For the first new refinery in the U.S. in seven years, the idea was simple: Buy cheap oil from shale producers, then score a quick profit by selling it right back to them as more expensive diesel needed to power their trucks and drilling rigs. Now the shale bust is threatening to ruin a renaissance in small refineries, known as teapots, before it even begins. When Dakota Prairie Refining LLC was building its plant in 2014, it could buy some of the cheapest oil in America and sell among the most expensive diesel in America. But the oil bust obliterated its local diesel market, along with the fat premium the fuel used to fetch, as its potential customers shut down operations. In the fall of 2014, when tiny Dakota Prairie was getting ready to open its processing plant in Dickinson, North Dakota, diesel fuel near the state’s Bakken oil […]