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ONLINE PROCESS MONITORING WITH A COMPACT FTIR SPECTROMETER

APACT 2016 (20-22 April 2016), Chester, UK

The use of modern continuous manufacturing processes to produce materials creates a requirement for online monitoring and control of the reaction. Fourier Transfer Infrared (FTIR) spectroscopy is a well-established analytical technique in the laboratory, but conventional instruments are bulky and fragile: susceptible to vibration, temperature changes, and requiring flexible, lossy interconnects to the reaction vessel. For these reasons, it is common practice to design FTIR instruments out of production process monitoring, and instead rely on alternative techniques that attempt to provide equivalent information.

The Keit microFTS® is compact and rugged FTIR spectrometer that contains no moving parts, and can be connected directly to a reaction vessel, permitting online real-time measurements of reactions.

Peaks in the absorbance spectra from the process are plotted to give an indication of the concentration of different components, and this allows the operator to characterise the progress of the reaction. The trends show the formation of the oil additive component in real time. The reaction chemistry is complex involving three phases, gas, liquid, and solid, but this complex environment was not found to affect the performance of the instrument. Because the microFTS® is insensitive to vibration, and is compact and lightweight, it was able to make in-situ FTIR measurements of the absorption spectrum without the use of complicated probes or additional sampling accessories.

The microFTS® was fitted with a ZnSe crystal ATR dip probe, and was directly inserted into the reaction vessel. This was agitated and maintained at an elevated temperature, and the reaction was monitored continuously over its duration, which was approximately 3 hours.

Authors: Tim Stephens1, Paul Wilson2, Chris Adams2

1 Keit Ltd., Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0QX, UK2 Infineum UK Ltd., Milton Hill Technology Centre, Abingdon, OX13 6BB, UKEmail: tim@keit.co.uk, Tel: +44 (0)1235 567232www.keit.co.uk