Method for preparing adsorbing material from kitchen biogas residues

Abstract

The invention relates to the technical field of solid waste recycling, in particular to a method for preparing an adsorption material from kitchen biogas residues, which comprises the following six steps: pretreatment, high-temperature pyrolysis carbonization, acid pickling, water washing, physical activation and sample detection. According to the method, kitchen anaerobic fermentation biogas residues and vulcanized carbon black recycled from rubber tires are scientifically, reasonably and synergistically mixed to prepare the adsorption material, and the kitchen biogas residues are subjected to series pretreatment, high-temperature pyrolysis carbonization, acid pickling and water washing and physical activation processing, so that the biogas residues are subjected to non-toxic treatment, and meanwhile, the adsorption efficiency is improved. According to the preparation method, the adsorption material with the porous structure can be prepared, the prepared adsorption material can be applied to various fields, diversified, multi-field and multi-scene application of the kitchen biogas residues is achieved, and meanwhile the prepared porous adsorption material can bring higher economic benefits and social utilization value.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste resource utilization, and particularly relates to a method for preparing an adsorption material from kitchen waste biogas residue. Background Art

[0002] Kitchen waste biogas residue is a kind of wet waste after anaerobic treatment of kitchen waste. It is rich in organic matter, humic acid, enzymes and microorganisms, etc. At the same time, it is rich in nutrient elements such as nitrogen, phosphorus and potassium, but has a low carbon-nitrogen ratio. Landfilling or incinerating it through existing treatment facilities shows the dilemmas of high energy consumption, large carbon emissions and low resource utilization efficiency. Therefore, how to effectively realize the resource utilization of kitchen waste biogas residue is the focus of the whole society.

[0003] The main component of carbon black is carbon. It is the earliest developed, applied and currently the largest output nanomaterial by humans. Its basic particle size is between 10 - 100 nm. It has excellent functions such as rubber reinforcement, coloring, conductivity or antistatic, and ultraviolet absorption. It is listed as one of the twenty-five basic chemical products and fine chemical products in the international chemical field. Carbon black is of great significance to the tire industry, the dyeing and chemical industry, and improving the quality of civil life products, etc.

[0004] At present, the main direction of the resource utilization of kitchen waste biogas residue is as a raw material for making organic fertilizer. Although this process realizes the recycling of kitchen waste biogas residue solid waste resources, it is easy to cause secondary pollution to the environment during the fertilizer production process, such as the emission of malodorous pollutants. At the same time, the economic benefits brought are general, and the scope of recycling and reuse is relatively limited. Therefore, in order to comprehensively improve the recycling and reuse effect of kitchen waste biogas residue, the present invention provides a method for preparing an adsorption material from kitchen waste biogas residue, which utilizes the physical and chemical characteristics of kitchen waste biogas residue itself and coordinates with the physical and chemical properties of carbon black to realize the diversified, multi-field and multi-scenario applications of kitchen waste biogas residue and carbon black. Summary of the Invention

[0005] The purpose of the present invention is to propose a method for preparing an adsorption material from kitchen waste biogas residue in order to solve the problems of single recycling and reuse treatment mode, general economic benefits and relatively limited application scope of kitchen waste biogas residue in the prior art.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions: A method for preparing an adsorption material from kitchen waste biogas residue, comprising the following steps: Step 1. Pretreatment: Place the kitchen waste biogas residue after anaerobic fermentation of kitchen waste in an oven for drying treatment, crush the dried kitchen waste biogas residue with a crusher and then screen it to prepare a sample for later use; Step 2. High-temperature pyrolysis carbonization: After taking the pretreated kitchen waste biogas residue sample and mixing it with carbon black powder according to a certain mass ratio, place it in a tubular furnace with a protective gas introduced, and carry out anaerobic pyrolysis. The heating rate is set at 5 °C / min, the final pyrolysis temperature is set at 300 °C - 700 °C, and it is maintained at the set final pyrolysis temperature for 60 min. Finally, it is cooled to room temperature in the protective gas environment, and the pyrolyzed sample is taken out and stored in a sealed bag; Step 3. Acid washing: To reduce the influence of acid-soluble salts and impurities in the adsorption material and expand the specific surface area and porosity of the adsorption material, add the pyrolyzed sample obtained in Step 2 to a hydrochloric acid / nitric acid solution with a mass concentration of 10%, ultrasonicate it in an ultrasonic cleaner for 60 min, and then filter it by suction. Collect the filter residue for standby; Step 4. Water washing: Add the filter residue obtained in Step 3 to water, adjust the pH of the system to 7, and then filter it by suction. Dry the obtained solid sample in an oven and store it in a sealed bag for standby; Step 5. Physical activation: Take the sample treated in Step 4, introduce steam at 800 - 900 °C for activation, and set the activation time to 40 - 60 min. After the activation is completed, take out the sample and store it in a sealed bag; Step 6. Sample detection: Take the pyrolyzed sample, the sample after acid washing + water washing, and the activated sample respectively for adsorption effect testing.

[0007] As a further description of the above technical solution: The drying temperature in Step 1 is set at 105 - 110 °C, and the drying time is set at 24 h.

[0008] As a further description of the above technical solution: The sieve mesh used in Step 1 is 100 meshes.

[0009] As a further description of the above technical solution: The protective gas in Step 2 is nitrogen or argon.

[0010] As a further description of the above technical solution: The mixing mass ratio of the sample and carbon black powder in Step 2 is 1.5 - 2:1.

[0011] As a further description of the above technical solution: The carbon black powder in Step 2 is one of activated carbon black, vulcanized carbon black or pyrolytic carbon black, and preferably vulcanized carbon black is used as the carbon black powder.

[0012] As a further description of the above technical solution: The mesh number of the carbon black powder in Step 2 is 100 meshes.

[0013] As a further description of the above technical solution: In Step 3, the pyrolyzed sample is added to the hydrochloric acid / nitric acid solution at a solid-liquid ratio of 1:10 (g:mL).

[0014] As a further description of the above technical solution: In Step 4, the sample is washed with deionized water until the pH reaches 7, and the temperature of the oven in Step 4 is set to 105 - 110 °C.

[0015] As a further description of the above technical solution: In Step 5, the mass ratio of water to the sample is set to 2 - 3:10.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are as follows: In the present invention, by scientifically and rationally co - mixing the anaerobic fermentation biogas residue from kitchen waste with the vulcanized carbon black recovered from rubber tires to prepare an adsorbent material, and subjecting the biogas residue from kitchen waste to a series of pretreatment, high - temperature pyrolysis carbonization, pickling, water washing, and physical activation processes. While detoxifying the biogas residue, an adsorbent material with a porous structure can be prepared. The prepared adsorbent material can be applied to fields such as environmental protection, energy, biomedicine, electronics, chemical engineering, and food industry, realizing the diversified, multi - field, and multi - scenario application of the biogas residue from kitchen waste. At the same time, the prepared porous adsorbent material can bring higher economic benefits and social utilization value. Description of the Drawings

[0017] Figure 1 It is a data chart of iodine adsorption values of biogas residue from kitchen waste after pyrolysis, pickling, water washing, and activation at 300 °C, 400 °C, 500 °C, 600 °C, and 700 °C.

[0018] Figure 2 It is a scanning electron microscope image of biogas residue from kitchen waste and the prepared adsorbent material.

[0019] Figure 3 It is a data chart of the yield of the adsorbent material prepared from biogas residue from kitchen waste during pyrolysis at 300 °C, 400 °C, 500 °C, 600 °C, and 700 °C.

[0020] Figure 4 It is a data chart of the adsorption efficiency of the adsorbent prepared from biogas residue from kitchen waste in low - concentration COD waste liquid.

[0021] Figure 5 It is a data chart of the adsorption efficiency of the adsorbent prepared from biogas residue from kitchen waste for COD in waste liquid during the scale - up experiment.

[0022] Figure 6 It is a data table of iodine adsorption values of ten samples in the preparation of the adsorbent material from biogas residue from kitchen waste. Detailed Embodiments

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0024] Please refer to Figures 1-6 As shown, a method for preparing an adsorption material from kitchen waste biogas residue includes the following six steps: First step: The kitchen waste biogas residue after anaerobic fermentation of kitchen waste is dried in an oven at 105 - 110 °C for 24 h. The dried biogas residue is crushed by a crusher and sieved through a 100-mesh sieve to prepare a sample for standby. Second step: Weigh 20 g of the sample and mix it evenly with carbon black powder with a mesh number of 100 according to a mass ratio of 2:1. The carbon black powder is one of activated carbon black, vulcanized carbon black, or pyrolytic carbon black. Preferably, vulcanized carbon black is used as the carbon black powder. The well-mixed mixture is placed in a tube furnace for anaerobic pyrolysis. Nitrogen is introduced as a protective gas, and the temperature is raised at a rate of 5 °C / min. The final pyrolysis temperatures are set at 300 °C, 400 °C, 500 °C, 600 °C, and 700 °C respectively, and maintained for 60 min at the set final pyrolysis temperature. Finally, it is cooled to room temperature in a protective gas environment and taken out and stored in a sealed bag. Third step: Add the sample obtained in the previous experiment to a hydrochloric acid / nitric acid solution with a mass concentration of 10% at a solid-liquid ratio of 1:10 (g:mL), ultrasonicate in an ultrasonic cleaner for 60 min, and then filter by suction to collect the filter residue for standby.

[0025] Fourth step: Take the filter residue sample from the previous step, add deionized water to wash until the pH reaches 7, then filter by suction, and dry in an oven at 105 - 110 °C, and store in a sealed bag for standby.

[0026] Fifth step: Take the experimental sample from the previous step, introduce steam for activation at 800 - 900 °C, set the mass ratio of water to the sample as 10:2, and set the activation time as 40 - 60 min. After the activation is completed, take out the sample and store it in a sealed bag. Sixth step: Take the pyrolyzed sample, the sample after acid washing with water, and the activated sample respectively to conduct an iodine adsorption value adsorption effect test. The iodine adsorption value determination reagent selected is a 0.02 mol / L potassium iodide solution. The specific experimental data are as Figure 1 shown.

[0027] Please refer to Figure 1, the iodine adsorption value of the untreated kitchen waste biogas residue powder is 110 mg / g, the iodine adsorption value of the added carbon black powder is 237 mg / g, the iodine adsorption value after pyrolysis at 300 °C is 358 mg / g, the iodine adsorption value after pickling and water washing is 518 mg / g, the iodine adsorption value after pyrolysis at 400 °C is 438 mg / g, the iodine adsorption value after pickling and water washing is 562 mg / g, the iodine adsorption value after pyrolysis at 500 °C is 614 mg / g, the iodine adsorption value after pickling and water washing is 933 mg / g, the iodine adsorption value after pyrolysis at 600 °C is 533 mg / g, the iodine adsorption value after pickling and water washing is 337 mg / g, the iodine adsorption value after pyrolysis at 700 °C is 375 mg / g, and the iodine adsorption value after pickling and water washing is 250 mg / g. It can be seen from the table that the iodine adsorption value of the kitchen waste biogas residue coordinated with carbon black is the highest and the adsorption effect is the best after pyrolysis at 500 °C followed by pickling and water washing.

[0028] Specifically, in order to further understand the pore structure of an adsorbent prepared from kitchen waste biogas residue: A small amount of kitchen waste biogas residue powder CZ-500 and the adsorbent CZX-500 prepared by pyrolysis at 500 °C followed by pickling and water washing were respectively placed on the sample stage, and the surface structure characteristics were observed using a scanning electron microscope. The results are as Figure 2 shown.

[0029] It was found from the scanning electron microscope (SEM) that compared with the original kitchen waste biogas residue, the surfaces of the newly prepared adsorbents are relatively rough, the pore structures are relatively rich and developed, and there are more micropores and small pore structures. Thus, it can be known that through this method, the surface of the kitchen waste biogas residue can become rougher, the pore structure can be more rich and developed, and the rough surface can effectively increase its specific surface area and increase the surface active sites, which is more conducive to removing pollutants such as COD in water, thereby achieving the purification and treatment of water quality.

[0030] Specifically, in order to further understand the yield of an adsorbent prepared from kitchen waste biogas residue at different pyrolysis temperatures: First step: Weigh 20 g of kitchen waste biogas residue powder passed through a 100-mesh sieve and 10 g of carbon black powder passed through a 100-mesh sieve respectively, and mix them evenly.

[0031] Second step: Place the well-mixed mixture in a tube furnace and introduce nitrogen as a protective gas for anaerobic pyrolysis. Set the program parameters to make the tube furnace continuously heat up at a heating rate of 5 °C / min to different carbonization and cracking temperatures (300 °C, 400 °C, 500 °C, 600 °C, 700 °C), and maintain it at the set carbonization and cracking temperature for 60 min.

[0032] The third step is to cool down to room temperature under protective gas environment after pyrolysis, take out the sample and store it in a sealed bag, weigh it with an electronic balance and record the weight of the sample after pyrolysis and carbonization, and obtain the yield of adsorption material at different pyrolysis temperatures. The specific experimental results are as follows: Figure 3 shown.

[0033] Specifically, in order to further verify the adsorption effect of the prepared food waste adsorption material at 500°C, a further adsorption experiment was conducted on the prepared food waste adsorption material. The specific steps are as follows: The first step is to prepare 500 mL of a solution with a COD concentration of about 300 mg / L, and take 4 groups of 100 mL samples for later use, numbered 1, 2, 3, and 4.

[0034] Step 2: add 1g of food digester carbon black adsorption material, 1g of food digester carbon black adsorption material after pyrolysis at 500℃, and 1g of food digester carbon black adsorption material after pyrolysis at 500℃ to groups 2, 3, and 4 respectively at a mass ratio of 1:100; sample No. 1 is used as the blank control group; Step 3: After stirring at a constant speed for 1 hour, filter and test the COD in the 4 groups of samples.

[0035] The specific experimental results are as follows Figure 4 As shown, through data analysis of sample 1, it can be known that the concentration of COD after artificial configuration is 274 mg / L.

[0036] Sample 2 used untreated food sludge carbon black adsorption material, which not only failed to reduce the COD content, but also caused the COD concentration data to increase due to the high organic matter content of the sludge itself.

[0037] Sample 3 was treated only by pyrolysis without acid washing and the COD removal rate was only 10%.

[0038] After pyrolysis, sample 4 was acid-washed and washed with water, and the COD removal rate reached 99.1%, which can effectively remove the COD concentration.

[0039] Specifically, in order to further verify the adsorption effect of the prepared food waste adsorption material at 500°C, a further enlarged adsorption experiment was conducted on the prepared food waste adsorption material. The specific steps are as follows: The first step is to take 50L of aerobic treated wastewater from a printing and dyeing company's sewage station and test its COD concentration. Take 10 groups of 5L of the above wastewater for use, numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0040] In the second step, 50g of acid-washed and water-washed food waste sludge carbon black adsorption material after pyrolysis at 500℃ was added to groups 2, 3, 4, 5, 6, 7, 8, 9, and 10 at a mass ratio of 1:100.

[0041] Step 3: After stirring evenly for 1 hour, filter and test the COD in 10 groups of samples.

[0042] The specific experimental results are as Figure 5 shown. By analyzing the data of the original sample, it is known that the COD concentration of the original wastewater from the printing and dyeing factory is 364 mg / L.

[0043] Specifically, in order to further understand the regeneration of an adsorbent material prepared from kitchen waste biogas residue: Step 1: Collect 10 groups of adsorbent materials from the previous adsorption experiment, dry them in a muffle furnace at 150 - 200 °C for 2 h, and bag the dried adsorbent materials for standby.

[0044] Step 2: Calcinate the above samples in a muffle furnace at 450 - 500 °C for 4 hours, crush the calcined adsorbent materials with a crusher and sieve them through a 100 - mesh sieve to prepare samples for standby; Step 3: Place the samples in a tube furnace with nitrogen as the protective gas for anaerobic pyrolysis, set the program parameters, set the heating rate at 5 °C / min, set the final pyrolysis temperature at 500 °C, and hold for 60 min at the set final pyrolysis temperature. Finally, cool to room temperature in the protective gas environment and take out and store in a sealed bag; Step 4: Take the samples after thermal regeneration and test the adsorption effect of the iodine adsorption value. The reagent used for measuring the iodine adsorption value is a 0.02 mol / L potassium iodide solution. The specific experimental data are as Figure 6 shown.

[0045] In summary, the method for preparing an adsorbent material by using kitchen waste biogas residue in combination with carbon black mixes kitchen waste biogas residue as solid waste with vulcanized carbon black, and through a series of treatments such as high - temperature pyrolysis carbonization, pickling, water washing, and physical activation, an adsorbent material with strong adsorption effect is prepared, realizing the recycling of solid waste, improving the resource utilization rate, effectively reducing the secondary pollution to the environment, and indirectly improving the economic benefits of the enterprise.

[0046] The above - mentioned is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A method for preparing an adsorption material from kitchen and restaurant biogas residues, characterized in that, It includes the following steps: Step 1, Pretreatment: Place the biogas residue from anaerobic fermentation of kitchen waste in an oven for drying, crush the dried biogas residue with a crusher and then sieve it to prepare a sample for standby; Step 2, High-temperature pyrolysis carbonization: Take the pretreated biogas residue sample, mix it with carbon black powder according to a certain mass ratio, place it in a tube furnace with a protective gas introduced, carry out anaerobic pyrolysis, set the heating rate to 5 °C / min, set the final pyrolysis temperature to 300 °C - 700 °C, and keep it for 60 min at the set final pyrolysis temperature. Finally, cool it to room temperature in the protective gas environment, take out the pyrolyzed sample and store it in a sealed bag; Step 3, Acid washing: To reduce the influence of acid-soluble salts and impurities in the adsorbent material, expand the specific surface area of the adsorbent material and increase the porosity, add the pyrolyzed sample obtained in Step 2 to a hydrochloric acid / nitric acid solution with a mass concentration of 10%, ultrasonicate it in an ultrasonic cleaner for 60 min and then filter it by suction to collect the filter residue for standby; Step 4, Water washing: Add the filter residue obtained in Step 3 to water, adjust the pH of the system to 7 and then filter it by suction. Dry the obtained solid sample in an oven and store it in a sealed bag for standby; Step 5, Physical activation: Take the sample treated in Step 4, introduce steam at 800 - 900 °C for activation, set the activation time to 40 - 60 min. After the activation is completed, take out the sample and store it in a sealed bag; Step 6, Sample detection: Take the pyrolyzed sample, the sample after acid washing + water washing and the activated sample respectively for adsorption effect testing.

2. The method for preparing an adsorption material from kitchen waste biogas residues according to claim 1, wherein, In Step 1, the drying temperature is set to 105 - 110 °C and the drying time is set to 24 h.

3. The method for preparing an adsorption material from kitchen waste biogas residue according to claim 1, characterized in that, The sieve used in Step 1 is 100 mesh.

4. The method for preparing an adsorbent material from kitchen waste biogas residue according to claim 1, characterized in that, The protective gas in Step 2 is nitrogen or argon.

5. A method for preparing an adsorption material from kitchen waste biogas residues according to claim 1, characterized in that, The mixing mass ratio of the sample and carbon black powder in Step 2 is 1.5 - 2:

1.

6. The method for preparing an adsorption material from kitchen waste biogas residues according to claim 1, characterized in that, The carbon black powder in Step 2 is one of activated carbon black, vulcanized carbon black or pyrolytic carbon black.

7. A method for preparing an adsorption material from kitchen and restaurant biogas residues according to claim 1, characterized in that The mesh number of the carbon black powder in Step 2 is 100 mesh.

8. A method for preparing an adsorption material from kitchen and restaurant biogas residues according to claim 1, characterized in that, In Step 3, add the pyrolyzed sample to hydrochloric acid or nitric acid solution at a solid-liquid ratio of 1:

10.

9. The method for preparing an adsorption material from kitchen waste biogas residue according to claim 1, characterized in that In Step 4, wash the sample with deionized water until the pH is 7. The temperature of the oven in Step 4 is set to 105 - 110 °C.

10. The method for preparing an adsorption material from kitchen waste biogas residue according to claim 1, characterized in that, In Step 5, the mass ratio of water to sample is set to 2 - 3:10.

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