I am not aware of any ban on petcoke in any use. I have no doubt that a lot of the Obama Energy outcomes are going to be very harsh on any fossil fuel & especially so for Coal & Petcokes. But he hasnt even got Trade & Cap (or Cap & Die more accurately) passed thusfar.
This sounds like the petcoke from Holly/Sun refinery in Tulsa & perhaps it is more a function of its 1..5%Sulfur no longer fitting the niche carbon markets nearby as result of Holly taking more agressive posture on crudes with higher sulfur. Some of the Ferro Alloys/Carbon/Specialty Fuel applications might have been impacted from BACT on furnace emissions along the lines of the Coal Coke furnace emissions that would push petcoke out of Met Coal blend?
