Modified porous microspheres, preparation method thereof, separation device and application of modified porous microspheres and preparation method thereof

Abstract

The invention relates to the field of gas separation, and discloses a modified porous microsphere, a preparation method thereof, a separation device and application of the modified porous microsphere and the separation device, and the modified porous microsphere comprises styrene-divinyl benzene-acrylonitrile copolymer with surface benzene ring sulfonation and halogenation modification. The preparation raw materials of the modified porous microspheres are simple and easy to obtain, a gas chromatography packed column prepared from the modified porous microspheres can effectively separate trace O2 and Ar in hydrogen for PEMFC, the analysis process can be completed within 3 min, qualitative and quantitative analysis can be carried out on a target object at the same time, the lowest detection limit is as low as 10 ppm, and the method is suitable for industrial production. And the long-acting operation of the PEMFC is effectively ensured.

Description

Technical Field

[0001] The present invention relates to the field of gas separation, and in particular to a modified porous microsphere, a method for preparing the modified porous microsphere, the modified porous microsphere prepared by the method, a separation device, and the modified porous microsphere or the separation device for separating O in hydrogen raw materials. 2 and Ar or O in the hydrogen feed 2 Application in determination of content of Ar. Background Art

[0002] As a high-efficiency, clean, low-carbon and environmentally friendly secondary energy source, hydrogen energy is one of the ideal solutions to replace petroleum fuels in the application of the new energy vehicle industry. Hydrogen fuel cell vehicles (FCVs) use proton exchange membrane fuel cells (PEMFCs) to convert chemical energy into electrical energy through the reaction between hydrogen and oxygen under the action of catalysts, and use water as the final product to achieve zero-emission, pollution-free and environmentally friendly new energy vehicles. As a fuel, the quality of hydrogen directly determines the performance and life of the fuel cell. At present, hydrogen production from fossil fuels is one of the important sources of hydrogen, and fossil fuels inevitably carry O in the process of hydrogen production. 2 and Ar impurities, O 2 Ar and Ar impurities are one of the main factors affecting the durability of fuel cells. Therefore, unlike hydrogen used in refineries, FCV hydrogen has requirements on purity, but more importantly, it is necessary to control the key trace impurities in it, otherwise it will seriously affect the operating efficiency and life of the battery.

[0003] The analysis of impurity components in PEMFC hydrogen is basically a trace analysis of less than one part per million (ppm). 2 and Ar can be detected by thermal conductivity detector (TCD) and pulse discharge helium ionization detector (PDHID). The sensitivity of TCD and PDHID detectors can meet the requirements of detecting trace amounts at the ppm level. The boiling point of hydrogen at normal pressure is -252.7℃, the boiling point of oxygen at normal pressure is -183.1℃, and the boiling point of argon at normal pressure is -185.7℃. 2 It is almost impossible to separate O and Ar by boiling point on a general chromatographic column. They need to be separated by weak bonding and other chemical properties of the substances. 2 The present invention develops a preparation process for a gas phase filled chromatographic column. The gas phase filled chromatographic column produced by this process can effectively separate O from hydrogen. 2 and Ar, completely separated O 2 and Ar can meet the ppm-level trace detection requirements. PEMFC hydrogen production companies can use this chromatographic column to detect trace O2 and Ar are detected to ensure the long-term operation of PEMFC. Summary of the invention

[0004] The purpose of the present invention is to provide a modified porous microsphere and a preparation method and application thereof to achieve O 2 and Ar, while making it possible to completely separate O 2 and Ar can meet the trace detection requirements of ppm level and ensure the long-term operation of PEMFC.

[0005] In order to achieve the above object, the first aspect of the present invention provides a modified porous microsphere, wherein the modified porous microsphere comprises a styrene-divinylbenzene-acrylonitrile copolymer whose surface is modified by benzene ring sulfonation and halogenation.

[0006] A second aspect of the present invention provides a method for preparing modified porous microspheres, the method comprising:

[0007] (1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a porogen to obtain a monomer solution;

[0008] (2) mixing the monomer solution with a dispersed phase containing a dispersant and performing suspension polymerization to obtain porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer;

[0009] (3) Under acidification conditions, the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer are subjected to sulfonation and halogenation reduction treatment to obtain the modified porous microspheres.

[0010] The third aspect of the present invention provides modified porous microspheres prepared by the method described above.

[0011] A fourth aspect of the present invention provides a separation device, wherein the separation device is filled with the modified porous microspheres as described above.

[0012] The fifth aspect of the present invention provides the modified porous microspheres or the separation device as described above for separating O in hydrogen raw materials. 2 and Ar or O in the hydrogen feed 2 Application in determination of content of Ar.

[0013] The raw materials for preparing the modified porous microspheres of the present invention are simple and easy to obtain, and the cost is low; the preparation process is simple, there is no environmental pollution, and the prepared modified porous microspheres have high consistency.

[0014] The chromatographic column filled with the modified porous microspheres described in the present invention can effectively separate trace amounts of O in hydrogen for PEMFC. 2The whole analysis process can be completed within 3 minutes, and the minimum detection limit is as low as 10ppm, which effectively ensures the long-term operation of PEMFC. Moreover, the chromatographic column is suitable for various gas chromatographs and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of the modified porous microspheres of the present invention is shown.

[0016] Figure 2 The separation of O from hydrogen in Example 1 is shown. 2 GC-MS chromatograms of Mg and Ar.

[0017] Figure 3 The separation of O from hydrogen in Example 1 is shown. 2 GC-NCD chromatograms of NH and Ar.

[0018] Figure 4 The results show that the separation of O from hydrogen in Comparative Example 1 2 GC-MS chromatograms of Mg and Ar.

[0019] Figure 5 The results show that the separation of O from hydrogen in Comparative Example 2 2 GC-MS chromatograms of Mg and Ar.

[0020] Figure 6 The results of the separation of O from hydrogen in Comparative Example 3 show that 2 GC-NCD chromatograms of NH and Ar.

[0021] Figure 7 The chromatogram obtained by using a chromatographic column filled with 13X molecular sieve in Comparative Example 3 is shown. DETAILED DESCRIPTION

[0022] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0023] The first aspect of the present invention provides a modified porous microsphere, wherein the modified porous microsphere comprises a styrene-divinylbenzene-acrylonitrile copolymer whose surface is modified by benzene ring sulfonation and halogenation. The schematic diagram of the structure can be as follows Figure 1 shown.

[0024] Preferably, in the styrene-divinylbenzene-acrylonitrile copolymer, the weight ratio of the styrene unit, the divinylbenzene unit and the acrylonitrile unit is (25-45, for example, it can be 25, 30, 35, 40, 45 and any range between any two values): (20-40, for example, it can be 20, 25, 30, 35, 40 and any range between any two values): (10-30, for example, it can be 10, 15, 20, 25, 30 and any range between any two values).

[0025] Preferably, in the modified porous microspheres, the content of styrene-divinylbenzene-acrylonitrile copolymer is 92-98wt%, for example, it can be 92, 94, 96, 98wt% and any range between any two values, preferably 94-96wt%; the content of sulfonic acid groups is 1.5-5.5wt%, for example, it can be 1.5, 2, 3, 4, 5, 5.5wt% and any range between any two values, preferably 2.8-4.2wt%; the content of halogenated groups is 0.5-2.5wt%, for example, it can be 0.5, 1, 1.5, 2, 2.5wt% and any range between any two values, preferably 1.2-1.8wt%.

[0026] Preferably, the number average molecular weight of the styrene-divinylbenzene-acrylonitrile copolymer is 10000-60000 g / mol, for example, it can be 10000, 20000, 30000, 40000, 50000, 60000 g / mol and any range between any two values.

[0027] Preferably, the divinylbenzene units are p-divinylbenzene units and / or m-divinylbenzene units.

[0028] The halogenated group may be a common halogenated group in the art, such as Cl and / or Br. Preferably, the halogenated group is chlorine.

[0029] Preferably, the mass ratio of the elements on the surface of the modified porous microspheres is C (65-75, for example, 65, 66, 68, 70, 72, 74, 75 and any range between any two values): O (8-15, for example, 8, 10, 12, 13, 14, 15 and any range between any two values): S (6-12, for example, 6, 8, 10, 12 and any range between any two values): Cl (7-13, for example, 7, 8, 10, 12, 13 and any range between any two values). X-ray fluorescence XRF is used to detect the content of each element.

[0030] Preferably, the particle size of the modified porous microspheres is 150-1000 μm.

[0031] Preferably, the pore size of the modified porous microspheres is 20-100 nm.

[0032] Preferably, the BET specific surface area of ​​the modified porous microspheres is 30-40 m 2 / g.

[0033] The above parameters can be determined by the BET method.

[0034] Preferably, the chromatographic column packing density of the modified porous microspheres is 0.2-0.5 g / mL. The chromatographic column packing density can be determined by weighing and filling column volume.

[0035] A second aspect of the present invention provides a method for preparing modified porous microspheres, the method comprising:

[0036] 1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a porogen to obtain a monomer solution;

[0037] (2) mixing the monomer solution with a dispersed phase containing a dispersant and performing suspension polymerization to obtain porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer;

[0038] (3) Under acidification conditions, the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer are subjected to sulfonation and halogenation reduction treatment to obtain the modified porous microspheres.

[0039] In the present invention, styrene, divinylbenzene and acrylonitrile can be obtained commercially, and the purity thereof can be higher than 90wt%. Generally speaking, before polymerization, the monomers need to be treated to remove the polymerization inhibitor, and the method for removing the polymerization inhibitor is a conventional method in the art and will not be described in detail here.

[0040] Preferably, the divinylbenzene is p-divinylbenzene and / or m-divinylbenzene.

[0041] Preferably, in step (1), the initiator is a peroxide and / or an azo compound, preferably at least one selected from azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide and tert-butyl hydroperoxide.

[0042] Preferably, the porogen is selected from one or more of ethyl acetate, paraffin, gasoline, kerosene, normal C12-C18 alkyl alcohols (such as dodecanol, tridecanol, hexadecanol, octadecyl alcohol, etc.).

[0043] Preferably, by weight, the amount ratio of styrene, divinylbenzene, acrylonitrile, initiator and porogen is (25-45, for example, 25, 30, 35, 40, 45 and any range between any two values): (20-40, for example, 20, 25, 30, 35, 40 and any range between any two values): (10-30, for example, 10, 15, 20, 25, 30 and any range between any two values): (0.5-3, for example, 0.5, 1, 1.5, 2, 2.5, 3 and any range between any two values): (0.5-3, for example, 0.5, 1, 1.5, 2, 2.5, 3 and any range between any two values).

[0044] Preferably, the solvent of the monomer solution is selected from at least one of toluene, p-xylene and ethylbenzene.

[0045] Preferably, compared to 1 part by weight of the total weight of styrene, divinylbenzene and acrylonitrile, the amount of the solvent in the monomer solution is 3-20 parts by weight, for example, 3, 5, 10, 15, 20 parts by weight and any range between any two values.

[0046] Preferably, in step (2), the dispersant is preferably a C12-C22 alkyl tri-C1-C6 alkyl ammonium halide, preferably one or more of dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltriethylammonium chloride, dodecyltriethylammonium bromide, tetradecyltrimethylammonium chloride, tetradecyltrimethylammonium bromide, tetradecyltriethylammonium chloride, tetradecyltriethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, hexadecyltriethylammonium chloride, hexadecyltriethylammonium bromide, octadecyltrimethylammonium chloride, octadecyltrimethylammonium bromide, octadecyltriethylammonium chloride and octadecyltriethylammonium bromide, more preferably one or more of dodecyltrimethylammonium chloride, dodecyltrimethylammonium bromide, dodecyltriethylammonium chloride, dodecyltriethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, hexadecyltriethylammonium chloride and hexadecyltriethylammonium bromide.

[0047] Preferably, the dispersed phase is an aqueous phase.

[0048] Preferably, compared to 1 part by weight of the total weight of styrene, divinylbenzene and acrylonitrile, the amount of water is 3-20 parts by weight, for example, 3, 5, 10, 15, 20 parts by weight and any range between any two values, and the amount of dispersant is 0.01-0.05 parts by weight, for example, 0.01, 0.03, 0.05 parts by weight and any range between any two values.

[0049] The modified porous microspheres obtained can be sieved to obtain porous microspheres with a target particle size. The obtained porous microspheres can also be dried, and the drying conditions are not particularly limited as long as the moisture can be removed, such as drying at 100-110° C. for 4-6 hours. The obtained porous microspheres can be sulfonated and halogenated.

[0050] Preferably, in step (2), the conditions for suspension polymerization include: temperature of 50-95° C. and time of 5-10 h.

[0051] The suspension polymerization process is preferably coordinated with ultrasonic dispersion and stirring. The stirring conditions preferably include: a rotation speed of 300-1500 rpm.

[0052] Gradient heating is preferably used during the suspension polymerization process. Specifically, preferably, the suspension polymerization is carried out at 55-65° C. for 0.5-1.5 h, then at 80-90° C. for 1-2 h, and then heated to 85-95° C. for 3-5 h.

[0053] In a preferred embodiment of the present invention, in step (3), the sulfonation and halogenation reduction treatment comprises: in a mixed solution of sulfuric acid and nitric acid, the porous microspheres of the styrene-divinylbenzene-acrylonitrile copolymer are contacted with sulfite and halide, and subjected to sulfonation and halogenation reduction treatment to obtain an acidified product. Preferably, the conditions of the sulfonation and halogenation reduction treatment include: a temperature of 50-70°C (for example, 50, 55, 60, 65, 70°C and any range between any two values), a vacuum degree of less than 0.1Mpa (for example, 0.01MPa, 0.02MPa, 0.04MPa, 0.06MPa, 0.08MPa, 0.09MPa, 0.095MPa, 0.098MPa and any range between any two values), and a time of 6-10h (for example, 6, 7, 8, 9, 10h and any range between any two values).

[0054] The porous microspheres may be dispersed (eg, by ultrasound) into the mixed solution of sulfuric acid and nitric acid, and then the sulfite and halide are added thereto under stirring.

[0055] In another preferred embodiment of the present invention, in step (3), the sulfonation and halogenation reduction treatment comprises: subjecting the porous microspheres of the styrene-divinylbenzene-acrylonitrile copolymer to an acid treatment, and then contacting the acid treatment product with a sulfite and a halide, and subjecting the acid treatment to a sulfonation and halogenation reduction treatment to obtain the modified porous microspheres.

[0056] Preferably, in step (3), the acidification treatment comprises: acidifying the porous microspheres in a mixed solution of nitric acid and sulfuric acid to obtain an acidified product.

[0057] Preferably, the conditions for the acidification treatment include: a temperature of 50-70°C (for example, it can be 50, 55, 60, 65, 70°C and any range between any two values), a vacuum degree of less than 0.1Mpa (for example, it can be 0.01MPa, 0.02MPa, 0.04MPa, 0.06MPa, 0.08MPa, 0.09MPa, 0.095MPa, 0.098MPa and any range between any two values), and a time of 2-6h (for example, it can be 2, 3, 4, 5, 6h and any range between any two values).

[0058] Preferably, in the mixed solution of sulfuric acid and nitric acid, the concentration of sulfate ion is 15-40wt%, for example, it can be 15, 20, 25, 30, 35, 40wt% and any range between any two values, more preferably 20-30wt%, and the concentration of nitrate ion is 30-65wt%, for example, it can be 30, 35, 40, 45, 50, 55, 60, 65wt% and any range between any two values, more preferably 40-50wt%.

[0059] Preferably, the weight ratio of the mixed solution of sulfuric acid and nitric acid to the porous microspheres is 5-15:1, for example, it can be 5:1, 7:1, 9:1, 11:1, 13:1, 15:1 and any range between any two values.

[0060] Preferably, compared to 100 parts by weight of the porous microspheres, the amount of the sulfite is 5-40 parts by weight, for example, 5, 10, 15, 20, 25, 30, 35, 40 parts by weight and any range between any two values, and the amount of the halide is 5-40 parts by weight, for example, 5, 10, 15, 20, 25, 30, 35, 40 parts by weight and any range between any two values.

[0061] Preferably, the sulfite is sodium sulfite and / or potassium sulfite.

[0062] Preferably, the halide is sodium chloride and / or potassium chloride.

[0063] Heat is generated during the sulfonation and halogenation reduction treatment. When the material temperature drops to room temperature, the obtained product can be repeatedly washed with acetone and centrifuged, and the separated product is finally dried to obtain sulfonated and halogenated microsphere powder, that is, the modified porous microspheres of the present invention. The obtained modified porous microspheres can also be sieved using a sieve with a certain mesh number (such as 20-100 mesh) to obtain modified porous microspheres with a specific particle size.

[0064] The third aspect of the present invention provides modified porous microspheres prepared by the method described above.

[0065] The parameters of the modified porous microspheres can be found in the first aspect and will not be described in detail here.

[0066] A fourth aspect of the present invention provides a separation device, wherein the separation device is filled with the modified porous microspheres as described above.

[0067] Preferably, the separation device is a chromatographic column.

[0068] Preferably, the chromatographic column packing density of the modified porous microspheres is 0.2-0.5 g / mL.

[0069] The method for preparing the chromatographic column may be a conventional method in the art, and those skilled in the art may prepare the chromatographic column as required.

[0070] For example, regarding the selection of chromatographic column tubes, glass tubes, stainless steel tubes or plastic tubes with uniform inner diameters and appropriate lengths can be selected. For example, the inner diameter of the filling column can be 1.2-4 mm, the length can be 0.5-3 m, and the shape can be U-shaped or spiral.

[0071] Before use, the column tube can be directly rinsed with clean water for about 20 minutes, and then a dilute acid or a dilute alkali (generally 0.05-0.2 mol / L nitric acid, hydrochloric acid or sodium hydroxide) is poured into the column tube, and it is allowed to soak for more than 2 hours, and then rinsed with clean water until the eluate is neutral, and then ethanol or acetone is injected in the same way, soaked for more than 2 hours, and then rinsed with distilled water and ethanol in turn, and dried in an oven.

[0072] The volume of microspheres required for the chromatographic column is estimated based on V = Lπr 2 , where r is the inner radius of the column (cm); L is the column length (cm); and V is the column volume (mL).

[0073] The filling method of the chromatographic column can be: connect a small funnel to the outlet of the washed and dried chromatographic column, fill the prepared microspheres into the column in batches, and tap the column wall continuously until it is filled to 1.5 cm from the column mouth. Move the glass funnel to the entrance of the chromatographic column, plug a small ball of silanized glass wool at the outlet, and wrap it with a thin layer of cotton or 2 layers of gauze, connect it to the vacuum pump through a rubber tube, turn on the vacuum pump, and continue to slowly add the prepared filler from the funnel, and tap the column wall continuously to make it filled evenly and tightly. After filling, also plug a small ball of silanized glass wool at the entrance, and press it appropriately to keep the filler in the column from moving.

[0074] The obtained chromatographic column can be aged before use. The specific method can be: connect the inlet of the chromatographic column to the vaporization chamber, do not connect the outlet to the detector, and pass the carrier gas (N) at a flow rate of 15 mL / min. 2 ), raise the temperature to 250℃ in stages and age at this temperature for at least 24h.

[0075] The chromatographic column of the present invention can be connected to a gas chromatograph and an MSD detector or an NCD detector can be used to detect NO and N 2 The content of O is determined, and the control, recording, qualitative and quantitative analysis of the chromatographic separation system are completed by the chromatographic workstation.

[0076] The fifth aspect of the present invention provides the modified porous microspheres or the separation device as described above for separating NO and N in propylene raw materials. 2 O or NO and N in the propylene feed 2 Application in determination of O content.

[0077] The use conditions of the chromatographic column may include: carrier gas is helium, carrier gas flow rate is 0.8-15mL / min, carrier gas pressure is 0.3-0.6Mpa, quantitative loop is 0.2-3mL, split ratio is 1:1-1:10, and chromatographic column temperature is 40-100°C.

[0078] The present invention will be described in detail below through examples.

[0079] Unless otherwise specified, all reagents and materials used are commercially available.

[0080] In the following examples, in the mixed solution of nitric acid and sulfuric acid, the concentration of sulfuric acid is 23.3 wt %, and the concentration of nitric acid is 46.7 wt %.

[0081] Example 1

[0082] This example is used to illustrate the preparation method of the modified porous microspheres and chromatographic columns and the method of determining the content of the components to be measured by gas chromatography according to the present invention.

[0083] 1. Preparation of porous microspheres

[0084] In 100 mL of p-xylene, 7 g of styrene, 6 g of p-divinylbenzene and 4 g of acrylonitrile from which the polymerization inhibitor has been removed are mixed with 0.2 g of benzoyl peroxide and 0.2 g of n-octadecyl alcohol, and nitrogen is passed through to deoxygenate, thereby obtaining a monomer phase solution.

[0085] 0.3g of hexadecyltrimethylammonium bromide was mixed with 100ml of distilled water, and the aqueous phase solution was obtained after nitrogen deoxygenation, and the aqueous phase solution was mixed with the monomer phase solution and ultrasonically dispersed for 30min. The mixed material was transferred to a three-necked flask, and the nitrogen was passed for 10min to deoxygenate, and then heating was started. At a stirring speed of 1040r / min, the temperature was raised to 60℃ and the reaction was carried out for 60min, and then the temperature was raised to 85℃ and the reaction was carried out for 90min. After the temperature was raised to 90℃ and the reaction was carried out for 4h, the heating was stopped. After the material temperature was cooled to room temperature, steam distillation was carried out to remove n-octadecyl alcohol. After filtering, the filter cake was placed in a fat extractor, and the chain polymer was extracted with toluene to remove the chain polymer. The remaining solid was dried and then sieved to obtain 70-80 mesh solid porous microspheres.

[0086] 2. Modification of porous microspheres

[0087] Ultrasonic disperse 12g of the solid porous microspheres obtained in step 1 into 100mL of a mixed solution of nitric acid and sulfuric acid, and continuously evacuate with a circulating water pump, and acidify and react at 60°C for 4h. Then add 3g of hydrated sodium sulfite and 3g of potassium chloride and stir continuously (and continuously evacuate with a circulating water pump), and carry out sulfonation and chlorination reduction at 60°C for 2h. When the mixed solution is cooled to room temperature, it is repeatedly washed with acetone and centrifuged, and the separated product is finally dried to obtain sulfonated and chlorinated modified porous microspheres. Screen the modified porous microspheres with a mesh size of 70-80 for use, and the obtained modified porous microspheres have a pore size of 20-100nm and a specific surface area of ​​30-40m 2 / g.

[0088] XRF analysis shows that the mass ratio of the elements on the surface of the modified porous microspheres is C 70:O 11:S 9:Cl10.

[0089] 3. Preparation of gas chromatography column

[0090] Select a U-shaped stainless steel chromatographic column tube with an inner diameter of 2mm and a length of 3m. First, rinse the chromatographic column tube with clean water for 20 minutes, then pour 0.1mol / L sodium hydroxide into the chromatographic column tube and soak it for 2 hours, then rinse it with clean water until the eluent is neutral. In the same way, inject ethanol into the chromatographic column tube and soak it for 2 hours, then rinse it with distilled water and ethanol in turn, and finally place the chromatographic column tube in an oven to dry.

[0091] Place the funnel at one end of the dried U-shaped chromatographic column tube, and fill the modified porous microspheres prepared in step 2 in portions through the funnel while constantly tapping the column wall until it is filled to 1.5 cm from the column mouth. Remove the funnel and plug the port with silanized glass wool wrapped with a thin layer of cotton. Finally, connect this end of the U-shaped chromatographic column tube to the vacuum pump through a rubber tube.

[0092] Place the funnel at the other end of the U-shaped chromatographic column tube, turn on the vacuum pump, and continue to fill the prepared modified porous microspheres into the U-shaped chromatographic column tube through the funnel, and keep tapping the column wall to make it filled evenly and tightly until it is filled to 1.5 cm from the column mouth. Remove the funnel and insert silanized glass wool wrapped with a thin layer of cotton into the port, and press the glass wool to keep the filling in the column from being moved. The packing density of the modified porous microspheres is 0.3 g / mL.

[0093] Connect the inlet of the chromatographic column to the vaporization chamber, do not connect the outlet to the detector first, and introduce carrier gas N at a flow rate of 15 mL / min. 2 The temperature was raised to 250°C in stages and aged at 250°C for 24 hours to obtain a gas chromatography column.

[0094] 4. Application of chromatographic columns (GC-MS)

[0095] Agilent 8890B (GC) gas chromatograph, thermal conductivity TCD detector, the control and recording of the chromatographic separation system are completed by the CDS workstation, and the qualitative and quantitative analysis is completed by customized software.

[0096] Separation chromatographic column: Use the gas chromatographic column prepared in step 3.

[0097] The working conditions of the chromatograph are as follows: the temperature is 50°C constant temperature, the flow rate is 10 mL / min constant flow, the injection volume is 0.25 mL, the split ratio is 1:15, the carrier gas is 0.5 MPa nitrogen (99.9999%), and the quantitative loop is 0.25 mL.

[0098] The hydrogen from the hydrogen storage tank for PEMFC enters the GC-TCD through the gas valve for separation and detection. The resulting chromatogram is as follows: Figure 2 shown.

[0099] Example 2

[0100] The operation was carried out according to the method described in Example 1, except that:

[0101] 3. Preparation of chromatographic columns

[0102] A U-shaped stainless steel chromatographic column tube with an inner diameter of 1.5 mm and a length of 2 m was selected.

[0103] 4. Application of chromatographic columns

[0104] Agilent 7890B (GC) gas chromatograph and pulse discharge helium ionization PDHID detector were used. The control and recording of the chromatographic separation system were completed by CDS workstation. Qualitative and quantitative analysis were completed by customized software.

[0105] Separation chromatographic column: Use the gas chromatographic column prepared in step 3.

[0106] The working conditions of the chromatograph are as follows: the temperature is 70°C constant temperature, the flow rate is 15 mL / min constant flow, the injection volume is 0.50 mL, the split ratio is 1:20, the carrier gas is 0.5 MPa helium (99.9999%), and the quantitative loop is 0.50 mL.

[0107] The hydrogen from the hydrogen storage tank for PEMFC enters the GC-PDHID through the gas valve for separation and detection. The resulting chromatogram is as follows: Figure 3 shown.

[0108] Example 3

[0109] The difference from Example 1 is that:

[0110] 2. Modification of porous microspheres

[0111] Ultrasonic disperse 12g of the solid porous microspheres obtained in step 1 into 100mL of a mixed solution of nitric acid and sulfuric acid, then add 3g of hydrated sodium sulfite and 3g of potassium chloride and stir continuously (and continuously draw out the vacuum with a circulating water pump), and simultaneously carry out acidification, sulfonation, and chlorination at 60°C for 6h. When the mixed solution is cooled to room temperature, it is washed with acetone repeatedly and centrifuged, and the separated product is finally dried to obtain sulfonated and chlorinated modified porous microspheres. Screen the modified porous microspheres with a mesh size of 70-80 for use, and the obtained modified porous microspheres have a pore size of 20-100nm and a specific surface area of ​​30-40m 2 / g.

[0112] The hydrogen from the hydrogen storage tank for PEMFC enters the GC-PDHID through the gas valve for separation and detection. The resulting chromatogram is as follows: Figure 4 shown.

[0113] Comparative Example 1

[0114] The difference from Example 1 is that a 5A molecular sieve is used to fill the chromatographic column (Molesieve 5A), and the chromatogram obtained is as follows: Figure 5 shown.

[0115] Comparative Example 2

[0116] The difference from Example 1 is that the porous microspheres prepared in step 1 are not subjected to the modification treatment in step 2 and are directly used to prepare the chromatographic column. The obtained chromatogram is as shown in FIG. Figure 6 shown.

[0117] Comparative Example 3

[0118] The difference from Example 1 is that a 13X molecular sieve is used to fill the chromatographic column (Molesieve 13X), and the chromatogram obtained is as follows Figure 7 shown.

[0119] It can be seen from Examples 1 to 3 and Comparative Examples 1 to 3 that the modified porous microsphere chromatographic column of the present invention can be used to purify ppm-level O in hydrogen. 2 and Ar are effectively separated, among which O 2 The separation degree of Ar is greater than 1.5, and the baseline is completely separated. Compared with Example 3, the chromatographic column prepared by the porous microspheres modified by acidification followed by sulfonation and chlorination in Examples 1 and 2 has a better separation effect.

[0120] However, other chromatographic columns cannot effectively separate ppm-level O in hydrogen. 2 Among them, O in hydrogen using 5A molecular sieve chromatographic column and 13X chromatographic column 2 and Ar are steamed bun peaks. However, the O 2 and Ar are combined peaks, O 2 The separation degrees of argon and Ar are both less than 1.5, and baseline separation cannot be achieved.

[0121] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A modified porous microsphere, characterized in that: The modified porous microspheres contain styrene-divinylbenzene-acrylonitrile copolymers with surfaces modified by benzene ring sulfonation and halogenation.

2. The modified porous microsphere according to claim 1, wherein In the styrene-divinylbenzene-acrylonitrile copolymer, the weight ratio of styrene units, divinylbenzene units and acrylonitrile units is (25-45):(20-40):(10-30); and / or The number average molecular weight of the styrene-divinylbenzene-acrylonitrile copolymer is 10000-60000 g / mol; and / or Preferably, the divinylbenzene units are p-divinylbenzene units and / or m-divinylbenzene units; Preferably, the halide group is chlorine; Preferably, the mass ratio of the elements on the surface of the modified porous microspheres is C (65-75): O (8-15): S (6-12): Cl (7-13).

3. The modified porous microsphere according to claim 1 or 2, wherein: The pore size of the modified porous microspheres is 20-100 nm; and / or The particle size of the modified porous microspheres is 150-1000 μm; and / or The BET specific surface area of ​​the modified porous microspheres is 30-40 m 2 / g; and / or The chromatographic column packing density of the modified porous microspheres is 0.2-0.5 g / mL.

4. A method for preparing modified porous microspheres, characterized in that: The method includes: (1) mixing styrene, divinylbenzene and acrylonitrile with an initiator and a porogen to obtain a monomer solution; (2) mixing the monomer solution with a dispersed phase containing a dispersant and performing suspension polymerization to obtain porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer; (3) Under acidification conditions, the porous microspheres of styrene-divinylbenzene-acrylonitrile copolymer are subjected to sulfonation and halogenation reduction treatment to obtain the modified porous microspheres.

5. The method according to claim 4, wherein: In step (1), the initiator is a peroxide and / or an azo compound, preferably at least one selected from azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide and tert-butyl hydroperoxide; and / or The porogen is selected from one or more of ethyl acetate, paraffin, gasoline, kerosene, and normal C12-C18 alkyl alcohol; and / or The divinylbenzene is p-divinylbenzene and / or m-divinylbenzene; Preferably, by weight, the ratio of styrene, divinylbenzene, acrylonitrile, initiator and porogen is (25-45):(20-40):(10-30):(0.5-3):(0.5-3); Preferably, the solvent of the monomer solution is selected from at least one of toluene, p-xylene and ethylbenzene.

6. The method according to claim 4 or 5, wherein: In step (2), the dispersant is a C12-C22 alkyl tri-C1-C6 alkyl ammonium halide, preferably one or more of dodecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, dodecyl triethyl ammonium chloride, dodecyl triethyl ammonium bromide, tetradecyl trimethyl ammonium chloride, tetradecyl trimethyl ammonium bromide, tetradecyl triethyl ammonium chloride, tetradecyl triethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, hexadecyl triethyl ammonium chloride, hexadecyl triethyl ammonium bromide, octadecyl trimethyl ammonium chloride, octadecyl trimethyl ammonium bromide, octadecyl triethyl ammonium chloride and octadecyl triethyl ammonium bromide, more preferably one or more of dodecyl trimethyl ammonium chloride, dodecyl trimethyl ammonium bromide, dodecyl triethyl ammonium chloride, dodecyl triethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, hexadecyl trimethyl ammonium bromide, hexadecyl triethyl ammonium chloride and hexadecyl triethyl ammonium bromide; and / or The dispersed phase is an aqueous phase; Preferably, compared to 1 part by weight of the total weight of styrene, divinylbenzene and acrylonitrile, the amount of water used is 3-20 parts by weight, and the amount of the dispersant used is 0.01-0.05 parts by weight.

7. The method according to any one of claims 4 to 6, wherein: In step (2), the suspension polymerization conditions include: temperature of 50-95° C., time of 5-10 h; Preferably, the suspension polymerization is carried out by reacting at 55-65° C. for 0.5-1.5 h, then reacting at 80-90° C. for 1-2 h, and then heating to 85-95° C. for 3-5 h.

8. The method according to claim 4, wherein: In step (3), the sulfonation and halogenation reduction treatment comprises: contacting the porous microspheres of the styrene-divinylbenzene-acrylonitrile copolymer with sulfite and halide in a mixed solution of sulfuric acid and nitric acid, and performing sulfonation and halogenation reduction treatment to obtain an acidified product; Preferably, in the mixed solution of sulfuric acid and nitric acid, the concentration of sulfate is 15-40wt%, more preferably 20-30wt%, and the concentration of nitrate is 30-65wt%, more preferably 40-50wt%; Preferably, the weight ratio of the mixed solution of sulfuric acid and nitric acid to the porous microspheres is 5-15:1; Preferably, the conditions for the sulfonation and halogenation reduction treatment include: temperature of 50-70° C., vacuum degree of less than 0.1 MPa, and time of 6-10 h.

9. The method according to claim 4, wherein: In step (3), the sulfonation and halogenation reduction treatment comprises: acidifying the porous microspheres of the styrene-divinylbenzene-acrylonitrile copolymer, contacting the acidified product with sulfite and halide, and performing sulfonation and halogenation reduction treatment to obtain the modified porous microspheres; Preferably, the acid treatment comprises acidifying the porous microspheres in a mixed solution of nitric acid and sulfuric acid to obtain an acidified product; Preferably, the conditions of the acidification treatment include: temperature of 50-70°C, vacuum degree less than 0.1Mpa, and time of 2-6h; Preferably, the conditions for the sulfonation and halogenation reduction treatment include: temperature of 50-70° C., vacuum degree of less than 0.1 MPa, and time of 1-3 h.

10. The method according to any one of claims 4 to 9, wherein: In step (3), compared to 100 parts by weight of the porous microspheres, the amount of the sulfite is 5-40 parts by weight, and the amount of the halide is 5-40 parts by weight; Preferably, the sulfite is sodium sulfite and / or potassium sulfite; Preferably, the halide is sodium chloride and / or potassium chloride.

11. Modified porous microspheres prepared by the method according to any one of claims 4 to 10.

12. A separation device, characterized in that: The separation device is filled with the modified porous microspheres according to any one of claims 1 to 3 and 11; Preferably, the separation device is a chromatographic column.

13. Use of the modified porous microspheres according to any one of claims 1 to 3 and 11 or the separation device according to claim 12 in separating O2 and Ar in a hydrogen raw material or in determining the contents of O2 and Ar in a hydrogen raw material.

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