Radiotracer investigation in a pilot-scale fluidized bed coal gasifier (FBCG)

Highlights: • Radiotracer investigations were carried out in a coal gasifier. • Gold-198-labeled coal particles were used as a radiotracer. • RTDs of coal particle were measured and MRTs determined. • The gasifier behaved as an ideal mixer at all the operating conditions for fine particles. • A small fraction of coarser particles was found to be bypassing at ambient temperature. - Abstract: :Radiotracer investigations were carried out for measurement and analysis of residence time distribution (RTD) of coal particles in a pilot-scale gasifier fitted with a flat air/steam distributor. Measurements were made at different operating conditions using gold-198 (¹⁹⁸Au) labeled coal particles as a radiotracer. The measured RTDs were treated and mean residence times (MRTs) were determined. Furthermore, the treated RTDs were simulated using a suitably conceptualized mathematical model and detailed information about hydrodynamics of coal particles within the gasifier was obtained. Results of model simulation indicated that the gasifier behaved as an ideal mixer of fine coal particles exiting from the top of the gasifier. A small fraction of the coarser particles was found to be bypassing at ambient temperature.