Regarding the interlock design logic of the hydrogenation unit, why must the feed pump be stopped after the compressor stops?
Thread Content
This post was last edited by liuquan1100 on 2017-1-11 20:29. Naphtha hydrogenation, straight-run diesel hydrogenation (without dewaxing) – why must the feed pump be stopped after the compressor is shut down? After the compressor stops, it is sufficient to turn off the heating furnace; continuing to feed material will only further lower the reaction temperature. Why must the feed pump be stopped according to the interlock logic? Prevent overheating and coking? ? ? If the temperature can be reduced, then what about overheating? LPG, gas oil and diesel hydrogenation design,
When the compressor stops, large amounts of crude oil will flow into the reaction system. Since the circulating hydrogen is no longer available, a significant amount of reaction heat cannot be removed, leading to an increase in temperature. This, combined with the reaction of this increased temperature with the fresh feedstock, results in catalyst coking
When the crude oil used as raw material for the major components enters the reaction product heat exchanger, it can very easily lead to sudden spikes and drops in temperature, resulting in leaks
First, it prevents coking; second, in the absence of hydrogen, the feed oil tends to remain in the catalyst bed, which has an impact on the catalyst, especially with low-quality feed oil.
After the hydrogen circulation machine stops, the heat generated by the reaction cannot be removed; there is no mixed hydrogen, and the oil may not be distributed evenly within the catalyst bed~~~~ The main issue is the inability to remove heat, which leads to coking of the catalyst
After the compressor stops, it is sufficient to turn off the heating furnace; continuing to feed material will only further lower the reaction temperature
Come in and learn*......
The feed pump must be stopped after the compressor is shut down
When the compressor stops due to circulation issues, the system can no longer circulate properly; heat is generated through the circulation of hydrogen. The circulation pump stops, and the heating furnace also stops, but the feed pump continues to operate. Firstly, there is a risk of leakage in the heat exchangers at the inlet and outlet of the hydrogenation reactor. Additionally, since oil enters the reactor in liquid form, the catalyst will not only coking but its strength will also be compromised
If feeding continues, with residual hydrogen present in the system and the temperature reaching the reaction conditions, the feed will continue to undergo hydrogenation reactions that release heat; however, in the absence of recycled hydrogen, the local heat cannot be removed, which may lead to overheating or even a surge in temperature.