Several issues regarding the shutdown of diesel hydrogenation
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I need some help from everyone: 1. How can the oil in the distillation column tubes be removed when the plant is shut down? Steam or N2? It feels like it can’t be cleaned properly. 2. When the reaction temperature and rate are reduced, there is flow deviation in the reaction reactor tube
It is best to use steam first and then nitrogen. During the process of reducing temperature and flow rate, the processing volume should be brought down to the minimum load while maintaining a constant oil supply. Under normal circumstances, there should be no deviation at the minimum load; it is necessary to monitor the outlet temperature of each stream at the furnace exit, and if any deviation is detected, the temperature should be reduced or the amount of circulating hydrogen increased promptly!
1. The method of using nitrogen and steam to displace oil cannot achieve thorough cleaning, and moreover, your purging line does not have sufficient power – it is generally quite thin. 2. There are several valves before the feed to the furnace, which can be used to control the flow in order to maintain balance.
1. Yes, both the nitrogen and steam pipes are relatively thin. When purging large pipelines, as long as the liquid level does not fill the pipeline, gas can easily cause short circuits; moreover, oil cannot be blown away during the process of rising pressure. 2. The reaction reactor has no valves
We have such devices here; what should we do in case of deviation in flow under normal conditions?