Q & A > Question Details
We are having reflux drum for primary absorber. the entrained net overhead liquid is collected in the reflux drum. the liquid of reflux drum is pumped out internittently to high pressure seperator. I want to know that can we line up this hydrocarbon back to main fractionator or to deutanizer feed line? If we line up it to main fractionator then it wont accumulate in primary absorber reflux drum and build up the level in reflux drum.
11/09/2014 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
After reviewing your sketch, I have the following answer:
In an FCC unit, there is enough hydrogen gas in the reactor products to make the use of a distillation column with an overhead condenser in the vapor recovery section impractical. With cooling water, an extremely high operating pressure would be required to make the cut between ethane and propane. Thus the use of an absorber and stripper combination at a reasonable pressure. Your design apparently has the absorber and sponge absorber required but with an “overhead” condenser and receiver in between. That part of the process should be bypassed or the small quantity of liquid it accumulates should be returned to the main fractionator with the rich sponge oil. In neither case would the pump be needed.
08/09/2014 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
Sending it to the debutanizer is not a good idea because the material would contain components that would make the debutanizer overhead product off spec. E-mail me a sketch, and I can comment on the other options.