阅读说明：本技术 一种用于高效分离混合气体的金属有机框架材料及其制法与应用 (Metal organic framework material for efficiently separating mixed gas and preparation method and application thereof ) 是由 李丹 陆伟刚 王婷 曾恒 于 2020-08-07 设计创作，主要内容包括：本发明提供了一种用于高效分离混合气体的金属有机框架材料,其化学式为(C<Sub>16</Sub>H<Sub>10</Sub>CoN<Sub>4</Sub>O<Sub>4</Sub>)·3H<Sub>2</Sub>O,所述金属有机框架材料的晶胞参数为：<Image he="71" wi="414" file="DDA0002622850120000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image><Image he="72" wi="524" file="DDA0002622850120000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>α＝90°,β＝95.81°,γ＝90°。本发明提供的金属有机框架材料,其孔径约为<Image he="75" wi="162" file="DDA0002622850120000013.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>由于该金属有机框架材料具有特定孔道结构的动态筛分作用,可从任意比例的丙烯和丙烷混合物中分离出高纯丙烯,同时也能从乙炔和乙烯混合物中分离高纯乙烯。(The invention provides a metal organic framework material for efficiently separating mixed gas, which has a chemical formula of (C) 16 H 10 CoN 4 O 4 )·3H 2 O, the unit cell parameters of the metal-organic framework material are as follows: α -90 deg., β -95.81 deg., and gamma-90 deg. the present invention provides a metal-organic framework material with a pore size of about 90 deg The metal organic framework material has the dynamic sieving function of a specific pore channel structure, so that high-purity propylene can be separated from a mixture of propylene and propane in any proportion, and high-purity ethylene can be separated from a mixture of acetylene and ethylene.)

1. A metal organic framework material for efficiently separating mixed gas is characterized in that the metal organic framework material has a chemical formula of (C)₁₆H₁₀CoN₄O₄)·3H₂O, the unit cell parameters of the metal-organic framework material are as follows:

2. the method for preparing the metal organic framework material for efficiently separating the mixed gas according to claim 1, which comprises the following steps:

(1) dissolving a ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid and a metal cobalt salt by using an organic solvent to obtain a mixed solution;

(2) placing the mixed solution in an oven, heating the mixed solution to 120-140 ℃ from room temperature, preserving the heat for 24-72 hours at the temperature of 120-140 ℃, then cooling the mixed solution to room temperature, filtering, washing and drying the cooled mixed solution to obtain purple crystals;

(3) and (3) cleaning the obtained purple crystal for multiple times by using an organic solvent, and then activating the purple crystal under the conditions that the temperature is 150 ℃ and the atmospheric pressure is 5-6 mu mHg for 22-24 hours to obtain the metal organic framework material.

3. The method for preparing the metal organic framework material for efficiently separating the mixed gas according to claim 2, wherein in the step (1), the ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid and the metal cobalt salt are respectively dissolved by two organic solvents, or the ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid and the metal cobalt salt are dissolved in the mixed solution of the two organic solvents.

4. The method for preparing a metal organic framework material for efficiently separating mixed gas according to claim 3, wherein the two organic solvents are N, N-dimethylacetamide and anhydrous methanol, and the volume ratio of the N, N-dimethylacetamide to the anhydrous methanol in the mixed solution of the two organic solvents is 0.8-1.2: 1.

5. the preparation method of the metal organic framework material for efficiently separating the mixed gas according to claim 2, wherein in the step (1), the mass ratio of the ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid to the metal cobalt salt is 1-2: 1.

6. the method for preparing a metal organic framework material for efficiently separating mixed gas according to claim 5, wherein the metal cobalt salt is cobalt chloride hexahydrate or cobalt nitrate hexahydrate.

7. The method for preparing a metal organic framework material for efficiently separating a mixed gas according to claim 2, wherein in the step (3), the organic solvent is methanol.

8. The application of the metal organic framework material for efficiently separating mixed gas is characterized in that the metal organic framework material prepared by the method of any one of claims 2 to 7 is used for effectively separating propylene from propylene/propane mixed gas.

9. The application of the metal organic framework material for efficiently separating mixed gas is characterized in that the metal organic framework material prepared by the method of any one of claims 2 to 7 is used for effectively separating ethylene from ethylene/acetylene mixed gas.

Technical Field

The invention belongs to the technical field of chemistry, and particularly relates to a metal organic framework material for efficiently separating mixed gas, and a preparation method and application thereof.

Background

Propylene (C)₃H₆) As one of the most important chemical raw materials in the chemical industry, the raw materials are basic raw materials of three major synthetic materials, are main raw materials of important chemical products such as polypropylene, acrylonitrile, propylene oxide, acrylic acid, butanol and octanol, and the annual output of the raw materials exceeds 1 hundred million tons; most of the propylene is recovered from the C3 fraction of cracked petroleum gas, and the main by-product is propane (C)₃H₈) Industrially produced C₃H₆Usually, the content of C is 40 to 50%₃H₈. At present, the mainstream mode for industrially separating propylene and propane is a low-temperature distillation technology, and the separation is realized by utilizing the slight difference of boiling points, but the energy consumption is extremely high. Meanwhile, ethylene is another important chemical product, and the yield of the ethylene reaches the hundred million tons level, and the ethylene occupies an important position in petrochemical products. Production of polymerization grade ethylene often requires removal of trace amounts of acetylene (1%), but ethylene and acetylene have similar physical properties and are generally difficult to separate. To obtain polymer grade ethylene, cryogenic high pressure rectification is often required industrially and this process consumes a significant amount of energy, which greatly increases the cost of production.

In recent years, Metal Organic Frameworks (MOFs) have attracted much attention as a new generation of porous materials that are easy to design and regulate. Currently, the method commonly used to separate propylene propane from ethylene acetylene is to utilize Open Metal Sites (OMSs) to selectively coordinate olefins to form pi complexes, but OMSs alone may not be sufficient to produce high purity olefins in one adsorption-desorption cycle because they also interact with alkanes to some extent by polarization. The precise pore size and shape are customized in the metal organic framework, the pore size between the kinetic diameters of the separated compounds is customized, and the molecular sieving mechanism is used for separating propylene, propane and ethylene acetylene, so that the separation mechanism has the minimum co-adsorption and the maximum selectivity, and is an ideal separation mechanism.

Therefore, it is very important to develop a metal organic framework material capable of simultaneously separating propylene/propane and ethylene/acetylene mixed gas.

Disclosure of Invention

In view of the above-mentioned disadvantages of the prior art, the present invention is directed to a metal organic framework material for effectively separating propylene and ethylene from a mixed gas of propylene/propane and ethylene/acetylene at room temperature and a normal atmospheric pressure, and a method for preparing the same.

In order to achieve the purpose, the invention provides the following technical scheme: a metal-organic frame material for high-efficiency separation of mixed gas has the chemical formula (C)₁₆H₁₀CoN₄O₄)·3H₂O, the unit cell parameters of the metal-organic framework material are as follows:

α＝90°，β＝95.81°，γ＝90°。

the metal organic framework material for efficiently separating the mixed gas is obtained by adopting the following preparation method:

(1) dissolving a ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid and a metal cobalt salt by using an organic solvent to obtain a mixed solution;

(2) placing the mixed solution in an oven, heating the mixed solution to 120-140 ℃ from room temperature, preserving the heat for 24-72 hours at the temperature of 120-140 ℃, then cooling the mixed solution to room temperature, filtering, washing and drying the cooled mixed solution to obtain purple crystals;

(3) and (3) cleaning the obtained purple crystal for multiple times by using an organic solvent, and then activating the purple crystal under the conditions that the temperature is 150 ℃ and the atmospheric pressure is 5-6 mu mHg for 22-24 hours to obtain the metal organic framework material.

Further, in the step (1), two organic solvents are adopted to dissolve the ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid and the metal cobalt salt respectively, or the ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid and the metal cobalt salt are dissolved in the mixed solution of the two organic solvents. For the dissolution of the ligand and the metal cobalt salt, separate dissolution or mixed dissolution can be adopted, and compared with the separate dissolution, the mixed dissolution is simpler in operation and better in dissolution effect.

Further, the two organic solvents are N, N-dimethylacetamide and anhydrous methanol, and the volume ratio of the N, N-dimethylacetamide to the anhydrous methanol in the mixed solution of the two organic solvents is 0.8-1.2: 1.

further, in the step (1), the mass ratio of the ligand 5- (3-methyl-5-pyridine-1, 2, 4-triazole) isophthalic acid to the metal cobalt salt is 1-2: 1.

further, the metal cobalt salt is cobalt chloride hexahydrate or cobalt nitrate hexahydrate.

Further, in the step (3), the organic solvent is methanol.

The metal organic framework material for efficiently separating the mixed gas prepared by the preparation method can be used for effectively separating propylene from propylene/propane mixed gas or ethylene from ethylene/acetylene mixed gas.

Compared with the prior art, the invention has the following beneficial effects:

(1) the metal organic frame material (named JNU-3) provided by the invention has a pore diameter of about

Due to the dynamic screening function of the metal organic framework material with a specific pore channel structure, high-purity propylene (with the highest purity of 99.5%) can be separated from a mixture of propylene and propane in any proportion, and high-purity ethylene (with the highest purity of 99.9999%) can also be separated from a mixture of acetylene and ethylene.

(2) According to the experimental values, 1kg of metal-organic framework material can yield about 34.2L of propylene with a purity of more than 99.5% in a mixture of propylene and propane (mol: 50). Therefore, the metal organic framework material prepared by the method can be used as a novel porous metal organic framework material for efficiently and selectively separating propane/propylene and acetylene/ethylene to obtain propylene and ethylene with polymerization-grade purity.

Drawings

FIG. 1 is a diagram of the structure of the channel of the metal organic frame material of the present invention;

FIG. 2 is an adsorption isothermal adsorption curve of Ar at 87K for the metal-organic framework material of the present invention;

FIG. 3 shows the metal-organic framework material of the present invention for pure C₃H₈Pure C₃H₆And equimolar mixing of C₃H₆/C₃H₈Adsorption isotherm at 303K;

FIG. 4 shows a metal organic framework material of the present invention for C₃H₆/C₃H₈(mol: 50) column cycle separation breakthrough curve (303K,1bar) for mixed gas;

FIG. 5 shows a metal organic framework material of the present invention for C₃H₆/C₃H₈(mol: 95:5) breakthrough curve for column cycling of mixed gas (303K,1 bar);

FIG. 6 is a schematic view of the interaction of the metal organic framework material of the present invention with propylene molecules;

FIG. 7 is a schematic representation of the interaction of the metal organic framework material of the present invention with propane molecules;

FIG. 8 shows a metal organic framework material of the present invention at 298K for C₂H₂And C₂H₄Isothermal adsorption curve of (a);

FIG. 9 shows a metal organic framework material of the present invention for C₂H₂/C₂H₄(mol: mol ═ 1:99) column circulation separation breakthrough curve (298K,1bar) for mixed gases.

Detailed Description

The process of the present invention will be described in detail with reference to specific examples. The invention utilizes micromeritics sASAP 2020 Plus accepted Surface Area and Porosimetry adsorption instrument to measure the 87K argon adsorption quantity of the material prepared by the invention

Firstly, the preparation of the cobalt-based metal-organic framework material of the invention