Biochar-based slow-release long-life ice and snow melting material and preparation method thereof

Abstract

The invention discloses a biochar-based slow-release long-life ice and snow melting material and a preparation method thereof, and belongs to the technical field of production of road ice and snow melting materials, the material comprises the following raw materials by mass: 25-40 parts of biochar, 1-3 parts of an organic modifier, 20-30 parts of a composite salt snow melting agent, and 1-3 parts of absolute ethyl alcohol. 2-5 parts of a modified gelatin phase change material used as a coating material, 45-75 parts of sodium sulfate and 2-5 parts of an ethanol solution. The biochar is used as a carrier, has the characteristics of strong adsorption, developed pore structure, large specific surface area and the like, can effectively store and slowly release salinization substances, has the characteristics of stable structure and property, high strength and the like after the meltable salinization substances are separated out, and can ensure that the pavement performance such as the long-term strength of the asphalt pavement meets the use requirements; meanwhile, the modified gelatin phase change material used as a coating material significantly improves the slow release property of the biochar-based slow-release long-life ice and snow melting material.

Description

Technical Field

[0001] The invention belongs to the technical field of production of road ice-melting materials, and specifically relates to a biochar-based slow-release long-life ice-melting material and a preparation method thereof. Background Art

[0002] Snow and ice on roads in winter seriously affect road safety. Although traditional passive snow and ice removal methods are simple to operate, they will bring a series of environmental problems and negative impacts: physical paving technology such as adding rubber particles and thermal snow and ice melting technology have disadvantages such as a significant impact on the structural strength of the asphalt pavement surface and the need to consume a lot of energy. Self-melting asphalt pavement that uses slow-release snow and ice melting materials based on salt storage has the advantages of active snow and ice melting, green environmental protection, and less road damage. It is currently a priority road snow and ice removal technology.

[0003] However, the long-term durability of slow-release snow-melting materials based on salt storage and the effective ice-melting time limit the further technical optimization of self-melting snow asphalt pavement. Therefore, it is necessary to analyze the various factors that limit self-melting snow asphalt pavement and propose countermeasures to solve them.

[0004] The choice of carrier determines the service life and performance of slow-release ice and snow melting materials based on salt storage. The role of the carrier in this material is to wrap up the meltable salt, which not only meets the requirements for the pavement structure when paving the road, but also can effectively reduce the release rate of the meltable salt and increase the service life of the material. The carrier material that adsorbs the meltable salt is evenly distributed in the asphalt mixture when the asphalt mixture is stirred, so that there are many tiny gaps inside the asphalt pavement. When the road snow accumulates in the early stage, as the snow water seeps into the road surface, the meltable salt adsorbed in the carrier will diffuse to the road surface due to the osmotic pressure, causing a large amount of salt solution to accumulate on the road surface. The presence of the salt solution lowers the freezing point of the road surface, thereby inhibiting the icing of the road surface; at the same time, as time goes by, vehicles continue to drive over the road surface, and the wheel load and capillary pressure will also cause the meltable salt in the carrier to be released to the road surface, lowering the freezing point of the road surface.

[0005] The carrier of traditional slow-release snow-melting materials based on salt-storage compounds is generally a mixture containing phenolic resin, which has the disadvantages of small pores and specific surface area, resulting in poor adsorption capacity and slow-release effect of the carrier. The carrier is evenly distributed in the asphalt when the mixture is mixed and formed, and the interior of the carrier is hollow after the soluble salt compound is precipitated, resulting in a decrease in the strength of the asphalt pavement, that is, the service life of the slow-release snow-melting material is short. This is also the key factor restricting the large-scale application of traditional slow-release snow-melting materials based on salt-storage compounds. Summary of the invention

[0006] The purpose of the present invention is to provide a biochar-based slow-release, long-life ice-melting and snow-melting material and a preparation method thereof in order to solve the above-mentioned problems. The biochar-based slow-release, long-life ice-melting and snow-melting material has excellent slow-release properties, snow-melting and ice-suppression capabilities, and road performance, and has a long service life, and is suitable for long-term and efficient snow melting on various types of road surfaces.

[0007] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0008] A biochar-based slow-release long-life snow and ice melting material comprises the following raw materials in parts by weight: 25-40 parts of biochar, 1-3 parts of an organic modifier, 20-30 parts of a composite salt snow melting agent, 1-3 parts of anhydrous ethanol, 2-5 parts of a modified gelatin phase change material used as a coating material, 45-75 parts of sodium sulfate, and 2-5 parts of an ethanol solution.

[0009] Preferably, the biochar is prepared from industrial sludge and domestic waste in a high-efficiency microwave heating device and processed into nanometer-sized particles by ball milling; the microwave frequency of the high-efficiency microwave heating device is 2450±50MHz, the pyrolysis temperature used is between 450℃-550℃, and the pyrolysis time is 1.5h.

[0010] Preferably, the organic modifier comprises the following raw materials in parts by weight: 10-30 parts of deionized water, 5-10 parts of methyltrichlorosilane, 4-8 parts of sodium hydroxide, and 2-4 parts of reverse osmosis bactericide.

[0011] Preferably, the composite salt de-icing agent comprises the following raw materials in parts by weight: 5-10 parts of potassium chloride, 30-40 parts of calcium chloride, 5-10 parts of magnesium chloride, 10-15 parts of calcium magnesium acetate, 20-30 parts of biological fermentation urea, and 2-5 parts of easily degradable neutral rust remover.

[0012] Preferably, the modified gelatin phase change material comprises the following raw materials in parts by mass: 15-30 parts of 12.5% ​​glycerol, 15-30 parts of gelatin, and 5-10 parts of plasticizer.

[0013] Preferably, the plasticizer is one of dioctyl terephthalate, dibutyl phthalate, octadecanoate, tributyl citrate and 2-propyl-1-heptanol.

[0014] A method for preparing a biochar-based slow-release long-life snow and ice melting material comprises the following steps:

[0015] Step 1: fully mix the biochar, organic modifier and anhydrous ethanol, pour the obtained mixture into a stirring pot, heat it to 65-75° C. (preferably 70° C.) and maintain the temperature, stir for 0.5-1.5 h (preferably 1 h), and form a modified biochar-based carrier solution;

[0016] Step 2: fully mix the composite salt deicing agent and the modified biochar-based carrier solution, and then stir evenly for 5-15 minutes (preferably 10 minutes) to obtain a capsule core solution, dry the capsule core solution with a dryer, and crush the dried material with a grinder (preferably a universal grinder) to obtain capsule core particles;

[0017] Step 3, dissolving the modified gelatin phase change material in deionized water at a temperature of 35-40° C. (preferably 37° C.) to obtain a modified gelatin phase change material solution, and dispersing the capsule core particles in the modified gelatin phase change material solution;

[0018] Step 4, placing sodium sulfate in deionized water and mixing thoroughly to obtain a saturated sodium sulfate solution; this step and step 3 can be interchanged in order or performed simultaneously;

[0019] Step 5, maintaining a temperature of 35-40°C, fully mix and stir the modified gelatin phase change material solution mixed with the capsule core particles and the saturated sodium sulfate solution, stop stirring when coagulation occurs, and then start cooling. During the cooling process, flocculent precipitates are continuously formed until the flocculent precipitates no longer increase significantly. First, add deionized water, stir evenly, then add ethanol solution to wash the flocculent precipitates, and stir the mixture for 4-6 minutes (preferably 5 minutes), then filter and dry, and then place it in a grinder for crushing. Finally, use a powder selector to screen powder particles with a particle size less than or equal to 0.4 mm to obtain a finished biochar-based slow-release long-life snow and ice melting material.

[0020] Preferably, the method for preparing the organic modifier in step 1 comprises the following steps:

[0021] Step 1.1, methyltrichlorosilane and deionized water are mixed evenly to allow the methyltrichlorosilane to be fully hydrolyzed, and then the hydrolyzate is filtered with filter paper, and the filtrate is washed with deionized water to obtain wet methylsilicic acid;

[0022] Step 1.2, mix sodium hydroxide and wet methylsilicic acid evenly, react at a temperature of 80-90° C. for 55-65 min (preferably 60 min), then add a reverse osmosis bactericide and stir evenly to obtain the organic modifier.

[0023] Preferably, the preparation method of the composite salt de-icing agent in step 2 is: pour potassium chloride, calcium chloride and magnesium chloride into pure deionized water at room temperature and mix them evenly to fully dissolve them, then add calcium magnesium acetate, bio-fermented urea and easily degradable neutral rust remover in sequence, stir evenly for 15-25 minutes (preferably 20 minutes) to obtain the composite salt de-icing agent.

[0024] Preferably, the preparation method of the modified gelatin phase change material in step 3 is: taking gelatin、 Glycerol and plasticizer with a mass fraction of 12.5% ​​are fully mixed, heated and stirred at 60-70° C. (preferably 65° C.) for 20-30 minutes (preferably 25 minutes) until the gelatin is completely dissolved, then ultrasonically defoamed, and then cooled and solidified under natural conditions to obtain the modified gelatin phase change material.

[0025] The beneficial effects of the present invention are:

[0026] The present invention uses biochar as a carrier of the slow-release snow-melting material, which has the characteristics of strong adsorption, developed pore structure and large specific surface area, can effectively store and slowly release salt compounds, enhance the durability and effectiveness of the anti-icing effect of asphalt pavement, and the hollow biochar after the soluble salt compounds are precipitated has the characteristics of stable structure and properties and high strength, which can ensure that the long-term strength of the asphalt pavement and other road performance meet the use requirements; at the same time, the modified gelatin phase change material used as the coating material is in a sol state in the spring, summer and autumn seasons with higher temperatures, with a complete structure, firmly wrapping the salt compounds, reducing the loss of salt caused by rain erosion, while in the winter when the temperature is lower, the gelatin film is in a gel state, with a shrinking structure, exposing the salt compounds, which are extracted from the inside of the road surface under the rolling of vehicles to form a layer of salt solution on the asphalt pavement, lowering the freezing point, achieving the effect of melting snow and inhibiting ice, and significantly improving the slow-release property of the biochar-based slow-release long-life snow-melting material of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of the method for preparing the biochar-based slow-release long-life snow and ice melting material of the present invention;

[0028] Figure 2 is a flow chart of the method for preparing the organic modifier of the present invention;

[0029] Figure 3 It is a flow chart of the preparation method of the composite salt deicing agent of the present invention;

[0030] Figure 4 The present invention is a flow chart of the method for preparing the modified gelatin phase change material. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with embodiments and drawings:

[0032] Embodiment 1:

[0033] refer to Figure 1 , the biochar-based slow-release long-life snow and ice melting material is prepared according to the following steps:

[0034] Step 1. Reference Figure 2 , prepare the organic modifier according to the following steps:

[0035] Step 1.1, 5 parts by mass of methyltrichlorosilane and 20 parts by mass of deionized water are mixed evenly to allow the methyltrichlorosilane to be fully hydrolyzed, and then the hydrolyzate is filtered with filter paper, and the filtrate is washed with deionized water to obtain wet methylsilicic acid;

[0036] Step 1.2, 6 parts by mass of sodium hydroxide and wet methylsilicic acid are mixed evenly, reacted at a temperature of 80-90° C., more preferably 90° C., for 55-65 min, more preferably 60 min, and then 3 parts by mass of a reverse osmosis bactericide are added and stirred evenly to obtain the organic modifier;

[0037] Step 2, preparing biochar: industrial sludge and domestic waste are prepared in a high-efficiency microwave heating device and processed into nanometer-sized particles by ball milling to obtain biochar; the microwave frequency of the high-efficiency microwave heating device is 2450±50MHz, more preferably 2400MHz, the pyrolysis temperature is between 450℃-550℃, more preferably 500℃, and the pyrolysis time is 1.5h;

[0038] Step 3. Reference Figure 3 , prepare the composite salt de-icing agent by the following method: pour 5 parts by mass of potassium chloride, 30 parts by mass of calcium chloride, and 5 parts by mass of magnesium chloride into pure deionized water at room temperature, mix them evenly, and fully dissolve them, then add 15 parts by mass of calcium magnesium acetate, 20 parts by mass of biological fermentation urea, and 4 parts by mass of easily degradable neutral rust remover in sequence, and stir evenly for 15-25 minutes, preferably 20 minutes, to obtain the composite salt de-icing agent;

[0039] Step 4. Reference Figure 4 , prepare the modified gelatin phase change material as follows: take 20 parts by mass of gelatin 、 20 parts by mass of 12.5% ​​propylene glycol and 6 parts by mass of dibutyl phthalate (plasticizer) are fully mixed, heated and stirred at 60-70° C., preferably 65° C., for 20-30 min, preferably 25 min, until the gelatin is completely dissolved, then ultrasonically defoamed, and then cooled and solidified under natural conditions to obtain the modified gelatin phase change material;

[0040] The order of the above steps 1 to 4 can be interchanged or performed simultaneously;

[0041] Step 5, 30 parts by mass of biochar, 2 parts by mass of organic modifier and 2 parts by mass of anhydrous ethanol are fully mixed, the resulting mixture is poured into a stirring pot, the temperature is raised to 65-75°C, preferably 70°C and maintained at the temperature, and stirred for 0.5-1.5h, preferably 1h, to form a modified biochar-based carrier solution;

[0042] Step 6: fully mix 25 parts by mass of the composite salt deicing agent with the modified biochar-based carrier solution, and then stir evenly for 5-15 minutes, preferably 10 minutes, to obtain a capsule core solution, dry the capsule core solution with a dryer, and crush the dried material with a crusher to obtain capsule core particles;

[0043] Step 7, dissolving 3 parts by weight of modified gelatin phase change material in deionized water at a temperature of 35-40° C., more preferably 37° C., to obtain a modified gelatin phase change material solution, and dispersing the capsule core particles in the modified gelatin phase change material solution;

[0044] Step 8, placing 60 parts by mass of sodium sulfate in deionized water and mixing thoroughly to obtain a saturated sodium sulfate solution; this step and step 7 can be interchanged in order or performed simultaneously;

[0045] Step 9, maintaining a temperature of 35-40°C, preferably 37°C, fully mix and stir the modified gelatin phase change material solution mixed with the capsule core particles and the saturated sodium sulfate solution, stop stirring when coagulation occurs, and then start cooling. During the cooling process, flocculent precipitates are continuously formed until the flocculent precipitates no longer increase significantly. First, add deionized water, stir evenly, then add 3 parts by mass of ethanol solution to wash the flocculent precipitates, and stir the mixture for 4-6 minutes, preferably 5 minutes, then filter and dry, and then place it in a grinder for crushing, and finally use a powder selector to screen powder particles with a particle size less than or equal to 0.4 mm to obtain a finished biochar-based slow-release long-life snow and ice melting material.

[0046] Embodiment 2:

[0047] On the basis of Example 1, the mass parts of the following raw materials were changed to: 6 parts of methyltrichlorosilane, 7 parts of sodium hydroxide, 35 parts of calcium chloride, 10 parts of magnesium chloride, 13 parts of calcium magnesium acetate, 22 parts of biological fermentation urea, 25 parts of 12.5% ​​propylene glycol, 25 parts of gelatin, 8 parts of plasticizer, and 35 parts of biochar; wherein the plasticizer was changed from dibutyl phthalate to tributyl citrate.

[0048] The other raw materials and the preparation method are the same as those in Example 1, and a biochar-based slow-release long-life snow and ice melting material product is obtained.

[0049] Embodiment 3:

[0050] On the basis of Example 1, the mass parts of the following raw materials are changed to: 8 parts of methyltrichlorosilane, 8 parts of sodium hydroxide, 4 parts of reverse osmosis fungicide, 6 parts of potassium chloride, 35 parts of calcium chloride, 8 parts of magnesium chloride, 11 parts of calcium magnesium acetate, 25 parts of biological fermentation urea, 5 parts of easily degradable neutral rust remover, 28 parts of 12.5% ​​propylene glycol, 30 parts of gelatin, 9 parts of plasticizer, 40 parts of biochar; 3 parts of organic modifier; 3 parts of anhydrous ethanol; 5 parts of modified gelatin phase change material used as a coating material; wherein the plasticizer is changed from dibutyl phthalate to 2-propyl-1-heptanol.

[0051] The other raw materials and the preparation method are the same as those in Example 1, and a biochar-based slow-release long-life snow and ice melting material product is obtained.

[0052] The mass parts of each raw material can be other parts in the following mass parts in addition to the parts listed in the above embodiment: 10-30 parts of deionized water, 5-10 parts of methyltrichlorosilane, 4-8 parts of sodium hydroxide, 2-4 parts of reverse osmosis fungicide, 5-10 parts of potassium chloride, 30-40 parts of calcium chloride, 5-10 parts of magnesium chloride, 10-15 parts of calcium magnesium acetate, 20-30 parts of biological fermentation urea, 2-5 parts of easily degradable neutral rust remover , 15-30 parts of 12.5% ​​propylene glycol, 15-30 parts of gelatin, 5-10 parts of plasticizer, 25-40 parts of biochar, 1-3 parts of organic modifier, 20-30 parts of composite salt snow-melting agent, 1-3 parts of anhydrous ethanol, 2-5 parts of modified gelatin phase change material used as coating material, 45-75 parts of sodium sulfate, and 2-5 parts of ethanol solution; the plasticizer can also be dioctyl terephthalate or n-decanoic acid ester.

[0053] The finished products of the biochar-based slow-release long-life snow and ice melting materials prepared in the above three embodiments were subjected to performance tests, and the invention patent application with patent application number "202111641936.9" was used as control 1, and the invention patent application with patent application number "202210906354.7" was used as control 2. The performance test results are shown in the following table:

[0054]

[0055] It can be seen from the above performance test results that the performance of the biochar-based slow-release long-life ice-melting snow material of the present invention in terms of road performance, ice-melting component release rate, and snow-melting and ice-melting ability is much higher than that of control 1 and control 2; the biochar-based slow-release long-life ice-melting snow material of the present invention has excellent ice-melting component release rate, road performance and high snow-melting and ice-melting ability, and is particularly suitable for use on various types of road surfaces that require high efficiency and long-term snow melting and ice suppression and have certain requirements on road performance.

[0056] The above embodiments are only preferred embodiments of the present invention and are not limitations of the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A biochar-based slow-release long-life snow and ice melting material, characterized by: The invention comprises the following raw materials in parts by weight: 25-40 parts of biochar, 1-3 parts of organic modifier, 20-30 parts of composite salt snow-melting agent, 1-3 parts of anhydrous ethanol, 2-5 parts of modified gelatin phase change material used as coating material, 45-75 parts of sodium sulfate and 2-5 parts of ethanol solution.

2. The biochar-based slow-release long-life snow and ice melting material according to claim 1, characterized in that: The biochar is prepared from industrial sludge and domestic garbage in a high-efficiency microwave heating device and processed into nanometer-scale particles by ball milling.

3. The biochar-based slow-release long-life snow and ice melting material according to claim 1, characterized in that: The organic modifier comprises the following raw materials in parts by weight: 10-30 parts of deionized water, 5-10 parts of methyltrichlorosilane, 4-8 parts of sodium hydroxide, and 2-4 parts of reverse osmosis bactericide.

4. The biochar-based slow-release long-life snow and ice melting material according to claim 1, characterized in that: The composite salt snow melting agent comprises the following raw materials in parts by weight: 5-10 parts of potassium chloride, 30-40 parts of calcium chloride, 5-10 parts of magnesium chloride, 10-15 parts of calcium magnesium acetate, 20-30 parts of biological fermentation urea, and 2-5 parts of easily degradable neutral rust remover.

5. The biochar-based slow-release long-life snow and ice melting material according to claim 1, characterized in that: The modified gelatin phase change material comprises the following raw materials in parts by mass: 15-30 parts of glycerol with a mass fraction of 12.5%, 15-30 parts of gelatin, and 5-10 parts of plasticizer.

6. The biochar-based slow-release long-life snow and ice melting material according to claim 5, characterized in that: The plasticizer is one of dioctyl terephthalate, dibutyl phthalate, octadecanoate, tributyl citrate and 2-propyl-1-heptanol.

7. A method for preparing a biochar-based slow-release long-life snow and ice melting material as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: fully mix the biochar, organic modifier and anhydrous ethanol, pour the obtained mixture into a stirring pot, heat it to 65-75°C and maintain the temperature, stir for 0.5-1.5h to form a modified biochar-based carrier solution; Step 2, fully mix the composite salt deicing agent and the modified biochar-based carrier solution, and then stir evenly for 5-15 minutes to obtain a capsule core solution, dry the capsule core solution with a dryer, and crush the dried material with a crusher to obtain capsule core particles; Step 3, dissolving the modified gelatin phase change material in deionized water at a temperature of 35-40° C. to obtain a modified gelatin phase change material solution, and dispersing the capsule core particles in the modified gelatin phase change material solution; Step 4, placing sodium sulfate in deionized water and mixing thoroughly to obtain a saturated sodium sulfate solution; this step and step 3 can be interchanged in order or performed simultaneously; Step 5, maintaining a temperature of 35-40°C, fully mix and stir the modified gelatin phase change material solution mixed with the capsule core particles and the saturated sodium sulfate solution, stop stirring when coagulation occurs, and then start cooling. During the cooling process, flocculent precipitates are continuously formed until the flocculent precipitates no longer increase significantly. First, add deionized water, stir evenly, then add ethanol solution to wash the flocculent precipitates, and stir the mixture for 4-6 minutes, then filter and dry, and then pulverize in a grinder, and finally use a powder selector to screen powder particles with a particle size less than or equal to 0.4 mm to obtain a finished product of a biochar-based slow-release long-life snow and ice melting material.

8. The method for preparing the biochar-based slow-release long-life snow-melting material according to claim 7, characterized in that: The preparation method of the organic modifier in step 1 comprises the following steps: Step 1.1, methyltrichlorosilane and deionized water are mixed evenly to allow the methyltrichlorosilane to be fully hydrolyzed, and then the hydrolyzate is filtered with filter paper, and the filtrate is washed with deionized water to obtain wet methylsilicic acid; Step 1.2, mix sodium hydroxide and wet methylsilicic acid evenly, react at a temperature of 80-90° C. for 55-65 minutes, then add a reverse osmosis bactericide and stir evenly to obtain the organic modifier.

9. The method for preparing the biochar-based slow-release long-life snow-melting material according to claim 7, characterized in that: The preparation method of the composite salt de-icing agent in step 2 is: pour potassium chloride, calcium chloride, and magnesium chloride into pure deionized water at room temperature and mix them evenly to make them fully dissolved, then add calcium magnesium acetate, biological fermentation urea, and easily degradable neutral rust remover in sequence, and stir evenly for 15-25 minutes to obtain the composite salt de-icing agent.

10. The method for preparing the biochar-based slow-release long-life snow-melting material according to claim 7, characterized in that: The preparation method of the modified gelatin phase change material in step 3 is: taking gelatin 、 The glycerol and plasticizer with a mass fraction of 12.5% ​​are fully mixed, heated and stirred at 60-70° C. for 20-30 minutes until the gelatin is completely dissolved, then ultrasonically defoamed, and then cooled and solidified under natural conditions to obtain the modified gelatin phase change material.

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