The reaction conditions when starting up hydrocracking with feedstock, as well as the selection of feedstock.
Thread Content
The reaction conditions when starting up hydrocracking with feedstock, as well as the selection of feedstock. How to reduce or eliminate the impact of startup on the activity of cracking catalysts!
Pre-vulcanization uses low-nitrogen diesel; when restarting, diesel and naphtha are used, and liquefied gas is also used in some cases
My question might not have been clear enough; by \"starting up\" I mean resuming operation after normal maintenance, without the need to regenerate or sulfurize the catalyst. In that case, what type of oil is used as feedstock, and what are the hydrogenation products? Low-nitrogen unhydrogenated oil? What are the reaction conditions? To reduce the startup time, we usually use the crude oil used in normal production; this results in a higher temperature rise and thus a shorter startup time. However, during the initial stage of oil feed, the temperature is low, and the oil entering the cracking reactor contains a high level of nitrogen, which causes poisoning of the cracking catalyst. It takes about a week for the catalyst to recover, and this also leads to some reduction in its activity. I wonder how your device takes this into account.
Thank you to the original poster for sharing; I’m learning*. I’m learning*.
For cracking, one has to wait until the nitrogen content in the feedstock decreases. There is also an extreme scenario in which we suspect poisoning of the cracking catalyst due to the hydrogenation of anthracene oil; in such cases, sulfur is injected into the cracking process to maintain a sulfur content of 5000 PPm, and this level is maintained for a week. I’m not sure if the catalyst is suitable for you; it’s best to consult the manufacturer
Can sulfur injection prevent nitrogen poisoning? What is the relationship between sulfur and nitrogen? I seem to have heard before that sulfur can absorb nitrogen
I studied at CNOOC; there they also feed the crude oil in at 280 degrees and raise the temperature rapidly to 370
It still seems inappropriate to go straight to the crude oil; although heating up quickly is possible, just how fast can it really be? It still relies on the stove. If the refining depth is insufficient, the cracking agent is prone to poisoning, right? . Besides, the catalyst you just replaced is zwar regenerated, but its activity is still higher than that of the one in its end-stage; could rapid heating lead to overheating? It seems that it would be better, and safer, to use low-nitrogen oil initially until the temperature drops below 300 degrees, before gradually switching to the crude oil. We have never used crude oil directly. I personally think it is like this.