KR100916286B1 - Selective separatin of xylene isomer from xylene mixture by inclusion using guanidinium biphenyl¡ª2,2¡¯¡ªdiyldimethanesulfonate host compound - Google Patents

Abstract

The present invention relates to a method for the selective separation of xylene isomers using the inclusion capacity of guanidinium biphenyl 2,2'-diyldimethane sulfonate host molecule.

The present invention is made by reacting a mixture of guanidinium biphenyl 2,2'-diyldimethane sulfonate with a xylene isomer mixture, and then including the inclusion ability of guanidinium biphenyl 2,2'-diyldimethane sulfonate. It provides a selective separation method of xylene isomers, characterized in that to separate the xylene isomers using.

The present invention provides high efficiency in a mixture of xylene isomers through a simple process by mixing and treating the guanidinium biphenyl 2,2'-diyldimethane sulfonate exhibiting a high affinity for ortho xylene from the xylene mixture. It is possible to separate and purify high purity ortho xylene.

Guanidinium biphenyl 2,2'-diyldimethane sulfonate, xylene isomer, separation method

Description

Guanidinium biphenyl 2,2'-selective separatin of xylene isomer from xylene mixture by inclusion using guanidinium biphenyl-2,2 '- diyldimethanesulfonate host compound}

The present invention relates to a method for selective separation of xylene isomers using the inclusion ability of guanidinium biphenyl 2,2'-diyldimethane sulfonate host molecule, and more particularly, ortho-xylene, meta-xylene And guanidinium biphenyl-2,2'-diyldimethanesulfonate having a selectively different affinity between xylene isomers consisting of para-xylene and host molecules. The present invention relates to a method of selectively encapsulating ortho-xylene isomers having a relatively high affinity from a mixture between xylene isomers, thereby separating the xylene isomers with high purity through a simple process.

Xylene isomers are important industrial raw materials produced from naphtha crakers or reformers, typically o -xylene, m -xylene, and para- Obtained as a mixture of xylene ( p -xylene). And in particular, the ortho-isomer from these mixtures, meta-, and para-xylene are phthalic acid (phthalic acid), iso-industrially it is respectively used as a raw material to make the acid (iso -phthalic acid), and polyester (polyester) It is widely used.

However, since these xylene isomers have very similar physicochemical properties, their separation is very difficult by methods using simple boiling point differences such as the conventionally used fractional distillation.

Therefore, as described above, the development of xylene isomer separation technology is very important in the petrochemical field, and many researches and prior arts for improving the separation method of these isomers have been reported for a long time. U.S. Patent Nos. 5,602,294 and 5,466,345 attempt to separate ortho xylene using an extractive distillation method that has developed from existing distillation methods. However, these prior art may be different from the technology to be achieved in the present invention, such as relatively high installation and maintenance costs, complicated processes, low selectivity.

Guanidinium biphenyl-2,2'-diyldimethanesulfonate is the first material synthesized by the author, and each guest from the xylene mixture using this host molecule. There has been no attempt to separate ortho-xylene with high selectivity from xylene isomeric mixtures, including ortho-xylene, which has shown the superiority of the selectivity of the molecules or what is proposed in the present invention.

Accordingly, the present inventors have used a host molecule of guanidinium biphenyl-2,2'-diyldimethanesulfonate in a mixture between xylene isomers to efficiently convert the xylene isomers In order to develop a selective separation method, guanidinium biphenyl 2,2'-diyldimethane sulfonate has different affinity between meta-xylene, ortho-xylene and para-xylene. By demonstrating selective inclusion, a method of separating xylene isomers with high purity from the xylene mixture was completed.

Accordingly, an object of the present invention is to selectively purify ortho-xylene isomer of high purity through a simple process using guanidinium biphenyl 2,2'-diyldimethane sulfonate in a mixture of xylene isomers. To provide a separation method.

In order to achieve the above object, the present invention is reacted by mixing a mixture of guanidinium biphenyl 2,2'- diyldimethane sulfonate with a xylene isomer mixture, and then guanidinium biphenyl 2,2 ' It provides a method for the selective separation of xylene isomers characterized in that the xylene isomers are separated using the inclusion ability of diyldimethane sulfonate.

Hereinafter, the present invention will be described in detail.

At this time, if there is no other definition in the technical terms and scientific terms used, it has a meaning commonly understood by those of ordinary skill in the art.

In addition, repeated description of the same technical configuration and operation as in the prior art will be omitted.

In the present invention, xylene isomers refer to meta-xylene, ortho-xylene and para-xylene.

The present invention provides a simple process of mixing and crystallizing guanidinium biphenyl 2,2'-diyldimethane sulfonate as a host molecule to a mixture of xylene isomers, thereby obtaining guanidinium biphenyl 2,2'-di. The affinity for ildimethane sulfonate allows the separation of different xylene isomers with high purity. Specifically, since guanidinium biphenyl 2,2'-diyldimethane sulfonate has the affinity of different affinity depending on the type of xylene isomer as host molecule, guanidi in a mixture of xylene isomers By mixing and reacting the niobium biphenyl 2,2'-diyldimethane sulfonate, a relatively affinity xylene isomer with a guanidinium biphenyl 2,2'-diyldimethane sulfonate is obtained. It is optionally encapsulated in guanidinium biphenyl 2,2'-diyldimethane sulfonate, so as to be effective with relatively low affinity xylene isomers with guanidinium biphenyl 2,2'-diyldimethane sulfonate. Will be separated. In this case, the present invention is the world's first affinity for the guanidinium biphenyl 2,2'- dimethyldimethane sulfonate of xylene isomers in the order of ortho-xylene> para-xylene> meta-xylene .

Accordingly, the present invention does not entrap the xylene isomers encapsulated in the guanidinium biphenyl 2,2'-diyldimethane sulfonate in a mixture of two or more types of xylene isomers in view of the difference in relative affinity described above. By separating the xylene isomers, it is possible to obtain a high purity xylene isomer consisting of one type of xylene isomer. As a specific example, the method for separating each xylene isomer from a mixture of xylene isomers consisting of meta-xylene, ortho-xylene and para-xylene is carried out in a mixture of guanidinium biphenyl 2 in the xylene isomer. The 2'-diyldimethane sulfonate is mixed to firstly encapsulate and crystallize ortho-xylene, which has a relatively higher affinity than para-xylene and meta-xylene, and then contain the para-xylene from the crystallized product. After recovery, the remaining xylene isomeric mixture was mixed with guanidinium biphenyl 2,2'-diyldimethane sulfonate again to be encapsulated by secondary inclusion and crystallization of para-xylene having higher affinity than meta-xylene. By recovering para-xylene from the crystallization, it is possible to separate the meta-xylene, ortho-xylene and para-xylene, respectively, with high purity.

In the present invention, the mixture of xylene isomers refers to a mixture of xylene isomers selected from at least two species in the group consisting of meta-xylene, ortho-xylene and para-xylene, specifically, ortho-xylene and meta-xylene Or mixtures of para-xylene and meta-xylene, mixtures of ortho-xylene and para-xylene or mixtures of ortho-xylene, meta-xylene and para-xylene.

In the present invention, guanidinium biphenyl 2,2'-diyldimethane sulfonate may use a liquid dissolved in an organic solvent such as methanol or ethanol depending on the type of solvent of the crystal powder or xylene mixture.

In the present invention, since guanidinium biphenyl 2,2'-diyldimethane sulfonate is hydrophilic and xylene is hydrophobic, it is enclosed in guanidinium biphenyl 2,2'-diyldimethane sulfonate. Xylene isomers can be recovered from guanidinium biphenyl 2,2'-diyldimethane sulfonate through methods such as liquid-liquid extraction. However, the present invention may be used in addition to the above-described recovery method as long as it is compatible with the present invention.

1 is a schematic diagram illustrating a selective separation process of xylene isomers according to the present invention, in which a mixture of xylene isomers is mixed with guanidinium biphenyl 2,2'-diyldimethane sulfonate as a host molecule. The xylene isomer, a relatively high affinity guest molecule, is entrapped and induced to crystallize, and the crystallized (solid) obtained by filtration is separated from the guest molecule and the host molecule through a liquid-liquid extraction method. It is a schematic of reuse.

As described above, the present invention provides a simple process of xyl by mixing and treating the guanidinium biphenyl 2,2'-diyldimethane sulfonate exhibiting a high affinity for para-xylene from the xylene mixture. It was possible to separate and purify high purity para-xylene in a mixture of lene isomers with high efficiency.

Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited by the following examples, and various modifications or changes can be made within the spirit and scope of the present invention to those skilled in the art.

[Example]

<Host Molecular Synthesis>

2,2'-bis (bromomethyl) -1,1'-biphenyl (2,2'-Bis (bromomethyl) -1,1'-biphenyl (99%), available from Sigma-Aldrich) 2 g Was added to a solution of 4 g of sodium sulfite (Na ₂ SO ₃ ) in 40 mL of water, and then refluxed at 100 ° C. for 20 hours to produce a white powder. At this time, in order to increase the purity of the white powder, the powder is dissolved in 20 mL of water and then 40 mL of methanol is added to carry out the precipitation reaction. After 10 hours at 4 degrees, the precipitated crystalline solid (biphenyl-2,2'-diyldimethane sulfonate salt, sodium biphenyl-2,2'-diyldimethanesulfonate) was separated by filtration. The separated crystalline solid was then dried for 2 days in a vacuum oven to completely remove the remaining moisture.

The prepared biphenyl-2,2'-diyldimethanesulfonate salt (sodium biphenyl-2,2'-diyldimethanesulfonate) was dissolved in acetone, and the solution was guanidinium tetrafluroborate [G (BF ₄ )]) was slowly added to the solution dissolved in acetone and reacted to synthesize guanidinium biphenyl-2,2'-diyldimethane sulfonate. At this time, biphenyl-2,2'- diyldimethane sulfonate salt and guanidinium tetraborate were adjusted to 1: 2 equivalent.

The synthesized guanidinium biphenyl-2,2'-diyldimethane sulfonate is separated from the acetone solution, and then guanidinium biphenyl-2,2'-diyldimethane sulfo is a host molecule in the present invention. It was dried for 2 days in a vacuum oven to remove the acetone contained in the nate. At this time, whether or not acetone is included in the dry host molecule was confirmed using the acetone characteristic peak through hydrogen nuclear magnetic resonance analysis.

In addition, the guanidinium tetraborate is guanidine carbonate (guanidine carbonate (99%), purchased from Sigma Aldrich) salt 22.5 g (0.5 mol) of tetrafluroboric acid (48 wt.% In H ₂ O, 182.9 g (1 mol) of Sigma Aldrich Co., Ltd. solution was mixed and reacted for about an hour, and the reaction solution was a guanidinium tetraborate powder obtained by drying a solvent using a rotary evaporator.

<Selectivity Experiment>

Xylene isomer mixtures uniformly mixed at a ratio of 0.1 to 0.9 to 0.9 to 0.1 by volume (ortho-xylene and meta-xylene, para-xylene and ortho-xylene, para-xylene and meta-, respectively) 1 mL of xylene) is placed in a disposable test tube, and the solution in which the solid apo guanidinium biphenyl 2,2'-diyldimethane sulfonate host molecule is dissolved in methanol is not mixed with the layer of the xylene mixture. The inclusion reaction was carried out very slowly. At this time, the methanol solution in which the host molecule was dissolved was dissolved until the host molecule was no longer dissolved in the methanol solution, and then the remaining host molecule was dissolved in a saturated solution.

When the reaction is complete and crystals are formed, it is filtered to separate solids and liquids, and the obtained solids are washed three times with cold methanol solution and dried to remove the guest molecules adhering to the surface. Crystals were obtained.

The obtained crystals were subjected to gas chromatography, and the guest molecules (ortho-xylene) contained in solids (guanidinium biphenyl 2,2'-diyldimethane sulfonate). , Meta-xylene, para-xylene).

The results are shown in Tables 1, 2, and 3 and FIG. In this case, Table 1 shows the results for the mixture of ortho-xylene and para-xylene, Table 2 shows the results for the mixture of ortho-xylene and meta-xylene, Table 3 is para-xyl Results are shown for a mixture of lene and ortho-xylene. FIG. 2 also shows that the xylene mixture is treated with guanidinium biphenyl 2,2'-diyldimethane sulfonate, followed by guanidinium biphenyl 2, after the reaction per mole fraction of the xylene mixture before the initial reaction. It is shown as the mole fraction of xylene isomers contained in 2'-diyldimethane sulfonate.

As shown in Tables 1 to 3 and FIG. 2, the guanidinium biphenyl 2,2'-diyldimethane sulfonate in the selective separation method of the xylene isomers according to the present invention is according to the type of xylene isomer. The selective inclusion effect was found to be very good.

That is, in the present invention, guanidinium biphenyl 2,2'-diyldimethane sulfonate has a different affinity of the inclusion affinity according to the type of xylene isomer, and the affinity of the inclusion affinity is ortho-xylene, para. -The purity of xylene and meta-xylene was found.

Furthermore, in the ortho-xylene and para-xylene and ortho-xylene and meta-xylene mixtures, the ortho-xylene has excellent separation efficiency in the whole range, and similarly in the mixture of para-xylene and meta-xylene It can be seen that para-xylene has excellent separation efficiency in the whole range.

Meanwhile, in the conventional method for separating ortho-xylene from para-xylene, ortho-xylene, and meta-xylene mixture, the separation effect using an extractive distillation method is described in the US patent as follows.

U.S. Patent 5,466,345 discloses adding 30 g of methyl propionate to a solution of 15 g of meta-xylene, 9 g of para-xylene, and 6 g of ortho-xylene. Reflux (extraction distillation) for 5 hours yielded 32.1% para-xylene and 52.6% meta-xylene and 15.3% ortho-xylene in the gas phase and 29.8% para-xylene in the liquid phase. 49.8% meta-xylene and 20.4% ortho-xylene were obtained. Comparing this to both ortho-xylene and para-xylene, the initial mixing ratio is about ortho-xylene (40%) to para-xylene (60%), and the separation result is about ortho-xylene on a liquid basis. 32.2%, 67.8% para-xylene, 29% ortho-xylene and 71% para-xylene on a weather basis. In addition, when comparing both ortho-xylene and meta-xylene, the initial mixing ratio is about ortho-xylene (40%) to meta-xylene (60%), and the separation result is about ortho-xyl on a liquid phase basis. 22.5% lene and 77.5% meta-xylene, 29% ortho-xylene and 71% meta-xylene on a weather basis.

Comparing the results of the separation technique of the conventional xylene isomer described above and the separation method according to the present invention, the separation efficiency of ortho-xylene from ortho-xylene and para-xylene according to the present invention is shown in Table 1. Similarly, the inclusion reaction when the mole fraction is 40% (ortho-xylene) versus 60% (para-xylene), similar to the above, results in 77.5% ortho-xylene and 22.5% separation of para-xylene. As a result, it was found to be 45.3% higher in the gas phase standard and 48.5% higher in the liquid phase level than the separation efficiency described in the conventional separation method disclosed in the US patent. Similarly, the separation efficiency of ortho-xylene from ortho-xylene and meta-xylene according to the present invention has a molar fraction of 40% (ortho-xylene) vs. 60% (as shown in Table 2 above). Meta-xylene) resulted in 81.8% ortho-xylene and 18.2% meta-xylene, which is 59.3% on a gaseous basis than the separation efficiency described in the conventional separation method disclosed in the US patent. And it was 52.8% higher than the liquid level.

Therefore, the separation method of ortho-xylene in ortho-xylene and para-xylene, ortho-xylene and meta-xylene mixture according to the present invention is a conventional method for separating ortho-xylene from a mixture of xylene. It is shown that it shows a very good separation efficiency in comparison with.

In addition, in the conventional method for separating para-xylene from para-xylene and meta-xylene mixtures, the separation effect using the extractive distillation method is described in the US patent as follows.

In US Patent No. 5,091,059, 40 g of isobonyl acetate was added to a solution of 25 g of meta-xylene and 25 g of para-xylene, followed by reflux (extraction distillation) for 6 hours. In the gas phase, 50.1% meta-xylene and 49.9% para-xylene were obtained, and in the liquid phase, 46.5% meta-xylene and 53.5% para-xylene were obtained.

Comparing the results of the separation technique of the conventional xylene isomer described above and the separation method according to the present invention, the separation efficiency of para-xylene from meta-xylene and para-xylene according to the present invention is shown in Table 1. Similarly, when the molar fraction was 50% (para-xylene) vs. 50% (meth-xylene), the inclusion reaction resulted in 66.1% of para-xylene and 33.9% of meta-xylene. The separation efficiency described in the disclosed conventional separation method was found to be 16.2% higher by gas phase and 12.6% by liquid phase.

Therefore, the separation method of para-xylene in the para-xylene and meta-xylene isomer mixtures according to the present invention is very compared to the method of separating para-xylene from the para-xylene and meta-xylene mixtures. It proved that it shows good separation efficiency.

1 is a schematic diagram illustrating a selective separation process of xylene isomers according to the present invention,

Figure 2 shows the separation effect of the inclusion reaction according to the mixture of the mixture of xylene isomer and guanidinium biphenyl 2,2'-diyldimethane sulfonate according to the present invention,

Figure 3 is a chemical structural formula of guanidinium biphenyl 2,2'-diyldimethane sulfonate.

Claims (2)

Guanidinium biphenyl 2,2'-diyldimethane sulfonate is reacted with a mixture of xylene isomers, and then the inclusion ability of guanidinium biphenyl 2,2'-diyldimethane sulfonate is used. Selective separation method of xylene isomer, characterized in that to separate the xylene isomer. The method of claim 1, The mixture of xylene isomers is a mixture of para-xylene and meta-xylene, a mixture of para-xylene and ortho-xylene, a mixture of ortho-xylene and meta-xylene or ortho-xylene, meta- A method for the selective separation of xylene isomers, characterized in that it is a mixture of xylene and para-xylene.

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