When I increased crude tower bottom stripping steam from 1,200 to 2,500 lbs/hr, I increased diesel yield by 1,000 BSD at the expense of LVGO. Vacuum, in the vacuum tower, improved from 25 to 18 mm Hg. Yet, vacuum resid yield failed to improve. Why not?
Reduction in vaporization of diesel in flash zone of vacuum tower, off-set reduction in pressure:
· % vaporized prop. to (V/1 • 1/P)