For example, I recently learned that I need to ship sulfuric acid to a corn mill (acid was used to produce corn oil). What kind of car do I use (and more importantly, how can I find out for myself?)?
Find _Tank Car Journeys_ in some used bookstore on the net. It's from the 30's and does a nice job of describing all sorts of stuff that went in tank cars. In some instances it explains quite a bit about individual industries too.