While you can tailor your cracking process to produce a little different stream, e.g., a bit more diesel or gasoline, it's not totally flexible. I used to work for Akzo, and we made catalysts for the cracking units that separate the streams into the various products. You wouldn't believe how different every single one is... we custom made catalysts not only for every refinery, but every cat cracker and then basing on the infinte variety of feedstocks. It's like being a gourmet chef with ingredients that are never the same.
As far as the ULSDs, the cost comes in from additional refining steps, like hydrotreating (we also made the catalysts for that).
Right now, the price of diesel at the pumps (road) is almost $1.00/gallon higher than gasoline. I guess if they say it's high demand for diesel worldwide, I can buy that. But with that in mind, should we really be thinking about switching more vehicles to diesel?? Of course, gas will shoot back up there someday.
Oh yea, as far as maintenance... My dad was an operator at Gulf (now Chevron - bastards) and my best friend is as well nowadays. Growing up in the refinery center of Texas and still living in one (Port Arthur, Houston) I can tell you that a true scheduled maintenance shutdown is pretty rare. They basically run the h-ll out of the units until something breaks down to where they just can't run, then they scramble like hell to do ALL the stuff at once. The downstream guys just aren't that profitable, believe it or not, and they try to skin the buffalo before they turn loose of the nickel. Witness some of the big explosions around here in the last few years... a couple at Amoco Texas City come to mind.
-- Edited by Keith at 05:05, 2008-12-07