(272f) A Case Study of Packed Column Maldistribution and Its Impact on Separation Efficiency

This paper presents a case study of a distillation column used to purify a process stream consisting of 2 components (a major component and a trace component ?B'). The separation efficiency of the distillation column declined after startup coming out of shutdown such that the desired separation was no longer achievable under design conditions. Use of gamma scans indicated liquid maldistribution in the bottom packed section of the column. The gamma scans also indicated the malfunctioning of the nuclear level transmitter in the column receiver, which was recalibrated. The lower column efficiency was partially offset by increasing reflux rate that allowed column to function for a few additional months till the scheduled shutdown. The visual observations made after opening up the column indicated severe damage to the bed limiter on top of the bottom packed section as the root cause of column malfunction.