Coking furnace outlet temperature

We control 490‑495℃

The outlet temperature of the coking heater is generally higher than the temperature in the coke tower (due to heat loss). In our country, the outlet temperature of the heating furnaces in delayed coking units is generally kept within the range of 495–505°C. In practice, fluctuations of plus or minus 1℃ are generally allowed.

We generally keep the outlet temperature of our furnace at 490–495 degrees, with the main considerations being the properties of the raw materials, the feed temperature at the bottom of the coke tower, and the volatility of the coke

The heating furnace in Huizhou Refining & Coking controls the outlet temperature at 507–513°C (introduced from Foster Wheeler in the United States). Due to the high outlet temperature and the hardness of the coke, the outlet pressure of the high-pressure water pump is controlled at 34.5 MPa (maximum 41.5 MPa).

The outlet temperature of the coking furnace must be determined based on the properties of the raw materials. At high temperatures, coke becomes hard, making it difficult to remove coking residues and increasing the likelihood of the formation of pellet coke. At low temperatures, coke becomes softer and has a higher volatile content; therefore, with a constant amount of heavy wax oil being removed, the circulation ratio increases. Typically, the furnace outlet temperature is controlled at 495–505 degrees.

We kept the outlet temperature of the furnace at 498±1°C, but for a period of time, due to changes in the properties of the feed oil, the coke formed was very hard, making it difficult to remove; as a result, the temperature was reduced to 495±1°C.

We: Residue 20–22%, 496 is greater than 22%, 495 is less than 20%, 497

The outlet temperature of the coking heater should be adjusted so that the volatility of petroleum coke remains within the specified range, while also ensuring that the petroleum coke is not too hard, which could make coke removal more difficult. The volatility of petroleum coke serves as the basis for determining the outlet temperature of coking heaters.

When the operating pressure and recycle ratio are fixed, increasing the temperature of the coke tower will increase the yields of gas and naphtha, decrease the yield of gas oil, reduce the coke yield, and lower the volatiles content in the coke. At constant pressure and recycle ratio, for every 5.5°C increase in coking temperature, the yield of gas oil increases by 1.1%; appropriately raising the reaction temperature is beneficial for coking. However, the specific value must be determined after taking into account various factors such as the properties of the raw materials, the requirements regarding the composition of the product materials, and the characteristics of the coke. Excessively high temperatures in the coke tower can easily lead to foam entrainment and promote the formation of pellet coke. The temperature of the coke tower also controls the combustible volatile matter (VCM) in the coke; this value is generally between 6-8%. As the temperature increases, the VCM level decreases, and the hardness of the coke rises, which makes it more difficult to remove the coke. Excessively high temperatures also increase the coking tendency of the heating furnace tubes and oil transfer lines, affecting the operation cycle. ? If the temperature of the coke tower is too low, the coking reaction will not be complete, resulting in the formation of soft coke or pitch. The volatile matter content is an important quality indicator for coke; in production, the volatile matter content of coke is generally controlled to be between 6.0% and 8.0%. In operation, the temperature of the coke tower is used to control the volatile content of the coke. However, the adjustable range of operating temperature for coking units is very narrow. ??

Depending on the properties of the raw materials, it generally does not exceed 510

We keep the outlet temperature of our furnace at 495±5°C; for some time, the coke produced was relatively soft, which is likely related to the properties of the raw materials