethylene and the oligomerized catalyst composition is added to the reactor in the state where the reaction solvent is added to the reactor, or the catalyst composition is added to the reactor while the reaction solvent and ethylene in the reactor It can be initiated by. In addition, the catalyst composition may include a solvent.

The reaction solvent is one selected from the group consisting of benzene, toluene, xylene, cumene, chlorobenzene, dichlorobenzene, heptane, cyclohexane, methylcyclohexane, methylcyclopentane, n-hexane, 1-hexene, 1-octene It may be abnormal.

In addition, the method for synthesizing alpha olefin may include obtaining a composition including 1-hexene and 1-octene as a product after the third step (ST3). Obtaining such a product may be a step of separating the products produced by the oligomerization reaction of ethylene through a device such as a distillation column. In the separation process, the energy required for separation may vary depending on the type of solvent used in the ethylene oligomerization reaction, and generally has a boiling point between the boiling point of 1-hexene and 1-octene, which are main products. The compound can be used as the reaction solvent. In this case it can be quite advantageous in terms of separation energy.

In the fourth step ST4, 50 to 90% by weight of the reaction solution in the reactor is discharged from the reactor 2 during the oligomerization reaction.

In the fifth step (ST5), the solution during the reaction exits the reactor 2 and passes through the first pipe 31 to the heat exchanger (3). The heat exchanger (3) is provided on the outside of the reactor (2) is connected to the first pipe line (31) to remove the heat entering the reaction medium solution, connected to the second pipe line (32) the reaction medium solution Is fed back into the reactor (2).

For example, the heat exchanger 3 has a high temperature of cooling water toward the side of the second conduit 32 where low temperature cooling water flows into the first pipe line 31 through which the high temperature reaction solution flows in and a low temperature of the reaction solution flows out. Acts as a heat exchanger.

The first pipe 31 is provided with a strainer or filter 311 and the circulation pump 312 to filter the reaction solution from the reactor 2 through the first pipe 31 to supply to the heat exchanger (3). . The second conduit 32 supplies the reaction medium solution, which has been deoxidized via the heat exchanger 3, by the pressure of the circulation pump 312 to the reactor 2.

The sixth step ST6 mixes the reaction solution heated in the heat exchanger 3 to the reaction solution inside the reactor 2 again through a mixing educator 4 or a sparging nozzle 8. This can be done by.

As an example embodiment, as shown in FIG. 2, the mixing eductor 4 may be connected to the heat exchanger 3 by a second conduit 32 and installed inside the reactor 2. Therefore, the mixing eductor 4 finishes the circulation of the heat exchanger 3 and further mixes the reaction solution inside the reactor 2 while passing through the heat-reacted reaction solution. Therefore, in the mixing eductor 4, a mixture of the de-heated reaction solution and the reaction solution inside the reactor flows into the reactor 2 to be finally mixed with the reaction solution inside.

As another embodiment, as shown in FIG. 7, the sparging nozzle 8 may be installed in the reactor 2 by being connected to the heat exchanger 3 by a second conduit 32. Therefore, the sparging nozzle 8 may be performed by injecting a solution in the reactor 2 inside the reactor 2, which is de-heated in the heat exchanger 3 by the pressure of the circulation pump 312 and circulated. At this time, the solution during the reaction is sprayed in a bubble state to the stirring solution.

First, a case in which the mixing eductor 4 is installed in the reactor 2 and the sixth step ST6 is performed through the mixing eductor 4 will be described in detail. 3 is a diagram illustrating an operating state of the mixing eductor applied to FIG. 2. 1 to 3, the mixing eductor 4 passes the nozzle 41 through the de-heated reaction solution, and the reaction solution through the nozzle 41 at high speed to allow the reactor 2 to flow through. It includes a diffuser (42) flowing in.

In the mixing eductor 4, the high-flow reaction medium solution further draws the reaction solution around the diffuser 42 from inside the reactor 2 into the diffuser 42. Therefore, the inside of the diffuser 42 may additionally mix the de-heated reaction solution and the reaction solution drawn into the reactor, and may flow into the reactor 2 at a higher speed.

To this end, the nozzle 41 is connected to the first passage 411 for connecting the diffuser 42 in the second conduit 32 to supply the heated solution during the reaction, and the side of the first passage 411 to be connected to the reactor. (2) a second passage 412 exposed inside to introduce the internal reaction solution.

That is, the high-speed flow of the reaction solution through the first passage 411 of the nozzle 41 provides a strong suction force to the second passage 412, so that the reaction solution in the reactor 2 around the diffuser 42 is removed. It is further introduced, and further mixed inside the nozzle 41 and the diffuser 42.

The additionally mixed reaction solution is injected into the reactor 2 at a higher speed through the diffuser 42 and mixed with the reaction solution inside the reactor 2. The reaction solution injected at such a high speed is effectively mixed with the catalyst composition solution (catalyst, cocatalyst and solvent) injected from the bottom and ethylene at the center of the reactor 2.

That is, the sixth step ST6 includes (a) a nozzle step in which the heated solution in the reaction passes through the nozzle 41 of the mixing eductor 4, and (b) the heated solution in the removed reaction through the nozzle 41. The diffuser stage in which the reaction solution inside the reactor 2 around the diffuser 42 flows into the diffuser 42 by passing through the diffuser 42 of the mixing eductor 4 at high speed, and (c) the diffuser 42. And a further mixing step in which the reaction intermediate solution deoxidized therein and the reaction solution inside the reactor 2 are additionally mixed and introduced into the reactor 2.

In the step (b), the heated solution in the reaction passes through the diffuser 42 at high speed, and further draws the reaction solution around the diffuser 42 from inside the reactor 2 into the diffuser 42.

In the step (c), the reaction solution in the reactor 2, which is heated and rapidly passes through the diffuser 42 and introduced into the diffuser 42, is additionally mixed and has a higher speed into the reactor 2. Flows into.

Therefore, the mixing efficiency of the solution present in the reactor 2 and the reaction solution introduced after the circulation is increased, and the influence of the mass transfer limitation is lowered. That is, the heat removal and reaction activity of the solution in the reactor 2 can be increased.

FIG. 4 is a diagram illustrating an operating state of a mixing eductor and an internal reactor applied to FIG. 2. 2 and 4, the reactor 2 includes an internal reactor 23 installed therein to inject a catalyst composition and ethylene upward from the bottom of the reactor 2 to form an upward flow.

1 to 4, the second step ST2 forms an upward flow F1 in the inner reactor 23 installed in the reactor 2. The sixth step ST6 forms a downward flow (F2) inside the internal reactor (23) by the mixing eductor (4), to the reaction medium of the upward flow (F1) in the center of the internal reactor (23) The heated solution of the down stream (F2) is mixed.

In addition, the sixth step (ST6) is rapidly injected into the second passage 412 of the mixing eductor 4, the nozzle 41 by rapidly injecting the reaction solution of the upward flow (F3) coming from the outside of the internal reactor (23) ) And further mixing inside the diffuser 42.

As described above, the mixing eductor 4 smoothly flows the reaction solution in the reactor 2, thereby lowering the temperature gradient in the reactor 2 and making the mixing of the solution uniform. And since one embodiment does not use a stirrer it is possible to prevent the fouling phenomenon by the stirrer in the reactor (2).

Therefore, the generation of scale inside the reactor 2 can be reduced. And since the cleaning of the reactor 2 is possible in a short time without additional cleaning operation, the period of stopping the device can be increased. That is, the running time of the device is increased. Since the mixing eductor 4 is simpler in structure than the stirrer, the installation space is small and the equipment installation cost is reduced.

A second embodiment of the present invention will be described below. Compared with the first embodiment, the same configuration will be omitted and different configurations will be described.

5 is a configuration diagram of an alpha olefin synthesis apparatus according to a second embodiment of the present invention, and FIG. 6 is a perspective view of a sparger applied to FIG. 5. 5 and 6, the reactor 61 further includes a sparger 7 installed upward from the bottom to inject the solvent and ethylene upward from the bottom of the reactor 61.

For example, the sparger 7 includes a donut part 71 formed in a cylinder and a plurality of nozzles 72 provided in the donut part 71. The donut part 71 contains the solvent and ethylene injected therein, and the nozzles 72 are disposed at equal intervals on the donut part 71 to uniformly inject the injected solvent and ethylene into the reactor 61.

In the second step ST2, a solvent and ethylene are injected into the reactor 61 through a sparger 7 installed upward from the bottom of the reactor 61. In this case, the catalyst composition including the catalyst and the cocatalyst may be separately injected from the outside of the sparger 7.

In the second step ST2, a solvent and ethylene are introduced into the reactor 61 through a plurality of nozzles 72 disposed at equal intervals between the donut part 71 and the donut part 71 of the sparger 7. It can spray uniformly.

The sparger 7 is disposed below the internal reactor 23 to uniformly form an upward flow F11 of the solvent and ethylene in the internal reactor 23, so as to flow downward by the mixing eductor 4. It can be mixed more uniformly in the defrosted reaction solution of (F2). Therefore, the temperature gradient inside the reactor 61 can be lowered.

Next, a case in which the sparging nozzle 8 is installed in the reactor 2 and the sixth step ST6 is performed through the sparging nozzle 8 will be described in detail. As shown in FIG. 8, the sparging nozzle 8 is installed to spray the heat-reduced reaction solution in the radial direction with respect to the reactor 2. Even in this case, the sparging nozzle 8 is installed to inject the solution during the reaction out of the rotation range (eg, the turning radius) of the stirrer 9 for stirring the solution inside the reactor 2. Therefore, an increase in the load of the stirrer 9 can be prevented.

As shown in FIG. 7, a sparging nozzle 8 is installed at the top of the reactor 2 to inject the de-heated reaction solution into the solution in the reactor 2. Although not shown, the sparging nozzle may be installed at the side or bottom of the reactor, and may be installed at any one or a plurality of the top, the side and the bottom.

When the reaction solution injected from the second conduit 32 and the sparging nozzle 8 is directly injected from the upper portion of the reactor 2 without the sparging nozzle, the solution during reaction generates a large bubble. As a result, as soon as the gaseous ethylene contained in the reaction solution is introduced, it may form one-through and discharged to the upper portion. Therefore, the probability that the injected reaction solution is in contact with the catalyst present in the solution in the reactor 2 may be reduced.

However, when the sparging nozzle is installed at the top, side or bottom of the reactor, gaseous ethylene contained in the injected reaction solution can be sufficiently brought into contact with the catalyst present in the solution in the reactor 2. In addition, the gaseous ethylene present in the upper portion is captured by the droplet of the sprayed reaction solution (caplet) can increase the reaction activity.

FIG. 9 is a side view of the sparging nozzle applied to FIGS. 7 and 8, and FIG. 10 is a cross-sectional view taken along the line VV of FIG. 9. 9 and 10, the sparging nozzle 8 forms a coupling structure to the body 82 with a cap 81.

The sparging nozzle 8 is provided with a plurality of injection holes 83 for directly injecting the solution during the reaction,

The injection hole 83 may be formed to a diameter of 0.5 to 5mm, or 1 to 4mm, or 1.5 to 3.5mm. When the diameter of the injection hole 83 is 0.5 mm or less, it is difficult to form the injection hole 83, and when the diameter of the injection hole 83 is greater than 5 mm, as the bubble of the reaction solution injected is too large, May become difficult to contact.

Although not shown, the sparging nozzle may have a rectangular injection hole. The rectangular injection hole is capable of injecting the solution in the reaction to the solution in the reactor in a desired injection pattern compared to the circular injection hole.

For example, the body 82 includes a first passage 821 for supplying a solution during the reaction and a second passage 822 for supplying injection air. The first and second passages 821 and 822 are connected to the injection hole 83.

Therefore, when the solution during the reaction is supplied to the first passage 821 connected to the second conduit 32 and the injection air is supplied to the second passage 822, the sparging nozzle 8 is the injection hole 83. Through the injection of the solution in the bubble state. The bubbled reaction solution can be effectively mixed with the solution in the reactor 2, so that it can be effectively contacted with the catalyst present in the solution.

In addition, although not shown, the injection hole may be formed in a multi-stage diameter. For example, the inner end of the injection hole may be formed in a multi-stage or gradually narrowing structure in which the outer end is narrowed. In this case, the injection pressure may be increased to increase the injection distance. In addition, the inner end of the injection hole may be formed in a multi-stage or progressively wider structure in which the outer end is wider. In this case, since injection pressure becomes low, it is required to exist in the range which maintains an allowable injection distance.

11 is a plan view showing a relationship between a reactor and a sparging nozzle in the alpha olefin synthesis apparatus according to the second embodiment of the present invention. Referring to FIG. 11, in the alpha olefin synthesis apparatus of the second embodiment, the sparging nozzle 8 is installed to inject the reaction solution in a tangential direction with respect to the reactor 2.

The solution during reaction sprayed tangentially to the inner wall of the reactor 2 at the sparging nozzle 8 is mixed into the solution while flowing along the inner wall without directly entering the solution inside the reactor 2. Therefore, overload of the stirrer 9 can be prevented.

In addition, the method for synthesizing the alpha olefin of the present invention further includes a seventh step (ST7) of outputting a reaction solution containing alpha-olefins such as 1-hexene and 1-octene prepared by the low-polymerization reaction in the reactor. can do.

As an example, before the reaction medium solution from the reactor of the fourth stage is introduced into the heat exchanger (3), the reaction completion solution and ethylene containing the alpha-olefin may be separated through the branched pipe (33).

Alternatively, the reaction completed solution including alpha-olefin and ethylene may be separated through the branched conduit 34 before the reacted intermediate solution, which has been passed through the heat exchanger 3, is introduced into the reactor again. In the process configuration, only one of the conduit 33 or the conduit 34 may be selected. Preferably, the reaction completed solution and ethylene are separated through the conduit 33.

In addition, it is possible to perform a step of separating and producing a composition comprising 1-hexene and a composition comprising 1-octene from the separated reaction completed solution through a device such as a distillation column. In addition, the separated ethylene can be introduced back into the reactor for reuse.

Low Polymerization Catalyst Composition

In the method for synthesizing the alpha olefin of the present invention, any conventionally known catalyst can be used, and is not particularly limited. As one example, the catalyst composition of the present invention comprises a ligand compound; Transition metal compounds; And promoters.

In order to increase the selectivity to the linear alpha olefin and to increase the multimerization activity, the molar ratio of the ligand: metal of the transition metal compound: aluminum or boron of the promoter is about 1: 1: 1 to 10: 1: 10,000, preferably about 0.5: 1: 1 to about 10: 1: 10,000, more preferably about 0.5: 1: 100 to about 5: 1: 3,000.

Hereinafter, a ligand compound constituting the catalyst composition; Transition metal compounds; And look at the configuration of the promoter in more detail.

Ligand Compound

According to one embodiment of the present specification, a ligand compound including one or more diphosphine moieties may be represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, A is N, P, As or Sb,

When the ligand compound includes one diphosphine moiety, * denotes an aliphatic hydrocarbon group of C 1 to C 20, a heteroaliphatic hydrocarbon group of C 2 to C 20, an alicyclic hydrocarbon group of C 3 to C 20, and a hetero group of C 3 to C 20 At least one group selected from the group consisting of an alicyclic hydrocarbon group, a C6-C20 aromatic hydrocarbon group and a C6-C20 heteroaromatic hydrocarbon group,

When the ligand compound includes two or more diphosphine moieties, * is a diphosphine moiety linked through a linking group, and the linking group is a C 2 to C 20 aliphatic hydrocarbon group, C 2 to C 20 heteroaliphatic hydrocarbon group, At least one member selected from the group consisting of C3 to C20 alicyclic hydrocarbon group, C3 to C20 heteroalicyclic hydrocarbon group, C6 to C30 aromatic hydrocarbon group, and C6 to C30 heteroaromatic hydrocarbon group,

R1 to R4 are each independently C6 ~ C20 aryl group or C7 ~ C20 alkylaryl group.

Transition metal compound

In the catalyst composition used in the polymerisation reaction of ethylene of the present invention, the transition metal of the transition metal compound is preferably chromium. As an example, the transition metal compound may be an organic or inorganic chromium compound having an oxidation state of chromium of 0 to 6, for example, a chromium metal or a compound in which any organic or inorganic radical is bonded to chromium. Here, the organic radical may be alkyl, alkoxy, ester, ketone, amido radical, etc. having 1 to 20 carbon atoms per radical. The inorganic radicals may be halides, sulfates, oxides, and the like.

Preferably, the chromium source is chromium (III) acetylacetonate, chromium trichloride tristetrahydrofuran, chromium (III) -2-ethylhexanoate, chromium (III) tris (2,2,6,6-tetramethyl At least one selected from the group consisting of -3,5-heptanedionate), chromium (III) benzoylacetonate, chromium (III) hexafluoro-2,4-pentanedionate and chromium (III) acetate hydroxide Can be.

Promoter

In the catalyst composition used in the oligomerization reaction of ethylene of the present invention, the promoter may be at least one selected from the group consisting of compounds represented by Formulas 2 to 4.

[Formula 2]

R _5- [Al (R ₆ ) -O] cR ₇

In Chemical Formula 2, R ₅ to R ₇ are each independently hydrogen, halogen, C 1 to C 20 hydrocarbyl group, or C 1 to C 20 hydrocarbyl group substituted with halogen, c is an integer of 2 or more,

[Formula 3]

D (R ₈ ) ₃

In Formula 3, D is aluminum or boron, R ₈ are each independently hydrogen, halogen, C 1 to C 20 hydrocarbyl group or C 1 to C 20 hydrocarbyl group substituted with halogen,

[Formula 4]

[LH] ⁺ [Q (E) ₄ ] ^-

In Chemical Formula 4,

L is a neutral Lewis base, [LH] ⁺ is Bronsted acid, Q is boron or aluminum in the +3 type oxidation state, each E is independently at least one hydrogen atom is a halogen, a C1-C20 hydrocarbyl group, It is a C6-C20 aryl group or C1-C20 alkyl group unsubstituted or substituted by the alkoxy functional group or the phenoxy functional group.

As the compound represented by Formula 2, for example, modified methyl aluminoxane (MMAO), methyl aluminoxane (MAO), ethyl aluminoxane, isobutyl aluminoxane, butyl aluminoxane and the like.

As the alkyl metal compound represented by the formula (3), for example, trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, dimethylisobutylaluminum, dimethylethylaluminum and diethyl Chloro aluminum, triisopropyl aluminum, tri-s-butyl aluminum, tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, ethyl dimethyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p- Tolyl aluminum, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron, tributyl boron and the like.

Examples of the compound represented by the formula (4) include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra (p-tolyl) boron, Tripropylammonium tetra (p-tolyl) boron, triethylammonium tetra (o, p-dimethylphenyl) boron, trimethylammonium tetra (o, p-dimethylphenyl) boron, tributylammonium tetra (p-trifluoromethylphenyl) Boron, trimethylammonium tetra (p-trifluoromethylphenyl) boron, tributylammoniumtetrapentafluorophenylboron, N, N-diethylaniliniumtetraphenyl boron, N, N-diethylaniliniumtetraphenylboron, N , N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron, trimethylphosphonium tetraphenylboron, triethylammo Tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra (p-tolyl) aluminum, tripropylammonium tetra (p-tolyl) aluminum, triethylammonium tetra ( o, p-dimethylphenyl) aluminum, tributylammonium tetra (p-trifluoromethylphenyl) aluminum, trimethylammonium tetra (p-trifluoromethylphenyl) aluminum, tributylammonium tetrapentafluorophenylaluminum, N, N- Diethylanilinium tetraphenylaluminum, N, N-diethylanilinium tetraphenylaluminum, N, N-diethylanilinium tetrapentafluorophenylaluminum, diethylammonium tetrapentafluorophenylaluminum, triphenylphosphonium tetra Phenyl aluminum, trimethyl phosphonium tetraphenyl aluminum, triphenyl carbonium tetra phenyl boron, triphenyl carbonium te La phenyl aluminum, triphenyl carbonyl titanium tetra (p- methylphenyl to triple) may phenylboronic the like as boron, triphenyl carbonyl titanium tetra-pentafluoropropane.

As an example, aluminoxane may be preferably used as a cocatalyst of the catalyst composition, and more preferably methylaluminoxane (MAO) or modified methylaluminoxane (MMAO) may be used.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited only to them.

Example 1

Preparation of Catalyst Composition

A transition metal compound using chromium (Cr) as the transition metal was prepared as a catalyst for ethylene oligomerization. Methylcyclohexane as a solvent and the catalyst were mixed to prepare a solution of 0.05 to 0.5 mM, and mMAO (8.6 wt% isoheptane solution) was prepared as a promoter. A solution and a cocatalyst in which the solvent and the catalyst were mixed were added to a glass jar, and mixed for 5 to 20 minutes to prepare a catalyst composition.

Ethylene oligomerization reaction

After preparing a 600 ml Parr reactor and vacuum for 2 hours at 120 ℃, the temperature was lowered to 60 ℃ and the inside was replaced with argon. Thereafter, the catalyst composition was injected into the reactor.

Thereafter, the reactor was filled with 60 bar of ethylene, and then circulated with ethylene and the reaction product using a circulation pump to control the temperature in the reactor (T <2 ° C.). At this time, the circulating reaction solution was put back into the reactor through the mixing eductor. After slowly venting the unreacted ethylene, 1 ml of nonane (GC internal standard) was added thereto.

Thereafter, a small portion of the liquid portion of the reactor was taken, quenched with water, and the organic layer was filtered with a PTFE syringe filter to separate and dry the produced polymer. The organic layer portion was removed using MgSO 4 to remove residual moisture, and the composition of the organic layer was confirmed by GC-MS, and found to be a mixture of alpha-olefin polymers according to the Schultz-Flory distribution.

A mixture of methanol and diluted HCl was added to the remaining reaction solution, followed by stirring to analyze the amount of solids.

Example 2

Experiment was carried out in the same manner as in Example 1 except that the sparging nozzle was used instead of the mixing eductor when the solution was added to the reactor.

Example 3

Experiment was carried out in the same manner as in Example 1, except that the sparging nozzle was used together with the mixing eductor when the solution was added to the reactor.

Comparative Example 1

The experiment was performed in the same manner as in Example 1, except that the mixing eductor was not used but a reactor provided with an agitator therein was used.

Comparative Example 2

The experiment was carried out in the same manner as in Example 1, except that the catalyst composition in which the catalyst and the co-catalyst were mixed beforehand was added to the reaction separately.

Comparative Example 3

A catalyst composition was prepared, but the same experiment as in Example 1 was conducted except that the mixing time of the catalyst and the promoter was set to 30 minutes.

Comparative Example 4

The experiment was carried out in the same manner as in Example 1, except that the catalyst composition in which the catalyst and the co-catalyst were mixed in advance was added to the reaction separately, and a sparging nozzle was used instead of the mixing eductor.

Experimental Example

The analysis results of the Examples and Comparative Examples are shown in Table 1 below.

Temperature (℃) Pressure (bar) Time (min) Catalyst activity (%) compared to Comparative Example 1 Oligomer content (% by weight) Solid (% by weight) C6 C8 C10 + Example 1 60 60 15 120 20-25 60-65 5-10 1-1.5 Example 2 60 60 15 110 20-25 60-65 5-10 1-1.5 Example 3 60 60 15 130 20-25 60-65 5-10 0.5-1 Comparative Example 1 60 60 15 100 20-25 60-65 5-10 1.5-2 Comparative Example 2 60 60 15 80 20-25 60-65 5-10 1.5-2 Comparative Example 3 60 60 15 70 20-25 60-65 5-10 2-2.5 Comparative Example 4 60 60 15 80 20-25 60-65 5-10 1.5-2

As summarized in Table 1 above, the catalyst and the cocatalyst were mixed in advance to prepare a catalyst composition, and then used in the reaction while mixing the eductor or spraying means (sparging nozzle) instead of the stirrer when recirculating the de-heated reaction solution. In the case of Example 1 and Example 2, the catalyst activity was increased and the solid content was decreased compared to Comparative Example 1 using a reactor equipped with a stirrer inside as in the prior art. This means that, when the mixed solution is reacted with the mixing eductor and the injection means in the reaction solution in the reactor, the mixing is more smoothly performed than the stirrer, and this means that the low-polymerization reaction is also active. will be.

In particular, in the case of Example 3 using the mixing eductor and the injection means, it can be seen that the two means by means of the synergistic effect, the catalyst activity is the highest and the solid content can be adjusted to the lowest.

In addition, the catalyst composition was prepared, but in Comparative Example 1 using a stirrer in the recycling of the reaction solution, it was confirmed that a large amount of by-product solid was formed. In addition, in Comparative Examples 2 and 4 in which the catalyst and the promoter were separately added without preparing the catalyst composition, the catalyst activity was lowered and the solid production amount was lowered because the catalyst was not pre-mixed to activate the catalyst. It was confirmed that the problem is increased. Through this, even when using a mixing eductor or sparging nozzle as a spraying means, it was found that the final catalyst activity was reduced and solid formation could not be prevented without going through the previous step of preparing the catalyst composition.

Furthermore, when mixed for more than 5 to 20 minutes for 30 minutes as in Comparative Example 3, when the catalyst composition is prepared through a result that the catalyst stability is lowered, the catalyst activity is lowered, and the solid content is increased. The mixing time acts as an important factor and it was confirmed that the mixing process for 5 to 20 minutes is an appropriate method for improving the catalytic activity and preventing the formation of by-products.

Through the above results, the catalyst composition is prepared in advance by mixing the catalyst and the cocatalyst, and when the mixing eductor or the injection means (sparging nozzle) is used instead of the stirrer when recycling the de-heated reaction solution, the solid formation is prevented. At the same time, it was confirmed that the ethylene oligomerization reaction can be efficiently performed by keeping the catalytic activity high. In this case, since there is no need to install a separate stirrer in the reactor, it will be possible to reduce the fouling phenomenon and increase the shutdown period.

Claims (17)

A first step of preparing a catalyst composition by mixing a catalyst mixture including a catalyst and a promoter for 5 to 20 minutes;
Injecting the catalyst composition and ethylene into a reactor;
A third step of conducting an ethylene oligomerization reaction in the reactor;
A fourth step of discharging 50 to 90% by weight of the reaction solution in the reactor from the reactor during the oligomerization reaction;
A fifth step of removing heat by passing the reaction solution from the reactor through a heat exchanger; And
And a sixth step of mixing the preheated reaction solution with the reaction solution in the reactor.
The sixth step
A method for synthesizing alpha olefins, wherein the decanted reaction solution is introduced into a reactor through at least one selected from the group consisting of a mixing eductor and spraying means.
The method according to claim 1,
The mixing of the first step is performed using an inline mixer, alpha olefin synthesis method.
The method according to claim 1,
The mixing of the first step is performed for 7 to 15 minutes, alpha olefin synthesis method.
The method according to claim 1,
The sixth step is that the heated solution in the reaction is mixed with the reaction solution in the reactor via the mixing eductor and then introduced into the reactor,
The sixth step
(a) passing the deoxidized solution through the nozzle of the mixing eductor,
(b) allowing the heated solution in the reactor to pass through the diffuser of the mixing eductor so that the reacted solution in the reactor around the diffuser flows into the diffuser;
(c) mixing the reaction intermediate solution de-heated in the diffuser and the reaction solution in the reactor to be introduced into the reactor
That comprises, alpha olefin synthesis method.
The method according to claim 1,
The second step is to inject the catalyst composition and ethylene upwards from the bottom of the reactor to form an upward flow,
The sixth step forms a downward flow by flowing the deoxidized reaction solution from the top of the reactor while passing through the mixing eductor provided in the upper part of the reactor,
Wherein the upstream and downflow are mixed at the center of the reactor.
The method according to claim 5,
Wherein the upstream and downflow are formed inside an internal reactor installed inside the reactor, and the upstream and downflow are mixed at the center of the internal reactor.
The method according to claim 5,
The mixing eductor includes a nozzle for passing the heated solution in the reaction, and a diffuser for passing the reaction solution through the nozzle at high speed and entering the reactor.
The nozzle is provided with a first passage through which the heated solution in reaction is supplied and a second passage through which the reaction solution in the reactor is supplied.
The sixth step is to perform the simultaneous injection of the reaction solution of the upflow into the second passage of the mixing eductor, alpha olefin synthesis method.
The method according to claim 1,
The sixth step is that the heated solution in the reaction is introduced into the reactor through the mixing eductor,
In the second step, the solvent and ethylene is injected into the reactor through a sparger installed at the bottom of the reactor, alpha olefin synthesis method.
The method according to claim 8,
The sparger includes a donut portion formed in a cylinder having a cavity in the center, and a plurality of nozzles disposed at equal intervals along the circumference of the donut portion as a passage through which solvent and ethylene are injected into the reactor.
And the solvent and ethylene are injected into the reactor through the plurality of nozzles.
The method according to claim 1,
The sixth step is to spray the reaction solution heated through the sparging nozzle to the inside of the reactor as the injection means, injecting radially or tangentially to the reactor so as to be out of the rotation range of the stirrer in the reactor, alpha Olefin Synthesis Method.
The method according to claim 1,
In the reactor further comprises a seventh step of sending out the reaction solution containing the alpha-olefin prepared by the low-polymerization reaction, alpha olefin synthesis method.
An inline mixer for preparing a catalyst composition by mixing a catalyst mixture comprising a catalyst and a promoter;
A reactor for performing an ethylene oligomerization reaction with the injected catalyst composition and ethylene;
A heat exchanger provided outside the reactor and connected to a first pipe line to remove heat of the reaction solution containing ethylene and the catalyst composition circulated after being discharged from the reactor after a predetermined time in the reactor; And
Means for introducing a heated reaction solution, which is connected to the heat exchanger to a second pipe line and installed in the reactor, and has finished circulation of the heat exchanger;
The means for introducing the decanted reaction solution into the reactor may include a mixing eductor and a mixed eductor for inducing the mixed reaction solution with the reaction solution in the reactor. At least one selected from the group consisting of sparging nozzles for injecting bubbles into the reactor.
The method according to claim 12,
The mixing eductor
And a diffuser through which the reaction solution passes through the nozzle, and a diffuser allowing the reaction solution to pass through the nozzle at high speed.
The method according to claim 12,
Wherein the reactor further comprises an internal reactor in which an upward flow of ethylene and a catalyst composition injected upward from the bottom of the reactor is formed.
The method according to claim 12,
The apparatus further comprises a sparger installed upwardly in the lower part of the reactor to inject solvent and ethylene upwards.
The method according to claim 15,
The sparger is a donut portion formed of a cylinder having a cavity in the center, and
A plurality of nozzles disposed at equal intervals along the circumference of the donut portion to a passage through which solvent and ethylene are injected into the reactor.
To include, alpha olefin synthesis apparatus.
The method according to claim 12,
The sparge nozzle is installed in at least one of the top, side and bottom of the reactor,
The reaction solution is installed in the radial or tangential direction with respect to the reactor, it is installed to spray outside the rotation range of the stirrer inside the reactor, alpha olefin synthesis apparatus.

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