May I ask about the details of operating the crude benzene regenerator?
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This post was last edited by haosf2000 on 2009-5-21 at 10:59. Our company’s chemical processing units consist of Phase I and Phase II; the top temperature of the regenerator in Phase II is 163 degrees, corresponding to wet slag, while in Phase I it is 185 degrees, corresponding to dry slag. What impact do these two temperatures have on the regeneration of washing oil? In fact, the viscosity of the oil after washing in phase two is higher than that in phase one. Everyone, what is the top temperature in your unit? Slag discharge method? What is the displacement per cycle? How does the regenerator top temperature affect the quality of the washing oil? Thank you.
Here, the temperature at the top of the regenerator tower is controlled between 180 and 200 degrees. Excessively high temperatures can reduce the quality of the cleaning oil ； If the temperature is too low, it is not possible to vaporize all of the qualified fractions of the washing oil, causing them to be lost along with the residue. Increase the oil washing consumption. The tower top temperature in Phase 2 of your facility is higher than that in Phase 1; consequently, the heavy components in the oil being washed increase, and thus the annual consumption rises slightly. However, it will not affect the oil washing and benzene removal efficiency.
2# Desert Poplar. Oh, I didn’t explain clearly: the viscosity of phase two is 163, while that of phase one is 185. It’s because of this high viscosity in phase two that I’m not sure of the reason
In our plant, the temperature at the top of the regeneration tower is kept around 200°C. If the temperature is too low, the slag removal process eliminates the high-melting-point components from the washed oil, resulting in significant losses of this oil.
4# aliqingfeng Haha, how do you remove the slag there? How much washing oil is consumed per ton of crude benzene?
We discharge the dry slag from our plant, but we base it on the temperature at the bottom of the regenerator; generally, a temperature at the top that is higher than that of the debenzing tower is sufficient. During normal slag discharge, the temperature at the bottom of the regenerator is around 205 degrees, resulting in good slag discharge efficiency. The amount of washing oil consumed per ton of crude benzene ranges from 44 Kg at its highest to 25 Kg at its lowest (statistics are taken once a month).
6# Wang Junqing – that’s quite low. How is the quality of the cleaning oil? Such as crystallization, etc
We deal with moisture-containing residues; we require the temperature at the bottom of the regenerator to be above 210 degrees. Generally, this cleaning is done twice a week, on Monday and Thursday. The oil consumption for cleaning should not exceed 80 units per month. It is mainly diluted with washing oil based on its low viscosity.
There are several layers of trays inside the regenerator; as the light components rise, they distribute evenly across these trays. The wash oil inlet is located above the trays, and the wash oil remaining there undergoes gas-liquid mass transfer with the light component vapor on the trays. The heavy components descend, allowing for repeated distillation； The light-component oil, gas, and water vapor enter the debenzene tower. During slag discharge, shut off the oil supply; the heavy components that remain at the bottom of the regenerator after several days of dry steaming are then removed from the equipment when the appropriate discharge temperature is reached.
What was said on the 6th floor makes sense; the slag formation process depends mainly on the temperature at the bottom of the regenerator at the end of the process. A low outlet temperature indicates that the quality of the superheated steam is poor, and this will certainly affect the quality of the slag formed.
There is no fixed method for the regeneration process; it mainly depends on the quality of the oil used in the recycling cycle. Whether draining solid slag or liquid slag, the distillation yield before 300 degrees in the cyclic oil washing process must be no less than 95%