Abstract

ROJAS G, Andrés Felipe  and  BARRAZA BURGOS, Juan Manuel. Char morphology characterization from pulverized coals: experimental determination. Rev.fac.ing.univ. Antioquia [online]. 2008, n.43, pp.42-58. ISSN 0120-6230.

During the devolatilisation process, coal particles change their structure due to the liberation of its volatile matter. A porous solid rich in fixed carbon ('Char') with different morphologies is obtained. At a tubular reactor the chars from three bituminous coal (La Yolanda, El Cerrejón and Thoresby), three devolatilization temperatures (900, 1000 and 1100ºC) and three times (100, 150 and 300 ms) were obtained. Those morphologies were identified using an automatic image analysis technique. By this technique, the average area, the half wall-thickness, the percentage of smaller wall-thickness to 3 and 5 µm, the porosity and the percentage of morphotypes for each particle char sample was determined. It was found that both the porosity and the smallest wall-thickness to 3 and 5 µm, decreased with the increase of the devolatilization time and temperature. The half wall-thickness had a contrary behaviour. It was also found that the coal from El Cerrejón produced high concentration of tenuisphere chars, while the coal from La Yolanda generates mainly crassinetwork chars.

Keywords : char morphology; pulverized coal; tube reactor; image analysis.

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