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CN-121975542-A - Continuous oxidized asphalt production method and system

CN121975542ACN 121975542 ACN121975542 ACN 121975542ACN-121975542-A

Abstract

A process for preparing continuous oxidized asphalt includes such steps as choosing vacuum residuum or straight-run petroleum asphalt, pretreating to obtain refined asphalt, continuously exchanging heat with the asphalt, heating, introducing nitrogen gas, oxidizing reaction, introducing compressed and dried air, decreasing air flow, regulating the softening point and penetration of asphalt, regulating heating temp and air flow, and discharging the tail gas. The air flow rate of the oxidation reaction is divided into two or three sections, the increase of product brittleness caused by local excessive oxidation is avoided, the contact area and uniformity of the gas and liquid are improved by the guide holes of the sieve tray and the baffle plate, and the softening point and penetration of the product are monitored in real time by the online detection device, so that the production stability is improved.

Inventors

  • REN CHANGYU
  • WANG DONGSHENG
  • Zhao Qixian
  • ZHANG JINGKUN
  • LIU LI

Assignees

  • 智汇(天津)工程设计院有限公司

Dates

Publication Date
20260505
Application Date
20260331

Claims (10)

  1. 1. A continuous oxidized asphalt production method is characterized by comprising the following steps: Vacuum residuum or straight-run petroleum asphalt is selected as a raw material, a refined asphalt raw material is obtained through pretreatment, the refined asphalt raw material is subjected to continuous heat exchange with postpartum asphalt, and then the refined asphalt raw material is heated, and nitrogen is introduced in the heating process for inert protection; Continuously carrying out oxidation reaction on the refined asphalt raw material after temperature rise, introducing compressed and dried air according to two or three sections of the upper section and the lower section in the oxidation reaction process, and sequentially reducing the air flow from bottom to top; And (3) monitoring the softening point and penetration of the outlet asphalt on line in real time, and when the asphalt deviates from the index, adjusting the heating temperature and the air flow, and discharging the tail gas generated by the oxidation reaction after the tail gas reaches the standard after advanced treatment.
  2. 2. The continuous asphalt oxide production method according to claim 1, wherein the ratio of the upper air flow to the lower air flow is 1:2-1:5 when air is introduced in two stages in the oxidation reaction process.
  3. 3. The continuous asphalt oxide production method according to claim 2, wherein the softening point of the outlet asphalt is set to a target value of 80 to 110 ℃, the penetration is set to a target value of 20 to 40dmm, the heating temperature is adjusted to a range of ±5 ℃ when the target value deviates from the target value, and the air flow rate is adjusted to a range of ±10%.
  4. 4. The continuous asphalt oxide production method according to claim 1, wherein the advanced treatment comprises electrostatic defogging and two-stage alkali washing which are sequentially carried out, the voltage of the electrostatic defogging is 30-40kV, and the concentration of first-stage alkali liquor in the two-stage alkali washing is 5-8% and the concentration of second-stage alkali liquor is 2-3%.
  5. 5. The continuous asphalt oxide production method according to claim 4, wherein the residual organic matters are removed by activated carbon adsorption after the two-stage alkaline washing.
  6. 6. The continuous asphalt oxide production method according to claim 1, further comprising post-treatment of the finished product, wherein the post-treatment comprises cooling the asphalt oxide subjected to the advanced treatment of the tail gas to 170-190 ℃, adding an anti-aging agent accounting for 0.5-1.5% of the mass of the asphalt, wherein the anti-aging agent is formed by mixing 2, 6-di-tert-butyl-p-cresol and phosphite ester according to a mass ratio of 3:1, the addition temperature of the anti-aging agent is 175-185 ℃, the stirring rate is 300-500r/min, and the stirring time is 20-30min.
  7. 7. A continuous asphalt oxide production system for realizing the continuous asphalt oxide production method according to any one of claims 1-6, which is characterized in that a tower type oxidation reactor is adopted in the oxidation reaction, a plurality of layers of sieve tray plates are arranged in the tower type oxidation reactor, the upper layer of sieve tray plates are used for introducing upper section air flow, the lower layer of sieve tray plates are used for introducing lower section air flow, the adjacent sieve tray plates are respectively an odd plate and an even plate, the asphalt liquid flow directions of the odd plate and the even plate are opposite, and an online detection device is arranged at the outlet of the tower type oxidation reactor.
  8. 8. The continuous asphalt oxide production system according to claim 7, wherein a baffle plate is arranged in the middle of the sieve tray, a diversion hole is arranged on the sieve tray near the baffle plate, the diversion holes of the odd plates and the even plates are opposite to the baffle plate, and the asphalt flows of the odd plates and the even plates respectively flow clockwise and anticlockwise.
  9. 9. The continuous asphalt oxide production system of claim 7, wherein the on-line detection device comprises an on-line softening point analyzer, an on-line softening point analyzer.
  10. 10. The continuous asphalt oxide production system according to claim 7, wherein the exhaust port of the tower oxidation reactor is connected with a two-stage alkaline washing tower, and an electrostatic demister is arranged between the tower oxidation reactor and the two-stage alkaline washing tower.

Description

Continuous oxidized asphalt production method and system Technical Field The invention relates to the technical field of asphalt modification production, in particular to a continuous oxidized asphalt production method and system. Background The oxidized asphalt is a modified asphalt product obtained by oxidizing and modifying petroleum asphalt or vacuum residuum, has the characteristics of high softening point, strong chemical stability, good weather resistance, excellent adhesiveness and the like, and is one of core raw materials in the fields of road engineering, building waterproof engineering and industrial corrosion prevention. With the rapid development of infrastructure construction, the market demand for oxidized asphalt continues to increase, and higher demands are being placed on the quality stability, production efficiency, environmental protection and durability of the product. Currently, the production process of oxidized asphalt is mainly divided into two major categories, namely intermittent and continuous. The batch production process adopts a kettle type reactor for batch production, has the defects of low production efficiency, large fluctuation of product quality, high energy consumption and high manual operation strength, and has the advantages that the single batch production time is 8-10 hours, the fluctuation of the softening point of the product can reach +/-3-5 ℃, and the large-scale and high-quality production requirements are difficult to meet. Although the traditional continuous production process realizes continuous production of asphalt, the production efficiency is improved compared with intermittent production, but a plurality of technical bottlenecks still exist, the industrialization application of the continuous production process is severely limited, and the following four problems are particularly solved: 1. The oxidation reaction has uneven gas-liquid contact and low mass transfer and reaction efficiency, and the key reaction of the oxidized asphalt is dehydrogenation, polymerization and condensation reaction of asphalt molecules, and the reaction needs the asphalt to be fully contacted with oxygen to realize uniform oxidation. The traditional continuous process has the defects of defect in the design of reactor tower internals, original distribution system, unreasonable spray layer nozzle layout, incomplete atomization angle coverage and easy blockage, asphalt has the characteristics of high viscosity and high surface tension, so that blown air forms a large bubble channel in asphalt colloid, serious channeling and short-circuiting phenomena occur, the contact area between the air and the asphalt is small, meanwhile, oxidation reaction only happens violently in local areas such as a near bubbling port, other areas are relatively static, the problem of coexistence of local overoxidation and integral oxidation is formed, asphalt in partial areas flows slowly and even stagnates to form a dead zone, and thus, the adhesive substances such as asphaltene, tar and the like are deposited and scaled, and further, the reactor channel is blocked, the reaction efficiency is reduced, and the maintenance cost of equipment is increased. 2. The reaction parameter regulation and control is dependent on manpower, and the product quality stability is poor, the reaction parameter (such as heating temperature and air flow) regulation and control of the traditional continuous process mainly depends on experience of operators, and a real-time product index detection and automatic regulation and control means is lacked. Basic indexes such as penetration and softening point of asphalt raw materials naturally fluctuate, when the raw material indexes change, hysteresis exists in manual adjustment, and the technological requirements of oxidation reaction are difficult to precisely match, so that key indexes such as the softening point and penetration of finished oxidized asphalt have large fluctuation, the product performance consistency is poor, and the severe requirements of high-end engineering on asphalt quality are difficult to meet. 3. The tail gas is not thoroughly treated, the environmental protection standard is poor in stability, asphalt smoke is generated in the oxidation reaction process,The tail gas of polycyclic aromatic hydrocarbon such as non-methane total hydrocarbon, benzo [ a ] pyrene, etc. has the characteristics of large toxicity, strong peculiar smell and easy formation of visual pollution, and is a main pollutant in the production of oxidized asphalt. The traditional tail gas treatment process mostly adopts a single alkaline washing or activated carbon adsorption mode, and has obvious technical limitations that the alkaline washing can only neutralize、The removal rate of the non-polar and hydrophobic polycyclic aromatic hydrocarbon and heavy hydrocarbon is lower than 30%, the activated carbon adsorption is greatly influenced by water vapor, when the humidity of the flue gas