CN-116904220-B - Preparation process of isotropic asphalt and high-softening-point coated asphalt

Abstract

The invention relates to a preparation process of isotropic asphalt and high softening point coated asphalt, which comprises the steps of taking aromatic-rich oil as raw oil, taking biological tar or/and biological asphalt as a co-carbonization agent, entering a pre-polymerization reactor from the bottom, carrying out pre-polymerization reaction under the induction of oxygen-containing linear polymers to obtain pre-polymerized materials, adding a photosensitive oxidation cross-linking agent into the pre-polymerized materials, feeding the pre-polymerized materials from a material distribution tray in the middle of an oxidation cross-linking reaction tower, feeding oxidation cross-linking gas from the lower part of the cross-linking reaction tower through a gas distributor, discharging the obtained cross-linking asphalt product from the bottom of the reaction tower, then entering the cross-linking asphalt from the middle of the polymerization reactor, carrying out polycondensation reaction under the induction of high-energy electron beam irradiation, obtaining a polycondensation asphalt product from the lower part of the polymerization reactor, entering an extraction separation tower from the upper part of the polycondensation asphalt product, entering a subcritical/supercritical solvent from the lower part of the extraction separation tower, carrying out countercurrent contact extraction separation of two phases, and obtaining the isotropic asphalt and the high softening point coated asphalt.

Inventors

• LIU DONG
• LOU BIN
• SHI NAN
• WEN FUSHAN
• LIU XIAODONG

Assignees

• 中国石油大学(华东)

Dates

Publication Date

20260508

Application Date

20230801

Claims (4)

1. 1. The preparation process of the isotropic asphalt and the high softening point coated asphalt is characterized by comprising the following specific steps: (1) The preparation method comprises the steps of fully mixing raw oil and a co-carbonization agent, preheating, introducing the mixture into a pre-polymerization reactor from the bottom, carrying out pre-polymerization under the induction of an oxygen-containing linear polymer to obtain pre-polymerized material, wherein the pre-polymerization temperature is 150-350 ℃, the residence time is 0.5-2h, the addition amount of the co-carbonization agent is 5-40% of the mass of the raw oil, the addition amount of the oxygen-containing linear polymer is 5-10% of the total mass of the raw oil and the co-carbonization agent, the raw oil is aromatic-rich oil and is selected from one or more of ethylene tar, catalytic slurry or coal tar fractions, and the co-carbonization agent is selected from one or more of polyethylene glycol, polyvinyl alcohol, polyvinyl chloride, polybutylene terephthalate or polyacrylic acid; (2) Adding a photosensitive oxidation crosslinking agent into the pre-polymerized material, mixing the photosensitive oxidation crosslinking agent with the pre-polymerized material, entering a material distribution column plate in the middle of an oxidation crosslinking reaction tower, enabling oxidation crosslinking gas to contact with the pre-polymerized material in a countercurrent way from the lower part of the oxidation crosslinking reaction tower through a gas distributor and generate oxidation crosslinking reaction, enabling oil gas generated in the oxidation crosslinking process to escape from the upper part of the oxidation crosslinking reaction tower, and discharging an obtained crosslinked asphalt product from the bottom of the oxidation crosslinking reaction tower, wherein the addition amount of the photosensitive oxidation crosslinking agent is 1-5% of the mass of the pre-polymerized material, the oxidation crosslinking reaction temperature is 200-350 ℃, the residence reaction time of the pre-polymerized material is 1-10h, the flow rate of the oxidation crosslinking gas is 0.5-5.0L. -1 ·kg -1 , and the oxidation crosslinking agent is one of benzophenone derivatives, alpha-hydroxy ketone or phenyl dimethyl ketal; (3) Introducing the cross-linked asphalt obtained from the bottom discharge into the middle of a high-energy electron beam irradiation tower, and performing polycondensation reaction under the induction of high-energy electron beam irradiation to generate a polycondensation asphalt product with relatively uniform molecular weight distribution and partial oil gas light components, wherein the irradiation dose of the high-energy electron beam is 10-50 kGy, the polymerization reaction temperature is 380-450 ℃, the reaction pressure is 0.1-3 MPa, and the reaction residence time is 2-8 h; (4) The method comprises the steps of enabling a polycondensation asphalt product at the bottom of a high-energy electron beam irradiation tower to enter a supercritical extraction separation tower, enabling an extraction solvent to enter from the lower part of the supercritical extraction separation tower in a supercritical state, carrying out countercurrent contact extraction separation on two phases, separating the extraction solvent from materials at the upper part of the extraction separation tower to obtain isotropic asphalt, wherein the extraction solvent is selected from one of n-pentane, n-heptane, cyclohexane, benzene, toluene, xylene, ethylbenzene or tetrahydrofuran, the volume ratio of the solvent to the oil is 1-20, the extraction temperature is 300-360 ℃, and the extraction pressure is 2.0-6.0 MPa; (5) And separating the extraction solvent from the heavy asphalt component at the bottom of the extraction separation tower to obtain the high-softening-point coated asphalt, wherein the softening point of the high-softening-point coated asphalt is 220-280 ℃.
2. 2. The process for preparing an isotropic asphalt and a high softening point coated asphalt according to claim 1, wherein the carbon residue value of the isotropic asphalt is 45-55%, and the softening point is 200-250 ℃; The carbon residue value of the high softening point coated asphalt is more than or equal to 70 percent, and the quinoline insoluble matter is less than or equal to 1 percent.
3. 3. The process for preparing isotropic asphalt and high-softening-point coated asphalt according to claim 1, wherein in the step (3), the light oil-gas component is condensed and recovered by a hot high-pressure separator and a cold low-pressure separator.
4. 4. An isotropic pitch and a high softening point coated pitch prepared by the process of any one of claims 1-3.

Description

Preparation process of isotropic asphalt and high-softening-point coated asphalt Technical Field The invention relates to a preparation process of isotropic asphalt and high-softening-point coated asphalt, and belongs to the technical field of preparation of high-grade novel carbon materials. Background The raw materials for producing the lithium battery mainly comprise four major parts of a positive electrode material, a negative electrode material, an electrolyte and a diaphragm, wherein the positive electrode material is a key material for determining the safety, performance, cost and service life of the battery, and accounts for about 30% of the manufacturing cost of the battery. The technology of the cathode material is relatively mature in market, the cost proportion is lowest, and the cathode material accounts for about 10% of the manufacturing cost of the battery. The lithium ion battery cathode materials which are commercially applied on a large scale are mainly graphite (including natural graphite, artificial graphite and MCMB), and the rest of the materials such as soft carbon, hard carbon, silicon/carbon composite materials, lithium titanate and the like are in the experimental development stage and are produced in a small amount. In order to overcome some structural defects of graphite, a layer of amorphous carbon is generally coated on the surface of the graphite by coating treatment so as to reduce the first irreversible capacity and improve the cycle performance, and therefore, the production process and the performance regulation of the coated asphalt become research hot spots. Oxidative crosslinking is the most commonly used process for producing coated bitumen. CN114752397a discloses a method for preparing coated asphalt, which comprises the steps of carrying out reduced pressure distillation on refined coal liquefied asphalt, carrying out a crosslinking reaction on the obtained light component asphalt, and finally obtaining the coated asphalt with low softening point and the coated asphalt with high softening point. CN115093874a discloses a preparation method of petroleum-based coated asphalt, which adopts an oxidation crosslinking reaction, and through the use of an external viscosity reducer and a reflux viscosity reducer, the conversion of beta resin into alpha resin is effectively prevented, and the high softening point and low quinoline insoluble content of the prepared coated asphalt are ensured. CN114426852B discloses a preparation method of high softening point coated asphalt, which comprises the steps of pre-crosslinking treatment of heavy oil raw materials in the presence of a catalyst and a crosslinking agent, deep oxidation crosslinking and decompression purging after the pre-crosslinking treatment to obtain the high softening point asphalt. CN115093872a discloses a preparation method of coated asphalt, after ethylene tar and catalytic slurry oil are fully mixed and impurity is removed, oxidation crosslinking catalytic reaction and polycondensation catalytic reaction are sequentially carried out, and the obtained crude asphalt product is extracted to obtain the coated asphalt, so that the effects of reducing the content of quinoline insoluble substances and improving the content of carbon-containing macromolecules and softening point are achieved. Disclosure of Invention The invention aims to overcome the defects of the prior art and designs a process method for producing isotropic asphalt and high-softening-point coated asphalt. The process integrates various working procedures of an oxygen-containing linear polymer induced polymerization reactor, an oxidation crosslinking reaction tower, a high-energy electron beam irradiation tower, an extraction separation tower and the like into a whole to produce high-performance isotropic asphalt, and the high-softening point coated asphalt with excellent performance is prepared by treating heavier isotropic asphalt components through a shallow thermal shrinkage polymerization reactor. The invention aims at adopting the following technical scheme: the preparation process of isotropic asphalt and high softening point coated asphalt uses aromatic oil rich in ethylene tar, catalytic slurry oil, coal tar fraction and the like as raw oil and biological tar or/and biological asphalt as a co-charring agent, and comprises the following specific steps: (1) The raw oil and 5-40 wt% of co-charring agent are fully mixed and preheated, then enter a prepolymerization reactor from the bottom, and perform prepolymerization reaction under the induction of an oxygen-containing linear polymer to obtain a prepolymer; the prepolymerization reaction temperature is 150-350 ℃ and the residence time is 0.5-2h; the addition amount of the oxygen-containing linear polymer is 5-10wt% of the total mass of the raw oil and the co-charring agent mixed oil, The oxygen-containing linear polymer includes, but is not limited to, polyethylene glycol, polyvinyl alcohol, pol