Michell Instruments’ Liquidew I.S. moisture in liquids analyser has been selected by a major producer of synthetic rubber to monitor critical process at its plant in Asia.
The plant produces Polybutadiene, a form of synthetic rubber commonly used in the manufacture of car tyres. This is generated from a feedstock of the gas 1,3 Butadiene, which is pressurised to form liquid phase and then dissolved in Hexane. The reaction to form the Polybutadiene requires a catalyst, which in this case is an alkyl-lithium compound. Lithium, being highly reactive with water will act as an effective catalyst only in near-anhydrous conditions where there is no more than 1ppmW of moisture present.
After the reaction has taken place, the Hexane solvent is evaporated to separate it from the newly-produced Polybutadiene using hot water in a separate vessel. It is then dried and purified before being re-introduced into the process. Since water is used to clean and recycle the hexane solvent, there is a risk of moisture contaminating the process if the solvent is not dried sufficiently before being reused.
The plant has installed six Liquidew I.S. moisture analysers at key points in the process to monitor moisture levels in the feedstock and the solvent as well as in the drying process used to regenerate the solvent. The Liquidew I.S. is capable of measuring moisture levels down to 0.001ppmW and can reliably give accurate readings in the low-moisture environment.
The Liquidew I.S. process moisture analyser was selected for this application for its ability to measure from 0.001 to 1000 ppmW with a fast response and recovery time, allowing the analyser to rapidly indicate changes in moisture concentration. Employing the analyser also helps reduce the number of drying cycles required to dry the solvent.
Michell Instruments products are available from AMS Instrumentation and Calibration .