Characterization of ash paricles with a micro heater and gas sensitive SiC field effect transistors
2014 (English)In: Journal of Sensors and Sensor Systems, Vol. 3, 305-313 p.Article in journal (Refereed) Published
Particle emission from traffic, power plants or, increasingly, stoves and fireplaces poses a serious riskfor human health. The harmfulness of the particles depends not only on their size and shape but also on adsorbates.Particle detectors for size and concentration are available on the market; however, determining content andadsorbents is still a challenge.In this work, a measurement setup for the characterization of dust and ash particle content with regard totheir adsorbates is presented. For the proof of concept, ammonia-contaminated fly ash samples from a coal-firedpower plant equipped with a selective non-catalytic reduction (SNCR) system were used. The fly ash samplewas placed on top of a heater substrate situated in a test chamber and heated up to several hundred degrees. Asilicon carbide field-effect transistor (SiC-FET) gas sensor was used to detect desorbing species by transportingthe headspace above the heater to the gas sensor with a small gas flow. Accumulation of desorbing species in theheater chamber followed by transfer to the gas sensor is also possible.A mass spectrometer was placed downstream of the sensor as a reference. A clear correlation between theSiC-FET response and the ammonia spectra of the mass spectrometer was observed. In addition, different levelsof contamination can be distinguished. Thus, with the presented setup, chemical characterization of particles,especially of adsorbates which contribute significantly to the harmfulness of the particles, is possible.
Place, publisher, year, edition, pages
2014. Vol. 3, 305-313 p.
IdentifiersURN: urn:nbn:se:liu:diva-113293DOI: 10.5194/jsss-3-305-2014OAI: oai:DiVA.org:liu-113293DiVA: diva2:780797