Coking and corrosion conditions on the inner wall surface of the bottom of atmospheric pressure towers in petrochemical units

In the petrochemical industry, vacuum distillation towers and atmospheric distillation towers are key equipment used to separate and purify different components in crude oil. The corrosion and coking on the inner wall surface at the base of the tower, as you mentioned, are common problems, especially under operating conditions of high temperature and certain pressure. ### Reasons for corrosion at the bottom of the tower: 1. **High-temperature operation**: The operating temperature you mentioned is 360 degrees, and such high temperatures accelerate the rate of chemical reactions, thereby intensifying the corrosion process. 2. **Chemical media**: The operating medium is crude base oil, which may contain corrosive chemicals such as sulfides and chlorides; these substances exert a stronger corrosive effect on metal materials at high temperatures. 3. **Material Selection**: The 16MnR material used does possess certain strength and toughness, but it may not be sufficient to resist corrosion in specific chemical environments and at high temperatures. ### Causes of coking: Coking usually results from solid deposits formed by the pyrolysis or polymerization of heavy components or impurities in the oil at high temperatures on the walls of the tower. This not only affects the heat transfer efficiency of the tower but may also cause fluid flow to be obstructed, increasing operational risks. ### Solutions and preventive measures 1. **Material upgrade**: Consider using materials that are more resistant to high temperatures and corrosion, such as stainless steel or special alloy materials. 2. **Inner wall coating**: The use of protective coatings resistant to high temperatures and chemical corrosion, such as ceramic coatings or special synthetic material coatings, can effectively isolate the medium from contact with the metal. 3. **Regular inspection and maintenance**: Increase the frequency of inspections of tower equipment to detect and address corrosion and coking issues promptly. Regularly inspect the condition inside the tower using high-temperature cameras or other detection techniques. 4. **Operation parameter optimization**: Adjust the operating temperature and pressure to operate under conditions that provide better chemical stability. Through these measures, the service life of the equipment can be effectively extended, reducing maintenance costs and potential safety risks associated with corrosion and coking. .