Patent Description:
An α-olefin (alpha-olefin) is an important material which is used in comonomers, cleaning agents, lubricants, plasticizers, and the like and is commercially widely used, and in particular, <NUM>-hexene and <NUM>-octene are often used as a comonomer for adjusting the density of polyethylene in the production of linear low-density polyethylene (LLDPE).

The α-olefins such as <NUM>-hexene and <NUM>-octene are produced representatively by an oligomerization reaction of ethylene. The ethylene oligomerization reaction is performed by an oligomerization reaction (trimerization reaction or tetramerization reaction) of ethylene in the presence of a catalyst by using ethylene as a reactant, and the product produced by the reaction includes not only a multi-component hydrocarbon mixture including <NUM>-hexene and <NUM>-octene to be desired but also a small amount of by-products including a polymer material of C20+ during a catalytic reaction. Fouling in which holes of a sparger are blocked may occur due to the by-products, and thus, a mixing efficiency is decreased and maintenance costs are incurred.

<CIT> discloses an ethylene gas-phase polymerization reactor comprising a primary fluidization grid being a plate with a plurality of first and second holes which may have difference size.

<CIT> discloses a sparger comprising a disk-shaped body with first and second holes having different size.

<CIT> discloses a distribution plate comprising a circular disk body divided into a central part having a plurality of central holes formed in a vertically formed through-hole and a peripheral part formed of a plurality of distributed holes formed in a vertically formed through-hole; and a guide member extending from the distribution hole and protruding upward, wherein fluid discharged upward from the lower part of the distribution hole through the guide member is formed to be discharged toward an outer edge of the disk body.

An object of the present invention is to provide a sparger which is designed to increase a mixing efficiency and to decrease a fouling occurrence, and a reactor comprising the sparger, in order to solve the above problems mentioned in Background Art.

In one general aspect, a sparger includes: a disc-shaped body; and a first hole and a second hole having different sizes from each other provided in the body, wherein a diameter of the second hole is smaller than a diameter of the first hole, wherein the second holes include a protrusion formed upward along an outer circumference surface of the second holes, wherein the protrusion is formed to have a constant diameter upward.

In another general aspect, a reactor includes: a monomer supply line to which a gaseous monomer stream is suppliable; and the above sparger capable for dispersing the gaseous monomer stream supplied through the monomer supply line.

According to the sparger of the present invention, first holes and second holes having different sizes from each other are provided in a body and the diameter of the second holes is formed to be smaller than the diameter of the first holes, thereby improving a mixing efficiency and extending a wash cycle.

In addition, the present invention is provided with a protrusion in the second holes provided in the sparger, thereby minimizing fouling of the second holes.

In the present invention, the term "stream" may refer to a fluid flow in the process, or may refer to the fluid itself flowing in a moving line (pipe). Specifically, the "stream" may refer to both a fluid itself flowing in a pipe connecting each device and a fluid flow. In addition, the fluid may refer to inclusion of any one or more of gas, liquid, and solid.

In the present invention, "C#", in which "#" is a positive integer, represents all hydrocarbons having # carbon atoms. Therefore, the term "C10" represents a hydrocarbon compound having <NUM> carbon atoms. In addition, the term "C#+" represents all hydrocarbon molecules having # or more carbon atoms. Therefore, the term "C10+" represents a mixture of hydrocarbons having <NUM> or more carbon atoms.

Hereinafter, the present invention will be described in more detail referring to the following <FIG>, for better understanding of the present invention.

According to the present invention, a sparger <NUM> is provided. The sparger <NUM> may include a disc-shaped body; and first holes <NUM> and second holes <NUM> having different sizes from each other provided in the body, as shown in <FIG>.

According to an exemplary embodiment of the present invention, the sparger <NUM> is, for example, provided in a lower portion of the reactor <NUM> to disperse a gaseous monomer stream supplied to the reactor <NUM> upward, to mix a liquid reaction medium in the reactor <NUM>, and to improve a conversion rate of the monomer.

The body of the sparger <NUM> may be freely designed depending on the shape of the reactor <NUM>, and for example, the body of the sparger <NUM> may be formed in a disc shape having an outer circumferential surface having the same structure as the inner surface of the reactor <NUM>. Here, the outer circumferential surface of the body may be designed to be closely adhered to the inner surface of the reactor <NUM>.

A diameter of the body may be, for example, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>, and a thickness of the body may be, for example, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>.

According to the present invention, the body of the sparger <NUM> includes first holes <NUM> and second holes <NUM> having different sizes from each other. Here, the diameter of the second holes <NUM> is smaller than the diameter of the first holes <NUM>. For example, the first holes <NUM> provided in the body of the sparger <NUM> may be already formed in the sparger <NUM>, and the second holes <NUM> having a smaller diameter than the first holes <NUM> may be further formed.

A plurality of first holes <NUM> may be formed at equal intervals in the center and along the circumference of the body. Specifically, a gaseous monomer stream may be uniformly sprayed into the reactor <NUM> through the first holes <NUM> formed at equal intervals in the center and along the circumference of the body.

The diameter of the first holes <NUM> may be, for example, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>. In addition, the diameter of the first holes <NUM> may be <NUM>% to <NUM>%, <NUM>% to <NUM>%, or <NUM>% to <NUM>% of the diameter of the body. The first holes <NUM> are provided to satisfy the above conditions, thereby preventing a fouling occurrence in the first holes <NUM> and spraying the gaseous monomer stream into the liquid reaction medium in the reactor <NUM> to be mixed with the liquid reaction media in the reactor <NUM>.

In addition, the second holes <NUM> have a smaller diameter than the first holes <NUM> and may be formed in an area between the first holes <NUM>. For example, the second holes <NUM> may be formed in any one or more areas between the first holes <NUM> formed in the center of the body and the first holes <NUM> formed in the circumference or between the first holes <NUM> formed at equal intervals along the circumference. As a specific example, a plurality of second holes <NUM> may be formed in each area between the first holes <NUM> formed in the center of the body and the first holes <NUM> formed in the circumference or between the first holes <NUM> formed at equal intervals along the circumference. Thus, a mixing efficiency in the reactor is increased and accumulation of by-products in the second holes <NUM> due to a high-volume flow rate of gas is prevented, thereby lowering a possibility of fouling in the sparger to further extend a wash cycle of the reactor <NUM>.

The diameter of the second holes <NUM> may be, for example, <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>. In addition, the diameter of the second holes <NUM> may be <NUM>% to <NUM>%, <NUM>% to <NUM>%, or <NUM>% to <NUM>% of the diameter of the body. The second holes <NUM> are provided to satisfy the above conditions, thereby allowing even a portion which is not mixed with the first holes <NUM> having a larger diameter to be mixed and increasing a mixing efficiency of the liquid reaction medium in the reactor <NUM>.

In addition, the diameter of the second holes <NUM> may be <NUM>% to <NUM>%, <NUM>% to <NUM>%, or <NUM>% to <NUM>% of the diameter of the first holes <NUM>. A ratio between the diameter of the second holes <NUM> and the diameter of the first holes <NUM> is formed to be in the above range, thereby preventing shutdown of the reactor due to the fouling in the sparger, and also increasing the mixing efficiency in the reactor to minimize a dead volume, so that an effect of increasing a reaction conversion rate may be obtained.

However, when a diameter is relatively small like the second holes <NUM>, the mixing efficiency of the reaction medium in the reactor <NUM> may be increased, but a possibility of fouling is increased as compared with the first holes <NUM> having a relatively large diameter. However, even in the case in which the second holes <NUM> are fouled, the reaction may be performed by the first holes <NUM>, and thus, a wash cycle in which the reactor <NUM> should be shut down and the inside of the reactor <NUM> and devices such as the sparger <NUM> should be washed may be extended.

According to the present invention, the second holes <NUM> include a protrusion <NUM> formed upward along the outer circumferential surface, as shown in <FIG>. Specifically, the second holes <NUM> have a higher possibility of fouling than the first holes <NUM> due to its smaller diameter, but the protrusion <NUM> is formed in the second holes <NUM>, thereby producing a height difference from the first holes <NUM>, and preventing accumulation of by-products due to an increased volume flow rate of gas passing through the first holes <NUM>, so that a possibility of fouling in the sparger is lowered to further extend the wash cycle of the reactor <NUM>.

A height of the protrusion <NUM> formed upward along the outer circumferential surface of the second holes may be <NUM>% to <NUM>%, <NUM>% to <NUM>%, or <NUM>% to <NUM>% of the thickness of the body. The protrusion <NUM> is formed at the height in the above range, thereby having a height difference from the first holes <NUM> to prevent fouling in the second holes <NUM> by the by-products accumulated in the sparger, and thus, to extend a shutdown cycle of the reactor.

The protrusion <NUM> is formed in a structure having a constant diameter upward. Specifically, the protrusion <NUM> has a structure protruding upward from the outer circumferential surface of the second holes <NUM> with a constant height, and is formed in a structure having a constant diameter upward from the protrusion <NUM>. Thus, a linear velocity of the gaseous monomer stream passing through the sparger and being supplied to the reactor is maintained constant, while a possibility of fouling occurrence may be lowered.

According to the present invention, a reactor <NUM> including the sparger <NUM> is provided. Specifically, in <FIG>, the reactor <NUM> may include a monomer supply line <NUM> to which the gaseous monomer stream is supplied; and the sparger <NUM> according to the present invention for dispersing the gaseous monomer stream supplied through the monomer supply line <NUM>.

According to an exemplary embodiment of the present invention, the reactor <NUM> may be a reactor appropriate for a continuous process. For example, the reactor <NUM> may include any one or more reactors selected from the group consisting of a continuous stirred-tank reactor, a plug flow reactor, and a bubble column reactor. As a specific example, the reactor <NUM> may be a bubble column reactor. Thus, the monomer may be continuously reacted.

According to an exemplary embodiment of the present invention, the reactor <NUM> may be for producing an oligomer by oligomerizing a monomer in the presence of a catalyst and a solvent.

The monomer may include ethylene. Specifically, a gaseous monomer stream including an ethylene monomer is introduced into the reactor <NUM> through a monomer supply line <NUM> provided in a lower portion of the reactor <NUM>, the gaseous monomer stream is dispersed by the sparger <NUM> to be oligomerized in a reaction medium in the reactor <NUM>, thereby producing an α-olefin product to be desired.

According to an exemplary embodiment of the present invention, a spray unit <NUM> provided to be extendable from the monomer supply line may be further included, as shown in <FIG>. A gaseous ethylene monomer transferred through the monomer supply line <NUM> may be sprayed through the spray unit <NUM> to pass through the sparger <NUM>.

The spray unit <NUM> may be formed to be extended from the monomer supply line <NUM> to branch into multiple pipes, and a spray nozzle may be formed at the end of each of the branched multiple pipes. Specifically, the gaseous ethylene monomer transferred through the monomer supply line <NUM> may be introduced to the reactor <NUM> through the spray nozzle of the spray unit <NUM>. As such, the gaseous ethylene monomer introduced to the reactor <NUM> may pass through the sparger <NUM> and be sprayed upward from the reactor <NUM>. As such, since the spray unit <NUM> is provided, no additional apparatus such as a conventional deflector is needed, and when the conventional deflector is used, a difficulty in maintaining a linear velocity constant of the gaseous monomer stream may be solved. As such, the linear velocity of the gaseous monomer stream is maintained constant, whereby a dispersion degree of a reaction solution and by-products in the reactor may be maintained uniform and accumulation of the by-products on one side may be prevented.

The oligomerization reaction is carried out in a lower or a middle area of the reactor <NUM>, and the oligomerization reaction of the monomer may be carried out in a liquid state being dissolved in a solvent in the presence of a catalyst and a cocatalyst.

The oligomerization reaction may refer to a reaction in which a monomer is oligomerized. The oligomerization may be referred to as trimerization or tetramerization depending on the number of monomers to be polymerized, and these are collectively called multimerization.

In the oligomerization reaction of the monomer, an unreacted monomer and a vaporized solvent in the reactor <NUM> may be discharged to the upper portion of the reactor <NUM>, and may be circulated to the reactor <NUM> and reused in the oligomerization reaction of the monomer. In addition, the oligomer produced by the oligomerization reaction of the monomer may be separated through the lower side of the reactor <NUM> and obtained.

The α-olefin, which is an important material used in copolymers, cleaning agents, lubricants, plasticizers, and the like, is commercially widely used, and in particular, <NUM>-hexene and <NUM>-octene are often used as a comonomer for adjusting the density of polyethylene in the production of linear low-density polyethylene (LLDPE). The α-olefin such as <NUM>-hexene and <NUM>-octene may be produced by, for example, a trimerization reaction or tetramerization reaction of an ethylene monomer.

The oligomerization reaction of the monomer may be carried out by a homogeneous liquid phase reaction, a slurry reaction in which the catalyst is in the form of being partially not dissolved or not dissolved at all, a two-phase liquid/liquid reaction, or a bulk phase reaction or gas phase reaction of which the product acts as a main medium, in the presence or absence of a solvent, by applying the reaction system and a common contact technology.

The solvent, the catalyst, and the cocatalyst may be supplied in a liquid phase to the lower side of the reactor <NUM>.

The catalyst may include a transition metal source. The transition metal source may be, for example, a compound including one or more selected from the group consisting of chromium (III) acetylacetonate, chromium (III) chloride tetrahydrofuran, chromium (III) <NUM>-ethylhexanoate, chromium (III) tris(<NUM>,<NUM>,<NUM>,<NUM>-tetramethyl-<NUM>,<NUM>-heptanedionate), chromium (III) benzoylacetonate, chromium (III) hexafluoro-<NUM>,<NUM>-pentanedionate, chromium (III) acetatehydroxide, chromium (III) acetate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) laurate, and chromium (III) stearate.

The cocatalyst may include, for example, one or more selected from the group consisting of trimethyl aluminum, triethyl aluminum, triisopropyl aluminum, triisobutyl aluminum, ethylaluminum sesquichloride, diethylaluminum chloride, ethyl aluminum dichloride, methylaluminoxane, modified methylaluminoxane, and borate.

The solvent used in the oligomerization reaction of the monomer may include one or more selected from the group consisting of n-pentane, n-hexane, n-heptane, cyclohexane, methylcyclohexane, octane, cyclooctane, decane, dodecane, benzene, xylene, <NUM>,<NUM>,<NUM>-trimethylbenzene, toluene, ethylbenzene, chlorobenzene, dichlorobenzene, and trichlorobenzene.

As such, in the process of oligomerizing a monomer in the presence of the catalyst and the solvent, by-products such as cohesive by-products for example a polymer are produced in addition to an oligomer product. The by-products may block holes formed in the sparger <NUM> to cause fouling.

Regarding this, the reactor <NUM> according to the present invention uses the sparger <NUM> according to the present invention described above, thereby preventing blockage of the holes in the sparger due to the fouling to extend the wash cycle of the reactor <NUM>, and thus, preventing a production decrease due to a decreased operation time and reducing costs required in the wash process.

According to an exemplary embodiment of the present invention, in the reactor <NUM>, an apparatus required for oligomer production such as a valve, a condenser, a reboiler, a pump, a cooling facility, a filter, an agitator, a compressor, and a mixer may be further installed, if necessary.

Hereinabove, the sparger according to the present invention and the reactor comprising the same have been described and illustrated in the drawings; however, the description and the illustration in the drawings are the description and the illustration of only core constitutions for understanding of the present invention, and in addition to the process and apparatus described above and illustrated in the drawings, the process and the apparatus which are not described and illustrated separately may be appropriately applied and used for using the sparger according to the present invention and the reactor comprising the same.

Hereinafter, the present invention will be described in more detail by the Examples.

The sparger <NUM> according to <FIG> was provided in a bubble column reactor <NUM> to perform an oligomerization reaction of an ethylene monomer, as shown in <FIG>. Specifically, a solvent, a catalyst, and a cocatalyst were supplied to a lower side of the reactor <NUM>, a gaseous ethylene monomer was supplied through a monomer supply line <NUM> and a spray unit <NUM> provided in a lower portion of the reactor <NUM>, and the sparger <NUM> was used to disperse the stream upward to perform an oligomerization reaction in a liquid reaction medium in the reactor <NUM>. An α-olefin produced by the oligomerization reaction was separated in the lower side of the reactor <NUM> and obtained, and an unreacted monomer and a vaporized solvent were discharged to an upper portion of the reactor <NUM>.

Here, a diameter of the body of the sparger <NUM> was <NUM>, the thickness of the body of the sparger <NUM> was <NUM>, the diameter of first holes <NUM> of the sparger <NUM> was <NUM>, and the diameter of second holes <NUM> of the sparger <NUM> was <NUM>.

In this case, a mixing efficiency of the ethylene monomer was increased to increase the production of the α-olefin. In addition, fouling occurrence in the sparger <NUM> was decreased to extend a shutdown cycle for washing the reactor <NUM>.

The process was performed in the same manner as in Example <NUM>, except that a sparger <NUM> having a protrusion <NUM> having a constant diameter formed upward along the outer circumferential surface of the second hole was used, as shown in <FIG>, as the sparger <NUM>. At this time, the height of the protrusion <NUM> was formed to be <NUM>.

In this case, the mixing efficiency of the ethylene monomer was increased to increase the production of the α-olefin, as in Example <NUM>. In addition, a possibility of fouling occurrence in the second holes <NUM> which is likely to cause fouling is decreased due to the protrusion <NUM> to decrease fouling occurrence in the sparger <NUM>, thereby extending a shutdown cycle for washing the reactor <NUM>, as compared with Example <NUM>.

The process was performed in the same manner as in Example <NUM>, except that a spray unit <NUM> was provided to spray the gaseous ethylene monomer through the spray unit <NUM> so that the monomer was supplied to pass through the sparger <NUM>, as shown in <FIG>.

In this case, the mixing efficiency of the ethylene monomer was increased as in Example <NUM> to increase the production of an α-olefin, and a fouling occurrence of the sparger <NUM> was decreased to extend the shutdown cycle for washing the reactor <NUM>. Also, it was confirmed that the spray unit <NUM> was used to maintain a linear velocity of the gaseous ethylene monomer supplied to the reactor <NUM> constant to maintain a dispersion degree of the reaction solution and the by-products in the reactor constant, thereby preventing accumulation of the by-products on one side.

The process was performed in the same manner as in Example <NUM>, except that a sparger <NUM> having only a first hole <NUM> formed was used, as shown in <FIG>, as the sparger <NUM>.

Claim 1:
A sparger (<NUM>) comprising:
a disc-shaped body; and
first holes (<NUM>) and second holes (<NUM>) having different sizes from each other provided in the body,
wherein the diameter of the second holes (<NUM>) is smaller than the diameter of the first holes (<NUM>),
wherein the second holes (<NUM>) include a protrusion (<NUM>) formed upward along an outer circumference surface of the second holes (<NUM>), wherein the protrusion (<NUM>) is formed to have a constant diameter upward.