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Ultrasensitive Analyzer Provides Real-Time Quantification of Acetylene and Reduces Operating Costs

Ethylene is the largest volume, largest revenue-generating organic chemical produced. Ethylene finds widespread use, serving as the building block for 50% of all organic chemicals and polymers. However, manufacturers who produce polymer-grade ethylene must constantly monitor, and if necessary, hydrogenate any acetylene that may be present in ethylene flows. Such measures are imperative because too high an increase in acetylene concentration has the potential to contaminate both the catalytic bed and the stored finished product, and if left unchecked, acetylene contamination can cost a chemical manufacturer more than $200,000 in losses per event. As a result, the ability to quickly and accurately monitor trace levels of acetylene is a critical need for ethylene manufacturers.

Los Gatos Research, in partnership with Dow Chemical and Analytical Specialties, Inc., has developed an industrial gas process control monitor that can replace gas chromatography. Through support funding provided by DOE's SBIR program, the new gas analyzer uses a patented technology having a variation of absorption spectroscopy. The new technology increases the path-length up to several kilometers of effective path using two highly reflective mirrors in the sample cavity and a diode laser that is not sensitive to alignment. The compact robust technology, Off-Axis ICOS (Integrated Cavity Output Spectroscopy) retains the sensitivity of older detection methods, while providing an absolute, accurate measurement of acetylene contamination that is fifty times faster and one-third less expensive than traditional gas chromatography.

The Off-Axis ICOS technology can be completely integrated into gas handling and computing subsystems. The analyzer is field serviceable to permit long-term deployment in the gas processing environment. Additionally, the highly reflective mirrors can be periodically replaced without any need for realignment or adjustment, which further increases the instrument's lifetime.

Diagram depicting path of lasers through the novel gas analyzer


  • Developed by Los Gatos Research in partnership with Dow Chemical Co., and Analytical Specialties, Inc.
  • Commercialized in 2006 with more than 25 units in operation.


Can be used to measure trace acetylene concentrations in ethylene gas flows, providing a real-time measurement of potential contamination.



  • Provides measurements 50 times faster than conventional gas chromatography.
  • Reduces the capital cost for analytical support technologies.
  • Allows for the optimization of the hydrogenation reactor and minimizes product contamination.




Integrates into complete gas handling, sampling, and computing systems with a compact, robust design.


Product Quality

Minimizes off-specification ethylene product quality through improved process control.



Improves raw material conversion to finished product and minimizes reprocessing and potential system contamination due to excess acetylene in the gas.


Contact Information

Dr. Manish Gupta
(650) 965-7874, ext. 226
Los Gatos Research