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[Display omitted] • A detailed mineralogical characterization study. • A feasibility study for the potential utilization of coal gasification ash. • First time study of a coal gasification waste generated from an Indian plant. • Optical and stereomicroscopy, FESEM with EDS, XRF, SEM-EDX, XRD, and TGA applied. This work aims to perform the applied mineralogical characterization of coal gasification ash (CGA) generated from a commercial fixed bed downdraft gasification plant in eastern India. Analytical and characterization techniques such as stereomicroscopy, optical microscopy, field emission scanning electron microscopy (FESEM) with energy dispersive spectroscopy (EDS) attached, X-ray fluorescence (XRF), energy dispersive x-ray spectrometer associated scanning electron microscope (SEM-EDX), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were applied for analyzing the coal and the corresponding gasification ash sample. These analytical techniques illustrate that SiO 2 and Al 2 O 3 are the major gasification ash phases, accounting for almost 85% of the entire CGA composition. The dominant mineral phases, such as quartz, mullite, and other aluminosilicates, provide an opportunity for utilization in construction and refractory material manufacturing. Moreover, confirming the presence of rare and valuable earth elements (RVEEs) in the CGA sample with SEM-EDX analysis unearths a new application window in meeting the requirement of the RVEEs starved nation like India, where very few commercial-scale coal gasification units are operational. [ABSTRACT FROM AUTHOR]

Steam gasification experiments were conducted with coal and petcoke in conjunction with potentially renewable biomass substances, namely coconut shell, coconut husk, and banana peduncle, which are usually considered waste materials. The gasification performance in a bench-scale externally heated fluidized bed gasifier was evaluated based on the product syngas quality and the detailed characterization of feed and product samples using X-ray fluorescence (XRF), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis. This work performed experiments at relatively constant operating parameters: solid feed rate, steam/O 2 ratio, feed particle size, and gasification reactor temperature. Biomass waste resources showed an augmentation in the syngas product quality for both the coal and petcoke samples, especially in cold gas efficiency (CGE) and carbon conversion efficiency (CCE). A maximum increase in CCE from 44.3 % to 72 % for the coal sample and from 19.3 % to 36.0 % for the petcoke sample was witnessed, whereas for the CGE, a rise of 35.8 %–91.7 % for the coal and 44.3 %–59.8 % for the petcoke with 80/20 blended biomass waste samples, was observed compared to the coal and petcoke only samples. The maximum hydrogen product gas yield between 53 and 73.7 vol % and combustible gas yields between 62.2 and 86.7 vol % were obtained on a nitrogen gas-free basis during the experiments. The solid residues of different gasification experiments were characterized and analyzed by scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and field emission-scanning electron microscopy (FE-SEM) analytical techniques to elucidate the high yield of energy-intensive gases. FTIR analysis was performed on all the liquid product samples obtained during the gasification experiments. The presence of alkali and alkaline earth metals (AAEMs) in biomass wastes highlighted the catalytic effect of these elements during the gasification experiments. The current work provides an opportunity to reduce carbon footprints with effective and efficient utilization of conventional energy feedstocks in conjunction with other waste substrates. [Display omitted] • A novel study of co-gasification of coal, petcoke with coconut, banana wastes. • High CGE, CCE, and combustible product gas yield due to the synergistic effect. • Catalytic effect of alkali and alkaline earth metals (AAEMs) of biomass wastes. • Analysis of feed samples applying proximate, ultimate, XRF, TGA, XRD, FTIR, etc. • FTIR, FE-SEM, and SEM-EDX-based gasification solid feed and product analysis. [ABSTRACT FROM AUTHOR]