SINTSENSE:Low-Cost Monitoring of VOC Emissions from the Ferroalloy Industry

Monitoring of emissions of polycyclic aromatic hydrocarbons (PAH) from ferroalloy industry is challenging from an analytical point of view. PAHs constitute a group of analytes with a wide range of boiling points, thus sampling requires considering both gaseous as well as condensed phase constituents. Sampling for the purpose of reporting emissions has traditionally been conducted over a 2-3-hour interval and large variations have been observed. It has been speculated that there are large fluctuations in the PAH emission levels, and that these fluctuations are to some extent process dependent. In order to improve on budgets for PAH emissions, sampling must either be conducted over a larger time interval in order to capture more of the variations, or knowledge about the nature of the variations must be established to aim sampling at representative time periods. There are currently no options for online monitoring of PAH emissions. By-proxy approaches to online monitoring could be established from knowledge of the PAH component distribution, where the total PAH emission is inferred from the monitoring of a subset of components. With fundamental knowledge of PAH formation and destruction it is also possible to correlate PAH emissions with other emissions parameters. SINTSENSE is a low-cost sensor system aiming at monitoring of volatile organic compounds in emission gas streams. A photo ionization detector is used in order to detect aromatic gas constituents. It is not selective towards aromatic gas constituents, but will report a total budget for VOC and PAH. The sensor system can also be fitted with 3 additional sensors (e.g. SO2, NO2, CO) in order to monitor other relevant gas constituents. The system has been installed at industrial emission points in order to map the variations in emissions from ferroalloy smelters and this paper describes some of the early results obtained from the system.