The last refinery built in the US was the Reliance refinery in Louisiana and it was built in the early 70's. Almost all of the small refineries (under 100,000 BPSD) have been closed. Compared to the early seventies, 50% of the refineries were closed by 1990. The small refineries that are still running are in niche markets. The big refineries have made up the loss by increasing capacity and efficiency.
I am sure you are aware that by 2006 all gasoline sold in the US must be less than 30 ppm sulfur. By 2007 all on road diesel sold in the US will be 15 ppm sulfur. Many of the remaining small refineries will close by the by 2007 since they can afford the expense of upgrading equipment to make gasoline and diesel to those low sulfur numbers. So by 2007, another 50% of refineries will be closed. Leaving only about a hundred or so refineries left in the US. I think in another 20 years there will be 20 to 30 very large refineries owned by large companies in the US. You are right almost every area in the US has a different blend of gasoline. The specs. are so numerous that it was that a book explain them.
