The QMA601 process moisture analyser from Michell Instruments has been
selected by a major European manufacturer to monitor trace moisture in ethylene
at the point of entry from the supply pipeline.
Following a year-long trial at the plant, Michell’s QMA601 quartz
crystal microbalance moisture analyser was shown to be measuring within
specification throughout with no adjustments needed. The QMA601 with its QCM
moisture sensor is a good choice for this application because it offers several
advantages: Ethylene will not polymerise on the quartz crystal sensor. The
sensor does not suffer from the interferences as its response is specific to
the water molecules in the ethylene. Unlike all other moisture analysis
techniques, quartz crystal microbalance technology operates on a
non-equilibrium basis, which provides some of the fastest response speeds
There are approximately 495km of ethylene pipelines in Germany, Belgium
and the Netherlands, connecting ethylene producers and consumers, and providing
an infrastructure for the petrochemical industry in these countries. The highly
flammable nature of ethylene necessitates a special permit if it is to be
transported in any other way.
Ethylene is an important chemical used in many petrochemical processes,
such as the manufacture of polythene; it’s therefore important to keep up the
supply via a pipeline. As with many other chemical processes, moisture must be
kept to a minimum – in this case less than 10 ppmV. Quartz crystal
technology has been proven to be fast, accurate and reliable in applications
far dryer than the 0 to 10 ppmV range required for ethylene purity monitoring.
The QMA601 has global hazardous area certifications and is available
with a full range of sample conditioning options.