Beneficiated coals' char morphology

Abstract

This work evaluated the char morphology of beneficiated and original coal (without beneficiation) from four Colombian coalmines: Cerrejón (La Guajira), La Jagua (Cesar), Guachinte (Valle del Cauca) and Nechí (Antioquia). Column flotation was used to obtain beneficiated coal, whereas a drop tube reactor at 1,000oC, 104 oC/s heating rate and 100 ms residence time was used to obtain char. The chars were analysed by image analysis which determined their shape, size, porosity and wall thickness. It was found that char morphology depended on coal rank and maceral composition. Morphological characteristics like high porosity, thinner walls and network-like morphology which are beneficial in improving combustion were present in vitrinite- and liptinite-rich lowest-ranking coals. Beneficiated coals showed that their chars had better performance regarding their morphological characteristics than their original coal chars.

Influence of the fertilizer type in the agronomic and energetic behaviour of the residues coming from oleander, cypress and quinoa

“…Quinoa husk (between 0.14 and 0.17) and oleander leaves (0.16 -0.17) had the lowest values for this ratio. All the new crops FC/VM values here obtained were lower than the obtained by other authors for both bituminous coals and chars [76]. However, results for this ratio here obtained were in line with other biomass sources like almond shell, pine pellets, olive stone, rice husk [77] or poplar sawdust [78] among others.…”