Fast Alternative Technology for Fuel Gas Analyses

Ronny McMurray, Modcon Systems, Akko, Israel
Gregory Shahnovski, Modcon Systems, Akko, Israel
Ariel Kigel, Modcon Systems, Akko, Israel


The composition of gaseous fuels, like LNG, Syngas, LPG, Biogas etc, is essential to determine the energy yield provided by the consumption of a gas in combustion processes.  Main significant resulting parameters include the component composition, caloric value (BTU) and the Wobbe Index.

Fuels having a lack of these required parameters reduce fuel efficiency, increase fuel consumption, have its impact on the emission, and other phenomena that may result from non-optimized gas combustion, like flashback, blow out, flame instability etc.

Real time measurement of the gas properties allow to take immediate steps to prevent any sudden impact resulting from fluctuations in the gas properties that may occur at any time.

Gas chromatography is a common method to determine the component  composition of the fuel and to calculate the calorific value. However, a lag-time between analyses and real composition and comprehensive maintenance of measuring system make this solution less preferable.

Tunable Filter Spectroscopy analyzers provide an effective alternative for fast on-line analyses of the gas composition and the resulting caloric value and Wobbe index.

Based on the Fabry Perot Etalon principle a beam of light is split into well-defined wavelengths by passing through tunable optical filters, and sweeps the sample with light of well-defined spectral bands that are characteristic for molecular properties, such as H₂O, THC, CO₂ CO, H₂S.

Scanning within a target band provides spectral data, or “fingerprints” that is characteristic for the property with a minimum of interference by other compounds, and eliminating undesired overlapping bands to provide a strong linearity across a full measuring range.

Chemometric algorithm processes the high-resolution spectra into highly accurate quantitative analytical results.

Being an optical method with an accuracy comparable to GC measurements, with results of the gas composition and required combustion parameters within seconds, forms the platform to efficient combustion optimization.