Their nickname — teapot refineries — may make them seem small and nonthreatening, but China’s privately owned, independent refining sector is anything but. Teapots have been growing in size and processing sophistication, and they now account for about one-quarter of total Chinese refining capacity. Their rise has raised the ire of China’s big national oil companies, who are pressing the government to rein in teapot refiners’ aggressive tactics and alleged circumvention of tax and environmental laws. Today we look at the growing role of China’s teapot refineries, the challenge they pose to much larger competitors and the Chinese government’s recent efforts to put a lid on the teapots’ ambitions.