Extraction processing technology of modified asphalt

Abstract

The invention discloses an extraction processing technology of modified asphalt, and relates to the technical field of asphalt, and the extraction processing technology comprises the following steps: S1, removing water from crude oil at the bottom of a dehydration tower, feeding the crude oil into a fraction tower connected with a primary distillation tower through a tubular heating furnace, and extracting medium-temperature asphalt from the primary distillation tower; s2, adding a sodium hydroxide aqueous solution into the obtained medium-temperature asphalt, uniformly mixing, and then filtering to obtain a filtrate which is purified asphalt without tar acid; s3, heating the purified asphalt to 200-400 DEG C, and adding functional modified lignin under the shearing conditions that the shearing rate is 1000-2000 rpm and the shearing time is 2-4 hours; and S4, after shearing is finished, putting the sample into a constant-temperature oven to swell and develop the asphalt, thereby obtaining the modified asphalt. The modified asphalt provided by the invention has excellent high-temperature stability, aging resistance and low-temperature crack resistance.

Description

Technical Field

[0001] This application relates to the field of asphalt technology, and particularly to an extraction and processing technology for modified asphalt. Background Art

[0002] In current road construction, the pavement structure is mainly divided into two categories: cement concrete pavement and asphalt concrete pavement. Compared with traditional cement pavements, asphalt pavements have the following advantages: (1) High surface flatness: After construction, the surface of asphalt pavements is flat, providing a more comfortable driving experience, reducing vehicle bumps, and lowering driving noise; (2) Convenient construction: The construction process of asphalt concrete is relatively simple, with a fast construction speed, enabling the pavement to be laid in a relatively short time and reducing the impact of construction on traffic; (3) Recyclable utilization: Asphalt pavement materials have good recyclability. Old asphalt pavement materials can be recycled and reused in pavement construction after regeneration treatment, realizing the circular utilization of resources and conforming to the concept of sustainable development. Therefore, they are more widely used.

[0003] However, traditional asphalt materials have deficiencies in terms of high-temperature stability, aging resistance, and low-temperature crack resistance, making it difficult to meet the usage requirements of modern asphalt roads. This results in a large consumption of asphalt mortar for their repair and maintenance. At the same time, asphalt is refined from petroleum, which is a non-renewable resource. With the continuous increase in demand, resources are becoming increasingly scarce, further driving up the price of petroleum and increasing the maintenance cost of asphalt. Therefore, how to modify asphalt materials to improve their performance not only helps to extend the service life of roads and reduce maintenance costs but also meets the requirements of sustainable development, which has important practical significance. Summary of the Invention

[0004] To solve the deficiencies of asphalt materials in high-temperature stability, aging resistance, and low-temperature crack resistance, this application provides an extraction and processing technology for modified asphalt.

[0005] An extraction and processing technology for modified asphalt provided by this application adopts the following technical solutions: An extraction and processing technology for modified asphalt includes the following steps: S1. Remove water from the crude oil at the bottom of the dehydration tower, send it through a tubular heating furnace to a fractionating tower connected to the primary distillation tower, and extract medium-temperature asphalt from the primary distillation tower; the top temperature of the dehydration tower is 80 - 110°C, the extraction temperature of the medium-temperature asphalt is 330 - 350°C, and the absolute pressure at the top of the fractionating tower is 40 - 45 kPa; S2. Add an aqueous sodium hydroxide solution to the obtained medium-temperature asphalt and mix evenly, then filter it. The filtrate is purified asphalt free of pyrocatechuic acid; S3. The purified asphalt is heated to 200-400°C, and the functional modified lignin is added under shear conditions of a shear rate of 1000-2000rpm and a shear time of 2-4h; S4. After shearing, the sample is placed in a constant temperature oven to allow the asphalt to swell and develop, thereby obtaining modified asphalt.

[0006] Preferably, the functional modified lignin is prepared from the following raw materials in parts by weight: 10-20 parts of polypropylene glycol, 8-16 parts of diphenylmethane diisocyanate, 0.3-0.6 parts of chain extender, and 0.2-0.4 parts of acetylated lignin.

[0007] Preferably, the chain extender is 3,3′-dichloro-4,4′-diaminodiphenylmethane.

[0008] Preferably, the acetylated lignin is prepared from the following raw materials in parts by weight: 1-2 parts of lignin, 10-20 parts of pyridine, and 6.5-13 parts of acetic anhydride.

[0009] Preferably, the method for preparing the acetylated lignin comprises the following steps: The lignin raw material is placed in an oven at 105-125°C, dried for 2-3 hours, taken out and cooled for use; then the lignin is fully ground; the dried lignin is evenly mixed with pyridine, acetic anhydride is added, and heated for reaction; the reaction mixture is poured into ice water, filtered and washed, the filter residue is collected, and dried in a vacuum drying oven to obtain acetylated lignin.

[0010] Preferably, the heating reaction temperature is 70-90°C and the reaction time is 20-28h.

[0011] Preferably, the method for preparing the functional modified lignin comprises the following steps: S1. pre-treating the polypropylene glycol by dehydration; S2. The dehydrated polypropylene glycol is stirred at 50-70°C and a stirring rate of 200-400 rpm for 15-30 minutes in a nitrogen atmosphere, and then diphenylmethane diisocyanate is added to react for 15-30 minutes; then, acetylated lignin is added and reacted for another 10-30 minutes, and then a chain extender is added. After mixing and reacting for 30-60 seconds, the reaction product is filtered and washed, and the filter residue is collected and dried in a vacuum drying oven to obtain functionally modified lignin.

[0012] Preferably, the step of dehydration pretreatment of polypropylene glycol comprises: The polypropylene glycol is dehydrated in a vacuum oven at 120-160° C. and 0.1-0.2 MPa for 3-5 hours to obtain dehydrated polypropylene glycol.

[0013] Preferably, the mass ratio of the purified asphalt to the functional lignin in S3 is 1:0.1-0.15.

[0014] Preferably, the temperature for the swelling and development of the asphalt in S4 is 180-200°C, and the swelling and development time is 1-3h.

[0015] In summary, the present application includes at least one of the following beneficial technical effects: 1. By adopting the above technical scheme, the present application removes water from crude oil through a dehydration tower, and separates medium-temperature asphalt using a fractionation tower, thereby ensuring the purity of the asphalt and providing a basis for subsequent modification; then, an aqueous sodium hydroxide solution is added to treat the medium-temperature asphalt, and impurities such as tar acid are removed by filtration to obtain purified asphalt, thereby helping to improve the compatibility of the asphalt and the subsequent modification effect; then, functional modified lignin is added at a high shear rate for modification, which effectively improves the high-temperature stability and anti-aging properties of the asphalt, and also enhances its low-temperature crack resistance; the sheared sample is subjected to swelling and development in a constant temperature oven, thereby helping the functional modified lignin to further absorb the light components in the asphalt, optimize its dispersion state in the asphalt matrix, and improve the storage stability and high-temperature performance of the modified asphalt; 2. By adopting the above technical solution, the present application acetylates lignin, which can convert the hydroxyl group in lignin into acetoxy group, thereby reducing its polarity and improving its hydrophobicity; at the same time, it reduces the aggregation of lignin in the polyurethane system and improves its compatibility with the polyurethane matrix; polyurethane has excellent mechanical properties, and the acetylated lignin is introduced into the polyurethane system for modification, which can make the lignin have better stability in high or low temperature environments; 3. This application makes full use of lignin, a renewable resource, which has a wide range of sources and low costs, and meets the requirements of sustainable development. DETAILED DESCRIPTION

[0016] The present application is further described in detail below in conjunction with embodiments. Preparation Example Preparation Example 1

[0017] S0. Preparation of functional modified lignin, the preparation method is as follows: 1g of lignin was placed in an oven at 105°C, dried for 2h, taken out and cooled for later use; then the lignin was fully ground; the dried lignin was evenly mixed with 10g of pyridine, 6.5g of acetic anhydride was added, and heated at 70°C for 20h; the reaction mixture was poured into ice water, filtered and washed, the filter residue was collected, and dried in a vacuum drying oven at 50°C to obtain acetylated lignin; S1. Dehydrate 10 g of polypropylene glycol in a vacuum oven at 120 ° C and 0.1 MPa for 3 h to obtain dehydrated polypropylene glycol; S2. After the dehydrated polypropylene glycol was stirred at 200 rpm at 50°C for 15 minutes in a nitrogen atmosphere, 8 g of diphenylmethane diisocyanate was added and reacted for 15 minutes; then 0.2 g of acetylated lignin was added and reacted for another 10 minutes, and 0.3 g of chain extender 3,3′-dichloro-4,4′-diaminodiphenylmethane was added. After mixing and reacting for 30 seconds, the reaction product was filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 50°C to obtain functionally modified lignin. Preparation Example 2

[0018] S0. Preparation of functional modified lignin, the preparation method is as follows: 1.5 g of lignin was placed in an oven at 115°C, dried for 2.5 hours, and then taken out and cooled for use; the lignin was then fully ground; the dried lignin was evenly mixed with 15 g of pyridine, and 9.5 g of acetic anhydride was added, and heated at 80°C for 24 hours; the reaction mixture was poured into ice water, and then filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 55°C to obtain acetylated lignin; S1. Dehydrate 10 g of polypropylene glycol in a vacuum oven at 120 ° C and 0.1 MPa for 3 h to obtain dehydrated polypropylene glycol; S2. After the dehydrated polypropylene glycol was stirred at 200 rpm at 50°C for 15 minutes in a nitrogen atmosphere, 8 g of diphenylmethane diisocyanate was added and reacted for 15 minutes; then 0.2 g of acetylated lignin was added and reacted for another 10 minutes, and 0.3 g of chain extender 3,3′-dichloro-4,4′-diaminodiphenylmethane was added. After mixing and reacting for 30 seconds, the reaction product was filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 50°C to obtain functionally modified lignin. Preparation Example 3

[0019] S0. Preparation of functional modified lignin, the preparation method is as follows: 2 g of lignin was placed in an oven at 125°C, dried for 3 hours, and then taken out and cooled for use; the lignin was then fully ground; the dried lignin was evenly mixed with 20 g of pyridine, and 13 g of acetic anhydride was added, and heated at 90°C for 28 hours; the reaction mixture was poured into ice water, and then filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 60°C to obtain acetylated lignin; S1. Dehydrate 10 g of polypropylene glycol in a vacuum oven at 120 ° C and 0.1 MPa for 3 h to obtain dehydrated polypropylene glycol; S2. After stirring the dehydrated polypropylene glycol in a nitrogen atmosphere at 50 °C for 15 min at a stirring rate of 200 rpm, 8 g of diphenylmethane diisocyanate was added and reacted for 15 min; then 0.2 g of acetylated lignin was added and reacted for another 10 min, and then 0.3 g of chain extender 3,3′-dichloro-4,4′-diaminodiphenylmethane was added. After mixing and reacting for 30 s, the reaction product was filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 50 °C to obtain functional modified lignin. Preparation Example 4

[0020] S0. Prepare functional modified lignin, and its preparation method is as follows: Place 1 g of lignin in an oven at 105 °C, dry for 2 h, take it out and cool for standby; then grind the lignin sufficiently; after mixing the dried lignin and 10 g of pyridine evenly, add 6.5 g of acetic anhydride and heat and react at 70 °C for 20 h; pour the reacted mixture into ice water, then filter and wash, collect the filter residue, and dry it in a vacuum drying oven at 50 °C to obtain acetylated lignin; S1. Dehydrate 15 g of polypropylene glycol in a vacuum oven at 140 °C and 0.15 MPa for 4 h to obtain dehydrated polypropylene glycol; S2. After stirring the dehydrated polypropylene glycol in a nitrogen atmosphere at 60 °C for 23 min at a stirring rate of 300 rpm, 12 g of diphenylmethane diisocyanate was added and reacted for 23 min; then 0.2 g of acetylated lignin was added and reacted for another 20 min, and then 0.45 g of chain extender 3,3′-dichloro-4,4′-diaminodiphenylmethane was added. After mixing and reacting for 45 s, the reaction product was filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 55 °C to obtain functional modified lignin. Preparation Example 5

[0021] S0. Prepare functional modified lignin, and its preparation method is as follows: Place 1 g of lignin in an oven at 105 °C, dry for 2 h, take it out and cool for standby; then grind the lignin sufficiently; after mixing the dried lignin and 10 g of pyridine evenly, add 6.5 g of acetic anhydride and heat and react at 70 °C for 20 h; pour the reacted mixture into ice water, then filter and wash, collect the filter residue, and dry it in a vacuum drying oven at 50 °C to obtain acetylated lignin; S1. Dehydrate 20 g of polypropylene glycol in a vacuum oven at 160 °C and 0.2 MPa for 5 h to obtain dehydrated polypropylene glycol; S2. The dehydrated polypropylene glycol was stirred at a stirring rate of 400 rpm for 30 min at 70 °C in a nitrogen atmosphere. After that, 16 g of diphenylmethane diisocyanate was added and reacted for 30 min. Subsequently, 0.2 g of acetylated lignin was added and reacted for another 30 min. Then, 0.6 g of chain extender 3,3′-dichloro-4,4′-diaminodiphenylmethane was added. After mixing and reacting for 60 s, the reaction product was filtered and washed, and the filter residue was collected and dried in a vacuum drying oven at 60 °C to obtain functional modified lignin. Example Example 1

[0022] S1. The crude oil was dehydrated at the bottom of the dehydration tower, sent through a tubular heating furnace to a fractionation tower connected to the primary distillation tower, and medium-temperature asphalt was taken out from the primary distillation tower. The top temperature of the dehydration tower was 80 °C, the extraction temperature of the medium-temperature asphalt was 330 °C, and the absolute pressure at the top of the fractionation tower was 40 kPa. S2. An aqueous sodium hydroxide solution with a mass fraction of 30% was added to the obtained medium-temperature asphalt and mixed evenly, and then filtered. The filtrate was purified asphalt free of pyrolytic acid. S3. 100 g of the purified asphalt was heated to 200 °C, and 10 g of the functional modified lignin prepared in Preparation Example 1 was added under the shearing conditions of a shearing rate of 1000 rpm and a shearing time of 2 h. S4. After shearing, the sample was placed in a constant-temperature oven at 180 °C to allow the asphalt to swell and develop for 1 h to obtain modified asphalt. Example 2

[0023] S1. The crude oil was dehydrated at the bottom of the dehydration tower, sent through a tubular heating furnace to a fractionation tower connected to the primary distillation tower, and medium-temperature asphalt was taken out from the primary distillation tower. The top temperature of the dehydration tower was 95 °C, the extraction temperature of the medium-temperature asphalt was 340 °C, and the absolute pressure at the top of the fractionation tower was 42.5 kPa. S2. An aqueous sodium hydroxide solution with a mass fraction of 30% was added to the obtained medium-temperature asphalt and mixed evenly, and then filtered. The filtrate was purified asphalt free of pyrolytic acid. S3. 100 g of the purified asphalt was heated to 300 °C, and 10 g of the functional modified lignin prepared in Preparation Example 1 was added under the shearing conditions of a shearing rate of 1500 rpm and a shearing time of 3 h. S4. After shearing, the sample was placed in a constant-temperature oven at 180 °C to allow the asphalt to swell and develop for 1 h to obtain modified asphalt. Example 3

[0024] S1. Remove the moisture from the crude oil at the bottom of the dehydration tower, send it into the fractionation tower connected to the atmospheric distillation tower through a tubular heating furnace, and extract medium-temperature asphalt from the atmospheric distillation tower; the top temperature of the dehydration tower is 100 °C, the extraction temperature of the medium-temperature asphalt is 350 °C, and the absolute pressure at the top of the fractionation tower is 45 kPa; S2. Add an aqueous sodium hydroxide solution with a mass fraction of 30% to the obtained medium-temperature asphalt and mix evenly, and then filter it. The filtrate is the purified asphalt free of pyrolytic acid; S3. Heat 100 g of the purified asphalt to 400 °C, and add 10 g of the functional modified lignin prepared in Preparation Example 1 under the shearing conditions of a shearing rate of 2000 rpm and a shearing time of 4 h; S4. After shearing, place the sample in a constant-temperature oven at 180 °C to allow the asphalt to swell and develop for 1 h to obtain the modified asphalt. Example 4

[0025] The difference between Example 4 and Example 1 is that in Example 4, 100 g of the purified asphalt and 12.5 g of the functional modified lignin prepared in Preparation Example 1 are used in S3. Example 5

[0026] The difference between Example 5 and Example 1 is that in Example 5, 100 g of the purified asphalt and 15 g of the functional modified lignin prepared in Preparation Example 1 are used in S3. Example 6

[0027] The difference between Example 6 and Example 1 is that in Example 6, 100 g of the purified asphalt and 7.5 g of the functional modified lignin prepared in Preparation Example 1 are used in S3. Example 7

[0028] The difference between Example 7 and Example 1 is that in Example 7, 100 g of the purified asphalt and 17.5 g of the functional modified lignin prepared in Preparation Example 1 are used in S3. Example 8

[0029] The difference between Example 8 and Example 1 is that in Example 8, the functional modified lignin used in S3 is from Preparation Example 2. Example 9

[0030] The difference between Example 9 and Example 1 is that in Example 9, the functional modified lignin used in S3 is from Preparation Example 3. Example 10

[0031] The difference between Example 10 and Example 1 is that in Example 10, the functional modified lignin used in S3 is from Preparation Example 4. Example 11

[0032] Example 11 is different from Example 1 in that the functional modified lignin used in S3 of Example 11 is from Preparation Example 5. Example 12

[0033] Example 12 is different from Example 1 in that the temperature for asphalt swelling and development in S4 of Example 12 is 190 °C; the swelling and development time is 2 h. Example 13

[0034] Example 13 is different from Example 1 in that the temperature for asphalt swelling and development in S4 of Example 13 is 200 °C; the swelling and development time is 3 h. Comparative Example Comparative Example 1

[0035] Comparative Example 1 is different from Example 1 in that the lignin used in Comparative Example 1 is not functionally modified. Comparative Example 2

[0036] Comparative Example 2 is different from Example 1 in that after shearing in S4, the sample in Comparative Example 2 is directly dried without swelling and development. Performance Detection Test

[0037] According to the provisions of JTGE20 - 2011 "Test Procedures for Bitumen and Bituminous Mixtures in Highway Engineering", the basic performance tests were carried out on the modified bitumens obtained from Examples 1 - 13 and Comparative Examples 1 - 2, and the results are shown in Table 1.

[0038] The specific detection results are as follows:

[0039] It can be seen from the detection results in Table 1 that for an extraction and processing process of a modified bitumen provided by the present application, the obtained modified bitumen has excellent high - temperature stability and low - temperature crack resistance.

[0040] This specific embodiment is only an interpretation of the present application, and it does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An extraction and processing process for modified asphalt, characterized in that: It includes the following steps: S1. Remove the moisture from the crude oil at the bottom of the dehydration tower, send it through a tubular heating furnace into a fractionation tower connected to the atmospheric distillation tower, and extract medium-temperature asphalt from the atmospheric distillation tower; the top temperature of the dehydration tower is 80 - 110 °C, the extraction temperature of the medium-temperature asphalt is 330 - 350 °C, and the absolute pressure at the top of the fractionation tower is 40 - 45 kPa; S2. Add an aqueous sodium hydroxide solution to the obtained medium-temperature asphalt and mix evenly, then filter it. The filtrate is the purified asphalt free of pyrolytic acid; S3. Heat the purified asphalt to 200 - 400 °C, and add functional modified lignin under the shearing conditions of a shear rate of 1000 - 2000 rpm and a shear time of 2 - 4 h; S4. After shearing, place the sample in a constant-temperature oven to allow the asphalt to swell and develop, and obtain the modified asphalt.

2. The extraction and processing technology of a modified asphalt according to claim 1, characterized in that: The functional modified lignin is prepared from the following raw materials in parts by weight: 10 - 20 parts of polypropylene glycol, 8 - 16 parts of diphenylmethane diisocyanate, 0.3 - 0.6 part of chain extender, and 0.2 - 0.4 part of acetylated lignin.

3. The extraction and processing technology of a modified asphalt according to claim 2, characterized in that: The chain extender is 3,3′-dichloro-4,4′-diaminodiphenylmethane.

4. The extraction and processing technology of a modified asphalt according to claim 2, characterized in that: The acetylated lignin is prepared from the following raw materials in parts by weight: 1 - 2 parts of lignin, 10 - 20 parts of pyridine, and 6.5 - 13 parts of acetic anhydride.

5. The extraction and processing technology of a modified asphalt according to claim 4, characterized in that: The preparation method of the acetylated lignin includes the following steps: Place the lignin raw material in an oven at 105 - 125 °C, dry it for 2 - 3 h, then take it out and cool it for standby; then grind the lignin sufficiently; mix the dried lignin evenly with pyridine, add acetic anhydride, and heat for reaction; pour the reaction mixture into ice water, then perform suction filtration and washing, collect the filter residue, and dry it in a vacuum drying oven to obtain acetylated lignin.

6. The extraction and processing technology of a modified asphalt according to claim 5, characterized in that: The temperature of the heating reaction is 70 - 90 °C, and the reaction time is 20 - 28 h.

7. The extraction and processing process of a modified asphalt according to claim 2, characterized in that: The preparation method of the functional modified lignin includes the following steps: S1. Perform dehydration pretreatment on the polypropylene glycol; S2. Under a nitrogen atmosphere, stir the dehydrated polypropylene glycol at a stirring rate of 200 - 400 rpm at 50 - 70 °C for 15 - 30 min, then add diphenylmethane diisocyanate and react for 15 - 30 min; subsequently add acetylated lignin and react for another 10 - 30 min, then add the chain extender, mix and react for 30 - 60 s, then perform suction filtration and washing on the reaction product, collect the filter residue, and dry it in a vacuum drying oven to obtain functional modified lignin.

8. The extraction and processing technology of a modified asphalt according to claim 7, characterized in that: The steps of the dehydration pretreatment of the polypropylene glycol include: Dehydrate the polypropylene glycol in a vacuum oven at 120 - 160 °C and 0.1 - 0.2 MPa for 3 - 5 h to obtain dehydrated polypropylene glycol.

9. The extraction and processing technology of a modified asphalt according to claim 1, characterized in that: In S3, the mass ratio of the purified asphalt to the functional lignin is 1:0.1 - 0.

15.

10. The extraction and processing technology of a modified asphalt according to claim 1, characterized in that: In S4, the temperature for the asphalt to swell and develop is 180 - 200 °C; the swelling and development time is 1 - 3 h.

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