The Industrial Applications Of Fractional Distillation

Distillation is one of the easiest and most common ways of seperating different components of mixtures of liquids. Eventhough the technique can be seen as simple the process of fractional distillation of liquid mixutres is one of the most important separation techniques in industrial chemistry.

One of the most common uses of fractional distillation is the seperation of petroleum. Fractional distillation of petroleum originated in Pennsylvania when an oil creek was discovered by E.L Drake. Kerosene was the main fraction utilised at first as kerosene lamps replaced oil lamps. Many industrial distillation towers can often have over 100 plates, with as many as ten different fractions being drawn off at different points. For crude oil a furnace heats the oil which then flows into the fractionating column. The majority of the fractions of crude oil are in the gaseous start when they enter the distillation column.

A standard column contains about 40 trays pierced with small holes. Condensed vapour flows over the trays and runs down into the tray below. The numerous fractions removed from petroleum include natural gas, gasoline, benzene, naptha, kerosene, diesel fuel, light and heavy heating oils and tars.

	The properties of these fractions differ from the top of the column to the bottom. The top fractions are short and light hydrocarbons, they have low boiling points and are very volatile.

One barrel of crude oil contains about 30-40% of gasoline. The high demand for gasoline means that less needed petroleum fractions are converted into it. This is done by a process called cracking

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