8/17/2019 Distillation_crude oil.pdf

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Crude oil

Condenser

Atmosphericgas oil

Crude tower

bottoms (SRAR)

Diesel

Kerosene

Heavystraight runnaphtha

Lightstraight runnaphtha

Butane andlightercomponents

Heater

Reboiler

Valve traysA variety of tray designs are used to

improve the separation process in a

distillation column. In this system, the

vapour rises through valves set into each

tray to enhance contact with the liquid

flowing over it. Unvapourised liquid

cascades over a weir onto the next level

down.

Crude oil distillationA distillation column partially vapourises liquid feedstock so that the resulting gas and liquid

components can be separated. The column contains a number of stages, called trays, to achieve

a higher degree of separation. Vapour rises up the column, bubbling through the liquid cascading

down the column from tray to tray. Lighter, lower boiling point components tend to be driven

upwards until they reach a level where the pressure and temperature is similar to their own.

Similarly, heavier, higher boiling point components are driven down the column. Consequently,

vapour becomes richer in lighter components as it rises while liquid becomes richer in heavycomponents as it descends, resulting in overall separation of the feedstock.

Valve

Trays

Liquiddowncomer

Weir

Distillationcolumn wall