Measuring Trace Moisture in an Electrolysis Plant
Industry:
Product:
Chemical
TDLS200
Introduction
Electrolysis plants create hydrogen and chlorine from a brine solution. Chlorine gas generated from the anolyte of the
electrolysis tank generally contains between 0.5 to 2.0 vol% H2O. The sample is then cooled and filtered to remove
brine, subsequently coming out as wet chlorine gas. The wet gas is sent to a drying tower where it is treated with
sulfuric acid to get moisture down to the ppm level. Acid mist remains in the dry chlorine gas and is sent to a dry
chloride tower to remove the mist. The dry chlorine gas is then sent to a reciprocating compressor for liquefaction.
The presence of moisture after the dry chloride tower, even at trace levels, causes corrosion of the chlorine
compressor and contaminates the product with chlorine hydrate and hydrous iron chloride. Trace moisture levels are
conventionally monitored before and after the compressor using phosphorous pentoxide (P2O5) sensors. The P2O5
sensors have slow response times, high maintenance costs (both time and money), and eventually deteriorate due to
process contact.
Process
TDLS-A-001
http://www.yokogawa.com/us
Measuring Trace Moisture in an Electrolysis Plant
Expected Benefits
-Quick identification of process upset and consequently corrective action
-Avoiding equipment damage and/or product contamination
-Highly sensitive measurements in the minimum range of 0-30 ppm H2O
-In-situ online validation and calibration minimizes downtime
Field Data
TDLS-A-001
http://www.yokogawa.com/us
Product Recommendations
TDLS200
* For additional information or assistance with these applications, please contact Analytical Product
Marketing.
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