Emission of Ultrafine Particles from Natural Gas Domestic Burners

An experimental study of the combustion characteristics of new burners used for home and water heating appliances and domestic stove tops is presented with the aim of evaluating the effect of burner configurations and operating conditions on the emissions of ultrafine particles. Advanced in-situ optical diagnostics, based on laser induced emission spectroscopy (LIE), and ex-situ measurements, based on scanning mobility particle size (SMPS) measurements, and particles collection by water-based sampling technique, were used in order to evaluate total particulate concentrations and size distribution functions. For home heating burners, three different configurations, two premixed and one diffusive, were studied under various operating conditions. Measurements showed that particulate matter with diameters in the 1 nm to 10 nm size range is formed. Emitted mass concentration of these compounds were very low, of the order of 0.1 mg/Nm(3). They were formed in large number concentrations in the flame region but were also strongly oxidized in the post-oxidation region of the device. On the contrary, a domestic stove top emits a larger amount of very small particles since their post-oxidization is not possible. Soot particles with size larger than 10 nm are not formed in all the examined conditions and burner configurations.