KR102193379B1 - Hydrocarbon solvent composition comprising normal heptane, method of preparing the same, and method of preparing conjugated diene polyer - Google Patents

Abstract

One embodiment provides a method of preparing a hydrocarbon-based solvent composition, comprising the steps of: distilling a feed containing C6 or less, C7, and C8 or more hydrocarbon components to remove the C8 or more and C6 or less components to separate the C7 component; adding the separated C7 component to a hydrotreating device for hydrogenation; separating the hydrogenated C7 component into an extract including normal heptane and a raffinate including the other components by introducing the hydrogenated C7 component into a simulated moving bed (SMB); distilling the extract in an extract column to separate normal heptane having a purity of 98 wt% or more; and mixing the normal heptane having a purity of 98 wt% or more with the raffinate.

Description

Method for producing a hydrocarbon-based solvent composition containing normal heptane, its hydrocarbon-based solvent composition, and a method for producing a conjugated diene-based polymer using the hydrocarbon-based solvent composition {HYDROCARBON SOLVENT COMPOSITION COMPRISING NORMAL HEPTANE, METHOD OF PREPARING THE SAME, AND METHOD OF PREPARING CONJUGATED DIENE POLYER}

The present invention relates to a method for producing a hydrocarbon-based solvent composition containing normal heptane, a hydrocarbon-based solvent composition thereof, and a method for producing a conjugated diene-based polymer using the hydrocarbon-based solvent composition.

Hydrocarbon solvents such as normal heptane, toluene, cyclohexane, and normal hexane are used as industrial solvents for the production of conjugated diene polymers such as butadiene rubber.

Among them, toluene has an advantage in terms of the polymerization reaction rate, but there is a problem in that it is difficult to control the molecular weight and molecular weight distribution of the polymer produced by a chain transfer phenomenon by toluene in the polymerization process.

In the case of cyclohexane, it is easier to control the molecular weight and molecular weight distribution compared to toluene, but these are expensive and have problems in process productivity, and because of high specific heat, the viscosity of the polymerization solution is high, requiring excessive use, thereby limiting the amount of polymerization.

In the case of normal hexane, it is easier to control the molecular weight and molecular weight distribution than toluene, but it is difficult to commercialize due to an increase in initial investment cost due to an increase in pressure in the reactor due to the reaction heat generated during the polymerization reaction due to its low boiling point.

On the other hand, in the case of normal heptane, it is easy to control the molecular weight and molecular weight distribution of the polymer to be produced, and it is advantageous for commercialization because it has higher specific heat than normal hexane, and it has good compatibility with the polymer, so the viscosity of the polymerization solution is lowered and the amount of solvent is significantly reduced. There is an advantage to be able to.

Conventional hydrocarbon-based solvent compositions containing normal heptane are products obtained by distilling C6~C7 hydrocarbons from Naphtha used in petrochemical processes, and contain high content of iso-paraffin and naphtene components. Since it is included as, it is difficult to control the content of normal heptane, and even if it is manufactured by narrowing the distillation range, there is a problem that the production cost is high and practical production is not easy.

Accordingly, it is possible to prepare a polymer having an appropriate molecular weight and molecular weight distribution in various applications, and there is a need to supply a solvent composition containing normal heptane that can realize high productivity.

In one embodiment of the present invention, a conjugated diene-based polymer having a molecular weight and molecular weight distribution generally required in the market can be prepared with high productivity, and a desired molecular weight and molecular weight by controlling the content of solvent components such as normal heptane It is intended to provide a hydrocarbon-based solvent composition capable of specifically preparing a conjugated diene-based polymer having a distribution, a method for producing the same, and a method for producing a conjugated diene-based polymer using the hydrocarbon-based solvent composition.

In one embodiment, distilling a feed containing C6 or less, C7, and C8 or more hydrocarbon components to remove C8 or more components and C6 or less components to separate C7 components; Hydrogenating the separated C7 component by introducing it into a hydrotreating device; Separating the hydrogenated C7 component into an extract including normal heptane and a raffinate including other components by introducing the hydrogenated C7 component into a simulated moving bed (SMB) device; Distilling the extract in an extract column to separate normal heptane having a purity of 98% by weight or more; And it provides a method for producing a hydrocarbon-based solvent composition comprising the step of mixing the raffinate with the normal heptane having a purity of 98% by weight or more.

The step of separating the C7 component by distilling the feed containing C6 or less, C7, and C8 or more hydrocarbon components to remove C8 or more components and C6 or less components may include distilling in a first distillation column to remove C8 or more components. ; And distilling in a second distillation column to remove C6 or less components.

The step of separating the C7 component by distilling the feed containing the C6 or less, C7, and C8 or more hydrocarbon components to remove the C8 or more and C6 or less components may include distilling in the first distillation column to remove the C6 or less component. step; And distilling in a second distillation column to remove C8 or more components.

The feed containing a hydrocarbon component of C6 or less, C7, and C8 or more may be desulfurized naphtha.

The feed containing a hydrocarbon component of C6 or less, C7, and C8 or more is 3% by weight or more and 10% by weight or less of normal paraffin of C6 or less, 5% by weight or more and 15% by weight or less C7 normal paraffin, based on 100% by weight of the total amount. 5% by weight or more and 20% by weight or less of normal paraffin, and the balance may include naphthene, isoparaffin, and aromatic components.

The hydrogenated C7 component may contain 0.1% by weight or less of an aromatic component based on 100% by weight of the total amount.

It may further include recycling some of the normal heptane separated in the extract separation tower to the front end of the similar moving bed adsorption separation device.

It may further include recycling some of the normal heptane separated in the extract separation tower between the rear end of the hydrotreating device and the front end of the similar moving bed adsorption separation device.

The recycling rate in the recycling step may be 30% or more and 60% or less.

The purity of normal heptane prepared in the step of separating the normal heptane may be 99.8% by weight or more.

In another embodiment, based on the total amount of 100% by weight, 15% by weight or more and 80% by weight of normal heptane, 10% by weight or more and 65% by weight of isoparaffin, 5% by weight or more and 40% by weight or less of naphsen, and an aromatic component and an olefin component It provides a hydrocarbon-based solvent composition containing the balance.

The hydrocarbon-based solvent composition includes 15% by weight or more and 60% by weight or less of normal heptane, 20% by weight or more and 50% by weight of isoparaffin, 10% by weight or more and 40% by weight or less of naxene, and aromatic components and olefins based on 100% by weight of the total amount. Ingredients may be included in balance.

The hydrocarbon-based solvent composition may contain 60% by weight or more and 90% by weight or less, 10% by weight or more and 35% by weight or less, and an aromatic component and an olefin component as a balance based on 100% by weight of the total amount of normal heptane and isoparaffin. have.

The hydrocarbon-based solvent composition may contain 0.5% by weight or less of the aromatic component and the olefin component based on 100% by weight of the total amount.

The normal heptane and isoparaffin may be included in a weight ratio of 1:0.1 to 1:4.

The hydrocarbon-based solvent composition may include normal heptane having a purity of 98% by weight or more; And raffinate in a weight ratio of 80:20 to 15:85.

The raffinate is, based on the total amount of 100% by weight, normal heptane 0% by weight or more and 15% by weight or less, isoparaffin 40% by weight or more and 70% by weight or less, naxene 25% by weight or more and 55% by weight or less, and aromatic components and olefin components May be included as the balance.

Another embodiment provides a method for preparing a conjugated diene-based polymer, for preparing a co-and-diene-based polymer by mixing a hydrocarbon-based solvent composition, a conjugated diene-based monomer, and a polymerization catalyst.

The polymerization catalyst may be a transition metal compound, an organoaluminum compound, or a Ziegler-Natta catalyst, which is a mixture thereof.

When using the hydrocarbon-based solvent composition of one embodiment of the present invention, a conjugated diene-based polymer having a molecular weight and molecular weight distribution generally required in the market can be prepared with high productivity, and the components within the composition of the hydrocarbon-based solvent composition By controlling the content, it may be possible to specifically prepare a polymer having a desired molecular weight and molecular weight distribution.

According to the present invention, a hydrocarbon-based solvent composition can be easily prepared by variously controlling the content of normal heptane.

According to the present invention, it is possible to easily prepare a hydrocarbon-based solvent composition containing an olefin component and an aromatic component in a low content compared to normal heptane, isoparaffin, and leadene components.

1 is a flowchart of a method of manufacturing a hydrocarbon-based solvent composition according to an embodiment.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used as meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. When a part of the specification "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated. Also, the singular form includes the plural form unless specifically stated in the text.

In the present specification, unless otherwise defined, "high purity normal heptane" may mean normal heptane having a purity of 98% by weight or more, and more specifically 99% by weight or more.

Unless otherwise defined in the present specification, "ultra-high purity normal heptane" may mean normal heptane having a purity of 99.8% by weight or more.

The present invention relates to a hydrocarbon-based solvent composition prepared by mixing high-purity normal heptane obtained from desulfurized naphtha and by-products of an adsorption process, a method for preparing the same, and a method for preparing a conjugated diene-based polymer through the same.

According to the manufacturing method of one embodiment of the present invention, it is possible to prepare high-purity normal heptane used as a solvent for pharmaceutical ingredient extracting agent, display coating process such as OLED, SBR polymerization process, etc., and standard fuel for which octane number measurement test is used ( reference fuel), high-performance liquid chromatography (HPLC), etc., and ultra-high purity normal heptane of 99.8% by weight or more that can be used in pharmaceutical manufacturing solvents, etc. Specific production of a polymer having a desired molecular weight and molecular weight distribution may be possible by appropriately controlling the content of the constituents in the composition of the hydrocarbon-based solvent composition.

A method for preparing a hydrocarbon-based solvent composition according to an embodiment of the present invention includes the steps of distilling a feed containing C6 or less, C7, and C8 or more hydrocarbon components to remove C8 or more components and C6 or less components to separate C7 components; Hydrogenating the separated C7 component by introducing it into a hydrotreating device; Separating the hydrogenated C7 component into an extract including normal heptane and a raffinate including other components by introducing the hydrogenated C7 component into a simulated moving bed (SMB) device; Distilling the extract in an extract column to separate normal heptane having a purity of 98% by weight or more; And mixing the normal heptane having a purity of 98% by weight or more with the raffinate.

The step of separating the C7 component by distilling the feed containing C6 or less, C7, and C8 or more hydrocarbon components to remove C8 or more components and C6 or less components may include distilling in a first distillation column to remove C8 or more components. , And distillation in the second distillation column may include the step of removing C6 or less components.

In the method for preparing a hydrocarbon-based solvent composition according to an embodiment of the present invention, distillation may be performed by a commonly known distillation method, and the number of stages of the distillation column may be adjusted as necessary. As a non-limiting example, a single or a plurality of distillation columns including a bottom reboiler and an overhead condenser and having 10 stages or more and 100 stages or less may be used.

In the step of distilling in the first distillation column to remove C8 or more components, components of C7 or less may be discharged to an overhead of the first distillation column, and components of C8 or more may be discharged to a bottom of the first distillation column. In addition, in the step of removing components of C6 or less by distilling in the second distillation column, components of C6 or less may be discharged to the overhead of the second distillation column, and C7 may be discharged to the bottom.

At this time, the first distillation column and the second distillation column are named for convenience, and the number does not mean the order, and after removing the component C6 or less, the component C8 or more can be removed, or the component C8 or more is removed. Afterwards, the components below C6 can be removed.

The feed including the hydrocarbon component of C6 or less, C7, and C8 or more may be desulfurized naphtha, and specifically, may be desulfurized naphtha after performing a desulfurization process on naphtha separated from crude oil. This desulfurized naphtha is 3% by weight or more and 10% by weight or less of C6 normal paraffin, 5% by weight or more and 15% by weight or less of C7 normal paraffin, 5% by weight or more and 20% by weight or less of C8 or more normal paraffin, and The balance may contain naphthene, isoparaffin, and aromatic components. More specifically, C6 or less normal paraffin 3 wt% or more and 10 wt% or less, C7 normal paraffin 5 wt% or more and 15 wt% or less, C8 or more normal paraffin 5 wt% or more and 20 wt% or less based on 100 wt% of the total amount of desulfurized naphtha , Naxene 20% by weight or more and 35% by weight or less, isoparaffin 25% by weight or more and 40% by weight or less, and 5% by weight or more and 15% by weight or less of an aromatic component may be included.

Subsequently, the C7 component separated in the distillation step is added to a hydrogenation device to perform hydrogenation.

Hydrogenation treatment can be performed by a process of hydrogenating unsaturated hydrocarbons such as aromatic components and olefins into saturated hydrocarbons.When injected into the reactor, the reactor and outlet temperature may be overheated due to the reaction heat generated during the hydrogenation reaction. It may be better to inject by lowering the temperature of the reactants introduced into the hydrogenation reactor. A specific hydrogenation method may be performed by a known method known in the art, and a liquid hydrogenation process according to the following exemplary embodiment may be applied, but the present invention is not limited thereto.

In the liquid phase hydrogenation process according to an embodiment, the reactor may be operated at a temperature of 70° C. or more and 110° C. or less and a pressure of 15 kg/cm ² g or more and 30 kg/cm ² g or less. However, the present invention is not limited thereto. As described above, since the process can be performed in such a temperature range, the heat duty of the liquid hydrogenation process is small, and only enough to dissolve hydrogen is required, so that a separate compressor for recirculation is not required, and for gas-liquid separation. Since there is no need to provide a separation device, the plant can be simplified, and the economics of the process can be improved.

The space velocity in the reactor of the C7 component in which hydrogen is dissolved in the liquid hydrogenation process is 6 hr ^-1 or more and 15 hr ^-1 or less, preferably 8 hr ^-1 or more and 12 hr ^-1 or less, and the recycling ratio is 2.5 or more and 5.0 or less, Preferably it can be between 2.9 and 4.3. However, the present invention is not limited thereto.

The recycle ratio may be defined as the volume ratio of the mixture recycled from the rear end to the front end of the liquid hydrogenation process to the volume of the C7 component introduced into the liquid hydrogenation process. In one embodiment of the present invention, the olefin and aromatic components in the liquid hydrogenation process are 0.5% by weight or less, preferably 0.4% by weight or less, more preferably 0.3% by weight or less by satisfying the space velocity and recycling ratio of the C7 component in the reactor. , Specifically, it may be removed to 0.2% by weight or less or 0.1% by weight or less, and specifically, the aromatic component may be removed to 0.1% by weight or less.

When the process mode of the liquid phase hydrogenation process is further described, the liquid phase hydrogenation process may be performed using a fixed bed reactor. Specifically, the liquid reactant may be continuously injected into a fixed bed reactor filled with a hydrogenation catalyst and hydrogen in a countercurrent or cocurrent direction to perform hydrogenation.

As the hydrogenation catalyst, a catalyst in which a metal catalyst is supported on a support that helps catalytic activity may be used, but the present invention is not limited thereto.

Here, the metal catalyst may be an alloy containing two or more of these, such as nickel (Ni), platinum (Pt), palladium (Pd), rhodium (Rh), lutetium (Lu), or a platinum-palladium alloy, and the support is It may be alumina (Al ₂ O ₃ ), silica (SiO ₂ ), titania (TiO ₂ ), zirconia (ZrO ₂ ), zeolite, clay material, or a combination thereof, but the present invention is not limited thereto.

In addition, the amount of the metal catalyst supported on the support may be used without limitation as long as the object of the present invention is achieved, and as an example, 10% by weight or more and 40% by weight based on 100% by weight of the catalyst supported on the support. It may be not more than 15% by weight, preferably not less than 15% by weight and not more than 30% by weight.

The method for preparing a hydrocarbon-based solvent composition according to an embodiment is, by performing the hydrogenation process before separating normal heptane and isoparaffin in a similar moving bed adsorption process (SMB process), based on 100% by weight of the hydrogenated C7 component. , Olefin component and aromatic component 0.5% by weight or less, preferably 0.4% by weight or less, more preferably 0.3% by weight or less, specifically 0.2% by weight or less or 0.1% by weight or less, specifically aromatic component 0.1 It may be included in weight percent or less.

Accordingly, in the subsequent adsorption process, the problem of deactivation of the adsorbent due to the formation of oligomers or concentration of olefin and aromatic components in the raw material in the adsorbent pores filled in the adsorption tower is solved, thereby reducing the purity and recovery rate of the separated normal heptane. It can be prevented from being reduced. In addition, since the regeneration process according to the deactivation of the adsorbent does not need to be additionally provided, the process can be simplified, which leads to a reduction in plant cost, maintenance cost, and operation cost, and thus industrial applicability can be greatly increased. On the other hand, if the hydrogenation reaction is performed after the adsorption process, the purity of normal heptane is not sufficiently secured because a lot of components other than normal heptane are contained even after the hydrogenation reaction, and hydrogenated substances of olefins and aromatic compounds having different properties from normal heptane are removed. Since is essential to be accompanied, an additional separation process such as a distillation process may be further added.

Subsequently, the hydrogenated C7 component is introduced into a simulated moving bed (SMB) and separated into an extract containing normal heptane and a raffinate containing other components. .

The SMB process uses a device including an adsorption bed filled with a zeolite-based adsorbent and an on-off valve, and components with high selectivity for the adsorbent are adsorbed by the adsorbent and extracted as an extract, and the remaining components are rafi. It can be carried out by a method of discharging as raffinate, and an adsorption process according to the following embodiment can be applied, but the present invention is not limited thereto.

In the adsorption process, normal heptane is selectively adsorbed by passing through an adsorption tower filled with a zeolite adsorbent. The step of discharging the unadsorbed isoparaffin-containing oil to the outside of the adsorption tower, and then purging butane to desorb and discharge the normal heptane adsorbed in the pores of the zeolite adsorbent.

In the adsorption process, butane is used as a desorbent. Since butane can be recovered in a liquid phase and recycled, investment cost can be reduced, and productivity of the process can be greatly increased due to excellent desorption performance. The butane may be preferably containing 70% by weight or more and 100% by weight or less of normal butane.

The adsorbent is not particularly limited, but specifically, it may be preferable to have pores of 5 Å or less, such as zeolite 5A, which is advantageous for adsorption of normal heptane.

In addition, the adsorption process uses at least 20 adsorption towers and is divided into an adsorption area, a purification area, a desorption area, and a buffer area according to the roles of adsorption and desorption. The adsorption process is performed in a continuous circulation type sequentially performed in each adsorption tower, and an optimal switching time is determined so that only normal heptane can be selectively separated.

The two most important variables in determining the optimal switching time between adsorption towers are the change in the content of normal heptane in the raw material and the decrease in the adsorption capacity of the zeolite molecular sieve according to the operating time due to repetition or regeneration of long adsorption and desorption processes. can do. The control of the adsorption separation process according to the change of these two variables can influence economic efficiency. Specifically, the optimal switching time can be determined in two ways: first, constructing an accurate process model that calculates the optimal time for specific raw materials and process conditions by measuring normal heptane in raw materials, and secondly, adsorbed components (normal Heptane) content is monitored to determine the time to switch the adsorption tower before normal heptane becomes contaminated. These two control strategies require fast, accurate and precise on-line analysis of the normal heptane content of raw materials or normal heptane products.

Subsequently, the extract obtained in the SMB process is distilled in an extract separation column to separate normal heptane.

Meanwhile, the raffinate obtained in the SMB process may be distilled in a raffinate column to separate the raffinate and a desorbent (butane) from each other, and the separated butane may be recycled to the adsorption column.

Specifically, the extract and the raffinate may be purified by distillation at a temperature of 60° C. or more and 200° C. or less and a pressure of 6 kg/cm ² g or more and 8 kg/cm ² g or less, respectively. Accordingly, normal heptane having a purity of 98% by weight or more can be recovered with a recovery rate of 98% or more.

The method for producing a hydrocarbon-based solvent composition according to an embodiment of the present invention may further include recycling some of the normal heptane separated in the extract separation tower to the front end of the SMB process. By further including this recycling step, it is possible to produce 99.8% by weight or more of ultra-high purity normal heptane in a high production amount.

Specifically, in order to increase the purity of normal heptane to 99.8% by weight or more in the manufacturing method of the hydrocarbon-based solvent composition of the embodiment of the present invention described above, the purity of normal heptane in the feed introduced into the SMB process must be increased. However, in order to increase the purity of normal heptane in the feed fed to the SMB process without recycling, it is necessary to reduce the processing capacity of the shearing processes, so that the throughput of the SMB process is reduced, making it impossible for practical commercial application. Production will decrease. That is, since the purity of normal heptane in the feed input to the SMB process and the processing capacity of the SMB process are in a trade-off relationship, there is a need for a solution to resolve this trade-off relationship. To this end, the method for preparing a hydrocarbon-based solvent composition according to an embodiment of the present invention may further include recycling some of the normal heptane separated in the extract separation tower between the front ends of the similar moving bed adsorption separation device (SMB). That is, by recycling some of the normal heptane separated in the extract separation column after the SMB process to the front end of the SMB process, the purity of the normal heptane in the feed input to the SMB process can be improved, and as a result, the processing capacity of the overall process It is possible to improve the purity of normal heptane in the final product without deterioration of the.

More specifically, the method for producing a hydrocarbon-based solvent composition according to an embodiment of the present invention comprises the steps of recycling some of the normal heptane separated in the extract separation tower between the rear end of the hydrotreating device and the front end of the similar moving bed adsorption separation device. It may further include.

It may be more advantageous to recycle some of the normal heptane separated in the extract separation tower between the rear end of the hydrotreating unit and the front end of the pseudo-moving bed adsorption separation unit. This means that if recycled to the front end of the hydrotreating device, the throughput between the hydrogenation process and the SMB process increases, and the amount that has to be treated in the separation process and stripping process such as distillation between the hydrogenation process and the SMB process increases, which increases unnecessary process costs. Because it can.

On the other hand, the recycling rate in the step of recycling may be 30% or more and 60% or less. More specifically, it may be 35% or more and 55% or less. In order to produce products while maintaining throughput above a certain level of the process, it is necessary to maintain an appropriate level of recycling rate. If the recycling rate is low, the output may decrease as the processing capacity of the process decreases.

In this range, by recycling some of the high purity normal heptane with a purity of 98% by weight or more separated in the extract separation column to the front end of the SMB process, ultra-high purity normal heptane having a purity of 99.8% by weight or more without deterioration of the processing capacity of the entire process was prepared. can do.

Here, the recirculation rate may mean an amount to be recycled based on 100% by weight of the total amount of the discharged product including normal heptane discharged from the extract separation tower.

Subsequently, high purity normal heptane separated by distillation in an extract separation column and raffinate obtained in the SMB process are mixed to obtain a hydrocarbon-based solvent composition according to an embodiment of the present invention.

1 is a flow chart of a method for preparing a hydrocarbon-based solvent composition according to an embodiment of the present invention. Hereinafter, an embodiment of a method for producing a hydrocarbon-based solvent composition according to an embodiment of the present invention will be described with reference to FIG. 1.

First, as shown in FIG. 1, desulfurized naphtha is introduced into the first distillation column 10 to remove C8 or more hydrocarbon components from the bottom of the distillation column, and C7 or less hydrocarbon components are separated from the top.

Thereafter, a hydrocarbon component of C7 or more is introduced into the second distillation column 11 to remove the hydrocarbon component of C6 or less from the top, and the C7 hydrocarbon component is separated from the bottom.

The separated C7 hydrocarbon component is introduced into the hydrotreating device 20, and unsaturated hydrocarbon components such as aromatic and olefin components are converted into saturated hydrocarbon components through hydrogenation.

Thereafter, a process for additionally removing a liquid low-boiling component through a distillation process by an additional third distillation column and/or a stripping process by a stripping device 30 for the hydrogenated discharge is performed. I can. However, this may be added as needed and does not necessarily have to be performed in the method for producing normal heptane according to an embodiment of the present invention.

Next, the hydrogenated effluent is put into the pseudo-moving bed adsorption separation device 40 to separate normal heptane from the upper part by extract and other components from the lower part by raffinate. At this time, a desorbent may be mixed with the extract and/or raffinate.

Here, the raffinate may be separated into a desorbent (top of the separation column) and a raffinate (bottom of the separation column) in a raffinate column 42.

The desorbent discharged from the top may be re-introduced into the SMB (similar moving bed separation device) 40 through the desorbent storage tank.

The extract discharged from the top of the pseudo-moving bed adsorption separation device 40 contains separated normal heptane, and this extract includes a desorbent (top of the separation column) and normal heptane in the extract column 41. It can be separated into an extract (lower separation tower) including.

The desorbent discharged from the top may be reintroduced into the similar moving bed separation device 40 through the desorbent storage tank.

Meanwhile, in order to raise the purity of the normal heptane product to 99.8% by weight or more, the normal heptane discharged from the lower part of the extract separation tower 41 is hydrogenated through a recycling pipe 101 in communication with the discharge pipe below the extract separation tower. It can be recycled between the rear end of the treatment device 20 and the front end of the similar moving bed adsorption separation device 40.

Thereby, as described above, it is possible to produce 99.8% by weight or more of ultra-high purity normal heptane without lowering the processing capacity of the entire process, and a hydrocarbon-based solvent by mixing the ultra-high purity normal heptane and the raffinate separated in the raffinate separation column The composition can be prepared.

In FIG. 1, the position at which the normal heptane discharged from the lower part of the extract separation tower 41 is recycled is illustrated as an example, and the position at which the discharged normal heptane is recycled is the rear end of the hydrotreating device 20 and a similar moving bed. It is not particularly limited as long as it is between the front ends of the adsorption separation device 40.

The hydrocarbon-based solvent composition of another embodiment of the present invention, prepared according to the method for preparing a hydrocarbon-based solvent composition of one embodiment of the present invention, is 15% by weight or more and 80% by weight or less of normal heptane, based on 100% by weight of the total amount, isoparaffin 10 It contains an aromatic component and an olefin component as a weight% or more and 65 weight% or less, 5 weight% or more and 40 weight% or less of leadene, and the balance.

Specifically, normal heptane 15% by weight or more, 25% by weight or more, 30% by weight or more, 35% by weight or more, 40% by weight or more, 45% by weight or more or 50% by weight or more, and 80% by weight or less with respect to the total amount of 100% by weight , 75 wt% or less, 70 wt% or less, 65 wt% or less, 60 wt% or less or 55 wt% or less, isoparaffin 10 wt% or more, 15 wt% or more, 20 wt% or more or 25 wt% or more, and 65 Wt% or less, 60 wt% or less, 55 wt% or less, 50 wt% or less, 45 wt% or less, 40 wt% or less, 35 wt% or less or 30 wt% or less, naphsen 5 wt% or more, 10 wt% or more, 15% by weight or more or 20% by weight or more, and 40% by weight or less, 35% by weight or less, 30% by weight or less or 25% by weight or less, and the balance may include an aromatic component and an olefin component.

More specifically, based on 100% by weight of the total amount of the hydrocarbon-based solvent composition, the total amount of normal heptane and isoparaffin is 60% by weight or more and 90% by weight or less, 10% by weight or more and 35% by weight or less, and the balance includes an aromatic component and an olefin component. And, for example, the total amount of normal heptane and isoparaffin is 60% or more, 65% or more, or 70% or more, and 90% or less, 85% or less, 82% or less, 80% or less, 79 Wt% or less, 78 wt% or less, 77 wt% or less, 76 wt% or less or 75 wt% or less, naphsen 10 wt% or more, 15 wt% or more or 20 wt% or more, and 35 wt% or less, 30 wt% or less Or 25% by weight or less, and 0.5% by weight or less, 0.4% by weight or less, 0.3% by weight or less, 0.2% by weight or less, or 0.1% by weight or less of the olefin component and the aromatic component.

The hydrocarbon-based solvent composition may include normal heptane and isoparaffin in a weight ratio of 1:0.1 to 1:4. Specifically, it may be included in a weight ratio of 1:0.1 to 1:3.5, 1:0.1 to 1:3, 1:0.15 to 1:3.5, or 1:0.15 to 1:2. If it is within the above range, a polymer having a desired molecular weight and molecular weight distribution can be prepared in high yield.

The hydrocarbon-based solvent composition may include normal heptane and naphsen in a weight ratio of 1:0.1 to 1:1.5. Specifically, it may be included in a weight ratio of 1:0.3 to 1:1.5 or 1:0.4 to 1:1.5. If it is within the above range, a polymer having a desired molecular weight and molecular weight distribution can be prepared.

The isoparaffin is a pulverized hydrocarbon having 7 carbon atoms, and may include, for example, 2-methylhexane, 3-methylhexane, 3-ethylpentane, 2,3-dimethylpentane, and 3,3-dimethylpentane.

The naphthene is a cyclic hydrocarbon having 7 carbon atoms, and may include, for example, cycloheptane, methylcyclohexane, ethylcyclopentane, 1,2-dimethylcyclopentane and 1,3-dimethylcyclopentane.

The hydrocarbon-based solvent composition can be obtained by mixing high-purity normal heptane and raffinate in a weight ratio of 80:20 to 15:85.

The mixing is a high purity normal heptane and raffinate in a weight ratio of 80:20 to 15:85, specifically a weight ratio of 80:20 to 25:75, 55:45 to 25:75 or 80:20 to 50:50 It may be mixed in a weight ratio.

The high purity normal heptane may have a purity of 99% or more or 99.8% or more, and the raffinate is 0% by weight or more, 1% by weight or more, 2% by weight or more, or 3% by weight or more, based on 100% by weight of the total amount. , And 15% by weight or less, 13% by weight or less, 11% by weight or less, 10% by weight or less, 8% by weight or less or 5% by weight or less, isoparaffin 40% by weight or more, 45% by weight or more, or 50% by weight or more, and 70 wt% or less, 65 wt% or less, 60 wt% or less or 55 wt% or less, naphsen 25 wt% or more, 30 wt% or more or 35 wt% or more, and 55 wt% or less, 50 wt% or less or 45 wt% Hereinafter, an aromatic component and an olefin component may be included as the balance.

Specifically, the raffinate may contain less than 0.5% by weight or less than 0.1% by weight of an aromatic component and an olefin component based on 100% by weight of the total amount.

Another embodiment of the present invention provides a method of preparing a conjugated diene-based polymer by solution polymerization using the hydrocarbon-based solvent composition.

The method of preparing the conjugated diene-based polymer may be to prepare a conjugated diene-based polymer by mixing a conjugated diene-based monomer, the hydrocarbon-based solvent composition, and a polymerization catalyst.

The conjugated diene-based polymer may be polybutadiene or butadiene rubber, preferably butadiene rubber.

The polymerization catalyst may be a Ziegler-Natta catalyst, preferably a transition metal compound, an organoaluminum compound, or a mixture thereof. For example, the transition metal compound may be nickel naphthenate or nickel octanoate, but the present invention is not limited thereto. In addition, the organoaluminum compound may be triethyl aluminum or triisobutyl aluminum, but the present invention is not limited thereto.

The conjugated diene monomer may be a 1,3-butadiene monomer, a vinyl compound monomer, or a mixture thereof, preferably a 1,3-butadiene monomer.

The conjugated diene-based polymer may be prepared by mixing a conjugated diene-based monomer, the hydrocarbon-based solvent composition, and a polymerization catalyst, and reacting at 30 to 50° C. for 0.3 to 1 hour.

The conjugated diene-based monomer and the hydrocarbon-based solvent composition are 6:1 to 2:1, for example 5:1 to 3:1, preferably 5:1 to 4:1 or 4:1 to 3:1 by weight It may be mixed with.

The specific gravity (60/60°F) of the hydrocarbon-based solvent composition may be 0.5 to 0.7, preferably 0.6 to 0.7, more preferably 0.65 to 0.7 or 0.68 to 0.7. When a hydrocarbon-based solvent composition having a specific gravity within the above range is used as a solvent, it is possible to prepare a conjugated diene-based polymer having excellent physical properties even if a small amount of solvent is used compared to the conjugated diene-based monomer.

Hereinafter, preferred examples and comparative examples of the present invention will be described. However, the following examples are only preferred examples of the present invention, and the present invention is not limited to the following examples.

Example

Examples 1 to 4 and Comparative Examples 1 to 2

After extracting the aromatic component in the sulfolane extraction process, the remaining desulfurized naphtha fraction was fractionally distilled in a 30-stage packing column to obtain a C7 fraction, and olefins were hydrogenated in a continuous reactor (hydrogenation reactor) using a catalyst. And the aromatic component was converted into paraffin and leadene component, and passed through an adsorbent in SMB and separated into extract and raffinate containing normal heptane.

The separated high-purity normal heptane and raffinate were respectively 0:100 weight ratio (Comparative Example 1), 15:85 weight ratio (Example 1), 25:75 weight ratio (Example 2), 51:49 weight ratio (Example 3), By mixing at a 77:23 weight ratio (Example 4) and a 100:0 weight ratio (Comparative Example 2), hydrocarbon-based solvent compositions of Comparative Examples 1, 2, and Examples 1 to 4 were obtained. The components and contents of the solvent composition are shown in Table 1 below.

Next, a butadiene rubber was prepared using the hydrocarbon-based solvent compositions prepared in Comparative Examples 1, 2, and Examples 1 to 4. After sufficiently blowing a 150 ml-pressure reactor with nitrogen, a solvent composition, a Ziegler-Natta catalyst and 1,3-butadiene as a monomer were added, followed by reaction at 40° C. for 0.5 hours to perform polymerization.

At this time, the weight ratio of the hydrocarbon-based solvent composition (polymerization solvent) and the 1,3-butadiene monomer (monomer/solvent composition) was 4, and the reaction was terminated by adding ethanol after the reaction.

The Ziegler-Natta catalyst used in the reaction was nickel naphthenate (6% aliphatic C7 hydrocarbon mixed solution), boron trifluoride diethyl ether (10.0% aliphatic C7 hydrocarbon mixed solution) and triethylaluminum (9.3% aliphatic C7 hydrocarbon mixed solution). And 8.0·10 ^-5 mol of nickel catalyst per 100 g of monomer was used.

Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Comparative Example 2 n-Heptane 3 18.4 25.2 50.3 75.5 99.6 Iso-paraffins (Iso-heptane) 54.3 62.6 41.9 27.8 13.8 0.3 Naphthenes(MCH) 42.3(19.4) 17.4(8.1) 32.6(15.0) 21.6(9.9) 10.7(4.9) 0.1(0.1) Aromatic/Olefin 0.4 0.3 0.3 0.2 0.1 0 Total 100 100 100.0 100.0 100.0 100 Specific gravity, 60/60F 0.722 0.703 0.697 0.693 0.690 0.688

*MCH: methyl cyclohexane

Referring to Table 1, it can be seen that the hydrocarbon-based solvent compositions of Examples 1 to 4 are prepared in the constituents and content ranges of the present invention, but Comparative Examples 1 and 2 are not.

Evaluation example

For each butadiene rubber prepared using the hydrocarbon-based solvent compositions of Examples 1 to 4, Comparative Example 1 and Comparative Example 2, the physicochemical properties were measured in the following manner, and are shown in Table 2 below.

*Conversion rate evaluation

Conversion rate was calculated as a percentage of the weight of the synthesized butadiene rubber relative to the added weight of the 1,3-butadiene monomer.

* Molecular weight (Mn) and molecular weight distribution (Mw/Mn) evaluation

The weight average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of the prepared polymer were measured using GPC.

*Microstructure analysis

The microstructure of the polymer was confirmed from the position of Peak through nuclear magnetic resonance analysis (125 MHz c-NMR).

Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Comparative Example 2 Conversion rate (%) 75 72 75 72 70 76 Molecular Weight Molecular weight (Mn) 65,600 73,950 79,400 83,250 106,600 68,500 Molecular weight distribution (Mw/Mn) 5.40 2.89 3.14 4.18 3.75 2.93 Microstructure Cis- 95.8 95.6 95.4 96.0 95.3 95.8 Trans- 2.4 2.5 2.4 2.5 2.7 2.3 Vinyl- 1.9 1.9 2.2 1.6 2.0 1.9

Referring to Table 2, in the case of Examples of the present invention, it was confirmed that butadiene rubber having a number average molecular weight (Mn) of 70,000 or more and a molecular weight distribution (Mw/Mn) of 2 or more and 5 or less was synthesized with a conversion rate of 70% or more. In addition, it can be seen that a butadiene rubber having physical properties such as molecular weight and molecular weight distribution required in various fields can be polymerized by changing the content of normal heptane in the solvent as in Examples 1 to 4.

In particular, referring to Table 1, since the specific gravity of the solvent compositions of Examples 2 to 4 was less than 0.7, it was found that polymerization of butadiene rubber was possible even with a small amount of the solvent composition when used in a commercial process.

As described above, the present invention has been described by specific matters and limited embodiments, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the field to which the present invention pertains. Those of ordinary skill in the above can make various modifications and variations from this description. Therefore, the spirit of the present invention is limited to the described embodiments and should not be defined, and all things that are equivalent or equivalent to the claims as well as the claims to be described later fall within the scope of the spirit of the present invention. .

10: first distillation column
11: second distillation column
20: hydrotreating device
30: stripping device
40: similar moving bed adsorption separation device
41: extract separation tower
42: raffinate separation tower
101: recirculation pipe

Claims (19)

Distilling a feed containing C6 or less, C7, and C8 or more hydrocarbon components to remove C8 or more components and C6 or less components to separate C7 components;
Hydrogenating the separated C7 component by introducing it to a hydrogenation device;
Separating the hydrogenated C7 component into an extract including normal heptane and a raffinate including other components by introducing the hydrogenated C7 component into a simulated moving bed (SMB) device;
Distilling the extract in an extract column to separate normal heptane having a purity of 98% by weight or more; And
Including the step of mixing the raffinate with the normal heptane having a purity of 98% by weight or more,
The raffinate contains 0 wt% or more and 15 wt% or less of normal heptane, 40 wt% or more and 70 wt% or less of isoparaffin having 7 carbon atoms, 25 wt% or more and 55 wt% or less of naphthene having 7 carbon atoms, and an aromatic component and an olefin component. Included as wealth,
Method for producing a hydrocarbon-based solvent composition.
In claim 1,
Separating the C7 component by distilling the feed containing the C6 or less, C7, and C8 or more hydrocarbon components to remove the C8 or more and C6 or less components,
Distilling in a first distillation column to remove C8 or more components; And
Distillation in a second distillation column to remove C6 or less components; a method for producing a hydrocarbon-based solvent composition comprising.
In claim 1,
Separating the C7 component by distilling the feed containing the C6 or less, C7, and C8 or more hydrocarbon components to remove the C8 or more and C6 or less components,
Distilling in a first distillation column to remove C6 or less components; And
Distillation in a second distillation column to remove C8 or more components; a method for producing a hydrocarbon-based solvent composition comprising.
In claim 1,
The method for producing a hydrocarbon-based solvent composition wherein the feed containing a hydrocarbon component of C6 or less, C7, and C8 or more is desulfurized naphtha.
In claim 1,
The feed containing a hydrocarbon component of C6 or less, C7, and C8 or more is 3% by weight or more and 10% by weight or less of normal paraffin of C6 or less, 5% by weight or more and 15% by weight or less C7 normal paraffin, based on 100% by weight of the total amount. A method for producing a hydrocarbon-based solvent composition comprising 5% by weight or more and 20% by weight or less of normal paraffin, and the balance being naphthene, isoparaffin, and an aromatic component.
In claim 1,
The hydrogenation-treated C7 component contains 0.1% by weight or less of an aromatic component based on 100% by weight of the total amount, a method for producing a hydrocarbon-based solvent composition.
In claim 1,
A method for producing a hydrocarbon-based solvent composition further comprising recycling some of the normal heptane separated in the extract separation tower to the front end of the similar moving bed adsorption separation device.
In claim 1,
A method for producing a hydrocarbon-based solvent composition further comprising recycling some of the normal heptane separated in the extract separation tower between a rear end of the hydrotreating device and a front end of the pseudo-moving bed adsorption separation device.
In clause 7,
A method for producing a hydrocarbon-based solvent composition having a recycle rate of 30% or more and 60% or less in the recycling step.
In clause 7,
A method for producing a hydrocarbon-based solvent composition having a purity of 99.8% by weight or more of normal heptane prepared in the step of separating normal heptane.
Based on the total amount of 100% by weight, 15% by weight or more and 80% by weight of normal heptane, 10% by weight or more and 65% by weight or less of isoparaffin having 7 carbon atoms, 5% by weight or more and 40% by weight or less of naphthene having 7 carbon atoms, and aromatic components and olefins A hydrocarbon-based solvent composition containing 0.5% by weight or less of the component.
The method of claim 11,
Based on the total amount of 100% by weight, normal heptane 15% by weight or more and 60% by weight or less, isoparaffin 20% by weight or more and 50% by weight or less, naxene 10% by weight or more and 40% by weight or less, and an aromatic component and an olefin component as balance. , A hydrocarbon-based solvent composition.
The method of claim 11,
A hydrocarbon-based solvent containing 60% by weight or more and 90% by weight or less of the total amount of normal heptane and isoparaffin, 10% by weight or more and 35% by weight or less, and 0.5% by weight or less of an aromatic component and an olefin component based on 100% by weight of the total amount Composition.
delete The method of claim 11,
The normal heptane and isoparaffin are contained in a weight ratio of 1: 0.1 to 1: 4, a hydrocarbon-based solvent composition.
The method of claim 11,
The hydrocarbon-based solvent composition may include normal heptane having a purity of 98% by weight or more; And Raffinate 80: 20 to 15: comprising a weight ratio of 85, a hydrocarbon-based solvent composition.
The method of claim 16,
The raffinate is, based on the total amount of 100% by weight, 0% by weight or more and 15% by weight or less of normal heptane, 40% by weight or more and 70% by weight of isoparaffin having 7 carbon atoms, and 25% by weight or more and 55% by weight or less of naphsen having 7 carbon atoms, And an aromatic component and an olefin component in balance.
A method for preparing a conjugated diene-based polymer by mixing the hydrocarbon-based solvent composition of any one of claims 11 to 13 and 15 to 17, a conjugated diene-based monomer, and a polymerization catalyst to prepare a co-and-diene-based polymer. .
The method of claim 18,
The polymerization catalyst is a Ziegler-Natta catalyst, which is a transition metal compound, an organoaluminum compound, or a mixture thereof, a method for producing a conjugated diene-based polymer.

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