Production method of hard road asphalt

Abstract

The invention discloses a production method of hard road asphalt. The method comprises the following steps: (1) carrying out reduced pressure distillation on ethylene tar to obtain a light component and a heavy component, with the light component as an extraction solvent; (2) carrying out oxidation treatment on the heavy component obtained in the step (1) to obtain a mixture subjected to oxidation treatment; and (3) carrying out countercurrent contact on the oxidized mixture obtained in the step (2), a modifier and the extraction solvent, and carrying out supercritical extraction, wherein the obtained raffinate heavy component is used as the hard asphalt. According to the method, the ethylene tar is used as a raw material to prepare the No.15 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.

Description

Technical Field

[0001] The invention relates to a method for preparing hard asphalt from ethylene tar, and belongs to the field of high value-added utilization of low-value resources. Background Art

[0002] Hard asphalt has a small penetration and a high softening point. It is used to improve the modulus and high-temperature deformation resistance of asphalt concrete. It is also called high modulus asphalt abroad. No. 15 hard asphalt is mainly used to produce high modulus fatigue-resistant asphalt mixture (HFM). HFM asphalt mixture can effectively reduce the deformation of the road surface under vehicle load, improve the road surface's ability to resist high-temperature deformation, and improve the road surface's fatigue resistance and extend the road surface's service life.

[0003] However, the low-temperature crack resistance of hard road asphalt is poor, and it is difficult to balance the high-temperature rutting resistance. 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. At present, many research units have tried to use low-grade road asphalt No. 50 or No. 30, and started to study high-modulus asphalt mixture technology by adding lake asphalt, rock asphalt, high modulus additives or anti-rutting agents. However, most hard asphalts are prepared by simple blending and modification methods. Their properties are unstable and vary greatly, and they often sacrifice the low-temperature performance and fatigue resistance of asphalt binders. There are also other modifiers such as SBS and rubber powder to modify asphalt binders to improve their high and low temperature performance and fatigue performance, but the high production cost of modifier technology still affects the large-scale promotion and application of this new road material.

[0004] Peng Yu (Development and Application of Hard Asphalt for High Modulus Asphalt Mixture [D]. Chang'an University, 2014.) et al. prepared hard asphalt using a composite modification process, which has good high temperature performance and low temperature crack resistance, and is suitable for northern regions with high low temperature crack resistance and fatigue resistance. CN104650602A discloses a high-grade road hard asphalt and a preparation method thereof, which uses deoiled asphalt, topped oil slurry, extracted oil and polymer modifiers such as SBS and SBR to prepare high-grade road hard petroleum asphalt with a needle penetration of 10-60 1 / 10mm. The above method needs to be further improved in terms of raw material cost performance, high and low temperature performance, etc., and the production cost is relatively high.

[0005] 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 for combustion, resulting in a huge waste of resources. Therefore, the rational use of ethylene tar to produce hard asphalt has a good application prospect. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a method for producing hard road asphalt. The method uses ethylene tar as a raw material to prepare No. 15 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.

[0007] The present invention provides a method for producing hard road asphalt, comprising the following steps:

[0008] (1) Ethylene tar is subjected to vacuum distillation to obtain light components and heavy components, wherein the light components are used as extraction solvent;

[0009] (2) subjecting the heavy component obtained in step (1) to oxidation treatment to obtain an oxidation-treated mixture;

[0010] (3) The oxidized mixture obtained in step (2), the modifier and the extraction solvent are countercurrently contacted to perform supercritical extraction, and the heavy component of the residue obtained is used as hard asphalt.

[0011] 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%.

[0012] In the method of the present invention, in step (1), during the reduced pressure distillation, the tower bottom temperature is 180-230° C., the tower top temperature is 120-150° C., and the fractionation pressure is 20-50 kPa (A).

[0013] In the method of the present invention, in step (2), the oxidation treatment uses an oxygen-containing gas as the 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 heavy components.

[0014] In the method of the present invention, in step (2), the temperature of the oxidation treatment is 200-300°C.

[0015] In the method of the present invention, in step (2), the oxidation treatment time is 50 to 100 minutes.

[0016] 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 treated mixture obtained in step (2) is 0.1 to 1:100.

[0017] In the method of the present invention, in step (3), the volume ratio of the extraction solvent to the treated mixture obtained in step (2) is 3 to 6:1.

[0018] In the method of the present invention, in step (3), the extraction temperature is 200-300° C. and the pressure is 4-6 MPa.

[0019] In the method of the present invention, in step (3), the light component of the extract obtained does not need to be separated by solvent and can be directly used as light tar.

[0020] In the method of the present invention, the needle penetration of the hard asphalt at 25°C is 10-20 0.1mm; the softening point is ≥75°C; the dynamic viscosity at 60°C is >5000Pa·s, and the elongation at 25°C before the membrane is ≥30cm.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 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.

[0023] 2. In the method of the present invention, ethylene tar is first subjected to vacuum distillation, and then the heavy components are subjected to short-term oxidation treatment. Under the action of oxygen, the tar molecules undergo oxidative cross-linking and dehydrogenation condensation, and the unsaturated bonds and small molecular aromatics are converted into condensed aromatics. After adding a modifier to the mixture after oxidation treatment, supercritical extraction is carried out with the light component of ethylene tar as the extraction solvent. On the one hand, the free radicals generated in the oxidation process are eliminated and the formed asphalt system is stabilized. On the other hand, the remaining light components in the system are separated, and the moderate polymerization of ethylene tar molecules is promoted. The obtained hard asphalt has a higher softening point, better low-temperature ductility, and better aging resistance.

[0024] 3. Different from conventional supercritical extraction, the present invention uses the light component of ethylene tar as the extraction solvent, which has higher extraction efficiency and the prepared hard asphalt has better high-temperature performance. At the same time, the solvent as part of the light tar does not need to be recovered separately, and the process is more energy-efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process of the present invention;

[0026] Explanation of the reference numerals: 1-fractionation tower, 2-oxidation treatment tower, 3-extraction tower, 4-solvent tank, 5-ethylene tar, 6-top material of the fractionation tower, 7-bottom material of the fractionation tower, 8-oxygen-containing gas, 9-top gas of the oxidation treatment tower, 10-mixture after oxidation treatment, 11-modifier, 12-residue, 13-light tar, 14-solvent. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below in conjunction with embodiments, but is not limited to the following embodiments.

[0028] Combine the following Figure 1 The method of the present invention is described in detail. The present invention provides a method for producing hard road asphalt, comprising: ethylene tar 5 enters a fractionation tower 1 for fractionation to obtain a light component 6 and a heavy component 7, wherein the light component 6 is used as a solvent of an extraction tower 3, and the solvent does not need to be recycled, the heavy component 7 and an oxygen-containing gas 8 enter an oxidation treatment tower 2 for reaction, gas 9 is discharged from the top of the oxidation treatment tower, and the oxidation-treated mixture 10 discharged from the bottom of the tower, a modifier 11 and an extraction solvent 14 are countercurrently contacted in the extraction tower 3 for extraction, and the obtained raffinate heavy component 12 is used as hard road asphalt, and the extract light component 13 is used as light tar.

[0029] The relevant parameter testing method of the present invention:

[0030] The penetration and penetration index PI are measured according to the Ministry of Transportation Standard T0604, the softening point (ring and ball method) is measured according to the Ministry of Transportation Standard T0606, the ductility is measured according to the Ministry of Transportation Standard T0605, the thin film heating test (TFOT) is carried out according to the Ministry of Transportation Standard T0609, and the asphalt dynamic viscosity test is carried out according to the Ministry of Transportation Standard T0620.

[0031] Example 1

[0032] In this example, Figure 1 The process is shown in Table 1. The modifier is diphenylamine. The properties of ethylene tar are shown in Table 1. Ethylene tar enters the fractionation tower, the bottom temperature is 220℃, the top temperature is 130℃, the fractionation pressure is 40kPa(A), the light component at the top of the tower is used as the solvent of the extraction tower, and the heavy component at the bottom of the tower and the air enter the oxidation treatment tower for reaction. The gas flow rate is 13L / min / 100kg of heavy component, the temperature in the tower is 250℃, and the mixture is obtained after treatment for 50min. The oxidized mixture and the modifier enter the extraction tower at 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 210℃, 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 does not need to be separated by solvent and can be used as light tar.

[0033] Example 2

[0034] In this example, Figure 1The process is as follows, the modifier is phenylenediamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar enters the fractionation tower, the bottom temperature is 200℃, the top temperature is 120℃, the fractionation pressure is 30kPa(A), the light component at the top of the tower is used as the solvent of the extraction tower, the heavy component at the bottom of the tower and the air enter the oxidation treatment tower for reaction, the gas flow rate is 10L / min / 100kg of heavy component, the temperature in the tower is 260℃, and the mixture is obtained after treatment for 60min. The oxidized mixture and the modifier enter the extraction tower at 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 210℃, the pressure is 4.5MPa, 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, and the properties are shown in Table 2. The light component of the obtained extract does not need to be separated by solvent and can be used as light tar.

[0035] Example 3

[0036] In this example, Figure 1 The process is shown in Table 1. The modifier is diphenylamine. The properties of ethylene tar are shown in Table 1. Ethylene tar enters the fractionation tower, the bottom temperature is 210℃, the top temperature is 130℃, the fractionation pressure is 20kPa(A), the light component at the top of the tower is used as the solvent of the extraction tower, and the heavy component at the bottom of the tower and the air enter the oxidation treatment tower for reaction. The gas flow rate is 18L / min / 100kg of heavy component, the temperature in the tower is 220℃, and the mixture is obtained after treatment for 70min. The oxidized mixture and the modifier enter the extraction tower at a mass ratio of 100:0.3, and are countercurrently contacted with the extraction solvent for supercritical extraction. The extraction conditions are as follows: the extraction temperature is 240℃, 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 does not need to be separated by solvent and can be used as light tar.

[0037] Example 4

[0038] In this example, Figure 1 The process is shown in Table 1. The modifier is phenylenediamine. The properties of ethylene tar are shown in Table 1. Ethylene tar enters the fractionation tower, the bottom temperature is 200℃, the top temperature is 120℃, the fractionation pressure is 40kPa(A), the light component at the top of the tower is used as the solvent of the extraction tower, and the heavy component at the bottom of the tower and the air enter the oxidation treatment tower for reaction. The gas flow rate is 7L / min / 100kg of heavy component, the temperature in the tower is 270℃, and the mixture is obtained after treatment for 60min. The oxidized mixture and the modifier enter the extraction tower at 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 250℃, 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 does not need to be separated by solvent and can be used as light tar.

[0039] Example 5

[0040] In this example, Figure 1 The process is shown in Table 1. The modifier is N-nitrosodiphenylamine. The properties of ethylene tar are shown in Table 1. Ethylene tar enters the fractionation tower, the bottom temperature is 230℃, the top temperature is 150℃, the fractionation pressure is 40kPa(A), the light component at the top of the tower is used as the solvent of the extraction tower, and the heavy component at the bottom of the tower and the air enter the oxidation treatment tower for reaction. The gas flow rate is 10L / min / 100kg of heavy component, the temperature in the tower is 230℃, and the mixture is obtained after treatment for 60min. The oxidized mixture and the modifier enter the extraction tower at 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 270℃, 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 does not need to be separated by solvent and can be used as light tar.

[0041] Example 6

[0042] In this example, Figure 1 The process is as follows, the modifier is N,N'-diphenyl-1,4-phenylenediamine, and the properties of ethylene tar are shown in Table 1. Ethylene tar enters the fractionation tower, the bottom temperature is 210℃, the top temperature is 140℃, the fractionation pressure is 50kPa(A), the light component at the top of the tower is used as the solvent of the extraction tower, the heavy component at the bottom of the tower and the air enter the oxidation treatment tower for reaction, the gas flow rate is 8L / min / 100kg heavy component, the temperature in the tower is 250℃, and the mixture is obtained after 90min of treatment. The oxidized mixture and the modifier enter the extraction tower at 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 250℃, 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, and the properties are shown in Table 2. The light component of the obtained extract does not need to be separated by solvent and can be used as light tar.

[0043] Comparative Example 1

[0044] Compared with Example 1, the difference is that the modifier diphenylamine is not added. The results are shown in Table 3.

[0045] Comparative Example 2

[0046] Compared with Example 1, the difference is that the oxidation temperature is reduced to 150° C. The results are shown in Table 3.

[0047] Comparative Example 3

[0048] Compared with Example 1, the difference is that no supercritical extraction is performed, and the mixture after oxidation treatment is used as the asphalt product. The results are shown in Table 3.

[0049] Table 1 Properties of ethylene tar

[0050] Analyze Project data Density at 25℃, g / cm 1.103 Kinematic viscosity at 60℃, cst 194.3 Carbon residue,% 16.31 Aromatic content, wt% 78.23 Ash content, % 0.034 Elemental composition, % C 92.56 H 7.30 S 0.05 N 0.03 O 0.06

[0051] Table 2 Product test results of each embodiment

[0052]

[0053] Table 3 Test results of products in various comparative examples

[0054] Comparative Example 1 Comparative Example 2 Comparative Example 3 Needle penetration (25℃) / 0.1mm 5 25 34 Penetration Index PI -0.96 -0.87 -0.93 Softening point / ℃ 84.5 61.3 53.0 Elongation (25℃) / cm 19.1 61.2 67.3 60℃ dynamic viscosity / Pa·s 7789 3401 2394 TFOT(5h) Needle ratio, % 75.0 64.0 70.5 Mass loss, % 0.05 0.12 0.11

[0055] 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 producing hard road asphalt, comprising the following steps: (1) Ethylene tar is subjected to vacuum distillation to obtain light components and heavy components, wherein the light components are used as extraction solvent; (2) subjecting the heavy component obtained in step (1) to oxidation treatment to obtain an oxidation-treated mixture; (3) The oxidized mixture obtained in step (2) and the modifier are countercurrently contacted with the extraction solvent to perform supercritical extraction, and the heavy component of the residue is obtained 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: In step (1), during the reduced pressure distillation, the tower bottom temperature is 180-230° C., the tower top temperature is 120-150° C., and the fractionation pressure is 20-50 kPa(A).

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

5. The preparation method according to claim 1 or 4, characterized in that: In step (2), the temperature of the oxidation treatment is 200 to 300° C., and the time of the oxidation treatment is 50 to 100 minutes.

6. 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 treated mixture obtained in step (2) is 0.1 to 1:

100.

7. The preparation method according to claim 1, characterized in that: In step (3), the volume ratio of the extraction solvent to the treated mixture obtained in step (2) is 3 to 6:

1.

8. The preparation method according to claim 1 or 7, characterized in that: In step (3), the extraction temperature is 200-300° C. and the pressure is 4-6 MPa.

9. The preparation method according to claim 1, characterized in that: In step (3), the light component of the extract obtained does not need to be separated by solvent and can be directly used as light tar.

10. The preparation method according to claim 1, characterized in that: The hard asphalt has a needle penetration of 10 to 20 0.1 mm at 25°C, a softening point of ≥75°C, a dynamic viscosity of >5000 Pa·s at 60°C, and an elongation of ≥30 cm before film formation at 25°C.

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