Spent Caustic Scrubber

[padovano]

We use caustic solution to remove H2S from LPG. The solution is placed in a batch and when we have a positive Doctor test, the solution is changed. Recently I carried out some analysis of the solution. I had a PH of 12.3 and a conductivity of 6.2. I would like to know if there are any minimum values that will indiacate that the solution is saturated and should be changed before waiting for a positive Doctor test.

 

[mbeychok]

padovano:

A great many years ago, when I worked in a refinery, we sampled the caustic once a shift and the laboratory ran a test called "Percent spent caustic" which involved titration to the Methyl Orange endpoint. We found that was the best way to determine when the caustic needed changing.

Milton Beychok
(Visit me at www.air-dispersion.com)
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