Process of coking feed oil under accident conditions
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I’m new to coking. I would like to know what the process is for the feed oil used in coking under emergency conditions (including the reaction and distillation stages) The more detailed, the better. Thank you
Tank farm → D1001 (feed oil tank) → P1001 (feed oil pump) → C1002 (fractionation tower) → P1002 (radial pump) → F1001 (heating furnace) → Top of C1001 (coking tower) → Bottom of C1001 (coking tower) → D1005 (drain tank) → P1012 (start-up drain pump) → E1014 (water tank) → Exit from the plant (drain valve assembly) → Tank farm. 1. Preheat the new tower. 2. Reduce temperature and flow rate. 3. Rapidly lower the temperature to 420°C; switch to the operating line and discharge oil. 4. Introduce wax oil for replacement. 5. Lower the temperature of the heating furnace to 200–230°C, and check the progress of the wax oil replacement. 6. Stop the pressure compressor in the distillation unit, discharge oil from the testing line, and stop the pumps
I’m asking you The accident response plan seems to be nothing but a formality.
This is the startup procedure, right? Can crude oil still be fed into the tower in an emergency situation?
It depends on the condition of the tower; in fact, it’s also possible to use the emergency vent line at the exit of the heating furnace, go to the water tank, then to the oil discharge valve assembly, and finally to the sewage oil tanks in the tank area.
The distillation tower activates its pressure relief valve immediately, with all the gas being sent to the flare or gas holder. The gas control valve of the heating furnace is shut off directly to cause a rapid temperature drop; at the same time, the amount of medium-pressure steam supplied is increased to prevent coking of the furnace tubes. The four-way valve is switched to the operation line, and the fluid is directed through the emergency vent line to the water tank, from where it goes to the waste oil tanks in the tank area via the oil rejection valve assembly. At the same time, steam is supplied to the coke tower to prevent coking pores from becoming blocked. Stop the compressor and close the inlet and outlet valves for pressure relief. Determine whether it is necessary to maintain the liquid level and pressure in the three towers; if not, drain the liquid as soon as possible. The other towers shall take corresponding actions based on the accident situation.
The valve in the pipeline that branches from the outlet line of the heating furnace to the water tank is generally not used. In the event of an accident, if there is a new tower, the process follows the aforementioned procedure; if there is no new tower, the four-way valve is switched to the operating line, and the gate valve at the outlet leading to the tower top is closed. There is a pipeline ahead of this valve that leads to the oil dumping tank, from where the oil is sent to the water tank via an oil pumping system, to the oil dumping valve assembly, and finally to the tank area