KR102186025B1 - A adsorbent with olefins sorption selectivity, manufacturing method of the same and method of selectively adsorbing olefin using the same - Google Patents

Abstract

The present invention relates to an olefin-selective adsorbent having a selective adsorption ability for olefins, a method for preparing the same, and a method for separating olefins using the same. In particular, the olefin-selective adsorbent according to an embodiment of the present invention is a form in which cupric salt (II) is reduced to cuprous salt (I) and dispersed in a porous metal organism, and can form an excellent π-complex bond with olefin. I can.
In addition, the pi bond using this can increase the selectivity for olefins having a double bond in a molecular structure because the bonding strength is stronger than that of a simple physical bond, thereby increasing the selective adsorption capacity for olefins in a mixed gas containing olefins and paraffins. It can have an effect.

Description

A adsorbent with olefins sorption selectivity, manufacturing method of the same and method of selectively adsorbing olefin using the same}

The present invention relates to an adsorbent having a selective adsorption ability for olefins, a method for preparing the same, and a method for separating olefins using the same.

In the oil refinery and petrochemical industries, the separation of olefins and bluefins mostly uses distillation. However, since the boiling points of olefin and paraffin are very similar, large energy is consumed to separate through distillation, and a very large number of stages in the distillation column is required. Accordingly, there is a problem that equipment investment and operation costs are largely incurred (ethylene/ethane: 160 stages, -25°C, 22 atm, propylene/propane: 220, 40°C, 16 atm). In order to solve this problem, research to separate olefins and paraffins through an adsorption separation process that can reduce equipment investment and operation costs has been studied since decades ago.

Accordingly, several adsorbents having an effect on olefin and paraffin separation have been discovered and developed. Among them, there is a porous organic-inorganic hybrid material, which is considered a promising material due to its extreme high surface area and tunable structure.

More specifically, porous organic-inorganic hybrids are generally referred to as porous coordination polymers as a broad term, and are also referred to as metal-organic frameworks (MOF).

The porous organic-inorganic hybrid material has begun to develop newly through the grafting of molecular coordination and material science.

In addition, since the hybrid material has a high surface area and a molecular size or nano-sized pores, it can be used as an adsorbent, gas mastication, sensor, membrane functional thin film, catalyst and catalyst carrier. In addition, the hybrid material is being actively studied because it can be used to capture guest molecules smaller than the pore size or to separate molecules according to the size of the molecules by using pores.

On the other hand, much effort has been made in the development of adsorbents for olefin/paraffin separation, but until now, adsorbents that simultaneously satisfy high selectivity, large operating capacity, room temperature/atmospheric pressure regeneration, and repeated adsorption and desorption capability have not been developed.

On the other hand, as an adsorbent for olefin/paraffin separation, copper chloride (cooper(I) chloride) is formed in the metal-organic framework to improve the selectivity of olefins through π-complexation of Cu(I) and olefins. /Technology to separate paraffin is being developed.

However, the Cu(I) is easily oxidized to Cu(II) in the air and is not easily dissolved in an aqueous solution, so there has been a difficulty in the method of impregnating Cu(I) in the adsorbent.

Korean Patent Registration No. 10-0806586 Korean Patent Registration No. 10-0803945

The present invention is to solve the above-described problems, and to provide an olefin-selective adsorbent having a selective adsorption ability for olefins so that olefins and paraffins can be easily separated.

In addition, it is intended to provide a method for producing an adsorbent having a selective adsorption ability for the olefin.

In addition, it is intended to provide a method for separating olefins using an adsorbent having a selective adsorption ability for olefins.

To achieve the above object,

In one embodiment according to the invention,

It is in the form of a porous particle, and includes a porous metal organic skeleton in which the cuprous salt (I) is dispersed at the unsaturated metal coordination site in the pore or the surface of the porous particle,

The porous metal organic skeleton is characterized in that the selectivity of olefins to paraffin is 1.2 or more in a pressure range of 273 to 353 K and 10 to 1000 kPa, based on a multi-component adsorption isothermal formula (ideal adsorbed solution theory, IAST). It provides an olefin selective adsorbent.

In addition, in another embodiment of the present invention,

Olefin, characterized in that to prepare an adsorbent having selective adsorption ability for olefins by reducing and dispersing cupric salt (II) into cuprous salt (I) at the unsaturated metal coordination site on the surface or pores of the porous metal organic skeleton. It provides a method for producing a selective adsorbent.

In addition, in another embodiment of the present invention,

It provides a method for separating olefins, characterized in that olefins are separated from a mixture of olefins and paraffins in an adsorption device performed by a pressure circulation adsorption method or a vacuum circulation adsorption method using an olefin-selective adsorbent.

In the olefin-selective adsorbent according to an embodiment of the present invention, the reduced cuprous chloride (I) may form an excellent π-complex bond with the olefin.

In particular, the olefin-selective adsorbent according to an embodiment of the present invention can form an excellent π-complex bond with an olefin by reducing cupric salt (II) to cupric salt (I) and dispersing it in a porous metal organism. .

The pi bond using this can increase the selectivity for olefins having a double bond in a molecular structure because the bonding strength is stronger than that of a simple physical bond, thereby increasing the selective adsorption capacity for olefins in a mixed gas containing olefins and paraffins. It works.

1 is a graph of MIL-100 (Fe) before and after impregnating copper ions with propylene and propane adsorption isotherms measured at 20°C ((a) Comparative Examples 1, (b) Examples 1, (c) Examples 2, (d) Example 3).
2 is a graph showing the adsorption amount of Example 2 according to pretreatment conditions ((a) primary heat treatment, (b) secondary heat treatment
3 is an image obtained by observing the surface of Cu@MIL-100 (Fe) prepared in Example 2 with a scanning electron micro-scopy (SEM) and EDX (Energy-dispersive X-ray).
4 is an X-ray photoelectron spectroscopy (XPS) spectrum in the copper region for Example 2 (Cu(M)@MIL-100(Fe)).
5 is a view showing a comparison of PXRD (powder X-ray diffraction) patterns of MIL-100 (Fe) before and after copper ion impregnation.
6 is a graph predicting propylene/propane selectivity for adsorbents of Example 2 and Comparative Example 1. FIG.
7 is a schematic diagram of a separation device diagram of an experimental example.
8 is a resolution graph showing changes in concentrations of propylene and propane at the outlet over time after passing the propylene/propane mixture of the present invention through adsorption towers respectively filled with adsorbents of Examples and Comparative Examples.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail in the detailed description.

However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, when it is determined that a detailed description of a related known technology may obscure the subject matter of the present invention, a detailed description thereof will be omitted.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In the present invention, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance the possibility.

The present invention relates to an olefin-selective adsorbent having a selective adsorption ability for olefins, a method for preparing the same, and a method for separating olefins using the same.

More specifically, according to an embodiment of the present invention, after immersing a porous metal organic framework having oxidation-reduction activity in an easily dispersed cupric salt (II) aqueous solution, an unsaturated metal coordination site having reducibility is utilized. Thus, it is characterized in that the cupric salt (II) is reduced to the cuprous salt (I).

The olefin-selective adsorbent according to an embodiment of the present invention has a selective adsorption ability for olefins, and uses the reducibility of the unsaturated metal coordination site of the metal organic skeleton itself to use the reduced cuprous salt (I) to the metal organic skeleton. It was distributed. For reference, the cuprous salt (I) may be dispersed in the form of cuprous chloride (I).

In the present invention, "olefin-selective adsorbent" refers to an adsorbent capable of separating olefin and paraffin by having a selective adsorption ability for olefin, and may be made of organic-inorganic hybrid particles.

In the present invention, the "metal organic framework" is a porous crystalline organic-inorganic polymer compound formed including a central metal ion and an organic ligand coordinating thereto, a hybrid nanoporous material, an organic-inorganic hybrid material, or a metal-organic framework (MOF) It has the same meaning as. The metal organic skeleton may include both organic and inorganic materials in the crystalline skeleton structure. For example, since the crystalline skeleton contains a polar metal ion and a carboxylic acid oxygen anion and a non-polar aromatic compound group coexists, it can have both hydrophilicity and hydrophobicity.

In the present invention, the term "empty metal site" refers to a position in which water or an organic solvent is removed from a metal organic framework and a position where an organometallic compound can form a covalent bond or a coordination bond.

Hereinafter, the present invention will be described in detail.

The present invention in one embodiment,

It is in the form of a porous particle, and includes a porous metal organic skeleton in which the cuprous salt (I) is dispersed at the unsaturated metal coordination site in the pore or the surface of the porous particle,

The porous metal organic skeleton is characterized in that the selectivity of olefins to paraffin is 1.2 or more in a pressure range of 273 to 353 K and 10 to 1000 kPa, based on a multi-component adsorption isothermal formula (ideal adsorbed solution theory, IAST). It provides an olefin selective adsorbent.

In the present invention, the porous metal-organic framework (MOF) is also referred to as porous coordination polymers, and is also referred to as hybrid nanoporous or organic-inorganic hybrid.

Such, the porous metal organic framework is characterized by having an open metal site (OMS). An empty metal site is also called a coordinatively unsaturated site (CUS), and specifically, as a coordinating site of a metal from which water or an organic solvent has been removed from the metal organic framework, an organometallic compound can form a covalent bond or a coordination bond. It means a position to be able to. Meanwhile, in order to secure the empty metal site of the metal organic skeleton, it may be preferable to perform a pretreatment step of removing water or a solvent component bound to the empty metal site. The pretreatment can be any method as long as water or solvent components can be removed without causing deformation of the metal organic framework. 1 shows a schematic diagram showing that empty metal sites are secured in a metal organometallic framework.

Referring to FIG. 1, it can be seen that water is dehydrated by subjecting the metal organic skeleton to a heat treatment at a temperature of 150° C. to secure an empty metal site (OMS) there.

Meanwhile, chromium (Cr), iron (Fe), aluminum (Al), magnesium (Mg), manganese (Mn), nickel (as the metal components of the metal organic framework that can secure empty metal sites through the heat treatment) Ni), molybdenum (Mo), zinc (Zn), and may be one or more selected from the group consisting of copper (Cu), but is not limited thereto. As an example, the metal oxide organic skeleton may be a structure in which a metal or a functional group containing a metal is substituted in an aromatic structure having 6 to 18 carbon atoms. Meanwhile, the metal ion may be a transition metal that makes a coordination compound well.

For example, the metal organic skeleton may be MIL-100 (MIL-Materials of Institut Lavoisier), preferably MIL-100 (M=Fe, Al, Cr) or Fe ^{2 +} and Fe ^{3 +} unsaturated metal It may be MIL-100 (M=Fe) having a coordination site.

Specifically, the porous metal organic framework may be represented by Formula 1 below.

[Formula 1]

Fe ₃ O(H ₂ O) ₂ X _1-y (OH) _y X[C ₆ H ₃ -(CO ₂ ) ₃ ] ₂

In Formula 1, X = Cl, Br, I or F; 0 ≤ y ≤ 1.

In addition, in the present invention, the organic ligand, which is another member of the metal-organic framework, may mean an organic material. Such an organic material is also called a linker, and any organic material having a functional group capable of coordination may be used.

On the other hand, functional groups that can be coordinated are carboxyl group (-COOH), carboxylic acid anionic group (-COO-), amine group (-NH ₂ ) and imino group (-NH), nitro group (-NO ₂ ), hydroxy group ( -OH), a halogen group (-X) and a sulfonic acid group (-SO ₃ H), and the like may be exemplified. In order to induce a more stable metal-organic framework, it may be an organic material having two or more sites capable of coordination, for example, bidentate or tridentate.

For example, 1-4-benzenedicarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2-5-dihydroxyteretal acid, 2-6-naphthalenedicarboxylic acid, azobenzenetetracarboxylic acid as organic substances It may include an acid or a derivative thereof, but is not limited thereto.

In one embodiment of the present invention, MIL-100 (Fe) was added to cupric salt (II) and then reduced to cupric salt (I).

Specifically, MIL-100 (Fe) is an iron benzene tricarboxylate composed of octahedral trimers made of Fe and a 1,3,5-benzenetricarboxylic acid ligand. . These are basically only have an unsaturated metal coordination sites of Fe ^{+ 3,} may have a CUS of Fe ^{2 +} at least 200 ℃ helium atmosphere or vacuum condition.

As described above, the olefin-selective adsorbent of the present invention is characterized in that the cuprous salt (I) is dispersed in the coordinatively unsaturated metal site (CUS) of the porous metal organic skeleton.

The cuprous salt (I) is obtained by immersing the porous metal organic framework in a cupric salt (II) aqueous solution, so that the cupric salt (II) is converted into the cuprous salt (I) at the unsaturated metal coordination site of the porous metal organic framework. It may be reduced and dispersed.

Specifically, the aqueous solution of cupric salt (II) includes cupric chloride (II) and copper (II) acetate, wherein the mixing ratio of the cupric chloride (II) and copper (II) acetate is 1:2 to It may be in the range of 1:5 weight ratio, or may be a ratio of 1:4. On the other hand, it may be a weight mixing ratio of the aqueous solution of cupric chloride (II) and copper (II) acetate.

In particular, in the mixing ratio of cupric chloride (II) and cupric acetate (II), compared to cupric chloride (II) 1 weight ratio, copper (II) acetate 2 weight ratio, or copper (II) acetate exceeds 5 weight ratio. If so, the production rate of the cuprous salt decreases, and thus the selectivity of the olefin to paraffin may decrease.

At this time, the concentration of the aqueous solution of cupric chloride (II) may be 0.1 to 5 M, and the concentration of the aqueous solution of copper (II) acetate may be 0.1 to 5 M. When the concentration of the cupric chloride (II) aqueous solution is less than 0.1 M, cupric chloride in the pores of the olefin-selective adsorbent cannot easily enter and may agglomerate on the surface. When it exceeds 5 M, the pH of the adsorbent is low. You can drop it. In addition, copper (II) acetate, like the cupric chloride (II), may be aggregated on the surface without easily entering copper (II) acetate in the pores of the olefin-selective adsorbent when the concentration of the aqueous solution is less than 0.1 M. If it exceeds 5 M, the pH is low, which may lower the crystallinity of the adsorbent.

At this time, the amount of cuprous chloride (I), which is the final dispersed cuprous salt (I), may be 10 to 150 parts by weight based on 100 parts by weight of the metal organic skeleton. Alternatively, it may be 20 to 130 parts by weight, or 50 to 110 parts by weight, or 60 to 100 parts by weight, based on 100 parts by weight of the organic metal skeleton.

Here, if the amount of cuprous chloride (I) is less than 10 parts by weight relative to 100 parts by weight of the metal organic skeleton, the selectivity for olefin may be insufficient, and if it exceeds 150 parts by weight, the adsorption capacity of the olefin-selective adsorbent This can drop significantly.

In one embodiment of the present invention, the olefin and paraffin of the mixed gas containing olefin and paraffin may be a C ₂ to C ₈ hydrocarbon having 2 to 8 carbon atoms. More specifically, olefins and paraffins in the mixed gas containing olefins and paraffins may be C ₂ hydrocarbons such as ethylene and ethane, C ₃ hydrocarbons such as propylene and propane, and C ₄ hydrocarbons such as butene and butane.

In addition, the olefin-selective adsorbent of the present invention has a high olefin/paraffin selectivity by making a π-complex bond with the reduced cuprous salt (I), which is the reduced cuprous salt (I), dispersed in the metal organic skeleton. I can.

Specifically, the olefin/paraffin selectivity of the olefin-selective adsorbent may be 1.2 or higher. In one embodiment of the present invention, Cu@MIL-100 (Fe) showed a much greater difference in adsorption amount of propylene and propane than that of MIL-100 (Fe) in the entire pressure range (see FIG. 1).

In addition, the olefin-selective adsorbent of the present invention exhibits selectivity for olefins by forming cuprous chloride (I) in large pores, and has a not too strong attraction, so that it has a large operating capacity, room temperature / normal pressure regeneration, and repeated adsorption and desorption performance. I can.

The operating capacity of the olefin-selective adsorbent of the present invention is 0.5 mmol/g to 3.0 mmol/ under PSA process conditions (2 to 10 atm adsorption, 1 atm desorption) or VSA process conditions (2 to 10 atm adsorption, 0.1 to 0.5 atm desorption). It is preferably g.

Hereinafter, a method for preparing the olefin-selective adsorbent will be described in detail.

A method of preparing an olefin selective adsorbent according to another embodiment of the present invention,

Provides a method for producing an olefin-selective adsorbent, comprising reducing and dispersing cupric salt (II) into cuprous salt (I) on the surface of a porous metal organic skeleton or at the coordination site of an unsaturated metal in the pores to prepare an adsorbent. do.

Specifically, the step of immersing the porous metal organic framework in a cupric salt (II) aqueous solution; And

Heat-treating the aqueous solution in which the porous metal organic framework is immersed; It provides a method for producing an olefin-selective adsorbent comprising a.

Here, the cupric salt (II) aqueous solution includes cupric chloride (II) and copper (II) acetate, and the mixing ratio of the cupric chloride (II) and copper (II) acetate is 1:2 to 1:5 It may be in a range of weight ratios.

That is, cupric chloride (II) and copper (II) acetate are reduced to cuprous chloride (I) and dispersed at the unsaturated metal coordination site in the pores or the surface of the porous metal organic framework, and thus olefins with selective adsorption ability for olefins It is characterized in that to prepare a selective adsorbent.

As described above, the porous metal organic framework of the present invention is characterized by having an empty metal site (OMS). At this time, it is characterized in that the cupric chloride (II) and copper (II) acetate are reduced to cuprous chloride (I) at the unsaturated metal coordination site, which is the empty metal site (OMS).

That is, by dispersing cuprous chloride (I) at the unsaturated metal coordination site in the pore or the surface of the metal organic skeleton having the empty metal site, it is possible to prepare a functionalized olefin-selective adsorbent. On the other hand, the olefin-selective adsorbent may mean the organic-inorganic hybrid particles described above.

And, it includes the step of immersing the porous metal organic framework in which the empty metal sites are activated in an aqueous solution of cupric chloride (II) and copper (II) acetate.

On the other hand, in order to disperse the cuprous chloride (I) in the surface or pores of the porous metal organic skeleton, only cupric chloride (II) can be reduced to cuprous chloride (I) and dispersed in the porous metal organic skeleton, For reasons of having a higher reduction rate, it is preferable to use cupric (II) chloride and copper (II) acetate together.

At this time, the concentration of the aqueous solution of cupric chloride (II) may be 0.1 to 5 M, and the concentration of the aqueous solution of copper (II) acetate may be 0.1 to 5 M. When the concentration of the cupric chloride (II) aqueous solution is less than 0.01 M, cupric chloride in the pores of the olefin-selective adsorbent cannot easily enter and may aggregate on the surface. When it exceeds 5 M, the pH is low and the crystallinity of the adsorbent is low. You can drop it. In addition, copper (II) acetate, like the cupric chloride (II), can be aggregated on the surface without easily entering copper (II) acetate in the pores of the olefin-selective adsorbent when the concentration of the aqueous solution is less than 0.01 M. If M is exceeded, the pH is low, which may lower the crystallinity of the adsorbent.

Next, it includes the step of heat-treating the aqueous solution immersed in the porous metal organic framework.

The heat treatment step is divided into a first heat treatment and a second heat treatment step.

First, by the primary heat treatment, it is possible to reduce the cupric chloride (II) to cupric chloride (I). In this case, the heat treatment temperature may be 130 to 170°C on average, and may be 135 to 165°C, 140 to 160°C, or 150°C.

Here, when the first heat treatment temperature is less than 130°C, the temperature is too low to cause a problem with a small primary reduction rate, and when the temperature exceeds 200°C, the temperature is too high to reduce reduction by Fe ^{2+, which} is the ^second reduction process. The first problem can arise. Therefore, the first heat treatment temperature is preferably 130 to 170°C.

Next, after the first heat treatment is completed, the second heat treatment is performed.

More specifically, the secondary heat treatment can be performed in a vacuum state, and by reducing the metal component of the porous metal organic framework, it reduces cupric (II) not reduced in the first heat treatment to copper chloride (I). It can act as a reducing agent.

For example, in the second heat treatment step, Fe ^{3 +} of the MIL-100 (Fe) structure is reduced to Fe ^{2 +} . At this time, the reduced Fe ^{2 +} acts as a reducing agent that reduces some copper (II) ions to copper (I) ions.

In this case, the secondary heat treatment temperature may be 230 to 270°C on average, and may be 235 to 265°C, 240 to 260°C, or 250°C. Here, when the secondary heat treatment temperature is lower than 230 ℃, and a temperature can result in too low Fe ^{2 +} generation rate is less problem, when it exceeds 270 ℃, the temperature is too high and may cause problems collapse the structure of the adsorbent. Therefore, the secondary heat treatment temperature is preferably 230 to 270°C.

In addition, the first heat treatment time is preferably 480 to 720 minutes, and the second heat treatment time is preferably 480 to 720 minutes.

In another embodiment of the present invention,

It provides a method for separating olefins, characterized in that olefins are separated from a mixture of olefins and paraffins in an adsorption device performed by a pressure circulation adsorption method or a vacuum circulation adsorption method using an olefin-selective adsorbent.

Here, the pressure swing adsorption (PSA) is a process technology that adsorbs and removes adsorbate from a mixed gas in order to purify a specific gas with high purity.When the adsorbate is desorbed and regenerated, the pressure is lowered. The pressure is periodically converted from high pressure to low pressure and is called a pressure swing. On the other hand, vacuum swing adsorption (VSA) belongs to the category of PSA.

In addition, in the PSA, desorption may be induced by lowering the partial pressure of the adsorbed substance in the mixed gas, or the partial pressure may be lowered by lowering the pressure of the mixed gas itself.

In the present invention, the pressure condition when performing the pressure circulation adsorption method may be 2 to 10 atmospheres during adsorption and 1 atmosphere during desorption. When performing the vacuum circulation adsorption method, the pressure condition may be 1 atm for adsorption and 0.1 to 0.5 atm for desorption.

When performing the pressure circulation adsorption method or the vacuum circulation adsorption method in the present invention, the driving temperature is preferably 0 to 80°C. If the temperature is less than 0 °C, desorption may be difficult, and at a temperature exceeding 80 °C, it is difficult to obtain satisfactory selectivity and adsorption amount.

Hereinafter, the present invention will be described in more detail by examples and experimental examples.

However, the following examples and experimental examples are merely illustrative of the present invention, and the contents of the present invention are not limited to the following examples and experimental examples.

<Example>

Example 1 Preparation of Olefin Selective Adsorbent

1-1. Manufacturing of MIL-100(Fe)

In the examples, a porous organic-inorganic hybrid MIL-100 (Fe) was prepared.

First, iron powder (Fe ⁰ ), 1,3,5-benzentricarboxylic acid (1,3,5-benzentricarboxylic acid; 1,3,5-BTC) and distilled water were added to the Teflon reactor to The final molar ratio was Fe ⁰ : 1,3,5-BTC: HNO3: HF: H ₂ O = 1.0: 0.67: 0.6: 2.0: 277.

In addition, the reactant was stirred at room temperature for 30 minutes to obtain a homogeneous reactant, and the reactor containing the reactant was maintained at 150° C. for 12 hours to perform a crystallization reaction. After cooling to room temperature, washing with distilled water, purification with ethanol and ammonium fluoride solution, and drying, a porous metal organic skeleton MIL-100 (Fe) was obtained.

1-2. Preparation of Cu@MIL-100(Fe)

The porous metal organic framework was immersed in an aqueous solution in which a 0.2 M aqueous solution of cupric chloride (CuCl ₂ ) and a 0.2 M aqueous solution of copper acetate (Cu (CH ₃ COO) ₂ 0.2 M aqueous solution were mixed for 30 minutes, and then heat-treated to obtain cuprous salt (I). An olefin-selective adsorbent, which is a dispersed porous metal organic skeleton, was obtained.

On the other hand, at this time, the mixing ratio of the aqueous solution of cupric chloride (CuCl ₂ ) and the aqueous solution of copper acetate (Cu (CH ₃ COO) ₂ was mixed at a weight ratio of 1: 4. And, the heat treatment was performed by dividing it into first and second steps, and specifically , The heat treatment was performed at 150° C. and 250° C. At this time, the first heat treatment was performed at a temperature of 150° C. for 720 minutes, and the second heat treatment was performed at a temperature of 250° C. for 480 minutes.

After the heat treatment, a porous metal organic framework in which the cuprous salt (I) was dispersed was prepared, and at this time, the copper chloride (CuCl) dispersed in the pores or surface of the porous metal organic framework was 60 parts by weight compared to 100 parts by weight of the metal organic framework. It was parts by weight.

In addition, before use in the adsorption process experiment, it was heated to 150°C or higher at atmospheric pressure or below atmospheric pressure while flowing helium gas, or heated for 8 hours in a vacuum state.

Example 2 Preparation of Olefin Selective Adsorbent

Except that the metal organic framework prepared in Example 1-1 was immersed in a cupric salt aqueous solution in which a 0.2 M aqueous solution of cupric chloride (CuCl ₂ ) and a copper acetate (Cu(CH ₃ COO) ₂ ) 0.2 M aqueous solution were mixed. Hagon, it was prepared in the same manner as in Example 1.

At this time, cuprous chloride (CuCl) dispersed in the pores or surfaces of the porous metal organic framework was 80 parts by weight based on 100 parts by weight of the metal organic framework.

Example 3 Preparation of Olefin Selective Adsorbent

Except that the metal organic framework prepared in Example 1-1 was immersed in a cupric salt aqueous solution in which a 0.2 M aqueous solution of cupric chloride (CuCl ₂ ) and a copper acetate (Cu(CH ₃ COO) ₂ ) 0.2 M aqueous solution were mixed. Hagon, it was prepared in the same manner as in Example 1.

At this time, copper chloride (CuCl) dispersed in the pores or surfaces of the porous metal organic framework was an average of 100 parts by weight based on the total weight of the prepared adsorbent.

<Comparative Example>

Comparative Example 1. Preparation of MIL-100 (Fe)

Except for the process of immersing the porous metal organic framework of Example 1 in a mixed solution of a cupric chloride (CuCl ₂ ) aqueous solution and copper acetate (Cu (CH ₃ COO) ₂ aqueous solution), the same conditions were applied to prepare an olefin-selective adsorbent. Was prepared.

<Experimental Example>

Experimental example 1.Cu@MIL-100( Fe ), MIL -100( Fe Propylene and propane adsorption isotherms for)

For the Cu@MIL-100(Fe) and MIL-100(Fe) adsorbents prepared in Example 1 and Comparative Example 1, propylene and propane adsorption isotherms were measured at 20°C.

And, the results are shown in FIG. 1. 1 is a graph comparing propylene and propane isotherms for adsorbents before and after impregnation of copper ions ((a) Comparative Examples 1, (b) Examples 1, (c) Examples 2, (d) Example 3 ))

Referring to FIG. 1, the adsorbents prepared in Examples 1 to 3 showed a much greater difference in adsorption amount between propane and propylene than in Comparative Example 1 in the entire pressure range.

Then, the adsorption amount of Example 2 according to the pretreatment conditions was compared, and the results are shown in FIG. 2. 2(a) shows the adsorption amount of the adsorbent after the first heat treatment at 150° C. in the preparation of the adsorbent of Example 2, and FIG. 2(b) is the second heat treatment at 250° C. in the preparation of the adsorbent of Example 2 It shows the adsorption amount of the adsorbent after drying.

When comparing (a) and (b) of FIG. 2, it can be seen that the adsorbent after the secondary heat treatment has excellent separation and adsorption performance of propylene and propane.

3 is an image obtained by observing the surface of Cu@MIL-100 (Fe) prepared in Example 2 with a scanning electron micro-scopy (SEM) and EDX (Energy-dispersive X-ray).

Referring to Figure 3, it can be seen that the copper salt is uniformly impregnated inside the crystal of Cu@MIL-100 (Fe).

4 is an XPS (X-ray photoelectron spectroscopy) spectrum in the copper region for Example 2 (Cu(M)@MIL-100(Fe)), and FIG. 5 is a MIL-100(Fe) before and after copper ion impregnation. A diagram showing a comparison of PXRD (powder X-ray diffraction) patterns of.

As can be seen from the XPS and PXRD results of FIGS. 4 and 5, it can be explained that the cupric salt impregnated with Cu@MIL-100 (Fe) was successfully reduced to the cuprous chloride salt. The reduced cuprous chloride salt appears to give high propylene selectivity by making a π-complex bond with propylene. From these results, an olefin-selective adsorbent was derived by dispersing the reduced cuprous salt in the metal organic framework by using the reducibility of the unsaturated metal coordination site of the metal organic framework itself without the use of an additional reducing agent and high temperature firing.

Experimental example 2: Cu@MIL-100( Fe ) And MIL -100( Fe Propylene/propane selectivity comparison for)

Ideal adsorbed solution theory (IAST) is a well-known theory for predicting the selectivity in mixture conditions from an experimentally measured pure component adsorption isotherm. It has already been verified through several studies that it can accurately predict the selectivity in a mixture of various adsorbents such as zeolite and metal organic framework. Therefore, using this ideal adsorption solution theory, from the propylene and propane adsorption isotherms measured in Experimental Example 1, Example 2 (Cu@MIL-100 (Fe)) and Comparative Example 1 (MIL-100 (Fe)) adsorbents Propylene/propane selectivity for was predicted.

In addition, the selectivity at the time of the first heat treatment was measured, and the selectivity at the time of the second heat treatment was calculated.

And, the results are shown in FIG. 6.

6, in the entire pressure range, Example 2 (Cu@MIL-100 (Fe)) showed higher propylene/propane selectivity than Comparative Example 1 (MIL-100 (Fe)).

Specifically, Example 2 had a selectivity of 9 at 293 K and a pressure of 100 kPa, whereas Comparative Example 1 had a selectivity of less than 4.

It can be explained that this is because it selectively adsorbs propylene on the reduced cuprous chloride inside Cu@MIL-100 (Fe).

Experimental example 3: Cu@MIL-100( Fe ) And MIL -100( Fe )of Charging tower mixture Breakthrough Propylene/propane separation performance comparison by experiment

The pressure swing adsorption (PSA) separation process is a process of continuously separating propylene and propane under a mixture condition after filling an adsorbent in a packed column. Therefore, in order to assess the applicability of the adsorbent to the PSA process, propylene and propane can be separated under the mixture condition by measuring the breakthrough curves of propylene and propane at the outlet while flowing the mixture after filling the adsorbent in the fixed tower. You should check whether there is.

In this experiment, the breakthrough separation device shown in FIG. 7 was used. The flow rate of each gas was precisely controlled using MFC (Mass Flow Controller). The composition of the gas passing through the adsorbent was analyzed using MS (Mass Spectrometer). A tube-type fixed tower (diameter = 1/4 inch, length 15 cm) specially manufactured to separate propylene/propane was used, and Cu@MIL-100 (Fe) of Example 1 and Comparative Example 1. 0.3 g of MIL-100 (Fe) powder was each pelletized and then charged into a fixed tower. After pretreatment of the fixed tower, a propylene/propane/helium mixture (25/25/50 molar ratio) was constantly flowed at a rate of 40 ml/min.

As can be seen in Figure 8, it was confirmed that Cu@MIL-100 (Fe) showed much better propylene/propane separation performance than MIL-100 (Fe). The propylene/propane selectivity calculated from the breakthrough curve was 4.234 for Cu@MIL-100(Fe), which was much higher than 2.124 for MIL-100(Fe). This is a result showing that Cu@MIL-100(Fe) is a promising adsorbent applicable to the PSA process for propylene/propane separation.

Claims (13)

By reducing and dispersing cupric salt (II) to cuprous salt (I) at the unsaturated metal coordination site on the surface of the porous metal organic framework or in the pores to prepare an adsorbent
Immersing the porous metal organic framework in an aqueous solution of cupric salt (II); And
Heat-treating the aqueous solution in which the porous metal organic framework is immersed; Including,
The heat treatment may include a first heat treatment step of heat treating an aqueous solution immersed in a porous metal organic framework at a temperature of 100 to 180°C; And
A second heat treatment step of heat-treating the first heat-treated aqueous solution at a temperature of 230 to 300 °C; Method for producing an olefin-selective adsorbent comprising a.
The method of claim 1,
The aqueous solution of cupric salt (II) contains cupric (II) chloride and copper (II) acetate,
The mixing ratio of the cupric chloride (II) and copper (II) acetate is in the range of 1:2 to 1:5 by weight, the method for producing an olefin-selective adsorbent.
The method of claim 1,
The olefin-selective adsorbent prepared by the method for producing an olefin-selective adsorbent is in the form of a porous particle, and includes a porous metal organic skeleton in which a cuprous salt (I) is dispersed at the surface of the porous particle or at the unsaturated metal coordination site in the pores, ,
The porous metal-organic framework is an olefin-selective adsorbent having a selectivity of 1.2 or more for paraffin in a pressure range of 273 K to 353 K and 10 to 1000 kPa based on a multi-component adsorption isotherm (IAST). Method of manufacturing.
The method of claim 3,
Olefins and paraffins are
A method for producing an olefin-selective adsorbent, characterized in that it is a C ₂ to C ₈ hydrocarbon.
The method of claim 3,
The porous metal organic framework is
Metal components include chromium (Cr), iron (Fe), aluminum (Al), magnesium (Mg), manganese (Mn), nickel (Ni), rubidium (Ru), rhodium (Rh), molybdenum (Mo), Production of an olefin-selective adsorbent comprising at least one selected from the group consisting of osmium (Os), cadmium (Cd), platinum (Pt), indium (In), zinc (Zn) and copper (Cu) Way.
The method of claim 5,
The porous metal organic framework is
A method for producing an olefin-selective adsorbent, characterized in that Fe ²⁺ and Fe ³⁺ have an unsaturated metal coordination site.
The method of claim 3,
The porous metal organic framework is
As organic substances, 1,4-benzenedicarboxylic acid, 1,3,5-benzenetricarboxylic acid, 2,5-dihydroxyterephthalic acid, 2,6-naphthalenedicarboxylic acid, azobenzenetetracarboxylic acid, or these A method for producing an olefin-selective adsorbent, comprising a derivative of.
The method of claim 3,
The porous metal organic framework is
A method for producing an olefin-selective adsorbent, characterized in that it has an unsaturated metal coordination site at a density of 0.2 to 10 mmol/g.
A method for separating olefins, characterized in that the olefin is separated from the olefin and paraffin mixture in an adsorption device performed by a pressure circulation adsorption method or a vacuum circulation adsorption method using an adsorbent prepared by the method for producing an olefin selective adsorbent according to claim 1 .
The method of claim 9,
When performing the pressure circulation adsorption method, the pressure conditions are 2 to 10 atmospheres during adsorption and 1 atmosphere during desorption.
The method of claim 9,
When performing the vacuum circulation adsorption method, the pressure conditions are 2 to 10 atmospheres during adsorption and 0.1 to 0.5 atmospheres during desorption. delete delete

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