This review article forms a guideline for LIBS contribution in coal analysis, encompassing fundamental aspects, operation modes, data processing, and analytical results. LIBS applications related to coal utilization are also highlighted (fly ash analysis and combustion monitoring).
Coal is one of the world's most abundant primary energy sources. Real-time coal analysis technology is imperative for coal blending, combustion optimization, pollution reduction, and pricing. Laser-induced breakdown spectroscopy (LIBS) has been a promising candidate for coal analysis because of its uniquely fast, in situ, and online capabilities. Coal is a sedimentary rock with a complex and heterogeneous composition, and therefore, laser–coal interaction exhibits multiple phenomena. A systematic study of the experimental conditions required for stable coal–plasma formation and evolution is a headway for enhancing LIBS results. In coal-fired power plants, LIBS offers three installation sets, namely, inline, at-line, and offline, with minimal space requirements and ease of retrofit. Moreover, LIBS is a safer technique with lower installation and maintenance costs and fits the concern of coal-fired power plants for multielemental detection in fast records. Coal analysis mainly includes calorific heat value determination, proximate analysis, ultimate analysis, and other related analyses. LIBS data is handled with continuously developing mathematical and statistical modeling techniques to provide the smart extraction of the required spectral information for coal analysis. In this tutorial review, we summarize the previous research contributions utilizing LIBS for coal analysis, including fundamentals and key factors, operation modes, data processing, and analytical results. Over and above, LIBS contribution in fly ash analysis and certain literature concerning combustion diagnostics might be included to present a simple guideline for researchers interested in LIBS applications for coal utilization.