The utilisation of fuel-rich flames as sulphur detectors

Abstract

Hydrogen-rich flames are rapidly assuming an important role as highly sensitive detectors for sulphur. S2-species are generated in the flame and the radiation emitted by them is measured in the UV range. A preliminary separation of sulphur, e.g. by chrormatography, is required for analysis of samples in which sulphur is associated with hydrocarbons, as in gas, fuel and petroleum samples, since hydrocarbons cause the emission to be diminished in proportion to both the concentration and number of carbon atoms per molecule of hydrocarbon. The quenching effect on the emission by carbon present as dioxide is negligible when compared with its effect when present as hydrocarbon. This finding has led to the use of preliminary oxidation to avoid the need of prior separation. A complete apparatus, which includes a stacked burner system, is described. Continuous monitoring of sulphur in a stream of hydrocarbon gases is possible.