A petroleum pitch-based magnetic porous carbon using waste acetate fiber to strengthen pore formation and its preparation method

Abstract

The present invention relates to a petroleum asphalt-based magnetic porous carbon that utilizes waste acetate fiber to enhance pore formation and a preparation method thereof. The present invention adopts a combined technical route of magnetic loading-compounding and blending-pore formation carbonization, utilizes waste acetate fiber to enhance the asphalt pore structure, and constructs a magnetic porous carbon with multi-level pores interconnected and connected. It has the advantages of rich pore structure, strong mechanical properties, magnetic recovery, efficient energy storage, and strong adsorption capacity. First, Fe3O4 is intercalated onto illite, which increases the interlamellar spacing of illite while generating magnetism, which is beneficial to enhancing pore formation. Then, Fe3O4-illite, waste acetate fiber and petroleum asphalt are uniformly mixed and carbonized by heating to obtain asphalt-based magnetic porous carbon. The porous carbon obtained by the present invention is simple to prepare, has excellent performance, and has broad application prospects. At the same time, the present invention also provides a new idea for the high-value-added utilization of petroleum asphalt, which is beneficial to solving the environmental pollution problem of discarded cigarette butts.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy materials, and in particular relates to a petroleum asphalt-based magnetic porous carbon using waste acetate fiber for enhanced pore formation and a preparation method thereof. Background Art

[0002] As crude oil becomes increasingly heavier and inferior, the production of heavy residues such as asphalt is increasing. Its efficient conversion and high-value utilization are becoming increasingly crucial to the high-quality development of the oil industry and a major strategic need in my country's energy sector. Currently, petroleum asphalt products are primarily used in roads and construction, with high-quality asphalt being used in the production of coatings, plastics, rubber, and other products. Petroleum asphalt is rich in carbon and has a natural potential for the preparation of high-value-added carbon materials. Therefore, expanding the traditional applications of petroleum asphalt and realizing its high-value-added utilization as a material has great development prospects and practical significance.

[0003] Porous carbon materials have the advantages of good conductivity, strong adsorption, and high chemical stability, and are widely used in electrochemical energy storage, adsorption, catalysis and other fields. Petroleum asphalt is a cheap high-carbon resource, which is suitable for conversion into porous carbon materials through directional conversion, thereby realizing its high-value utilization. At present, the asphalt-based carbon materials obtained after conventional activation and pore creation have problems such as a single pore structure and mostly large pores, which seriously affect their performance. The construction and optimization of the pore structure is the core of improving the application performance of porous carbon materials. How to optimize the pore structure and size of asphalt-based carbon materials and directionally construct multi-level hierarchical pores are key technical problems that need to be solved urgently.

[0004] Approximately 5.7 trillion cigarette butts (1.2 million tons) are discarded into the natural environment each year. The acetate filters in discarded cigarette butts are not only difficult to biodegrade but also contain large amounts of tar, polycyclic aromatic hydrocarbons, and other harmful substances, causing serious ecological pollution. Acetate, with its fibrous structure and pyrolysis properties, is expected to play a role in forming pores during thermal volatilization. Based on this, the present invention incorporates acetate from discarded cigarette butts into petroleum asphalt for co-carbonization. This not only enriches and optimizes the pore structure of petroleum asphalt-based carbon materials and improves their application performance, but also effectively addresses the environmental pollution issues associated with discarded cigarette butts. This approach has broad application prospects and important practical significance. Summary of the Invention

[0005] The purpose of the present invention is to provide a petroleum asphalt-based magnetic porous carbon using waste acetate fiber to enhance pore formation and a preparation method thereof. The prepared magnetic porous carbon has a developed and rich multi-level through-pore structure and can be widely used in supercapacitor electrodes, sewage treatment and other fields.

[0006] In response to the shortcomings of the existing technology, the present invention proposes a new method for preparing functional porous carbon, namely a combined technical route of magnetic loading-compound blending-pore-forming carbonization. Waste acetate fiber is used to strengthen the asphalt pore structure to construct a magnetic porous carbon with multi-level pores interconnected. It has the advantages of rich pore structure, strong mechanical properties, magnetic recovery, efficient energy storage, and strong adsorption capacity.

[0007] The technical solution of the present invention is a petroleum pitch-based magnetic porous carbon using waste acetate fiber to enhance pore formation and a preparation method thereof, comprising the following steps:

[0008] A petroleum pitch-based magnetic porous carbon using waste acetate fiber to enhance pore formation and a preparation method thereof, comprising the following steps:

[0009] (1) Preparation of Fe3O4-illite: 12-20 g illite was added to 250-350 mL deionized water and ultrasonically dispersed for 40-60 min; 25-35 g Fe(NO3)3·9H2O was dissolved in 150-200 mL deionized water and stirred to mix; the two solutions were poured into a round-bottom flask and heated under reflux for 5-7 h under stirring, and then the solvent was evaporated to dryness using a rotary evaporator. The residue was dried at 95-105°C for 10 h; the dried solid was calcined at 400°C for 3 h to obtain a magnetic Fe3O4-loaded illite composite material;

[0010] (2) Collection and pretreatment of waste acetate fiber: Collect discarded cigarette butts from the natural environment and separate them into three parts: acetate fiber filter tips, cigarette paper, and residual tobacco. Take 10-20 g of acetate fiber filter tips and add them to 800-1200 mL of solvent and soak them for 5-7 hours. Collect the soaked acetate fiber by filtration and dry it at 75-95°C for 24 hours. Place the dried acetate fiber in a grinder for 5-25 minutes to obtain waste acetate fiber powder.

[0011] (3) Preparation of magnetic porous carbon: 0.1-0.2 g of the Fe3O4-illite composite material obtained in step (1), 0.5-1.5 g of the waste cellulose acetate powder obtained in step (2) and 2.5-3.5 g of petroleum asphalt are placed in a mortar and ground thoroughly, and then 4-15 g of potassium hydroxide as an activator is added and continued to grind and mix evenly; the above mixture is placed in a square nickel crucible with a lid, and then the crucible is placed in a tube furnace; the tube furnace is heated from room temperature to 200°C and kept at a constant temperature for 40 minutes, and then the temperature is continued to be raised to 750-850°C and carbonized at a constant temperature for 1 hour, and then cooled naturally. The whole process is carried out in a nitrogen atmosphere. When the temperature of the tube furnace drops below 50°C, the product is taken out to obtain magnetic porous carbon.

[0012] In the aforementioned petroleum asphalt-based magnetic porous carbon using waste acetate fiber to enhance pore formation and its preparation method, in step (2), the solvent used to soak the waste acetate fiber is water, ethanol or toluene.

[0013] The aforementioned petroleum asphalt-based magnetic porous carbon using waste acetate fiber to enhance pore formation and its preparation method, in step (3), the magnetic porous carbon can be used as an adsorbent in sewage treatment and can be magnetically recovered, and can also be used to make supercapacitor electrode materials.

[0014] The beneficial effects of the present invention are as follows: (1) It provides a pitch-based magnetic porous carbon composite material with strong adsorption, recyclability and excellent electrochemical performance and a preparation method thereof; (2) It innovatively recycles the acetate fiber of discarded cigarette butts for forming holes in asphalt materials and optimizing the construction of multi-level pore structures, which greatly improves the application performance of asphalt-based porous carbon. At the same time, it solves the environmental pollution problem of discarded cigarette butts and realizes the high-value recycling of acetate fiber of cigarette butts; (3) It uses flaky clay mineral illite as Fe3O4 carrier to form Fe3O4-illite magnetic composite, which optimizes the porous carbon pore structure while enhancing its adsorption performance and mechanical properties, and makes it have magnetic function, resulting in a multi-component synergistic effect; (4) The prepared magnetic porous carbon can effectively adsorb and treat heavy metal wastewater, and can also be used as a raw material for electrode materials for supercapacitors. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the synthesis route of the petroleum pitch-based magnetic porous carbon of the present invention.

[0016] Figure 2 is the SEM image of the porous carbon obtained in Example 1.

[0017] Figure 3 This is a TEM image of the porous carbon obtained in Example 1.

[0018] Figure 4 This is the infrared spectrum of the porous carbon obtained in Example 1.

[0019] Figure 5 Graph showing the specific surface area of ​​the porous carbons obtained in Examples 1-4. Implementation Method

[0020] The effects and results of the method of the present invention are further illustrated below with reference to the following examples, but are not limited to the following examples.

[0021] Example 1: 15 g of illite was added to 300 mL of deionized water and ultrasonically dispersed for 50 min; 30 g of Fe(NO3)3•9H2O was dissolved in 200 mL of deionized water and stirred to mix; the two solutions were poured into a round-bottom flask, mixed and heated under reflux for 6 h under stirring, and then the solvent was evaporated to dryness using a rotary evaporator, and the residue was dried at 105°C for 10 h; the dried solid was calcined at 400°C for 3 h to obtain a magnetic Fe3O4-loaded illite composite material; cigarette butts discarded in the natural environment were collected and separated into three parts: acetate filter tips, cigarette paper sheets and residual tobacco; 15 g of acetate filter tips were added to 1000 mL of solvent and soaked for 6 h; the soaked acetate was collected by filtration and dried at 90°C for 24 h; the dried acetate was placed in a grinder for 20 min to obtain waste acetate powder; 0.1 g of the Fe3O4-illite composite material obtained in step (1), 0.5 g of the waste cellulose acetate powder obtained in step (2) and 3 g of petroleum asphalt are placed in a mortar and ground thoroughly, and then 10 g of potassium hydroxide as an activator is added and continued to be ground and mixed evenly; the above mixture is placed in a square nickel crucible with a lid, and then the crucible is placed in a tube furnace; the tube furnace is heated from room temperature to 200°C and kept at a constant temperature for 40 minutes, and then continued to heat and heat to 800°C and carbonized at a constant temperature for 1 hour, and then cooled naturally. The whole process is carried out in a nitrogen atmosphere. When the tube furnace drops below 50°C, the product is taken out to obtain magnetic porous carbon.

[0022] Example 2: The steps are the same as those described in Example 1, except that the amount of waste acetate fiber powder is changed from 0.5 g to 0 g.

[0023] Example 3: The steps are the same as those described in Example 1, except that the amount of waste cellulose acetate powder is changed from 0.5 g to 1 g.

[0024] Example 4: The steps are the same as those described in Example 1, except that the amount of waste acetate fiber powder is changed from 0.5 g to 1.5 g.

[0025] The pore structure of the porous carbon obtained in Example 1 is as follows Figure 2 and Figure 3 Its infrared spectrum is shown as Figure 4 The specific surface area of ​​the porous carbon obtained in Examples 1-4 is shown in FIG. Figure 5 As shown in the above examples, the petroleum pitch-based magnetic porous carbon prepared by the present invention using waste acetate fiber for enhanced pore formation has a rich multi-level pore structure, abundant functional group sites, a large specific surface area, and strong adsorption and electrochemical energy storage properties. Compared with conventional technologies, the present invention represents a significant technological advancement.

Claims

1. A method for preparing petroleum pitch-based magnetic porous carbon using waste acetate fiber to enhance pore formation, comprising the following steps: (1) Preparation of Fe3O4-illite: 12-20 g illite was added to 250-350 mL deionized water and ultrasonically dispersed for 40-60 min; 25-35 g Fe(NO3)3·9H2O was dissolved in 150-200 mL deionized water and stirred to mix; the two solutions were poured into a round-bottom flask, mixed, and heated under reflux for 5-7 h under stirring, and then the solvent was evaporated to dryness using a rotary evaporator. The obtained residue was dried at 95-105°C for 10 h; the dried solid was calcined at 400°C for 3 h to obtain a magnetic Fe3O4-loaded illite composite material; (2) Collection and pretreatment of waste acetate fiber: Collect discarded cigarette butts from the natural environment and separate them into three parts: acetate fiber filter tips, cigarette paper, and residual tobacco. Take 10-20g of acetate fiber filter tips and add them to 800-1200mL of solvent and soak them for 5-7h. Collect the soaked acetate fiber by filtration and dry it at 75-95℃ for 24h. Place the dried acetate fiber in a grinder for 5-25min to obtain waste acetate fiber powder. (3) Preparation of magnetic porous carbon: 0.1-0.2 g of the Fe3O4-illite composite material obtained in step (1), 0.5-1.5 g of the waste cellulose acetate powder obtained in step (2) and 2.5-3.5 g of petroleum asphalt are placed in a mortar and thoroughly ground and mixed, and then 4-15 g of activator potassium hydroxide are added and continued to be ground and mixed evenly; the above mixture is placed in a square nickel crucible with a lid, and then the crucible is placed in a tube furnace; the tube furnace is heated from room temperature to 200°C and kept at a constant temperature for 40 minutes, and then the temperature is continued to be raised to 750-850°C and carbonized at a constant temperature for 1 hour, and then cooled naturally. The whole process is carried out in a nitrogen atmosphere. When the temperature of the tube furnace drops below 50°C, the product is taken out to obtain magnetic porous carbon.

2. The method for preparing petroleum pitch-based magnetic porous carbon by using waste acetate fiber to enhance pore formation according to claim 1, characterized in that: In the step (2), the solvent used to soak the waste acetate fiber is water, ethanol or toluene.

3. The method for preparing petroleum pitch-based magnetic porous carbon by using waste acetate fiber to enhance pore formation according to claim 1, characterized in that: In the step (3), the magnetic porous carbon is used as an adsorbent for sewage treatment and can be magnetically recovered, or used to prepare supercapacitor electrode materials.

4. A petroleum pitch-based magnetic porous carbon obtained by the preparation method according to any one of claims 1 to 3 using waste acetate fiber to enhance pore formation.

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