Modified pitch, method for producing the same, and use thereof

Abstract

This invention provides a method for preparing modified asphalt, comprising the following steps: adding a crosslinking agent to petroleum-based heavy oil slurry to carry out an oxidative crosslinking reaction, followed by cooling and molding; wherein the crosslinking agent is selected from at least one of epoxy resin, diallyl phthalate, and C2-C8 diol compounds. The crosslinking agent selected in the preparation method of this invention requires a smaller amount compared to existing peroxide crosslinking agents, and can lower the temperature of the oxidative crosslinking reaction. This invention also provides a modified asphalt prepared by the above method and its application.

Description

Technical Field

[0001] This invention belongs to the field of asphalt modification technology, specifically relating to a modified asphalt, its preparation method, and its application. Background Technology

[0002] Currently, China's electrolytic aluminum production has reached 40 million tons per year. Typically, 0.5 tons of pre-modified anodes are needed to smelt one ton of aluminum. The preparation of pre-modified anodes requires the addition of approximately 15% modified bitumen, thus the demand for modified bitumen in the electrolytic aluminum industry will reach 3 million tons per year. However, with the gradual implementation of the dual-carbon policy, the real estate industry is gradually becoming saturated, and the demand for steel is decreasing, leading to a reduction in the demand for coke, a decrease in the operating rate of coking plants, and consequently, an increase in coal tar prices. Currently, coal tar is the main raw material for the preparation of modified bitumen, and the increase in coal tar prices has led to an increase in the price of modified bitumen. Therefore, finding other raw materials with large quantities and low prices as precursors for modified bitumen is of great significance.

[0003] Petrochemical enterprises have a large amount of heavy oil slurry, which is usually high in aromatics and low in ash. Its chemical composition is similar to that of coal tar pitch, but its benzo[a]pyrene content is significantly lower than that of coal tar pitch. Therefore, it is a potential high-quality precursor for the preparation of modified bitumen.

[0004] The current mainstream method for preparing coal-based modified bitumen is to use coal tar pitch through a reduced-pressure polymerization process. This process is not only time-consuming, but also requires high control over the composition of the raw coal tar pitch and the reaction temperature.

[0005] Therefore, developing a method for preparing modified asphalt from petroleum-based heavy oil slurry is of great significance for improving the quality of modified asphalt, reducing the emission of toxic and harmful substances, and increasing the value of heavy oil slurry. Summary of the Invention

[0006] The purpose of this invention is to increase the added value of petroleum-based heavy oil slurry, solve the problem of insufficient raw materials for modified asphalt when coal tar is reduced, and provide a method for preparing modified asphalt using petroleum-based heavy oil slurry as raw material.

[0007] Therefore, in a first aspect, the present invention provides a method for preparing modified asphalt, comprising the following steps: adding a crosslinking agent to petroleum-based heavy oil slurry for oxidative crosslinking reaction, followed by cooling and molding; wherein the crosslinking agent is selected from at least one of epoxy resin, diallyl phthalate, and C2-C8 diol compounds.

[0008] The preparation method of this invention uses petroleum-based heavy oil slurry as a raw material in combination with a specific crosslinking agent. Compared with existing peroxide crosslinking agents, the amount used is less, and the temperature of the oxidative crosslinking reaction can be lowered. Simultaneously, using petroleum-based heavy oil slurry as a raw material can increase the added value of the petroleum-based heavy oil slurry, while reducing the release of toxic and harmful substances such as benzo[a]pyrene during the traditional coal tar pitch preparation process, and obtaining high-quality modified pitch with high β-resin content, exhibiting stronger adhesion compared to coal-based modified pitch. Therefore, when the modified pitch prepared by this invention is used as a binder in carbon products, it helps to reduce the amount of binder used, thereby reducing the cost of carbon products.

[0009] As a specific embodiment of the present invention, the diol compound is a C2-C6 diol compound.

[0010] As a specific embodiment of the present invention, the diol compound is selected from at least one of ethylene glycol, propylene glycol, butanediol and pentanediol, and more preferably ethylene glycol.

[0011] In a specific embodiment of the present invention, the crosslinking agent is a C2-C8 diol compound.

[0012] As a specific embodiment of the present invention, the crosslinking agent is a C2-C6 diol compound, and preferably the crosslinking agent is added before the petroleum-based heavy oil slurry is heated.

[0013] In a specific embodiment of the present invention, the crosslinking agent is ethylene glycol, preferably added before the petroleum-based heavy oil slurry is heated. Ethylene glycol is a liquid crosslinking agent that can be added to the reaction vessel along with the raw materials at low temperature. Compared with solid peroxide crosslinking agents (which need to be added after the reaction system temperature is above about 170°C to about 200°C), the operation is simpler; at the same time, ethylene glycol is inexpensive and used in low quantities, which can reduce the production cost of the product.

[0014] As a specific embodiment of the present invention, the crosslinking agent is selected from at least two of epoxy resin, diallyl phthalate and C2-8 diol compounds, and preferably the crosslinking agent is added after the petroleum-based heavy oil slurry has been heated to a temperature of 160°C to 190°C.

[0015] As a specific embodiment of the present invention, the crosslinking agent is selected from at least two of ethylene glycol, epoxy resin and diallyl phthalate.

[0016] In a specific embodiment of the present invention, the crosslinking agent is epoxy resin and diallyl phthalate, preferably, the mass ratio of epoxy resin to diallyl phthalate is 1:1.5 to 4.

[0017] As a specific embodiment of the present invention, the crosslinking agent is a C2-C8 diol compound and at least one selected from epoxy resin and diallyl phthalate. Preferably, the content of the C2-C8 diol compound in the crosslinking agent is 20wt% to 80wt%. The combination of the C2-C8 diol compound with epoxy resin and / or diallyl phthalate as a crosslinking agent can further reduce the temperature or time of the oxidative crosslinking reaction of the solid crosslinking agent (epoxy resin and diallyl phthalate).

[0018] As a specific embodiment of the present invention, the crosslinking agent is a C2-C6 diol compound and at least one selected from epoxy resin and diallyl phthalate. Preferably, the content of the C2-C6 diol compound in the crosslinking agent is 20wt% to 80wt%. The combination of the C2-C6 diol compound with epoxy resin and / or diallyl phthalate as a crosslinking agent can further reduce the temperature or time of the oxidative crosslinking reaction of the solid crosslinking agent (epoxy resin and diallyl phthalate).

[0019] In a specific embodiment of the present invention, the crosslinking agent is ethylene glycol and at least one selected from epoxy resin and diallyl phthalate. Preferably, the content of ethylene glycol in the crosslinking agent is 20 wt% to 80 wt%. Using ethylene glycol in combination with epoxy resin and / or diallyl phthalate as a crosslinking agent can further reduce the temperature or time of the oxidative crosslinking reaction of the solid crosslinking agent (epoxy resin and diallyl phthalate).

[0020] As a specific embodiment of the present invention, the ash content in the petroleum-based heavy oil slurry is less than 0.05 wt%, and the aromatic content is greater than 50 wt%.

[0021] The preparation method of the present invention selects low-ash, high-aromatic petroleum-based heavy oil slurry as raw material, which can obtain higher quality modified asphalt with high β resin content and low ash content.

[0022] As a specific embodiment of the present invention, the aromatic content in the petroleum-based heavy oil slurry is higher than 70 wt%.

[0023] As a specific embodiment of the present invention, the sulfur content in the petroleum-based heavy oil slurry is less than or equal to 0.5 wt%. This is because sulfur will undergo a gasification reaction at around 1500℃ during the carbonization process of carbon products, causing crystal expansion in the carbon products and forming cracks or pores. When modified asphalt is used as a binder in carbon products, excessive sulfur content in the asphalt will lead to the formation of too many cracks or pores during the carbonization process, which is detrimental to the quality of the carbon products.

[0024] As a specific embodiment of the present invention, the petroleum-based heavy oil slurry includes at least one of catalytic oil slurry, ethylene tar, low-ash petroleum asphalt, and low-ash petroleum residue oil.

[0025] As a specific embodiment of the present invention, the amount of crosslinking agent added is 0.2wt% to 2wt% of the raw material, preferably 0.3wt% to 1.5wt%, and more preferably 0.5wt% to 1.0wt%.

[0026] As a specific embodiment of the present invention, the preparation method further includes a heating stage set before the oxidative crosslinking reaction.

[0027] As a specific embodiment of the present invention, the conditions of the heating stage include: pressure of -0.5 MPa to 2 MPa, stirring speed of 30 rpm to 100 rpm, and heating to 350°C to 420°C at a heating rate of 3°C to 20°C.

[0028] As a specific embodiment of the present invention, the preparation method further includes: a cooling stage set between the oxidative crosslinking reaction and the cooling molding.

[0029] As a specific embodiment of the present invention, the conditions for the cooling stage include: natural cooling to below 150°C, preferably 150°C to 130°C.

[0030] In a specific embodiment of the present invention, the reaction medium is air.

[0031] In a specific embodiment of the present invention, the reaction medium is a mixture of oxygen and an inert gas, wherein the oxygen volume content in the mixture is 15% to 35%.

[0032] As a specific embodiment of the present invention, the conditions for the oxidative crosslinking reaction include: a reaction pressure of -0.5 to 2 MPa, a temperature of 350°C to 420°C, and a time of 0.5 h to 6 h.

[0033] As a specific embodiment of the present invention, the method for preparing modified asphalt of the present invention includes the following steps:

[0034] S1. Select petroleum-based heavy oil slurry with an ash content of less than 0.05 wt% and an aromatic content of more than 50 wt% as raw material;

[0035] S2. Add 0.2wt% to 2wt% of a crosslinking agent to the raw material to carry out an oxidative crosslinking reaction, wherein the crosslinking agent is selected from at least one of ethylene glycol, epoxy resin and diallyl phthalate;

[0036] S3. The reaction products obtained in step S2 are cooled and molded to obtain modified asphalt.

[0037] Therefore, in a second aspect, the present invention provides a modified asphalt prepared by the above-described preparation method.

[0038] As a specific embodiment of the present invention, the softening point of the modified asphalt is 110℃~120℃, the toluene insoluble content is 30wt%~35wt%, the quinoline insoluble content is 5%~10wt%, the coking value is 55wt%~60wt%, the β resin content is 21wt%~27wt%, and the ash content is less than 0.05wt%.

[0039] Therefore, in a third aspect, the present invention provides the application of the above-mentioned modified asphalt as a binder in carbon products.

[0040] As a specific embodiment of the present invention, the carbon product includes a graphite electrode and a pre-anode; especially an ultra-high power graphite electrode (φ>600mm).

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The preparation method of the present invention uses a crosslinking agent that is used in smaller quantities than existing peroxide crosslinking agents, and can reduce the temperature of the oxidative crosslinking reaction.

[0043] (2) The preparation method of the present invention selects low-ash, high-aromatic petroleum-based heavy oil slurry as raw material. While increasing the added value of petroleum-based heavy oil slurry, it reduces the release of toxic and harmful substances such as benzo[a]pyrene during the traditional coal tar pitch preparation process. At the same time, it obtains high-quality modified pitch with high β resin content and low ash content. Compared with coal-based modified pitch, it has stronger adhesion and lower cost.

[0044] (3) The preparation method of the present invention can shorten the reaction time, reduce equipment investment, broaden the raw materials for modified asphalt, and improve the utilization value of petroleum-based heavy oil slurry.

[0045] (4) When the modified asphalt prepared by the present invention is used as a binder in carbon products, it helps to reduce the amount of binder used, thereby reducing the cost of carbon products. Detailed Implementation

[0046] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified, the experimental methods used in the examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified.

[0047] The testing methods and standards for raw materials and products mentioned in this article are as follows:

[0048] Ash content was determined according to GB / T508-1985 "Determination of Ash Content in Petroleum Products";

[0049] The sulfur content was determined using a CLS-3000 microcomputer coulometric sulfur analyzer.

[0050] Aromatic hydrocarbon content, according to national standard SH / T0509-92 "Determination of Petroleum Asphalt Components";

[0051] The toluene insoluble matter (TI) content was determined in accordance with the international standard GB / T2292-1997 "Determination of Toluene Insoluble Matter Content in Coking Products";

[0052] The determination of quinoline insoluble matter (QI) shall be performed in accordance with the national standard GB / T2293-1997 "Determination of Quinoline Insoluble Matter Content in Coking Products";

[0053] Coking value shall be determined in accordance with GB / T 8727 Method for Determination of Coking Value of Coal Pitch Products;

[0054] Softening point, according to GB / T 4507 Petroleum Asphalt Softening Point Determination Method and "Simplified Determination of Softening Point and Spinability of Asphalt by Penetration Method";

[0055] The β resin content is the toluene-insoluble matter (TI) content minus the quinoline-insoluble matter (QI) content. The higher the β resin content, the better the product adhesion.

[0056] Example 1

[0057] A method for preparing modified bitumen from petroleum-based heavy oil slurry, comprising the following specific steps:

[0058] (1) The selected raw material is catalytic cracking slurry oil, which has a sulfur content of 0.42 wt%, an ash content of 0.04 wt%, and an aromatic content of 73.2 wt%.

[0059] (2) Measure 1L of the above catalytic cracking slurry and put it into a 2L reactor, and add 0.5wt% of crosslinking agent ethylene glycol (based on the raw material).

[0060] (3) During the reaction process, the reaction pressure in the reactor is 0.1 MPa, the stirring rate is 50 rpm, the heating rate is 5℃ / min, and after the temperature in the reactor reaches 360℃, the reaction temperature is maintained, and the reaction medium air is introduced to carry out the oxidation crosslinking reaction. After 2 hours of reaction, the reaction is stopped.

[0061] (4) After the reaction stops, wait for the temperature inside the reactor to drop below 150°C, then use a clamping device to remove the reactor and pour the asphalt into a water tank filled with cooling water to cool and solidify, thereby obtaining the modified asphalt product.

[0062] The modified asphalt produced by the above method, after testing, has a softening point of 115℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 8wt%, a coking value of 55wt%, an ash content of 0.05wt%, and a β-resin content of 24wt%. Compared with coal-based modified asphalt, the modified asphalt produced by the above method has the advantages of low ash and high adhesion.

[0063] Comparative Example 1-1

[0064] The difference from Example 1 is that the crosslinking agent ethylene glycol is replaced with dicumyl peroxide (0.5 wt%).

[0065] The modified asphalt produced by the above method, after testing, has a softening point of 114℃, a toluene-insoluble content of 29wt%, a quinoline-insoluble content of 11wt%, a coking value of 50wt%, an ash content of 0.05wt%, and a β-resin content of 18wt%.

[0066] As can be seen from the comparison between Example 1 and Comparative Example 1-1, the modified asphalt prepared in Example 1 has a higher β resin content, better bonding effect, higher coking value, and higher yield of carbon products.

[0067] Comparative Examples 1-2

[0068] The difference from Example 1 is that the crosslinking agent ethylene glycol is replaced with dicumyl peroxide (1.0 wt%).

[0069] The modified asphalt produced by the above method, after testing, has a softening point of 116℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 13wt%, a coking value of 55wt%, an ash content of 0.05wt%, and a β-resin content of 19wt%.

[0070] Comparing Comparative Examples 1-1 and 1-2, it can be seen that increasing the amount of crosslinking agent increases the softening point, toluene insoluble content, and coking value of the modified asphalt. However, the β resin content of the modified asphalt in this comparative example is still lower than that of the modified asphalt prepared in Example 1, and the amount of crosslinking agent is higher than that in Example 1. This indicates that the modified asphalt prepared in Example 1 has a better bonding effect and requires less crosslinking agent, which can reduce production costs.

[0071] Comparative Examples 1-3

[0072] The difference from Example 1 is that the crosslinking agent ethylene glycol was replaced with dicumyl peroxide (0.5 wt%), and the reaction temperature was 380°C.

[0073] The modified asphalt produced by the above method, after testing, has a softening point of 120℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 13wt%, a coking value of 55wt%, an ash content of 0.05wt%, and a β-resin content of 19wt%.

[0074] A comparison of Comparative Examples 1-1 and 1-3 shows that increasing the reaction temperature can increase the cross-linking depth of the reaction, thereby generating more high molecular weight toluene-insoluble and quinoline-insoluble components, which increases the coking value and softening point of the modified asphalt. However, the content of quinoline-insoluble matter also increases at the same time. When the content of quinoline-insoluble matter exceeds 10 wt%, it will reduce the fluidity of the product and deteriorate the product quality. On the other hand, the β resin content of the modified asphalt in this comparative example is still lower than that of the modified asphalt prepared in Example 1, indicating that the modified asphalt prepared in Example 1 has a better bonding effect and requires a lower reaction temperature, which can reduce production costs.

[0075] Comparative Examples 1-4

[0076] The difference from Example 1 is that the feedstock catalytic cracking slurry is replaced with coal tar pitch, wherein the sulfur content is 0.15 wt%, the ash content is 0.24 wt%, and the aromatic content is 75.6 wt%.

[0077] The modified asphalt prepared by the above method was tested and found to have a softening point of 116℃, a toluene-insoluble content of 30wt%, a quinoline-insoluble content of 12wt%, a coking value of 55wt%, an ash content of 0.28wt%, and a β-resin content of 18wt%.

[0078] As can be seen from the comparison between Example 1 and Comparative Examples 1-4, the modified asphalt prepared in Example 1 has a higher β resin content and better bonding effect; the ash content is significantly lower than that of coal-based modified asphalt, which can result in lower ash content in downstream carbon products and better product performance; at the same time, the modified asphalt prepared in Comparative Examples 1-4 has a quinoline insoluble content >10%, which reduces the fluidity of the modified asphalt and is not conducive to improving product quality.

[0079] Example 2

[0080] A method for preparing modified bitumen from petroleum-based heavy oil slurry, comprising the following specific steps:

[0081] (1) The selected raw materials are 50wt% catalytic cracking slurry and 50wt% ethylene tar. The sulfur content in the mixed slurry is 0.26wt%, the ash content is 0.02wt%, and the aromatic content is 74.7wt%.

[0082] (2) Measure 1L of the above mixed oil slurry and put it into a 2L reaction vessel. After the reaction temperature in the reaction vessel rises to 180℃, add 0.8wt% of crosslinking agent (based on the raw material). The crosslinking agent consists of 30wt% epoxy resin and 70wt% diallyl phthalate.

[0083] (3) During the reaction process, the reaction pressure in the reactor is 0.1 MPa, the stirring rate is 60 rpm, the heating rate is 8℃ / min, and after the temperature in the reactor reaches 370℃, the reaction temperature is maintained, and the reaction medium air is introduced to carry out the oxidation crosslinking reaction. After 2 hours of reaction, the reaction is stopped.

[0084] (4) After the reaction stops, wait for the temperature inside the reactor to drop below 150°C, then use a clamping device to remove the reactor and pour the asphalt into a water tank filled with cooling water to cool and solidify, thereby obtaining the modified asphalt product.

[0085] The modified asphalt produced by the above method, after testing, has a softening point of 118℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 8wt%, a coking value of 57wt%, an ash content of 0.04wt%, and a β-resin content of 24wt%.

[0086] Comparative Example 2-1

[0087] The difference from Example 2 is that the crosslinking agent epoxy resin and diallyl phthalate are replaced with dicumyl peroxide (0.8 wt%).

[0088] The modified asphalt produced by the above method, after testing, has a softening point of 116℃, a toluene-insoluble content of 30%, a quinoline-insoluble content of 12%, a coking value of 53%, an ash content of 0.04%, and a β-resin content of 18%.

[0089] As can be seen from the comparison between Example 2 and Comparative Example 2-1, the modified asphalt prepared in Example 2 has a higher β resin content and better bonding effect; a higher coking value and a higher yield of carbon products; and a lower quinoline insoluble content and better fluidity of the modified asphalt.

[0090] Comparative Example 2-2

[0091] The difference from Example 2 is that the crosslinking agent epoxy resin and diallyl phthalate are replaced with dicumyl peroxide (1.0 wt%).

[0092] The modified asphalt produced by the above method, after testing, has a softening point of 119℃, a toluene-insoluble content of 31wt%, a quinoline-insoluble content of 13wt%, a coking value of 55wt%, an ash content of 0.04wt%, and a β-resin content of 18wt%.

[0093] As can be seen from the comparison between Example 2 and Comparative Example 2-2, the modified asphalt prepared in Example 2 has a higher β resin content and better bonding effect, while reducing the amount of crosslinking agent and lowering production costs.

[0094] As can be seen from the comparison between Comparative Example 2-1 and Comparative Example 2-2, the softening point and coking value of the modified asphalt were increased after increasing the amount of crosslinking agent. However, the β resin content of the modified asphalt in this comparative example was still lower than that of the modified asphalt prepared in Example 2, and the amount of crosslinking agent was higher than that in Example 1. This indicates that the modified asphalt prepared in Example 2 has a better bonding effect and requires less crosslinking agent, which can reduce production costs.

[0095] Comparative Examples 2-3

[0096] The difference from Example 2 is that the crosslinking agent epoxy resin and diallyl phthalate are replaced with dicumyl peroxide (0.8 wt%), and the reaction temperature is 380°C.

[0097] The modified asphalt produced by the above method, after testing, has a softening point of 120℃, a toluene-insoluble content of 33wt%, a quinoline-insoluble content of 15wt%, a coking value of 58wt%, an ash content of 0.04wt%, and a β-resin content of 18wt%.

[0098] As can be seen from the comparison between Comparative Example 2-1 and Comparative Example 2-3, although increasing the reaction temperature can increase the coking value of the modified asphalt, the β resin of the modified asphalt in this comparative example is still lower than that of the modified asphalt prepared in Example 2. This indicates that the modified asphalt prepared in Example 2 has a better bonding effect and requires a lower reaction temperature, which can reduce production costs.

[0099] Comparative Examples 2-4

[0100] The difference from Example 2 is that the raw material petroleum-based slurry is replaced with coal tar pitch, wherein the sulfur content is 0.14 wt%, the ash content is 0.28 wt%, and the aromatic content is 76.1 wt%.

[0101] The modified asphalt prepared by the above method was tested and found to have a softening point of 118℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 14wt%, a coking value of 55wt%, an ash content of 0.31wt%, and a β-resin content of 18wt%.

[0102] As can be seen from the comparison between Example 2 and Comparative Examples 2-4, the modified asphalt prepared in Example 2 has a higher β resin content and better bonding effect; the ash content is significantly lower than that of coal-based modified asphalt, which can result in lower ash content in downstream carbon products and better product performance; the quinoline insoluble content is lower, and the modified asphalt has better fluidity.

[0103] Example 3

[0104] A method for preparing modified bitumen from petroleum-based heavy oil slurry, comprising the following specific steps:

[0105] (1) The selected raw materials are 20wt% petroleum asphalt, 10wt% vacuum residue and 70wt% catalytic cracking slurry. The sulfur content in the mixed slurry is 0.45wt%, the ash content is 0.045wt% and the aromatic content is 75.8wt%.

[0106] (2) Measure 1L of the above mixed oil slurry and put it into a 2L reaction vessel. After the reaction temperature in the reaction vessel rises to 175℃, add 2wt% of crosslinking agent (based on the raw material). The crosslinking agent consists of 20wt% ethylene glycol, 30wt% epoxy resin and 50wt% diallyl phthalate.

[0107] (3) During the reaction process, the reaction pressure in the reactor is -0.5 MPa, the stirring rate is 60 rpm, the heating rate is 5℃ / min, and after the temperature in the reactor reaches 350℃, the reaction temperature is maintained and the medium air is introduced to carry out the cross-linking oxidation reaction. After 3 hours of reaction, the reaction is stopped.

[0108] (4) After the reaction stops, wait for the temperature inside the reactor to drop below 150°C, then use a clamping device to remove the reactor and pour the asphalt into a water tank filled with cooling water to cool and solidify, thereby obtaining the modified asphalt product.

[0109] The modified asphalt produced by the above method, after testing, has a softening point of 116℃, a toluene-insoluble content of 34wt%, a quinoline-insoluble content of 9wt%, a coking value of 55wt%, an ash content of 0.04wt%, and a β-resin content of 25wt%.

[0110] Comparative Example 3-1

[0111] The difference from Example 3 is that the crosslinking agent 20wt% ethylene glycol, 30wt% epoxy resin and 50wt% diallyl phthalate are replaced with dicumyl peroxide (2wt%).

[0112] The modified asphalt produced by the above method, after testing, has a softening point of 118℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 13wt%, a coking value of 55wt%, an ash content of 0.04wt%, and a β-resin content of 19wt%.

[0113] As can be seen from the comparison between Example 3 and Comparative Example 3-1, the modified asphalt prepared in Example 3 has a higher β resin content and better bonding effect; the quinoline insoluble content is lower (less than 10 wt%), and the modified asphalt has better fluidity.

[0114] Comparative Example 3-2

[0115] The difference from Example 3 is that the crosslinking agent 20wt% ethylene glycol, 30wt% epoxy resin and 50wt% diallyl phthalate are replaced with dicumyl peroxide (2wt%), and the reaction temperature is 380°C.

[0116] The modified asphalt produced by the above method, after testing, has a softening point of 120℃, a toluene-insoluble content of 34wt%, a quinoline-insoluble content of 15wt%, a coking value of 58wt%, an ash content of 0.04wt%, and a β-resin content of 19wt%.

[0117] A comparison of Comparative Examples 3-1 and 3-2 shows that while increasing the reaction temperature can improve the coking value of the modified asphalt, the β-resin content of the modified asphalt in this comparative example is still lower than that of the modified asphalt prepared in Example 3. This indicates that the modified asphalt prepared in Example 3 has a better bonding effect, requires a lower reaction temperature, and can reduce production costs. Furthermore, the modified asphalt prepared in Example 3 has a lower quinoline insoluble content (below 10 wt%) and better fluidity.

[0118] Comparative Example 3-3

[0119] The difference from Example 3 is that the raw material petroleum-based slurry is replaced with coal tar pitch, wherein the sulfur content is 0.17 wt%, the ash content is 0.35 wt%, and the aromatic content is 75.6 wt%.

[0120] The modified asphalt prepared by the above method was tested and found to have a softening point of 118℃, a toluene-insoluble content of 33wt%, a quinoline-insoluble content of 15wt%, a coking value of 55wt%, an ash content of 0.39wt%, and a β-resin content of 18wt%.

[0121] As can be seen from the comparison between Example 3 and Comparative Example 3-3, the modified asphalt prepared in Example 3 has a higher β resin content and better bonding effect; the ash content is significantly lower than that of coal-based modified asphalt, which can result in lower ash content in downstream carbon products and better product performance; the quinoline insoluble content is lower, and the modified asphalt has better fluidity.

[0122] Example 4

[0123] A method for preparing modified bitumen from petroleum-based heavy oil slurry, comprising the following specific steps:

[0124] (1) The selected raw materials are 10wt% petroleum pitch and 90wt% ethylene tar. The sulfur content in the mixed oil slurry is 0.09wt%, the ash content is 0.04wt%, and the aromatic content is 71.5wt%.

[0125] (2) Measure 1L of the above mixed oil slurry and put it into a 2L reaction vessel. After the reaction temperature in the reaction vessel rises to 160℃, add 0.6wt% of crosslinking agent (based on the raw material). The crosslinking agent consists of 80wt% ethylene glycol and 20wt% diallyl phthalate.

[0126] (3) During the reaction process, the reaction pressure in the reactor is 2 MPa, the stirring rate is 80 rpm, the heating rate is 10℃ / min, and after the temperature in the reactor reaches 420℃, the reaction temperature is maintained, and the reaction medium air is introduced to carry out the cross-linking oxidation reaction. After 0.5 h of reaction, the reaction is stopped.

[0127] (4) After the reaction stops, wait for the temperature inside the reactor to drop below 150°C, then use a clamping device to remove the reactor and pour the asphalt into a water tank filled with cooling water to cool and solidify, thereby obtaining the modified asphalt product.

[0128] The modified asphalt produced by the above method was tested and found to have a softening point of 116℃, a toluene-insoluble content of 31wt%, a quinoline-insoluble content of 5wt%, a coking value of 55wt%, an ash content of 0.04wt%, and a β-resin content of 26wt%.

[0129] Comparative Example 4-1

[0130] The difference from Example 4 is that the crosslinking agents ethylene glycol and diallyl phthalate are replaced with dicumyl peroxide (0.6 wt%).

[0131] The modified asphalt produced by the above method, after testing, has a softening point of 114℃, a toluene-insoluble content of 30wt%, a quinoline-insoluble content of 11wt%, a coking value of 54wt%, an ash content of 0.04wt%, and a β-resin content of 19wt%.

[0132] As can be seen from the comparison between Example 4 and Comparative Example 4-1, the modified asphalt prepared in Example 4 has a higher β resin content and better bonding effect; the quinoline insoluble content is lower and the modified asphalt has better fluidity.

[0133] Comparative Example 4-2

[0134] The difference from Example 4 is that the crosslinking agents ethylene glycol and diallyl phthalate are replaced with dicumyl peroxide (1.0 wt%).

[0135] The modified asphalt produced by the above method, after testing, has a softening point of 116℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 14wt%, a coking value of 56wt%, an ash content of 0.04wt%, and a β-resin content of 18wt%.

[0136] A comparison of Comparative Examples 4-1 and 4-2 shows that while increasing the amount of crosslinking agent can slightly increase the coking value of the modified asphalt, the β-resin content of the modified asphalt in this comparative example is much lower than that of the modified asphalt prepared in Example 4. This indicates that the modified asphalt prepared in Example 4 has a better bonding effect, requires a lower reaction temperature, and can reduce production costs. Furthermore, the modified asphalt prepared in Comparative Example 4-2 has a higher content of quinoline insolubles, resulting in poorer fluidity.

[0137] Comparative Example 4-3

[0138] The difference from Example 4 is that the crosslinking agents ethylene glycol and diallyl phthalate are replaced with dicumyl peroxide, and the reaction temperature is 380°C.

[0139] The modified asphalt produced by the above method, after testing, has a softening point of 119℃, a toluene-insoluble content of 33wt%, a quinoline-insoluble content of 14wt%, a coking value of 58wt%, an ash content of 0.04wt%, and a β-resin content of 19wt%.

[0140] A comparison of Comparative Examples 4-1 and 4-3 shows that while increasing the oxidative crosslinking reaction temperature can improve the coking value of the modified asphalt, the β-resin content of the modified asphalt in this comparative example is significantly lower than that of the modified asphalt prepared in Example 4. This indicates that the modified asphalt prepared in Example 4 has a better bonding effect, requires a lower reaction temperature, and can reduce production costs. Furthermore, the modified asphalt prepared in Comparative Example 4-4 has a higher content of quinoline insolubles, resulting in poorer fluidity.

[0141] Comparative Example 4-4

[0142] The difference from Example 4 is that the raw material petroleum-based slurry is replaced with coal tar pitch, wherein the sulfur content is 0.13 wt%, the ash content is 0.31 wt%, and the aromatic content is 76.2 wt%.

[0143] The modified asphalt prepared by the above method was tested and found to have a softening point of 117℃, a toluene-insoluble content of 32wt%, a quinoline-insoluble content of 14wt%, a coking value of 55wt%, an ash content of 0.36wt%, and a β-resin content of 18wt%.

[0144] As can be seen from the comparison between Example 4 and Comparative Example 4-4, the modified asphalt prepared in Example 4 has a higher β resin content and better bonding effect; the ash content is significantly lower than that of coal-based modified asphalt, which can result in lower ash content in downstream carbon products and better product performance; the quinoline insoluble content is lower, and the modified asphalt has better fluidity.

[0145] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing modified asphalt, characterized in that, The process includes the following steps: adding a crosslinking agent to a petroleum-based heavy oil slurry to carry out an oxidative crosslinking reaction, followed by cooling and molding; the crosslinking agent is selected from at least one of epoxy resin, diallyl phthalate, and C2-C8 diol compounds.

2. The preparation method according to claim 1, characterized in that, The diol compound is a C2-C6 diol compound; preferably, the diol compound is selected from at least one of ethylene glycol, propylene glycol, butanediol and pentanediol, and more preferably ethylene glycol.

3. The preparation method according to claim 1 or 2, characterized in that, The crosslinking agent is a C2-C8 diol compound, preferably a C2-C6 diol compound, and more preferably added before the petroleum-based heavy oil slurry is heated; or... The crosslinking agent is selected from at least two of epoxy resin, diallyl phthalate, and C2-C8 diol compounds, and preferably the crosslinking agent is added after the petroleum-based heavy oil slurry has been heated to a temperature of 160°C to 190°C. Preferably, the crosslinking agent is selected from at least two of ethylene glycol, epoxy resin, and diallyl phthalate; More preferably, the crosslinking agent is epoxy resin and diallyl phthalate, and even more preferably, the mass ratio of epoxy resin to diallyl phthalate is 1:1.5 to 4. More preferably, the crosslinking agent is a C2-C8 diol compound and at least one selected from epoxy resin and diallyl phthalate; even more preferably, the content of the C2-C8 diol compound in the crosslinking agent is 20wt% to 80wt%. More preferably, the crosslinking agent is ethylene glycol and at least one selected from epoxy resin and diallyl phthalate; more preferably, the content of ethylene glycol in the crosslinking agent is 20wt% to 80wt%.

4. The preparation method according to any one of claims 1-3, characterized in that, The petroleum-based heavy oil slurry has an ash content of less than 0.05 wt% and an aromatic content of more than 50 wt%. Preferably, the aromatic content in the petroleum-based heavy oil slurry is higher than 70 wt%. Preferably, the sulfur content in the petroleum-based heavy oil slurry is less than or equal to 0.5 wt%. More preferably, the petroleum-based heavy oil slurry includes at least one of catalytic slurry, ethylene tar, low-ash petroleum bitumen, and low-ash petroleum residue; and / or The amount of the crosslinking agent added is 0.2wt% to 2wt% of the raw material, preferably 0.3wt% to 1.5wt%, and more preferably 0.5wt% to 1.0wt%.

5. The preparation method according to any one of claims 1-4, characterized in that, The preparation method further includes: a heating stage set before the oxidative crosslinking reaction; Preferably, the conditions for the heating stage include: pressure of -0.5 MPa to 2 MPa, stirring speed of 30 rpm to 100 rpm, and heating to 350°C to 420°C at a heating rate of 3°C to 20°C per minute.

6. The preparation method according to claim 5, characterized in that, The preparation method further includes: a cooling stage set between the oxidative crosslinking reaction and the cooling molding; Preferably, the conditions for the cooling stage include: natural cooling to below 150°C, preferably 150°C to 130°C.

7. The preparation method according to claim 5, characterized in that, The reaction medium is air, or a mixture of oxygen and an inert gas, wherein the oxygen volume content in the mixture is 15% to 35%.

8. The preparation method according to any one of claims 1-7, characterized in that, The conditions for the oxidative crosslinking reaction include: a reaction pressure of -0.5 to 2 MPa, a temperature of 350°C to 420°C, and a time of 0.5 to 6 hours.

9. A modified asphalt prepared by any one of claims 1-8, preferably wherein the modified asphalt has a softening point of 110°C to 120°C, a toluene-insoluble content of 30 wt% to 35 wt%, a quinoline-insoluble content of 5 wt% to 10 wt%, a coking value of 55 wt% to 60 wt%, a β-resin content of 21 wt% to 27 wt%, and an ash content of less than 0.05 wt%.

10. The application of the modified bitumen of claim 9 as a binder in carbon products, preferably, the carbon products include graphite electrodes and pre-coated anodes.