Full-bio-based asphalt prepared from bio-heavy oil and preparation method of full-bio-based asphalt

Abstract

The invention relates to the field of renewable resource utilization and bio-based material preparation, in particular to full-bio-based asphalt prepared from bio-heavy oil and a preparation method of the full-bio-based asphalt. The method for preparing the full-bio-based asphalt through vacuum distillation and thermal modification is suitable for the fields of road pavement, corrosion prevention, sealing and the like. The whole bio-based asphalt product has no fluidity, and the yield of methyl ester is about 20.44%; the acid value is reduced to 2.01 mgKOH / g; the cold filter plugging point is 19 DEG C; and the closed flash point is greater than 234 DEG C. Pyrolysis of biological heavy oil is effectively avoided through vacuum control, and the integrity of the asphalt structure is guaranteed; the flash point is higher than that of traditional petroleum asphalt, so that the use is safer; no petroleum-based raw material is introduced in the whole process, and renewable resources are utilized; the raw materials are wide in variety, and the method is suitable for biological heavy oil from different sources. The method can be used for large-scale preparation of the full-bio-based asphalt, meets the requirements of green low-carbon building materials such as road engineering and waterproof sealing materials, and has good popularization and application prospects.

Description

Technical Field

[0001] The present invention relates to the fields of renewable resource utilization and bio-based material preparation, specifically to a fully bio-based asphalt prepared from heavy bio-oil and its preparation method. The method, which involves vacuum distillation and thermal modification, is suitable for use in road paving, anti-corrosion sealing, and other fields. Background Art

[0002] With the gradual depletion of fossil resources and intensified environmental problems, the production and use of traditional petroleum asphalt are facing dual pressures on resources and the environment. Fully bio-based asphalt, as a new material with a renewable source and stable performance, is gradually gaining attention.

[0003] Bio-heavy oil is a highly viscous oil produced by high-temperature pyrolysis or transesterification of plant waste, oils, and fats. It contains a certain proportion of methyl esters, macromolecular organic compounds, and polar functional groups. If its composition and structure can be properly controlled, it has the potential to serve as a building block for all-bio-based asphalt. However, in practice, bio-heavy oil is susceptible to cracking at high temperatures, and its high impurities, high fluidity, and poor stability make it difficult to use directly. Therefore, a gentle, controllable process for processing bio-heavy oil is needed to produce high-quality all-bio-based asphalt. Summary of the Invention

[0004] The present invention is directed to the technical solutions mentioned in the background technology. Firstly, it provides a fully bio-based asphalt prepared from bio-heavy oil, and secondly, it provides a method for preparing the fully bio-based asphalt.

[0005] The technical solution adopted by the present invention is: a fully bio-based asphalt prepared from bio-heavy oil, the fully bio-based asphalt product has no fluidity, wherein the methyl ester yield is about 20.44%; the acid value is reduced to 2.01 mgKOH / g; the cold filter point is 19°C; and the closed cup flash point is greater than 234°C.

[0006] A method for preparing fully bio-based asphalt comprises the following steps: S1 Raw material preparation Pre-treat bio-heavy oil to remove impurities; S2 Vacuum Distillation Process Distilling the material after the treatment in step S1 through a vacuum system to obtain bio-heavy oil from which methyl esters have been removed; S3 additive thermal modification Adding a thermal modification additive to the bio-heavy oil obtained in step S2 to form a precursor asphalt; S4 Cooling and Collection After the reaction is completed, the mixture is slowly cooled to 60°C to obtain a fully bio-based asphalt product with uniform color and stable structure.

[0007] In step S1, the bio-heavy oil pretreatment method is as follows: the bio-heavy oil raw material is placed in a heating device and heated to 100-110° C., stirred and dehydrated for 2 hours, and then filtered using a 300-mesh filter cloth to remove impurities to obtain a clarified oil phase for subsequent treatment.

[0008] In step S2, the vacuum system uses two rotary vane vacuum pumps to operate alternately to ensure that the system vacuum is stable at ≤15 mmHg; the distillation temperature does not exceed 300°C; the maximum temperature of the gas phase is controlled within 220°C, and the stable distillation stage is maintained for no less than 90 minutes.

[0009] In step S2, the distillation temperature is 280-295°C.

[0010] The additives in step S3 are polycaprolactone-polylactic acid block copolymer and itaconic anhydride, and the ratio of the added amount of the two to the number of materials is 1:1:10-18.

[0011] The polycaprolactone and polylactic acid are bio-based.

[0012] In step S3, the method of adding the additive is as follows: (1) Prepare a three-necked flask for use; (2) When the temperature of the bio-heavy oil after the treatment in step S2 drops to 180°C, an appropriate amount of the bio-heavy oil is poured into a three-necked flask; (3) Stirring at room temperature, slowly add polycaprolactone-polylactic acid block copolymer during stirring, and continue stirring until it is completely dissolved to form a uniform reaction system; (4) Then continue stirring and add itaconic anhydride, and continue stirring and reacting at 130-150°C for 6-8 hours.

[0013] The ratio of the oil injected into the three-necked flask to the polycaprolactone-polylactic acid block copolymer added in step (3) and the itaconic anhydride added in step (4) is 10-18:1:1.

[0014] Compared with the existing technology, the present invention successfully obtains a fully bio-based asphalt product with high flash point, high viscosity and excellent thermal stability by optimizing the vacuum system, strictly controlling the distillation temperature, and combining additive regulation. This method has the advantages of wide raw materials, low energy consumption, and stable process, and can realize high added value utilization of waste biological resources.

[0015] The preparation method of the present invention achieves breakthroughs in the following aspects: (1) High thermal stability: Vacuum control effectively avoids cracking of bio-heavy oil and ensures the integrity of the asphalt structure; (2) Good safety: The flash point is higher than that of traditional petroleum asphalt, making it safer to use; (3) Green and environmentally friendly: No petroleum-based raw materials are introduced in the entire process, and renewable resources are used; (4) Strong adaptability: It has a wide range of raw materials and is suitable for bio-heavy oils from different sources.

[0016] The method of the present invention can be used to prepare all-biobased asphalt on a large scale, meeting the needs of green and low-carbon building materials such as road engineering and waterproof sealing materials, and has good prospects for promotion and application. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to the embodiments.

[0018] The fully bio-based asphalt prepared from bio-heavy oil disclosed in the present invention has no fluidity as the final product and has ideal asphalt characteristics, and has: a methyl ester yield of approximately 20.44%; an acid value reduced to 2.01 mgKOH / g; a cold filter point of 19°C; and a closed cup flash point greater than 234°C.

[0019] The method for preparing the fully bio-based asphalt comprises the following steps: S1 Raw material preparation Pre-treat the bio-heavy oil to remove impurities.

[0020] The bio-heavy oil raw material was placed in a heating device and heated to 100-110°C. After stirring and dehydrating for 2 hours, it was filtered using a 300-mesh filter cloth to remove impurities and obtain a clarified oil phase for subsequent treatment.

[0021] The selected bio-heavy oil complies with the NB / T 10770-2021 standard. The specific indicators are as follows:

[0022] S2 Vacuum Distillation Process The material treated in step S1 is distilled through a vacuum system to obtain bio-heavy oil from which methyl esters have been removed.

[0023] The vacuum system uses two rotary vane vacuum pumps operating alternately to ensure a stable vacuum level of ≤15 mmHg. The distillation temperature does not exceed 300°C, preferably between 280-295°C. The maximum vapor phase temperature is controlled below 220°C, and the stable distillation phase is maintained for at least 90 minutes to promote the recombination of polymer components.

[0024] S3 additive thermal modification A thermal modification additive is added to the bio-heavy oil obtained in step S2 to form a precursor asphalt. The additive is polycaprolactone-polylactic acid block copolymer and itaconic anhydride, and the ratio of the amount of the additive to the number of materials is 1:1:10-18.

[0025] S4 Cooling and Collection After the reaction is completed, the mixture is slowly cooled to 60°C to obtain a fully bio-based asphalt product with uniform color and stable structure.

[0026] As a preferred embodiment, in step S3, the method of adding the additive is as follows: (1) Prepare a 1000 mL three-necked flask; (2) When the temperature of the bio-heavy oil from which methyl esters have been removed by distillation after step S2 drops to 180°C, 500 mL of the oil is poured into a three-necked flask; (3) Stirring at room temperature, slowly add 30-50 g of polycaprolactone-polylactic acid (PCL and PLA are both bio-based) block copolymer during stirring, and continue stirring until it is completely dissolved to form a uniform reaction system; (4) Continue stirring and add 30-50g of itaconic anhydride. Continue stirring and reacting at 130-150℃ for 6-8 hours. No catalyst is required during the reaction. Itaconic anhydride reacts with the hydroxyl groups in the PLA segments to undergo esterification, while free radical grafting occurs on the PCL segments. The mixture gradually transforms into a viscous, non-flowing substance, forming the precursor asphalt.

[0027] The typical properties of the fully bio-based asphalt prepared by the present invention are as follows:

Claims

1. A fully bio-based asphalt prepared from bio-heavy oil, characterized in that: The all-biobased asphalt product has no fluidity, with a methyl ester yield of approximately 20.44%; the acid value drops to 2.01 mgKOH / g; the cold filter point is 19°C; and the closed cup flash point is >234°C.

2. A method for preparing the fully bio-based asphalt according to claim 1, characterized in that: The following steps are involved: S1 Raw material preparation Pre-treat bio-heavy oil to remove impurities; S2 Vacuum Distillation Process Distilling the material after the treatment in step S1 through a vacuum system to obtain bio-heavy oil from which methyl esters have been removed; S3 additive thermal modification Adding a thermal modification additive to the bio-heavy oil obtained in step S2 to form a precursor asphalt; S4 Cooling and Collection After the reaction is completed, the mixture is slowly cooled to 60°C to obtain a fully bio-based asphalt product with uniform color and stable structure.

3. The preparation method according to claim 2, characterized in that In step S1, the bio-heavy oil pretreatment method is as follows: the bio-heavy oil raw material is placed in a heating device and heated to 100-110° C., stirred and dehydrated for 2 hours, and then filtered using a 300-mesh filter cloth to remove impurities to obtain a clarified oil phase for subsequent treatment.

4. The preparation method according to claim 2, characterized in that In step S2, the vacuum system uses two rotary vane vacuum pumps to operate alternately to ensure that the system vacuum is stable at ≤15 mmHg; the distillation temperature does not exceed 300°C; the maximum temperature of the gas phase is controlled within 220°C, and the stable distillation stage is maintained for no less than 90 minutes.

5. The preparation method according to claim 2, characterized in that In step S2, the distillation temperature is 280-295°C.

6. The preparation method according to claim 2, characterized in that The additives in step S3 are polycaprolactone-polylactic acid block copolymer and itaconic anhydride, and the ratio of the added amount of the two to the number of materials is 1:1:10-18.

7. The preparation method according to claim 6, characterized in that The polycaprolactone and polylactic acid are of bio-based origin.

8. The preparation method according to claim 6, characterized in that In step S3, the method of adding the additive is as follows: (1) Prepare a three-necked flask for use; (2) When the temperature of the bio-heavy oil after the treatment in step S2 drops to 180°C, take an appropriate amount of the above oil and inject it into a three-necked flask; (3) Stirring at room temperature, slowly add polycaprolactone-polylactic acid block copolymer during stirring, and continue stirring until it is completely dissolved to form a uniform reaction system; (4) Then continue stirring and add itaconic anhydride, and continue stirring and reacting at 130-150°C for 6-8 hours.

9. The preparation method according to claim 8, characterized in that The ratio of the oil injected into the three-necked flask to the polycaprolactone-polylactic acid block copolymer added in step (3) and the itaconic anhydride added in step (4) is 10-18:1:1.

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