Hydrogenation reactors typically are equipped with two sets of emergency pressure relief valves, at 7 bae and 14 bar. How is the sequence in which they are activated or the operating procedures controlled?
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Emergency pressure relief in hydrogenation reactors typically involves two sets of valves set at 7 bae and 14 bar; this is a proven protection method used both domestically and internationally, and it is mentioned in many documents as well as in established processes. The issue now is determining how these two sets of valves are controlled when the reactor temperature rises excessively, for example, in a reactor where the temperature rises to 500°C and the pressure relief interlock is triggered. How is the sequence in which these valves operate controlled? What are the steps for operating them?
First, start the 7 bar/min pressure relief; since the bed temperature cannot be controlled, then activate the 14 bar/min pressure relief
I’m quite curious as to why the design pressure for this reactor is set at that level. Also, it seems strange that the discharge pressures of the two safety valves differ by a factor of two...
Are they to be started in interlock mode or manually? Should they be incorporated into the reverse ESD system?
For a more secure approach, it is recommended to use a cascade system: when P=P1, one pressure relief valve activates; when P=P2, another one activates as well. Manual operation is required – which leads to chaos in emergency situations, so manual control is not highly recommended. Using ESD is also an option, but the configuration of the subsequent pressure relief pipelines needs to be taken into consideration