Diesel hydrogenation emergency pressure relief
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Why do some say that the system pressure must be released completely, while others say that it is sufficient to stop releasing pressure once the reaction temperature drops to 230°C, as then the reaction temperature can be controlled? In which situations do these two statements apply respectively? Thank you!
It is also said that pressure release can be stopped once the reaction temperature drops to 230°C or when the reaction temperature can be controlled
I won’t unload it all at once, for fear that it will continue to overheat after you stop
Few systems are designed to release the pressure to atmospheric levels when the bed temperature becomes excessively high or there is a spike in temperature; generally, the pressure is released only after the temperature reaches a specified level, once it is possible to control the reactor temperature.
This post was last edited by Silent Lamb_QOQW on 2018-7-3 at 15:32. Generally, it seems that high-speed pressure release must be carried out to the end, while low-speed pressure release can be stopped midway. When the temperature becomes extremely high and gets out of control, pressure is naturally released at full speed. If the temperature rise is only slight and the increase is gradual, pressure can be released at a lower speed; our system releases pressure at a low speed when the circulating hydrogen compressor is shut down. During low-speed pressure relief, the process can be stopped as long as the temperature rise is brought under control and reduced.
Based on the temperature fluctuations, it happened once before: after two intermittent pressure releases, the situation stabilized pretty much~~~~ Whether to release the pressure all the way depends on the actual conditions
Full discharge is characteristic of true hydrocracking units; it prevents excessive temperature rise in certain areas due to the failure of temperatures to drop, while diesel hydrogenation does not require this.
Stopping the pressure release midway depends on the interlock logic; if the valve opens after interlock reset, it can lead to high pressure flowing into the low-pressure area.
Generally, for a pressure relief interlock of 2.1 MPa, a complete release is required; it is an interlock related to the reactor temperature, while a rate of 0.7 MPa per minute is controllable
I think the extent to which pressure is released depends mainly on how much oil is carried out of the reactor; the more thoroughly the oil is removed, the lower the likelihood of a temperature spike
The 21 bar emergency pressure relief in the hydrocracking unit operates by releasing pressure completely, with the aim of bringing all the oil inside the reactor out. Generally, the emergency pressure relief of foreign process packages cannot be stopped midway, while low-pressure emergency pressure relief can be stopped during operation.