Causes of Distillation Overpressure

Common possible causes of distillation column overpressure are listed below and illustrated in Fig. 9.1. The list is not comprehensive. Sources and possible causes of overpressure vary from column to column, and each column must be thoroughly studied to determine its own overpressure sources. The list below can best serve as an initial checklist or a starting point. Overpressure in distillation columns may result from any one, or a combination of, the following conditions (9,10, 60, 293, 351, 414). 

Loss of coolant (cooling water, refngerant, air fan, air louvers, pumparound coolers, feed cooler) 

Controller failure (alternatively, human error which opens controller fully the wrong way)  

Failure of feed controller (each feed should he considered, including stripping steam) 

Loss of heating in an upstream column (upstream column will dump, which will simultaneously increase feed rate and fraction of lights entering the column) 

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