Electric light by the first practical electric arc light in 1806. By the 1870s, Davy's arc lamp had been successfully commercialized, and was used to light many public spaces. The development of a steadily glowing filament suitable for interior lighting took longer, but by the early twentieth century inventors had successfully developed options, replacing the arc light with incandescents. The energy efficiency of electric lighting has increased radically since the first demonstration of arc lamps and the incandescent light bulb of the 19th century. Modern electric light sources come in a profusion of types and sizes adapted to many applications. Most modern
Atmospheric distillation of crude oil Atmospheric distillation of crude oil Distillation of crude oil is typically performed either under atmospheric pressure and under a vacuum. Low boiling fractions usually vaporize below 400 °C at atmospheric pressure without cracking the hydrocarbon compounds. Therefore, all the low boiling fractions of crude oil are separated by atmospheric distillation. A crude distillation unit (CDU) consists of pre-flash distillation column. The petroleum products obtained from the distillation process are light, medium, and heavy naphtha, kerosene, diesel, and oil residue. Crude oil obtained from the desalter at temperature of 250 °C–260 °C is further heated by a tube-still heater to a