Atmospheric pipe still

Normally, all of the heat is removed from the fractionator by three or more circulating reflux streams. The proportion of gas and naphtha in the cracked products is much higher than in crude oil, so it is seldom possible to reduce the diameter of the tower top as in atmospheric pipe still design. Due to the low operating pressure, it is necessary to provide expensive compression capacity to permit recovery of these light hydrocarbons in subsequent equipment. 

In the atmospheric distillation process (Figure 2.1), heated crude oil is separated in a distillation column (distillation tower, fractionating tower, atmospheric pipe still) into streams which are then purified, transformed, adapted, and treated... 

When crude oil comes into a refinery, it is processed in an atmospheric pipe still. The side stream of the pipe still is rich with light gas oil. Fluid catalytic cracking units, or catcrackers, split this gas oil into smaller, more useful molecules (Figure 11-9). Fluid catalytic cracking units use the following equipment during operation ... 

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