Method for preparing biomass porous activated carbon-based adsorbent using waste PET degradation products

Abstract

The present invention discloses a method for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products, specifically comprising: x The MXene two-dimensional material is mixed with deionized water, sonicated, dried, and ground to obtain a mixed pharmaceutical powder; potassium hydroxide is mixed with deionized water, sonicated, dried, and ground to obtain a potassium hydroxide pharmaceutical powder; the pharmaceutical powder is calcined to obtain a biomass porous activated carbon-based adsorbent. This invention is the first to use a co-carbonization method to prepare a biomass porous activated carbon-based adsorbent by combining waste PET degradation products with biomass materials in the presence of MXene two-dimensional materials. In addition, the method of the present invention requires the placement of potassium hydroxide powder first, followed by the mixed powder of GOPs, biomass materials, and MXene two-dimensional materials. This not only ensures sufficient activation but also improves yield.

Description

Technical Field

[0001] The invention belongs to the technical field of adsorbent preparation, and particularly relates to a method for preparing a biomass porous activated carbon-based adsorbent by utilizing waste PET degradation products. Background Art

[0002] Polyethylene terephthalate (PET) exhibits excellent mechanical properties, resistance to friction and wear, rigidity, and hardness at room temperature. It is non-toxic, odorless, and has excellent transparency. Therefore, PET is widely used in a variety of fields, including food packaging, film and sheeting, electronics, automotive parts, and mechanical equipment materials. PET's use in packaging bottles has evolved from its initial use in carbonated beverages to current applications such as beer, cooking oil, condiment bottles, pharmaceutical bottles, and cosmetics. Due to its inherent stability and resistance to degradation, it poses serious environmental challenges. Discarded PET bottles constitute a significant source of packaging waste, and addressing their environmental impact while increasing their reusability is of great significance.

[0003] Biomass carbon refers to a solid carbon-rich material prepared from biomass as raw material through pyrolysis, hydrothermal carbonization, gasification, and rapid carbonization. The advancement of science and technology and the continuous updating of industrial equipment have brought huge economic benefits as well as serious environmental problems. In particular, the continuous discharge of industrial wastewater has caused serious damage to water resources. How to better solve the problems of pigments, heavy metals, and microplastics in industrial wastewater is urgent. The carbon materials prepared by pyrolysis and carbonization have excellent performance and extremely high application value. They can be used in many fields such as environmental remediation and adsorption. Especially in the field of adsorption, such as the adsorption of methylene blue and methylene orange in industrial wastewater, the adsorption of carbon dioxide, etc., biomass carbon materials have excellent performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a biomass porous activated carbon-based adsorbent by utilizing waste PET degradation products. The biomass porous activated carbon-based adsorbent has good adsorption capacity.

[0005] The technical solution adopted by the present invention is a method for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products, which is specifically implemented according to the following steps:

[0006] Step 1, preparing waste PET degradation products;

[0007] Step 2: weigh the waste PET degradation products, lignin, potassium hydroxide, Ti3C2T x -MXene two-dimensional materials;

[0008] Step 3: waste PET degradation products, lignin, Ti3C2T x-MXene two-dimensional material is mixed with deionized water, sonicated, dried, and ground to obtain a mixed pharmaceutical powder;

[0009] Step 4, mixing potassium hydroxide with deionized water, ultrasonically treating, drying, and grinding to obtain potassium hydroxide pharmaceutical powder;

[0010] Step 5: roasting the drug powder, washing it with deionized water to neutrality, and drying it to obtain a biomass porous activated carbon-based adsorbent.

[0011] The present invention is also characterized in that:

[0012] In step 1, specifically:

[0013] Step 1.1, cutting the waste PET into plastic sheets, then adding 3 to 5 times the amount of deionized water, and pre-treating the plastic sheets under stirring conditions to obtain PET plastic sheets;

[0014] Step 1.2: 10-25 parts of PET plastic flakes, 5-25 parts of methylpropylene glycol, 5-25 parts of 1,5-pentanediol, and 1-5 parts of n-butyl titanate are mixed, and the mixture is stirred and alcoholyzed in an oil bath at a temperature of 210-230° C. for 7-9 hours to obtain waste PET flakes;

[0015] In step 1.3, the alcoholyzed PET flakes were placed in a multifunctional crusher and crushed for one minute at a time. After five cycles of crushing, a white powder was obtained, which was the GOPs, a degradation product of the waste PET.

[0016] In step 1.1, the stirring speed is 370-520 r / min, the pretreatment temperature is 200° C. to 250° C., and the pretreatment time is 2-3 h.

[0017] In step 2, 1 to 5 parts of waste PET degradation product GOPs, 1 to 5 parts of lignin, 2 to 10 parts of potassium hydroxide, 0.1 to 5 parts of Ti3C2T x -MXene two-dimensional materials.

[0018] In step 3 and step 4, the ultrasonic treatment time is 20-40 minutes; the drying temperature is 60-80° C., and the drying time is 24-48 hours.

[0019] In step 5, specifically:

[0020] Potassium hydroxide powder is first added to a white porcelain ark, and then the mixed powder is added, and the ark is placed in a tubular furnace and calcined in a nitrogen atmosphere to obtain a biomass porous activated carbon-based adsorbent containing potassium hydroxide; the biomass porous activated carbon-based adsorbent containing potassium hydroxide is placed in a conical flask for vacuum filtration, and the powder is continuously rinsed with deionized water during the filtration until the pH value of the solution becomes neutral, and then dried to obtain a biomass porous activated carbon-based adsorbent.

[0021] During calcination: the nitrogen flow rate is 150-200 mL / min, the temperature is raised to 700°C-900°C at a rate of 5-10°C / min and kept warm for 60-120 minutes.

[0022] The drying temperature is 60-80℃ and the drying time is 12-24h.

[0023] The beneficial effect of the present invention is that the present invention proposes a new method for co-carbonization of polyester degradation products with biomass materials and MXene materials. The biomass materials can be selected from lignin, cellulose, wood chips, sawdust, etc. The waste packaging PET bottles are recycled, pre-treated by hydrolysis, and then the degradation products are prepared by chemical method. The degradation products are then mixed with Ti3C2T prepared by freeze-drying. x A mixture of MXene and lignin, a biomass-based porous activated carbon-based adsorbent, was used to prepare a biomass-based porous activated carbon-based adsorbent. Using the MXene-based two-dimensional material, the activator was first added, followed by the remaining experimental materials, and then co-carbonized to prepare the biomass-based porous activated carbon-based adsorbent. This adsorbent can absorb methylene blue and methylene orange from industrial wastewater, as well as carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the SEM image of the carbon-based adsorbent prepared by direct carbonization of degradation products;

[0025] Figure 2 This is the SEM spectrum of the carbon-based adsorbent prepared by the degradation product of the present invention and the biomass material at a ratio of 1:1;

[0026] Figure 3 is a graph showing the carbonization yield of GOPs by direct carbonization and co-carbonization at different temperatures of the present invention; DETAILED DESCRIPTION

[0027] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] The method of the present invention for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products is specifically implemented according to the following steps:

[0029] Step 1, preparing waste PET degradation products; specifically:

[0030] Step 1.1, cutting the waste PET into plastic sheets, then adding 3 to 5 times the amount of deionized water, and pre-treating the plastic sheets under stirring conditions to obtain PET plastic sheets;

[0031] The stirring speed is 370-520r / min, the pretreatment temperature is 200℃~250℃, and the pretreatment time is 2-3h;

[0032] Step 1.2, mixing 10 to 25 parts of PET plastic flakes, 5 to 25 parts of methylpropylene glycol, 5 to 25 parts of 1,5-pentanediol, and 1 to 5 parts of n-butyl titanate, and performing alcoholysis with stirring in an oil bath to obtain waste PET flakes;

[0033] The alcoholysis temperature is 210-230°C and the alcoholysis time is 7-9h;

[0034] In step 1.3, the alcoholyzed PET flakes were placed in a multifunctional crusher and crushed for one minute at a time. After five cycles of crushing, a white powder was obtained, which was the GOPs, a degradation product of the waste PET.

[0035] Step 2: weigh 1-5 parts of waste PET degradation product GOPs, 1-5 parts of lignin, 2-10 parts of potassium hydroxide, 0.1-5 parts of Ti3C2T x -MXene two-dimensional materials;

[0036] Step 3: GOPs, biomass lignin, and freeze-dried Ti3C2T x -MXene two-dimensional material is mixed with deionized water, ultrasonicated, dried, and ground to obtain a mixed pharmaceutical powder;

[0037] The ultrasonic treatment time is 20-40 min;

[0038] The drying temperature is 60-80℃ and the drying time is 24-48h;

[0039] Step 4, mixing potassium hydroxide with deionized water, ultrasonically treating, drying, and grinding to obtain potassium hydroxide pharmaceutical powder;

[0040] The ultrasonic treatment time is 20-40 min;

[0041] The drying temperature is 60-80℃ and the drying time is 24-48h;

[0042] Step 5: first add potassium hydroxide powder to a white porcelain ark, then add the mixed powder, and place it in a tubular furnace for calcination in a nitrogen atmosphere to obtain a biomass porous activated carbon-based adsorbent containing potassium hydroxide; place the biomass porous activated carbon-based adsorbent containing potassium hydroxide into a conical flask for vacuum filtration, and continuously rinse the powder with deionized water during filtration until the pH value of the solution becomes neutral, so that the potassium hydroxide can be removed and dried to obtain a biomass porous activated carbon-based adsorbent.

[0043] During calcination: the nitrogen flow rate is 150-200 mL / min, the temperature is raised to 700℃~900℃ at a rate of 5~10℃ / min and kept at this temperature for 60~120min;

[0044] The drying temperature is 60-80℃ and the drying time is 12-24h;

[0045] Example 1

[0046] The method of the present invention for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products is specifically implemented according to the following steps:

[0047] Step 1, preparing waste PET degradation products; specifically:

[0048] Step 1.1, cutting the waste PET into plastic sheets, then adding 4 times the amount of deionized water, and pre-treating the plastic sheets under stirring conditions to obtain PET plastic sheets;

[0049] The stirring speed was 400 r / min, the pretreatment temperature was 200 °C, and the pretreatment time was 3 h;

[0050] Step 1.2, 15 parts of PET plastic sheets, 15 parts of methyl propylene glycol, 15 parts of 1,5-pentanediol, and 2 parts of n-butyl titanate are mixed, and stirred and alcoholyzed in an oil bath to obtain waste PET flakes;

[0051] The alcoholysis temperature was 210°C and the alcoholysis time was 9 h;

[0052] In step 1.3, the alcoholyzed PET flakes were placed in a multifunctional crusher and crushed for one minute at a time. After five cycles of crushing, a white powder was obtained, which was the GOPs, a degradation product of the waste PET.

[0053] Step 2: weigh 1 part of waste PET degradation product GOPs, 1 part of lignin, 2 parts of potassium hydroxide, 0.2 parts of Ti3C2T x -MXene two-dimensional materials;

[0054] Step 3: GOPs, biomass lignin, and freeze-dried Ti3C2T x-MXene two-dimensional material is mixed with deionized water, ultrasonicated, dried, and ground to obtain a mixed pharmaceutical powder;

[0055] The ultrasonic treatment time was 20 min; the drying temperature was 60 °C and the drying time was 48 h;

[0056] Step 4, mixing potassium hydroxide with deionized water, ultrasonically treating, drying, and grinding to obtain potassium hydroxide pharmaceutical powder;

[0057] The ultrasonic treatment time was 20 min; the drying temperature was 60 °C and the drying time was 48 h;

[0058] Step 5: first add potassium hydroxide powder to a white porcelain ark, then add the mixed powder, and place it in a tubular furnace for calcination in a nitrogen atmosphere to obtain a biomass porous activated carbon-based adsorbent containing potassium hydroxide; place the biomass porous activated carbon-based adsorbent containing potassium hydroxide into a conical flask for vacuum filtration, and continuously rinse the powder with deionized water during filtration until the pH value of the solution becomes neutral, so that the potassium hydroxide can be removed and dried to obtain a biomass porous activated carbon-based adsorbent.

[0059] During calcination: nitrogen flow rate is 150 mL / min, the temperature is raised to 800 °C at a rate of 5 °C / min and kept at this temperature for 120 min;

[0060] The drying temperature is 80°C and the drying time is 12h;

[0061] MB and MO solutions were pre-prepared at 1000 mg / L. Using these pre-prepared solutions, 50 ml of MB and MO solutions of varying concentrations were prepared in 100 ml beakers. 10 mg of carbon-based adsorbent was added to these solutions for MB and MO adsorption testing. The results showed that the adsorption effect increased significantly with increasing reaction time.

[0062] Example 2

[0063] The method of the present invention for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products is specifically implemented according to the following steps:

[0064] Step 1, preparing waste PET degradation products; specifically:

[0065] Step 1.1, cutting the waste PET into plastic sheets, then adding 3 times the amount of deionized water, and pre-treating the plastic sheets under stirring conditions to obtain PET plastic sheets;

[0066] The stirring speed was 370 r / min, the pretreatment temperature was 220 °C, and the pretreatment time was 3 h;

[0067] Step 1.2, 18 parts of PET plastic sheets, 18 parts of methyl propylene glycol, 18 parts of 1,5-pentanediol, and 3 parts of n-butyl titanate are mixed, and stirred and alcoholyzed in an oil bath to obtain waste PET flakes;

[0068] The alcoholysis temperature was 220°C and the alcoholysis time was 8 h;

[0069] In step 1.3, the alcoholyzed PET flakes were placed in a multifunctional crusher and crushed for one minute at a time. After five cycles of crushing, a white powder was obtained, which was the GOPs, a degradation product of the waste PET.

[0070] Step 2: weigh 1 part of waste PET degradation product GOPs, 2 parts of lignin, 3 parts of potassium hydroxide, 0.3 parts of Ti3C2T x -MXene two-dimensional materials;

[0071] Step 3: GOPs, biomass lignin, and freeze-dried Ti3C2T x -MXene two-dimensional material is mixed with deionized water, ultrasonicated, dried, and ground to obtain a mixed pharmaceutical powder;

[0072] The ultrasonic treatment time was 30 min; the drying temperature was 70 °C and the drying time was 30 h;

[0073] Step 4, mixing potassium hydroxide with deionized water, ultrasonically treating, drying, and grinding to obtain potassium hydroxide pharmaceutical powder;

[0074] The ultrasonic treatment time was 30 min; the drying temperature was 70 °C and the drying time was 30 h;

[0075] Step 5: first add potassium hydroxide powder to a white porcelain ark, then add the mixed powder, and place it in a tubular furnace for calcination in a nitrogen atmosphere to obtain a biomass porous activated carbon-based adsorbent containing potassium hydroxide; place the biomass porous activated carbon-based adsorbent containing potassium hydroxide into a conical flask for vacuum filtration, and continuously rinse the powder with deionized water during filtration until the pH value of the solution becomes neutral, so that the potassium hydroxide can be removed and dried to obtain a biomass porous activated carbon-based adsorbent.

[0076] During calcination: nitrogen flow rate is 160 mL / min, the temperature is raised to 800 °C at a rate of 8 °C / min and kept at this temperature for 120 min;

[0077] The drying temperature is 70°C and the drying time is 18 hours;

[0078] MB and MO solutions were pre-prepared at 1000 mg / L. Using these pre-prepared solutions, 50 ml of MB and MO solutions of varying concentrations were prepared in 100 ml beakers. 10 mg of carbon-based adsorbent was added to these solutions for MB and MO adsorption testing. The results showed that the adsorption effect increased significantly with increasing reaction time.

[0079] Example 3

[0080] The method of the present invention for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products is specifically implemented according to the following steps:

[0081] Step 1, preparing waste PET degradation products; specifically:

[0082] Step 1.1, cutting the waste PET into plastic sheets, then adding 5 times the amount of deionized water, and pre-treating the plastic sheets under stirring conditions to obtain PET plastic sheets;

[0083] The stirring speed was 520 r / min, the pretreatment temperature was 240 °C, and the pretreatment time was 2 h;

[0084] Step 1.2, 20 parts of PET plastic sheets, 20 parts of methyl propylene glycol, 20 parts of 1,5-pentanediol, and 4 parts of n-butyl titanate are mixed, and stirred and alcoholyzed in an oil bath to obtain waste PET flakes;

[0085] The alcoholysis temperature was 230°C and the alcoholysis time was 7 h;

[0086] In step 1.3, the alcoholyzed PET flakes were placed in a multifunctional crusher and crushed for one minute at a time. After five cycles of crushing, a white powder was obtained, which was the GOPs, a degradation product of the waste PET.

[0087] Step 2: weigh 1 part of waste PET degradation product GOPs, 3 parts of lignin, 4 parts of potassium hydroxide, 0.4 parts of Ti3C2T x -MXene two-dimensional materials;

[0088] Step 3: GOPs, biomass lignin, and freeze-dried Ti3C2T x -MXene two-dimensional material is mixed with deionized water, ultrasonicated, dried, and ground to obtain a mixed pharmaceutical powder;

[0089] The ultrasonic treatment time was 40 min; the drying temperature was 80 °C and the drying time was 24 h;

[0090] Step 4, mixing potassium hydroxide with deionized water, ultrasonically treating, drying, and grinding to obtain potassium hydroxide pharmaceutical powder;

[0091] The ultrasonic treatment time was 40 min; the drying temperature was 80 °C and the drying time was 24 h;

[0092] Step 5: first add potassium hydroxide powder to a white porcelain ark, then add the mixed powder, and place it in a tubular furnace for calcination in a nitrogen atmosphere to obtain a biomass porous activated carbon-based adsorbent containing potassium hydroxide; place the biomass porous activated carbon-based adsorbent containing potassium hydroxide into a conical flask for vacuum filtration, and continuously rinse the powder with deionized water during filtration until the pH value of the solution becomes neutral, so that the potassium hydroxide can be removed and dried to obtain a biomass porous activated carbon-based adsorbent.

[0093] During calcination: the nitrogen flow rate was 200 mL / min, the temperature was raised to 800 °C at a rate of 5 °C / min and kept at this temperature for 120 min;

[0094] The drying temperature is 60°C and the drying time is 24h;

[0095] MB and MO solutions were pre-prepared at 1000 mg / L. Using these pre-prepared solutions, 50 ml of MB and MO solutions of varying concentrations were prepared in 100 ml beakers. 10 mg of carbon-based adsorbent was added to these solutions for MB and MO adsorption testing. The results showed that the adsorption effect increased significantly with increasing reaction time.

[0096] The present invention is the first to use the co-carbonization method to prepare biomass porous activated carbon-based adsorbents by combining waste PET degradation products with biomass materials under the action of MXene two-dimensional materials. Compared with the direct carbonization of waste PET degradation products, the adsorbent prepared by this method not only has a significant increase in yield at 800°C, but also has a significant adsorption effect. In addition, compared with the traditional method (carbonization first, activation, and then carbonization), this method basically does not produce waste liquid during the entire process and saves energy. In the method of the present invention, potassium hydroxide powder must be placed first, and then a mixed powder of GOPs, biomass materials, and MXene two-dimensional materials must be placed. This not only ensures sufficient activation, but also improves the yield.

[0097] Figure 1 This is the SEM image of the adsorbent obtained by direct carbonization of PET degradation products. Figure 2 This is the SEM image of the biomass porous activated carbon-based adsorbent of the present invention. The biomass carbon-based adsorbent not only has a significant increase in yield, but also has a higher specific surface area and pore volume. The carbonization yield of a single waste PET degradation product is only about 16%, while the yield of the activated carbon-based adsorbent prepared by the one-step method of the present invention is about 30%, which is a significant improvement. In addition, its yield is determined by changing the experimental temperature, such as Figure 3As shown in Figure 2, biomass porous activated carbon-based adsorbents prepared by co-carbonizing degradation products with biomass materials and an activator in varying ratios were used to adsorb methylene blue (MB) and methylene orange (MO). The results showed that a 1:1 ratio of degradation products to biomass materials yielded the highest adsorption capacity for MB and MO. The adsorbent also exhibited rapid adsorption rates, good reusability, and excellent color removal capabilities.

[0098] Compared with similar adsorbents such as Ni nanospheres, functional multi-walled carbon nanotubes, and activated CNTs, the carbon-based adsorbent MB at a 1:1 ratio exhibited stronger adsorption capacity and better adsorption effects. Compared with similar adsorbents such as sugar beet bagasse and polyaniline nano adsorbents, the carbon-based adsorbent MO at a 1:1 ratio exhibited stronger adsorption capacity and better adsorption effects.

Claims

1. A method for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products, characterized in that: Please follow the steps below to implement it: Step 1, preparing waste PET degradation products; specifically: Step 1.1, cutting the waste PET into plastic sheets, then adding 3 to 5 times the amount of deionized water, and pre-treating the plastic sheets under stirring conditions to obtain PET plastic sheets, where PET is polyethylene terephthalate; the stirring speed is 370-520 r / min, the pre-treatment temperature is 200°C to 250°C, and the pre-treatment time is 2-3 hours; Step 1.2: 10-25 parts of PET plastic flakes, 5-25 parts of methylpropylene glycol, 5-25 parts of 1,5-pentanediol, and 1-5 parts of n-butyl titanate are mixed, and the mixture is stirred and alcoholyzed in an oil bath at a temperature of 210-230° C. for 6-8 hours to obtain waste PET flakes; In step 1.3, the waste PET flakes after alcoholysis were placed in a multifunctional pulverizer and pulverized for one minute at a time. After five cycles of pulverization, a white powder was obtained, which was the GOPs degradation product of the waste PET. Step 2: Weigh 1-5 parts of waste PET degradation product GOPs, 1-5 parts of lignin, 2-10 parts of potassium hydroxide and 0.1-5 parts of Ti3C2T x -MXene two-dimensional materials; Step 3: GOPs, lignin, Ti3C2T3 x -MXene two-dimensional material is mixed with deionized water, sonicated, dried, and ground to obtain a mixed pharmaceutical powder; Step 4, mixing potassium hydroxide with deionized water, ultrasonically treating, drying, and grinding to obtain potassium hydroxide pharmaceutical powder; Step 5: first add potassium hydroxide powder to a white porcelain ark, then add the mixed powder, and place it in a tubular furnace for roasting in a nitrogen atmosphere. During roasting, the nitrogen flow rate is 150-200 mL / min, and the temperature is increased to 700°C~900°C at a rate of 5~10°C / min and kept warm for 60~120 minutes to obtain a biomass porous activated carbon-based adsorbent containing potassium hydroxide; the biomass porous activated carbon-based adsorbent containing potassium hydroxide is placed in a conical flask for vacuum filtration, and the powder is continuously rinsed with deionized water during filtration until the pH value of the solution becomes neutral, and dried at 60-80°C for 12-24 hours to obtain a biomass porous activated carbon-based adsorbent.

2. The method for preparing a biomass porous activated carbon-based adsorbent using waste PET degradation products according to claim 1, characterized in that: In step 3 and step 4, the ultrasonic time is 20-40 min; the drying temperature is 60-80° C., and the drying time is 24-48 h.

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