US oil refineries exporting filthy fuel to India

U.S. oil refineries are the world’s biggest producer of a waste product that’s too dirty to sell or burn at home. So they are exporting vast quantities of it to India. Petroleum coke, the bottom-of-the-barrel leftover from refining Canadian tar sands crude and other heavy oils, is cheaper and burns hotter than coal. But it also contains more planet-warming carbon and far more heart and lung-damaging sulphur - a key reason few American companies use it. The petcoke being burned in countless factories and plants is contributing to dangerously filthy air in India, which already has many of the world's most polluted cities.