Preparation method of hard road asphalt

Abstract

The invention discloses a preparation method of hard road asphalt. The method comprises the following steps: (1) mixing ethylene tar with a polymer modifier, and shearing to obtain a mixture; (2) oxidizing the mixture obtained in the step (1) to obtain an oxidized mixture; and (3) carrying out countercurrent contact on the oxidized mixture obtained in the step (2), a modifier and an extraction solvent, and carrying out supercritical extraction, wherein an obtained raffinate heavy component is used as the hard asphalt. According to the method, the ethylene tar is used as the raw material to prepare the hard road asphalt, so that high value-added utilization of the ethylene tar can be realized, and the obtained hard road asphalt has better high-temperature and low-temperature performance and good storage stability.

Description

Technical Field

[0001] The invention belongs to the field of petroleum industry and basic material chemistry, and specifically relates to a method for preparing hard road asphalt, which is particularly suitable for high modulus fatigue-resistant asphalt mixture. Background Art

[0002] With the rapid growth of traffic volume on high-grade roads and the intensification of heavy traffic, the middle and lower layers of asphalt pavements are prone to compression deformation under vehicle load, and rutting, cracking and other damages will occur prematurely. Therefore, improving the rutting resistance of the middle and lower layers of asphalt pavements has become one of the key technologies to solve the rutting problem. Since 1980, France has adopted hard asphalt in high modulus asphalt mixture technology to improve the rutting resistance of asphalt pavements, achieving good results. It has been widely used in countries such as the United Kingdom and North Africa, and has become a research hotspot.

[0003] Hard asphalt can significantly improve the ability of asphalt concrete to resist permanent deformation at high temperatures due to its hard texture, high viscosity, high stiffness, and good adhesion to stones. The hard production of road asphalt is an inevitable trend to improve its anti-rutting performance. However, the low-temperature cracking resistance of hard road asphalt is poor, and it is difficult to balance the high-temperature anti-rutting performance. There is a contradictory relationship between the two. On the basis of maintaining high-temperature performance, optimizing low-temperature performance is a technical problem that needs to be solved in the current research and development of hard road asphalt.

[0004] CN101492570A discloses a hard road asphalt composition and a preparation method thereof. The composition comprises hard asphalt with a high asphaltene content and a penetration of less than 35 1 / 10 mm, a softener, a chemical modifier and a base asphalt, and the preparation process is as follows: the hard asphalt, the softener and the base asphalt are added to a reactor, sheared and stirred at a temperature of 150 to 170°C, and then the chemical modifier is added, and after shearing and stirring, a hard road asphalt composition is obtained. The hard road asphalt composition has excellent high temperature stability, fatigue resistance and adhesion to aggregates, but its low temperature performance is insufficient and the ductility is low.

[0005] CN109535747A discloses a No. 30 hard road asphalt and its preparation method. The raw materials of the asphalt include vacuum residue oil, deoiled asphalt mixture, and furfural extracted oil mixture. The hard asphalt prepared by blending has certain low temperature performance, but the high temperature performance is not outstanding enough.

[0006] Ethylene tar is a byproduct produced during the high-temperature condensation of raw materials in the production of ethylene, accounting for about 15% of ethylene production. Due to the lack of awareness of the use of low-quality resources in the past, ethylene tar was only used as fuel oil, resulting in a huge waste of resources. Therefore, if ethylene tar can be reasonably used to produce road asphalt, it will have a good application prospect. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention provides a method for preparing hard road asphalt. The method uses ethylene tar as a raw material to prepare hard road asphalt, which can not only realize the high added value utilization of ethylene tar, but also the obtained hard road asphalt has better high temperature and low temperature performance and good storage stability.

[0008] The present invention provides a method for preparing hard road asphalt, comprising the following steps:

[0009] (1) Ethylene tar and a polymer modifier are mixed and then sheared to obtain a mixture;

[0010] (2) subjecting the mixture obtained in step (1) to oxidation treatment to obtain an oxidized mixture;

[0011] (3) The oxidized mixture obtained in step (2) and the modifier are countercurrently contacted with an extraction solvent to perform supercritical extraction, and the heavy component of the residue obtained is used as hard asphalt.

[0012] In the method of the present invention, the properties of the ethylene tar are: density at 25°C is 1.0-1.2 g / cm 3 The residual carbon value is 12wt% to 20wt%, and the mass content of aromatic hydrocarbons is more than 70wt%.

[0013] In the method of the present invention, the polymer modifier is one or more of a thermoplastic elastomer, a rubber polymer, and a resin polymer. The thermoplastic elastomer is one or more of SBS, SEBS, and SIS. The rubber polymer is styrene-butadiene rubber. The resin polymer is one or more of PE, PET, and EVA.

[0014] In the method of the present invention, the mass ratio of the ethylene tar to the polymer modifier in step (1) is 100:1-10: preferably 100:2-8.

[0015] In the method of the present invention, the shearing temperature in step (1) is 150-180° C., and the particle size of the polymer modifier after shearing is less than 10 μm. The shearing is preferably carried out in a colloid mill.

[0016] In the method of the present invention, in step (2), the oxidation treatment uses an oxygen-containing gas as an oxidizing gas, wherein the oxygen content of the oxygen-containing gas is more than 15% by volume, such as air. The flow rate of the oxygen-containing gas is 5-20 L / min / 100 kg of the mixture, i.e., per 100 kg of the mixture obtained in step (1).

[0017] In the method of the present invention, in step (2), the temperature of the oxidation treatment is 180 to 280°C.

[0018] In the method of the present invention, in step (2), the oxidation treatment time is 30 to 60 minutes.

[0019] In the method of the present invention, in step (3), the modifier is at least one of diphenylamine or phenylenediamine and its derivatives (preferably at least one of N,N'-diphenyl-1,4-phenylenediamine, N-nitrosodiphenylamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N-phenyl-N'-cyclohexyl-p-phenylenediamine). The mass ratio of the modifier to the oxidized mixture obtained in step (2) is 0.1 to 1:100.

[0020] In the method of the present invention, in step (3), the extraction solvent is a C3-C5 alkane, such as at least one of propane, butane and pentane. The volume ratio of the extraction solvent to the oxidized mixture obtained in step (2) is 3-6:1.

[0021] In the method of the present invention, in step (3), the extraction temperature is 80-180° C. and the pressure is 4-6 MPa.

[0022] In the method of the present invention, in step (2), the light components of the extract obtained are separated to obtain light tar and solvent. The solvent can be recycled. The separation temperature is 200-250°C and the pressure is 5-10MPa.

[0023] In the method of the present invention, the properties of the hard road asphalt are as follows: needle penetration at 25°C is 20-40 0.1mm; softening point is ≥70°C; elongation at 15°C before film is ≥70cm; softening point difference in segregation test is ≤0.5°C.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The method of the present invention uses ethylene tar as raw material, which has a wide source and is low in price. The hard road asphalt produced has excellent high and low temperature performance, realizing high added value utilization of low-value resources.

[0026] 2. In the method of the present invention, ethylene tar and polymer modifier are mixed and sheared, and a large amount of aromatic components contained in ethylene tar promote the swelling development of polymer modifier. After a short oxidation treatment, under the action of oxygen, tar and polymer modifier are cross-linked to quickly form a network structure. After adding the modifier, supercritical extraction is performed to eliminate free radicals generated during the oxidation process and stabilize the formed network structure. On the other hand, the remaining light components in the system are separated to promote the moderate polymerization of ethylene tar molecules. The obtained hard asphalt has a higher softening point, better low-temperature ductility, better aging resistance, and good storage stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1It is a schematic diagram of the process of the present invention;

[0028] Explanation of the reference numerals: 1-colloid mill, 2-oxidation treatment tower, 3-extraction tower, 4-separator, 5-solvent tank, 6-ethylene tar, 7-polymer modifier, 8-sheared material, 9-oxygen-containing gas, 10-oxidation treatment tower top gas, 11-oxidation treatment mixture, 12-modifier, 13-raffinate, 14-extract, 15-light tar, 16-solvent. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below in conjunction with embodiments, but is not limited to the following embodiments.

[0030] Combine the following Figure 1 The method of the present invention is described in detail. The present invention provides a method for preparing hard road asphalt, comprising: ethylene tar 6 and polymer modifier 7 enter colloid mill 1 for shearing to obtain sheared material 8, the sheared material 8 and oxygen-containing gas 9 enter oxidation treatment tower 2 for reaction, gas 10 is discharged from the top of oxidation treatment tower, the oxidation mixture 11 discharged from the bottom of the tower, modifier 12 and extraction solvent 16 are countercurrently contacted in extraction tower 3 for extraction, the obtained raffinate heavy component 13 is used as hard road asphalt, the extract 14 enters separator 4, light tar 15 is obtained at the bottom, solvent 16 is obtained at the top, solvent 16 enters solvent tank 5, and the solvent can be recycled.

[0031] The relevant parameter testing method of the present invention:

[0032] The penetration and penetration index PI were measured according to the Ministry of Transportation Standard T0604, the softening point (ring and ball method) was measured according to the Ministry of Transportation Standard T0606, the ductility was measured according to the Ministry of Transportation Standard T0605, and the thin film heating test (TFOT) was carried out according to the Ministry of Transportation Standard T0609.

[0033] Example 1

[0034] In this example, Figure 1The process is as follows, the polymer modifier is SBS, the extraction solvent is propane, the modifier is diphenylamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar and polymer modifier are mixed in a mass ratio of 100:4, sheared at 160°C, and sheared until the polymer modifier particle size is less than 10 microns to obtain a mixture. After shearing, the mixture enters the oxidation treatment tower, and air is introduced into the bottom of the tower. The gas flow rate is 15L / min / 100kg. The sheared mixture is at a temperature of 260°C in the tower. After 40 minutes of treatment, the mixture is obtained. The oxidized mixture and the modifier enter the extraction tower in a mass ratio of 100:0.5, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 100°C, the pressure is 5MPa, the volume ratio of the extraction solvent to the oxidized material is 5:1, and the heavy component of the extract obtained after extraction is used as hard asphalt. The properties are shown in Table 2. The light component of the obtained extract is separated, and the separation conditions are: temperature 200°C, pressure 9MPa, to obtain light tar and solvent. The solvent can be recycled.

[0035] Example 2

[0036] In this example, Figure 1 The process is as follows, the polymer modifier is SEBS, the extraction solvent is butane, the modifier is diphenylamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar and polymer modifier are mixed in a mass ratio of 100:5, sheared at 180°C, and sheared until the polymer modifier particle size is less than 10 microns to obtain a mixture. After shearing, the mixture enters the oxidation treatment tower, and air is introduced into the bottom of the tower. The gas flow rate is 10L / min / 100kg. The sheared mixture is at a temperature of 240°C in the tower. After treatment for 30 minutes, the mixture is obtained. The oxidized mixture and the modifier enter the extraction tower in a mass ratio of 100:0.4, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 150°C, the pressure is 4MPa, the volume ratio of the extraction solvent to the oxidized material is 4:1, and the heavy component of the extract obtained after extraction is used as hard asphalt. The properties are shown in Table 2. The light component of the obtained extract is separated, and the separation conditions are: temperature 220°C, pressure 6MPa, to obtain light tar and solvent. The solvent can be recycled.

[0037] Example 3

[0038] In this example, Figure 1The process is as follows, the polymer modifier is SIS, the extraction solvent is pentane, the modifier is phenylenediamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar and polymer modifier are mixed in a mass ratio of 100:6, sheared at 170°C, and sheared until the polymer modifier particle size is less than 10 microns to obtain a mixture. After shearing, the mixture enters the oxidation treatment tower, and air is introduced into the bottom of the tower. The gas flow rate is 12L / min / 100kg. The sheared mixture is at a temperature of 220°C in the tower. After 50 minutes of treatment, the mixture is obtained. The oxidized mixture and the modifier enter the extraction tower in a mass ratio of 100:0.2, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 175°C, the pressure is 4MPa, the volume ratio of the extraction solvent to the oxidized material is 3:1, and the heavy component of the extract obtained after extraction is used as hard asphalt. The properties are shown in Table 2. The light component of the obtained extract is separated, and the separation conditions are: temperature 240°C, pressure 6MPa, to obtain light tar and solvent. The solvent can be recycled.

[0039] Example 4

[0040] In this example, Figure 1 The process is as follows, the polymer modifier is styrene-butadiene rubber, the extraction solvent is propane, the modifier is phenylenediamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar and polymer modifier are mixed in a mass ratio of 100:3, sheared at 180°C, and sheared until the polymer modifier particle size is less than 10 microns to obtain a mixture. After shearing, the mixture enters the oxidation treatment tower, and air is introduced into the bottom of the tower. The gas flow rate is 6L / min / 100kg. The sheared mixture is at a temperature of 270°C in the tower. After treatment for 30 minutes, the mixture is obtained. The oxidized mixture and the modifier enter the extraction tower in a mass ratio of 100:0.6, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 95°C, the pressure is 5MPa, the volume ratio of the extraction solvent to the oxidized material is 4:1, and the heavy component of the extract obtained after extraction is used as hard asphalt. The properties are shown in Table 2. The light component of the obtained extract is separated, and the separation conditions are: temperature 200°C, pressure 8MPa, to obtain light tar and solvent. The solvent can be recycled.

[0041] Example 5

[0042] In this example, Figure 1The process is as follows, the polymer modifier is EVA, the extraction solvent is pentane, the modifier is N,N'-diphenyl-1,4-phenylenediamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar and polymer modifier are mixed in a mass ratio of 100:5, sheared at 170°C, and sheared until the polymer modifier particle size is less than 10 microns to obtain a mixture. The sheared mixture enters the oxidation treatment tower, and air is introduced into the bottom of the tower. The gas flow rate is 10L / min / 100kg. The sheared mixture is at a temperature of 200°C in the tower. After treatment for 30 minutes, the mixture is obtained. The oxidized mixture and the modifier enter the extraction tower in a mass ratio of 100:0.4, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 170°C, the pressure is 4MPa, the volume ratio of the extraction solvent to the oxidized material is 3:1, and the heavy component of the raffinate obtained after extraction is used as hard asphalt. The properties are shown in Table 2. The light components of the obtained extract are separated under the conditions of temperature 250°C and pressure 5MPa to obtain light tar and solvent, wherein the solvent can be recycled.

[0043] Example 6

[0044] In this example, Figure 1 The process is as follows, the polymer modifier is PET, the extraction solvent is butane, the modifier is N-nitrosodiphenylamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar and polymer modifier are mixed in a mass ratio of 100:7, sheared at 160°C, and sheared until the polymer modifier particle size is less than 10 microns to obtain a mixture. After shearing, the mixture enters the oxidation treatment tower, and air is introduced into the bottom of the tower. The gas flow rate is 8L / min / 100kg. The sheared mixture is at a temperature of 250°C in the tower. After 40 minutes of treatment, the mixture is obtained. The oxidized mixture and the modifier enter the extraction tower in a mass ratio of 100:0.7, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 150°C, the pressure is 5MPa, the volume ratio of the extraction solvent to the oxidized material is 4:1, and the heavy component of the extract obtained after extraction is used as hard asphalt. The properties are shown in Table 2. The light component of the obtained extract is separated, and the separation conditions are: temperature 220°C, pressure 7MPa, to obtain light tar and solvent. The solvent can be recycled.

[0045] Comparative Example 1

[0046] Compared with Example 1, the difference is that no polymer modifier is added and the ethylene tar enters the oxidation treatment tower. The results are shown in Table 3.

[0047] Comparative Example 2

[0048] Compared with Example 1, the difference is that no oxidation treatment is performed, and the sheared mixture and the modifier are countercurrently contacted with the extraction solvent for supercritical extraction. The results are shown in Table 3.

[0049] Comparative Example 3

[0050] Compared with Example 1, the difference is that no supercritical extraction treatment is performed, and the mixture after oxidation treatment is used as an asphalt product. The results are shown in Table 3.

[0051] Comparative Example 4

[0052] Compared with Example 1, the difference is that no modifier is added during the supercritical extraction process. The results are shown in Table 3.

[0053] Table 1 Properties of ethylene tar

[0054]

[0055]

[0056] Table 2 Product test results of each embodiment

[0057] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Needle penetration (25℃) / 0.1mm 31 30 28 34 31 25 Penetration Index PI -0.54 -0.46 -0.51 -0.73 -0.65 -0.34 Softening point / ℃ 81.2 83.2 89.5 80.2 84.1 93.2 Elongation (15℃) / cm 87.4 88.0 81.2 91.2 90.1 78.5 Segregation test softening point difference / ℃ 0.1 0.2 0.2 0.3 0.1 0.3 TFOT(5h) Needle ratio, % 80.6 80.0 82.1 79.4 80.6 84.0 15℃ elongation / cm 43.6 47.4 40.2 48.3 45.4 38.4

[0058] Table 3 Test results of products in various comparative examples

[0059] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Needle penetration (25℃) / 0.1mm 45 56 63 22 Penetration Index PI -0.83 -0.93 -1.08 -0.87 Softening point / ℃ 65.3 58.3 63.2 83.2 Elongation (15℃) / cm 65.4 73.1 70.2 40.3 Segregation test softening point difference / ℃ 0.6 5.7 7.9 9.2 TFOT(5h) Needle ratio, % 75.5 73.2 66.7 72.7 15℃ elongation / cm 34.1 45.2 43.2 8.9

[0060] The embodiments of the present invention are only detailed descriptions of the technical solutions of the present invention, but the present invention is not limited to the above embodiments, that is, the present invention can be implemented without relying on the steps described in the above embodiments. In summary, any improvements made to the present invention by those skilled in the art, as long as they do not deviate from the content of the technical solutions of the present invention, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention, shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing hard road asphalt, comprising the following steps: (1) Ethylene tar and a polymer modifier are mixed and then sheared to obtain a mixture; (2) subjecting the mixture obtained in step (1) to oxidation treatment to obtain an oxidized mixture; (3) The oxidized mixture obtained in step (2) and the modifier are countercurrently contacted with an extraction solvent to perform supercritical extraction, and the heavy component of the residue obtained is used as hard asphalt.

2. The preparation method according to claim 1, characterized in that: The properties of the ethylene tar: density at 25°C is 1.0-1.2 g / cm 3 The residual carbon value is 12wt% to 20wt%, and the mass content of aromatic hydrocarbons is more than 70wt%.

3. The preparation method according to claim 1, characterized in that: The polymer modifier is one or more of a thermoplastic elastomer, a rubber polymer, and a resin polymer; preferably, the thermoplastic elastomer is one or more of SBS, SEBS, and SIS; the rubber polymer is styrene-butadiene rubber; and the resin polymer is one or more of PE, PET, and EVA.

4. The preparation method according to claim 1, characterized in that: The mass ratio of the ethylene tar to the polymer modifier in step (1) is 100:1-10: preferably 100:2-8.

5. The preparation method according to claim 1, characterized in that: The shearing temperature in step (1) is 150-180° C., and the particle size of the polymer modifier after shearing is less than 10 microns.

6. The preparation method according to claim 1, characterized in that: In step (2), the oxidation treatment uses oxygen-containing gas as the oxidizing gas, the oxygen volume content of the oxygen-containing gas is more than 15%, and preferably, the flow rate of the oxygen-containing gas is 5-20L / min / 100kg mixture.

7. The preparation method according to claim 1 or 6, characterized in that: In step (2), the temperature of the oxidation treatment is 180 to 280° C., and the time of the oxidation treatment is 30 to 60 minutes.

8. The preparation method according to claim 1, characterized in that: In step (3), the modifier is at least one of diphenylamine or phenylenediamine and its derivatives (preferably at least one of N,N'-diphenyl-1,4-phenylenediamine, N-nitrosodiphenylamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, and N-phenyl-N'-cyclohexyl-p-phenylenediamine); the mass ratio of the modifier to the oxidized mixture obtained in step (2) is 0.1 to 1:

100.

9. The preparation method according to claim 1, characterized in that: In step (3), the extraction solvent is C3-C5 alkane; the volume ratio of the extraction solvent to the oxidized mixture obtained in step (2) is 3-6:

1.

10. The preparation method according to claim 1 or 9, characterized in that: In step (3), the extraction temperature is 80-180° C. and the pressure is 4-6 MPa.

11. The preparation method according to claim 1, characterized in that: In step (2), the light components of the obtained extract are separated to obtain light tar and solvent, wherein the solvent is preferably recycled; preferably, the separation temperature is 200-250° C. and the pressure is 5-10 MPa.

12. The preparation method according to claim 1, characterized in that: The properties of the hard road asphalt are as follows: needle penetration at 25°C is 20-40 0.1mm; softening point is ≥70°C; elongation at 15°C before film is ≥70cm; softening point difference in segregation test is ≤0.5°C.

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