Hate burst your bubble sunshine but any design needs to have at least 10% overdesign <not to wax historically but prior 1980’s computers filled basements & had use punch cards and relied mostly on slide rules for calc’s and the overdesign was often required to be in 25-50% range to handle big swings from winter minimums to stay in tankage & summer maximums to meet demands……why lot of US refineries are able to keep up with demand even though half of them were shutdown>
And you don’t have to “put in bottlenecks” for a 10% swing – you hit some of them anyway! Using todays annual capacity creep on cokers it will chew thur that 10% in fairly short order anyway. Also most coker designs still have equipment life guarantee’s on 18-24 hr cycles but operational cycles are often as low as 16 – 10 hr cycles that has to be met on performance runs …… Coking industry should work to change that but wall you hit is that you pretty much only have about 5000 (+/- 1-2,000) cycles in drum & you can take them slow over 20-30 years at 24 hr cycles or fast in 10-15 years at lower cycles/shorter life.
So where cokers are concerned putting in this large expansion they got jipped (I dont think Motiva boys did & I dont think their Coker Tech boys would take that short cut either) if they dont have hell lot more than a 10% turn-up ratio!
Regards
Charlie Randall
