Coking operation approach
Thread Content
In coking units, fluctuations most often occur during preheating and the four-way valve switching, which requires timely adjustments to distillation and stabilization processes. What approach should be taken to stabilize positions? In my opinion, during preheating, the gas-phase load decreases, so the amount of absorbent, that is, stabilizer for gasoline, should be reduced accordingly. Slightly increase the temperature at the bottom of the absorption tower and reduce the absorption pressure a bit. When cutting through the four connections, it follows an operation principle that is the opposite of preheating! I’m not sure how others proceed – could we discuss the changes in preheating and the four-way switching?
The cut-four-way operation is similar to the preheating process; during cut-four-way, the amount of oil and gas is relatively small
Reply to 1# Zuijiu Tianxia: The switching of coking towers will more or less cause fluctuations in the system; the key is to adjust the reflux and distillation temperatures of various components in a timely manner to maintain relative balance. In response to the periodic fluctuations in coking, namely the periodic changes in heat and materials within the system, it is possible to increase the outlet temperature of the radiant furnace and raise the feed rate appropriately based on the cycle of these fluctuations. This helps to compensate for the significant reduction in materials and heat resulting from the switching process, thereby ensuring a more stable operation of the system
During the preheating of oil and gas, as long as the operator of the coke tower has sufficient experience, it generally does not have a significant impact on distillation; almost no adjustments to the distillation process are required. Coking products are usually refined through hydrogenation, so the separation of light fractions in distillation is not subject to strict requirements. After cutting off the flow, the reflux and product output can be adjusted as appropriate according to changes in the temperature of the oil and gas.
In fact, the factor that has the greatest impact on distillation is likely the change from using small amounts of steam to using an exhaust tower; as a result, part of the oil and gas flows into the exhaust tower, leading to significant heat loss