A waste plastic derived porous support, method of making and use thereof

Abstract

The application provides a waste plastic derived porous carrier and a preparation method and application thereof, and belongs to the technical field of carbon dioxide adsorbent preparation.The porous carrier is prepared by using waste plastic as raw material, and the carrier has good adsorption performance through simple chemical modification and high-temperature treatment, so that the synthesis cost of the porous carrier is greatly reduced, the upgrading utilization means of the waste plastic is enriched, and the resource recycling of the waste plastic is realized.The waste plastic derived porous carrier prepared by the application has good loading effect on organic amine reagents, can significantly improve the loading capacity of the organic amine reagents, so that the solid amine adsorbent obtained by loading has high carbon dioxide adsorption capacity, and has superior environmental and economic performance.The technical scheme provided by the application is expected to cope with the two environmental problems of global climate warming and plastic solid waste pollution.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide adsorbent preparation, and particularly relates to a waste plastic derived porous carrier and a preparation method and application thereof. BACKGROUND

[0002] The massive emission of greenhouse gases dominated by CO2 has caused increasingly serious global climate problems. In order to achieve the 1.5℃ target of the Paris Agreement, CO2 emission reduction is urgent. Carbon capture, utilization and storage technology plays a key role in carbon emission reduction. Direct air carbon capture technology is a kind of negative emission technology that removes CO2 from the atmosphere through carbon capture materials. Due to the flexibility of equipment arrangement, direct air carbon capture can eliminate the cost of carbon transportation to storage or utilization sites, and is a promising route for carbon capture. At present, the capture methods of direct air carbon capture are divided into two categories: solution absorption and solid adsorption. The use of organic amine solution to absorb CO2 has been widely used in flue gas carbon capture, but the high gas treatment requirement of direct air carbon capture makes the solution absorption technology have problems such as a large amount of amine solution volatilization and significant increase in capture cost. Compared with the solution absorption method, solid material adsorption avoids the high heat of heating the absorption solution, has obvious advantages in reducing equipment corrosion and degradation, and can effectively reduce amine volatilization and water loss. At present, the solid adsorbents for direct air carbon capture mainly include solid amine adsorbents, physical adsorbents, alkaline earth metal-based adsorbents and humidity swing adsorbents.

[0003] Solid amine adsorbents are the most mature direct air carbon capture solid materials at present. The preparation method of this kind of material is to use amine as the active component of CO2 adsorption, and load it on a porous carrier with suitable structure to prepare a solid amine material. There are three methods for loading amine reagents on porous carriers, including physical impregnation method, chemical grafting method and in-situ polymerization method, among which the physical impregnation method is the most widely used due to its simple process and considerable loading capacity, and PEI and TEPA are the two most commonly used amine reagents.

[0004] At present, the porous carriers commonly used for loading amine groups mainly include mesoporous silica-based materials, composite metal oxides and porous resins. Mesoporous silica-based materials are the most commonly used, and this kind of carrier has uniform mesoporous pore size. The amine loading performance of silica-based carriers has been widely verified. However, the synthesis of silica-based mesoporous carriers mainly uses the template method, and the synthesis cost is high, which restricts the large-scale application of amine-loaded adsorbents. Therefore, it is very important to develop a carrier with high adsorption capacity, low synthesis cost and good recycling performance for carbon dioxide capture, which is a technical problem to be solved in the field. SUMMARY

[0005] The application aims to provide a waste plastic derived porous carrier, a preparation method and application thereof.

[0006] To achieve the above-mentioned application purposes, the application provides the following technical solutions.

[0007] The application provides a preparation method of a waste plastic derived porous carrier, comprising the following steps.

[0008] (1) waste plastics are crushed to obtain plastic powder, and then the plastic powder is mixed with a chemical modifier to obtain a mixture; the chemical modifier comprises any one of a solid base, a base solution and an acid solution;

[0009] (2) the mixture obtained in the step (1) is subjected to heat treatment to obtain a waste plastic derived porous carrier.

[0010] Preferably, the waste plastics in the step (1) are PET plastics.

[0011] Preferably, the particle size of the plastic powder in the step (1) is greater than or equal to 40 mesh.

[0012] Preferably, the solid base in the step (1) is potassium hydroxide or sodium hydroxide; the base solution is a potassium hydroxide solution or a sodium hydroxide solution, and the concentration of the base solution is 0.5-0.8 g / mL; the acid solution is a phosphoric acid solution, and the mass concentration of the phosphoric acid solution is 80-85%.

[0013] Preferably, when the chemical modifier in the step (1) is a solid base, the mass ratio of the plastic powder to the solid base is 1:(1-5).

[0014] Preferably, when the chemical modifier in the step (1) is a base solution, the mass of the plastic powder to the volume of the base solution is (2-5) g:(8-15) mL.

[0015] Preferably, when the chemical modifier in the step (1) is an acid solution, the mass ratio of the plastic powder to the acid solution is 1:(1-5).

[0016] Preferably, the temperature of the heat treatment in the step (2) is 600-800 DEG C, the time of the heat treatment is 0.2-3 h, the heating rate for heating to the heat treatment temperature is 3-10 DEG C / min, and the atmosphere of the heat treatment is nitrogen, and the flow rate of the nitrogen is 100-300 mL / min.

[0017] The application provides a waste plastic derived porous carrier prepared by the preparation method. 2 ·g -1 The total pore volume of the waste plastic derived porous carrier is 1.25-1.45 mL·g -1 The BJH method pore volume of the waste plastic derived porous carrier is 0.85-1.15 cm 3 / g, the HK method micropore volume of the waste plastic derived porous carrier is 0.44-0.5 cm 3 / g, and the BJH method average pore diameter (4V / A) of the waste plastic derived porous carrier is 10-20 nm.

[0018] The application provides an application of the waste plastic derived porous carrier in preparation of a solid amine adsorbent.

[0019] The application provides a preparation method of a waste plastic derived porous carrier, which comprises the following steps: (1) crushing waste plastic to obtain plastic powder, and then mixing the plastic powder with a chemical modifier to obtain a mixture; the chemical modifier comprises any one of a solid base, a base solution and an acid solution; (2) performing heat treatment on the mixture obtained in the step (1) to obtain a waste plastic derived porous carrier. The waste plastic is used as a raw material to prepare the porous carrier, and the porous carrier has good adsorption performance through simple chemical modification and high-temperature treatment, so that the synthesis cost of the porous carrier is greatly reduced, the upgrading utilization means of the waste plastic is enriched, and the resource recycling of the waste plastic is realized. The waste plastic derived porous carrier prepared by the application has good loading effect on an organic amine reagent, can significantly improve the loading capacity of the organic amine reagent, so that the obtained solid amine adsorbent has high carbon dioxide adsorption capacity and has superior environmental and economic performance. The technical scheme provided by the application can simultaneously cope with the two environmental problems of global climate warming and plastic solid waste pollution. The results of the embodiments show that the BET specific surface area of the waste plastic derived porous carrier prepared by the preparation method is 800-1100 m 2 ·g -1 The total pore volume of the waste plastic derived porous carrier is 1.25-1.45 mL·g -1 The BJH method pore volume of the waste plastic derived porous carrier is 0.85-1.15 cm 3 / g, the HK method micropore volume of the waste plastic derived porous carrier is 0.44-0.5 cm 3The average pore diameter (4V / A) of the waste plastic derived porous support by BJH method is 10-20 nm; the solid amine adsorbent prepared by using the waste plastic derived porous support has a CO2 adsorption capacity of 1.33 mmol / g at 25 DEG C and an atmospheric CO2 partial pressure (i.e. 40 Pa), and has a high direct air carbon capture capacity. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The CO2 adsorption isotherm of the solid amine adsorbent prepared in application example 1. DETAILED DESCRIPTION

[0021] The application provides a preparation method of a waste plastic derived porous support, comprising the following steps:

[0022] (1) crushing waste plastic to obtain plastic powder, and then mixing the plastic powder with a chemical modifier to obtain a mixture; the chemical modifier comprises any one of a solid base, a base solution and an acid solution;

[0023] (2) performing heat treatment on the mixture obtained in the step (1) to obtain a waste plastic derived porous support.

[0024] The application crushes waste plastic to obtain plastic powder, and then mixes the plastic powder with a chemical modifier to obtain a mixture.

[0025] In the application, the waste plastic is preferably PET plastic. The application does not have special limitations on the specific source of the waste plastic, and recycled waste PET plastic known to those skilled in the art can be used.

[0026] The application preferably washes the waste plastic before crushing. The application does not have special limitations on the specific operation of the washing, and the impurities on the waste plastic can be removed.

[0027] In the application, the crushing method is preferably as follows: first, the waste plastic is cut into pieces, then immersed in liquid nitrogen, then crushed, and finally sieved to obtain plastic powder.

[0028] The application does not have special limitations on the specific operation of the cutting, and the size of the cut plastic can meet the requirements. In the examples in the application, the cut plastic is a 5mm*5mm rhombus piece.

[0029] In the application, the immersion time in liquid nitrogen is preferably 0.5-3 min. By immersing the plastic in liquid nitrogen, the application can improve the brittleness of the plastic, so that it is easier to form fine powder during subsequent crushing. As an embodiment of the application, the immersion time can be 0.5 min, 1 min, 2 min or 3 min.

[0030] In the present application, the pulverization is preferably performed in a pulverizer. The present application does not have special limitation on the specific model and source of the pulverizer, and a commercially available pulverizer well known to those skilled in the art can be used. The present application does not have special limitation on the time of the pulverization, and the particle size of the plastic powder can be made to meet the requirements. As an embodiment of the present application, the time of the pulverization can be 30 seconds, 1 minute or 2 minutes.

[0031] In the present application, the sieving is preferably performed through a 40-mesh sieve. In the present application, the particle size of the plastic powder is preferably ≥ 40 mesh. By controlling the particle size of the plastic powder, the present application can ensure that the subsequent chemical modifier can sufficiently modify the plastic powder.

[0032] In the present application, the chemical modifier includes any one of a solid base, a base solution and an acid solution; the solid base is preferably potassium hydroxide or sodium hydroxide, and more preferably potassium hydroxide; the base solution is preferably a potassium hydroxide solution or a sodium hydroxide solution, and more preferably a potassium hydroxide solution; the solvent of the base solution is water; the concentration of the base solution is preferably 0.5-0.8 g / mL, and more preferably 0.6 g / mL; the acid solution is preferably a phosphoric acid solution; the solvent of the acid solution is water; the mass concentration of the phosphoric acid solution is preferably 80-85%, and more preferably 85%.

[0033] In the present application, when the chemical modifier is a solid base, the mass ratio of the plastic powder to the solid base is preferably 1:(1-5), more preferably 1:(2-4), and further preferably 1:(2-3). In the present application, the mixing of the plastic powder and the solid base is preferably performed in a blender. The present application does not have special limitation on the specific model and source of the blender, and a commercially available blender well known to those skilled in the art can be used. The present application does not have special limitation on the rotation speed and time of the blending, and the solid base can be broken and uniformly mixed with the plastic powder. In the embodiments of the present application, the time of the mixing and blending can be 10 seconds.

[0034] In the present application, when the chemical modifier is an alkali solution, the ratio of the mass of the plastic powder to the volume of the alkali solution is preferably (2-5) g:(8-15) mL, more preferably (3-4) g:(10-12) mL. In the present application, the mixing method of the plastic powder and the alkali solution is preferably as follows: the plastic powder and the alkali solution are mixed, then subjected to magnetic stirring, and then dried. In the present application, the temperature of the magnetic stirring is preferably 50-80℃; the time of the magnetic stirring is preferably 1-6 h; the temperature of the drying is preferably 70-80℃; the time of the drying is preferably 8-12 h. As an embodiment of the present application, the temperature of the magnetic stirring can be 60-70℃; the time of the magnetic stirring can be 2-5 h, and can also be 3-4 h; the time of the drying can be 9-11 h, and can also be 10 h.

[0035] In the present application, when the chemical modifier is an acid solution, the mass ratio of the plastic powder to the acid solution is preferably 1:(1-5), more preferably 1:(2-4), and further preferably 1:(2-3). In the present application, the mixing method of the plastic powder and the acid solution is preferably as follows: the plastic powder and the acid solution are mixed, then subjected to magnetic stirring, and then dried. In the present application, the temperature of the magnetic stirring is preferably 50-80℃; the time of the magnetic stirring is preferably 1-6 h; the temperature of the drying is preferably 70-80℃; the time of the drying is preferably 8-12 h. As an embodiment of the present application, the temperature of the magnetic stirring can be 60-70℃; the time of the magnetic stirring can be 2-5 h, and can also be 3-4 h; the time of the drying can be 9-11 h, and can also be 10 h.

[0036] After obtaining the mixture, the present application subjects the mixture to heat treatment to obtain a waste plastic derived porous carrier.

[0037] In the present application, the heat treatment is preferably performed in a tube furnace. The present application does not have special limitations on the specific model and source of the tube furnace, and a commercially available tube furnace known to those skilled in the art can be used.

[0038] In the present application, the temperature of the heat treatment is preferably 600-800℃; the time of the heat treatment is preferably 0.2-3 h; the heating rate for heating to the heat treatment temperature is preferably 3-10℃ / min; the atmosphere of the heat treatment is preferably nitrogen; and the flow rate of the nitrogen is preferably 100-300 mL / min. By performing heat treatment, the chemical modifier can play a role in plasticizing the pores of the plastic powder under the action of high temperature in the present application, thereby increasing the specific surface area of the carrier and further improving the adsorption effect of the carrier.

[0039] In one embodiment of the present invention, the heat treatment temperature can be 600℃, 620℃, 650℃, 680℃, 700℃, 720℃, 750℃, 780℃, or 800℃; the heat treatment time can be 0.2h, 0.5h, 1h, 1.5h, 2h, 2.5h, or 3h; the heating rate to the heat treatment temperature can be 3℃ / min, 4℃ / min, 5℃ / min, 8℃ / min, or 10℃ / min; and the nitrogen flow rate can be 100mL / min, 120mL / min, 150mL / min, 180mL / min, 200mL / min, 220mL / min, 250mL / min, 280mL / min, or 300mL / min.

[0040] The present invention preferably further includes sequentially filtering and drying the heat-treated product.

[0041] In this invention, the filtration is preferably performed by first filtering with hydrochloric acid once, followed by filtering with deionized water three times. This invention does not impose any special limitations on the specific operation of the filtration; any operation well-known to those skilled in the art that can completely remove alkaline impurities is acceptable.

[0042] This invention does not impose specific limitations on the drying temperature and time, as long as the product is completely dried. In one embodiment of this invention, the drying temperature can be 80°C, and the drying time can be 12 hours.

[0043] The BET specific surface area of ​​the waste plastic-derived porous carrier prepared by the method provided by this invention is preferably 800-1100 m². 2 ·g -1 The total pore volume of the waste plastic-derived porous carrier is preferably 1.25–1.45 mL·g. -1 The preferred pore volume of the waste plastic-derived porous carrier using the BJH method is 0.85–1.15 cm³. 3 / g; the preferred micropore volume of the waste plastic-derived porous carrier using the HK method is 0.44–0.5 cm³. 3 / g; The average pore diameter (4V / A) of the waste plastic-derived porous carrier by the BJH method is preferably 10-20nm.

[0044] The porous carrier prepared by taking waste plastics as raw materials has good adsorption performance through simple chemical modification and high-temperature treatment, not only greatly reduces the synthesis cost of the porous carrier, but also enriches the upgrading utilization means of waste plastics, and realizes the resource recycling of waste plastics. The waste plastic derived porous carrier prepared in the application has good loading effect on organic amine reagents, can significantly improve the loading capacity of organic amine reagents, so that the obtained solid amine adsorbent has higher carbon dioxide adsorption capacity, and has superior environmental and economic performance. The technical scheme provided by the application can cope with the two environmental problems of global climate warming and plastic solid waste pollution.

[0045] The application further provides a waste plastic derived porous carrier prepared by the preparation method.

[0046] The BET specific surface area of the waste plastic derived porous carrier provided by the application is preferably 800-1100m 2 -1 The total pore volume of the waste plastic derived porous carrier is preferably 1.25-1.45mL·g -1 The BJH method pore volume of the waste plastic derived porous carrier is preferably 0.85-1.15cm 3 The HK method micropore volume of the waste plastic derived porous carrier is preferably 0.44-0.5cm 3 The BJH method average pore diameter (4V / A) of the waste plastic derived porous carrier is preferably 10-20nm.

[0047] The application further provides an application of the waste plastic derived porous carrier in preparing a solid amine adsorbent.

[0048] In the application, the method for preparing a solid amine adsorbent by using the waste plastic derived porous carrier comprises the following steps:

[0049] The organic amine, the solvent and the waste plastic derived porous carrier are mixed, and then rotary evaporation is performed to obtain a solid amine adsorbent.

[0050] In the application, the organic amine is preferably polyethyleneimine, and the solvent is preferably methanol or ethanol, and more preferably methanol. In the application, the mass ratio of the organic amine to the waste plastic derived porous carrier is preferably 1:(1-2). By using the above organic amine, the waste plastic derived porous carrier has better adsorption performance on the organic amine.

[0051] ​In the present application, the mixing method of the organic amine, the solvent and the waste plastic derived porous support is preferably as follows: the organic amine and the solvent are mixed and then subjected to magnetic stirring for 10-30 min, and then the waste plastic derived porous support is added and stirring is continued for 3-10 h. The present application does not have a special limitation on the rotating speed of the magnetic stirring, which can be determined according to the technical common sense of those skilled in the art. The waste plastic derived porous support can be fully combined with the organic amine by mixing in the above-mentioned manner. As an embodiment of the present application, the time for magnetic stirring of the mixture of the organic amine and the solvent can also be 15-20 min; and the time for continuing stirring after adding the waste plastic derived porous support can also be 5-6 h.

[0052] In the present application, the rotary evaporation is preferably carried out in a rotary evaporator. The present application does not have a special limitation on the specific model and source of the rotary evaporator, and a commercially available rotary evaporator known to those skilled in the art can be used.

[0053] In the present application, the temperature of the rotary evaporation is preferably 50-80℃; the time of the rotary evaporation is preferably 20-60 min; and the rotary evaporation is preferably carried out under the condition of water bath heating. The solvent can be removed by rotary evaporation. As an embodiment of the present application, the temperature of the rotary evaporation can be 60-70℃; and the time of the rotary evaporation can be 30-40 min.

[0054] The solid amine adsorbent prepared by using the waste plastic derived porous support provided by the present application has an adsorption capacity of 1.33 mmol / g under the condition of 25℃ and atmospheric CO2 partial pressure (i.e. 40 Pa), and has a relatively high direct air carbon capture capacity.

[0055] The technical solutions in the present application will be described clearly and completely below by combining with the embodiments in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0056] Example 1

[0057] A preparation method of a waste plastic derived porous support is as follows:

[0058] (1) The waste plastic is washed and cut into 5mm*5mm rhombus fragments, then immersed in liquid nitrogen for 1min, followed by crushing in a crusher for 1min, and sieved through a 40 mesh sieve to obtain plastic powder with a particle size of ≥40 mesh. The plastic powder is mixed with a chemical modifier in a magnetic stirrer, stirred for 1h under the condition of a 60℃ water bath, and finally dried in a 80℃ drying oven for 12h to obtain a mixture; the waste plastic is PET plastic; the chemical modifier is a potassium hydroxide solution with a concentration of 0.6g / mL; the mass of the plastic powder to the volume of the chemical modifier is 3g:10mL;

[0059] (2) The mixture obtained in step (1) is subjected to heat treatment in a tube furnace, the temperature of the heat treatment is 700℃, the time of the heat treatment is 1h, the atmosphere of the heat treatment is nitrogen, the flow rate of the nitrogen is 200mL / min, and the product is naturally cooled to room temperature after the heat treatment, first filtered once with hydrochloric acid, then filtered three times with deionized water, and finally dried in a 80℃ drying oven for 12h to obtain a waste plastic derived porous support, denoted as PET-K2-700.

[0060] Application Example 1

[0061] The method for preparing a solid amine adsorbent using the waste plastic derived porous support provided in Example 1 is as follows:

[0062] Polyethyleneimine and methanol are first mixed in a beaker and then magnetically stirred for 30min, then the waste plastic derived porous support is added, the beaker is sealed with a plastic film and continues to be stirred for 6h, and finally the mixture is poured into a rotary bottle and rotary evaporation is performed in a rotary evaporator to obtain a solid amine adsorbent, denoted as PET-K2-700-PEI50; the mass ratio of the polyethyleneimine to the waste plastic derived porous support is 1:1; the temperature of the rotary evaporation is 60℃, the time of the rotary evaporation is 30min, and the rotary evaporation is performed under the condition of water bath heating.

[0063] Example 2

[0064] A method for preparing a waste plastic derived porous support is as follows:

[0065] (1) The waste plastic is washed and cut into 5mm*5mm rhombus fragments, then immersed in liquid nitrogen for 1min, followed by crushing in a crusher for 1min, and sieved through a 40 mesh sieve to obtain plastic powder with a particle size of ≥40 mesh. The plastic powder is mixed with a chemical modifier in a magnetic stirrer, stirred for 1h under the condition of a 60℃ water bath, and finally dried in a 80℃ drying oven for 12h to obtain a mixture; the waste plastic is PET plastic; the chemical modifier is a potassium hydroxide solution with a concentration of 0.6g / mL; the mass of the plastic powder to the volume of the chemical modifier is 3g:10mL;

[0066] (2) The mixture obtained in step (1) is subjected to heat treatment in a tube furnace, the temperature of the heat treatment is 700℃, the time of the heat treatment is 1 h, the heating rate for heating to the temperature of the heat treatment is 5℃ / min, the atmosphere of the heat treatment is nitrogen, the flow rate of the nitrogen is 200 mL / min, the product is naturally cooled to room temperature after the heat treatment, it is first suction filtered once with hydrochloric acid, then suction filtered three times with deionized water, and finally dried in a drying box at 80℃ for 12 h, to obtain a waste plastic derived porous support, denoted as PET-K2-mix-700.

[0067] Application Example 2

[0068] The method for preparing a solid amine adsorbent using the waste plastic derived porous support provided in Example 2 is as follows:

[0069] Polyethyleneimine and methanol are first mixed in a beaker and then subjected to magnetic stirring for 30 min, then the waste plastic derived porous support is added, the beaker is sealed with a plastic film and stirring is continued for 6 h, and finally the mixture is poured into a rotary bottle and subjected to rotary evaporation in a rotary evaporator, to obtain a solid amine adsorbent, denoted as PET-K2-mix-700-PEI50; the mass ratio of the polyethyleneimine to the waste plastic derived porous support is 1:1; the temperature of the rotary evaporation is 60℃, the time of the rotary evaporation is 30 min, and the rotary evaporation is carried out under the condition of water bath heating.

[0070] Example 3

[0071] A method for preparing a waste plastic derived porous support is as follows:

[0072] (1) The waste plastic is washed and then cut into rhombic fragments of 5mm*5mm, then immersed in liquid nitrogen for 1 min, then crushed in a crusher for 1 min, and then passed through a 40-mesh sieve to obtain plastic powder with a particle size of ≥40 mesh, the plastic powder and a chemical modifier are mixed in a magnetic stirrer, stirred for 1 h under the condition of a 60℃ water bath heating, and finally dried in a 80℃ drying box for 12 h, to obtain a mixture; the waste plastic is PET plastic; the chemical modifier is a phosphoric acid solution with a mass concentration of 85%; the mass ratio of the plastic powder to the phosphoric acid solution is 1:2;

[0073] (2) The mixture obtained in step (1) is subjected to heat treatment in a tube furnace, the temperature of the heat treatment is 700℃, the time of the heat treatment is 1 h, the heating rate for heating to the temperature of the heat treatment is 5℃ / min, the atmosphere of the heat treatment is nitrogen, the flow rate of the nitrogen is 200 mL / min, the product is naturally cooled to room temperature after the heat treatment, it is first suction filtered once with hydrochloric acid, then suction filtered three times with deionized water, and finally dried in a drying box at 80℃ for 12 h, to obtain a waste plastic derived porous support, denoted as PET-P2-700.

[0074] Example 3

[0075] The method for preparing the solid amine adsorbent using the waste plastic derived porous carrier provided in Example 3 is as follows:

[0076] First, polyethyleneimine and methanol are mixed in a beaker and then subjected to magnetic stirring for 30 min, then the waste plastic derived porous carrier is added, the beaker is sealed with a plastic film and stirring is continued for 6 h, finally the mixture is poured into a rotary bottle and subjected to rotary evaporation in a rotary evaporator to obtain a solid amine adsorbent, which is denoted as PET-P2-700-PEI50; the mass ratio of the polyethyleneimine and the waste plastic derived porous carrier is 1:1; the rotary evaporation is carried out at a temperature of 60°C for 30 min under water bath heating.

[0077] The pore structure of the waste plastic derived porous carrier prepared in Examples 1-3 is tested as follows:

[0078] 0.2 g of the waste plastic derived porous carrier is loaded into a sample tube, heated and vacuum degassed at the degassing position of the physical adsorption instrument, the heating temperature is set to 110°C and the degassing time is 10 h, then nitrogen adsorption testing is carried out at the testing position, a dewar flask filled with liquid nitrogen is used to provide a temperature environment, pure nitrogen gas is introduced into the adsorption instrument, and the pressure and adsorption amount in the sample tube in the equilibrium state are detected. The pore structure of the waste plastic derived porous carrier of Examples 1-3 obtained by testing is shown in Table 1:

[0079] Table 1 Pore structure of waste plastic derived porous carrier of Examples 1-3

[0080]

[0081]

[0082] As can be seen from Table 1, the BET specific surface area of the waste plastic derived porous carrier prepared by the preparation method provided by the present application is 800-1100 m 2 / g -1 ; the total pore volume of the waste plastic derived porous carrier is 1.25-1.45 mL·g -1 ; the BJH pore volume of the waste plastic derived porous carrier is 0.85-1.15 cm 3 / g; the HK micropore volume of the waste plastic derived porous carrier is 0.44-0.5 cm 3 / g; and the average pore diameter (4V / A) of the waste plastic derived porous carrier by BJH method is 10-20 nm.

[0083] The solid amine adsorbent PET-K2-700-PEI50 prepared in application example 1 was subjected to carbon dioxide adsorption isotherm test, and the process was as follows:

[0084] 0.2 g of the solid amine adsorbent was loaded into a sample tube, and was subjected to heating and vacuum degassing at the degassing position of the physisorption instrument, the heating temperature was set to 110℃, and the degassing time was 5 h; then the sample tube was transferred to the test position, and was continuously subjected to in-situ degassing at the test position, the degassing time was 5 h; then pure CO2 was introduced for adsorption test, a dewar flask filled with water at 25℃ was used to provide temperature environment, and the pressure and adsorption amount in the sample tube at equilibrium state were detected, and the test results were as shown in Figure 1 Figure 1 It can be seen that the solid amine adsorbent PET-K2-700-PEI50 provided in application example 1 has an adsorption capacity of 1.33 mmol / g at 25℃ and atmospheric CO2 partial pressure (i.e. 40 Pa), and has a high direct air carbon capture capacity.

[0085] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.​

Claims

1. Use of a waste plastic derived porous support in the preparation of a solid amine adsorbent; The preparation method of the waste plastic derived porous support comprises the following steps: (1) crushing waste plastic to obtain plastic powder, and then mixing the plastic powder with a chemical modifier to obtain a mixture; the chemical modifier comprises any one of a solid base, a base solution and an acid solution; (2) heat treating the mixture obtained in step (1) to obtain a waste plastic derived porous support; The BET specific surface area of the waste plastic derived porous support is 800-1100 m 2 ·g -1 The total pore volume of the waste plastic derived porous support is 1.25-1.45 mL·g -1 The BJH pore volume of the waste plastic derived porous support is 0.85-1.15 cm 3 / g, the HK micropore volume of the waste plastic derived porous support is 0.44-0.5 cm 3 / g, and the BJH average pore diameter (4V / A) of the waste plastic derived porous support is 10-20 nm.

2. Use according to claim 1, characterized in that, The waste plastic in step (1) is PET plastic.

3. Use according to claim 1, characterized in that, The particle size of the plastic powder in step (1) is ≥40 mesh.

4. Use according to claim 1, characterized in that, The solid base in step (1) is potassium hydroxide or sodium hydroxide; the base solution is a potassium hydroxide solution or a sodium hydroxide solution, and the concentration of the base solution is 0.5-0.8 g / mL; the acid solution is a phosphoric acid solution, and the mass concentration of the phosphoric acid solution is 80-85%.

5. The use according to claim 1, characterized in that, When the chemical modifier in step (1) is a solid base, the mass ratio of the plastic powder to the solid base is 1:(1-5).

6. Use according to claim 1 or 4, characterized in that, When the chemical modifier in step (1) is a base solution, the mass of the plastic powder to the volume of the base solution is (2-5) g:(8-15) mL.

7. Use according to claim 1 or 4, characterized in that, When the chemical modifier in step (1) is an acid solution, the mass ratio of the plastic powder to the acid solution is 1:(1-5).

8. The use according to claim 1, characterized in that, The temperature of the heat treatment in step (2) is 600-800°C, and the heat treatment time is 0.2-3 h; the heating rate for heating to the heat treatment temperature is 3-10°C / min; the atmosphere of the heat treatment is nitrogen, and the flow rate of the nitrogen is 100-300 mL / min.

Images