Online Laser Diagnostics for High-Temperature Chemistry in Biomass Combustion
Research output: Book/Report › Doctoral thesis › Collection of Articles
|Number of pages||106|
|Publication status||Published - 29 Mar 2019|
|Publication type||G5 Doctoral dissertation (article)|
|Name||Tampere University Dissertations|
Microwave-Assisted Laser-Induced Breakdown Spectroscopy (MW-LIBS) is demonstrated for the ﬁrst time at ambient atmospheric conditions with impressive 93fold enhancement in limit of detection (LOD). MW-LIBS is further applied for online elemental monitoring during thermal conversion of biomass fuels as it improves detection of trace elements and reduces adverse self-absorption eﬀects in high-concentration conditions. To enable the beneﬁts of MW-LIBS, a novel burner for ﬂame calibration is introduced. The burner allows calibration of LIBS for extended concentration range enabling quantitative elemental release monitoring during thermal conversion of diﬀerent biomass fuels with varying elemental content. The elemental release behavior of biomass fuels is paramount for thermal conversion models and simulations that provide boiler operators and manufacturers crucial information on how to optimize the thermal processes and mitigate the alkali associated problems. Furthermore, as the novel MW-LIBS approach requires no or minimal sample preparation, it has great application potential for online elemental monitoring in diﬀerent ﬁelds of science where low LOD or high sensitivity is required.
The novel CPFAAS and MW-LIBS approaches provide simple and versatile methods for online high-temperature chemistry monitoring from laboratory-scale systems up to full-scale power plant boilers. Laser diagnostics will play a signiﬁcant role in optimization and in process control of future thermal power generation as it enables development of online sensor networks to monitor and forecast the plant behavior.