Crude Oil Distilled in a Cylinder Still: Benzine, Burning Oil and Residuum (Sadtler, in Thorpe 1913)

The first step of an American refinery around 1910: crude oil is boiled in a huge horizontal still and split into a light benzine cut, the burning oil that becomes kerosene, and a heavy residuum for the tar stills. Variable: how hard you run the end of the distillation. Run as a plain fractional distillation, Pennsylvania crude gives 35 to 50 % burning oil and 20 to 30 % lubricating oils. Let the heavy vapours fall back on the hot oil and they crack: burning oil rises to 75 to 80 % and the residuum drops to 6 %. Source: Sadtler, American Petroleum, in Thorpe's Dictionary of Applied Chemistry, vol. 4 (1913). Not given: the temperature or gravity at which each cut is switched. Crude oil vapour is highly flammable. Picture drawn by Youblob.