Photothermal characterization of natural gas automotive fuel

In this paper, we describe a new, simple and fast photothermal method for characterizing the quality of natural gas used as automobile fuel. The method consists essentially in measuring the thermal properties of a sequence of natural gas diluted in nitrogen with a photothermal gas analyser time especially designed for this purpose. It is shown that the proposed method is capable of measuring the thermal properties with an accuracy of 3%. It is also shown that the proposed method is capable of detecting traces of H2S greater than 7.8 mg m−3 in the natural gas. This good accuracy, together with its fast response and portability, suggests it as a simple routine, local, checking device for natural gas quality assurance at retailers' stations.