Suitability of laser-induced breakdown spectroscopy in screening potential additives to mitigate fouling deposits

Abstract

Alkali vapors present in the flue gas generated during coal-based combustion form fouling deposits as they condense. An additive added to coal can trap alkali elements in ash, therefore suppress the growth rate of fouling deposits, and increase thermal efficiency of a coalfired thermal power plant. Laser-induced breakdown spectroscopy (LIBS) technique is proposed and demonstrated to screen potential additives to trap alkali elements in ash. Five additives-namely, kaolinite, alumina, silica, magnesia, and pumice-were analyzed for their effectiveness on four Indian coals for retaining/confining alkali elements in ash during coal combustion. Ratio analysis based on LIBS emission intensity values clearly shows that kaolinite and pumice are promising additives to trap sodium. Similarly, kaolinite, pumice, and silica exhibited good potassium retention.

Laser-Induced Breakdown Spectroscopy Combined with Temporal Plasma Analysis of C2 Molecular Emission for Carbon Analysis in Coal

“…Various studies have reported the characterization of coal using LIBS to determine C content, ash content, calorific value, volatile matter content, etc. 5–9 Most of the reported studies involve sample preparation where the coal samples were ball milled and compacted into pellets to achieve an even surface and homogeneous composition. 10,11 But in real-time, coal composition is not uniform throughout the sample, and coal pieces are irregularly shaped, which is the major challenge in LIBS analysis of coal.…”