Hydrogenation shutdown
Thread Content
What does \"large circulation\" refer to, in the context of reducing the volume and temperature of diesel hydrogenation operations during shutdowns, and switching to a large-circulation process?
The diesel produced through hydrogenation goes straight to the inlet; no oil is returned within the unit. It has low sulfur content and few impurities, making it convenient for the next startup.
Hydrogenation units generally have two cycles: one is the sulfidation cycle, and the other is the main reaction cycle. The sulfiding cycle, as the name implies, refers to the cycle that the catalyst goes through during pre-sulfiding; it involves the return of the liquid phase from the low-pressure separator to the crude oil tank. The larger cycle involves the return of diesel from the point where it is sent out to the crude oil tank
Hydrogenation units generally have two cycles: one is the sulfidation cycle, and the other is the main reaction cycle. The sulfiding cycle, as the name implies, is the cycle that the catalyst goes through during pre-sulfiding – it involves returning from the liquid phase in the low-pressure separator to the crude oil tank. The larger cycle involves returning from the diesel product to the crude oil tank. I agree with your view!
The large loop is equivalent to the cycle in which the oil exiting the device returns to the feedstock entering the device. There are generally reaction cycles, distillation cycles, and large cycles~~~~