Effects of pyrolysis conditions on the structure of chars prepared from an Argentine asphaltite

DANIELA NASSINI; G. G. FOUGA; HORACIO E.P. NASSINI; A. E. BOHÉ

FUEL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2016 vol. 182 p. 623 - 631

0016-2361

As gasification reactivity of carbonaceoussolid material chars is known to be strongly dependent on their formationconditions, a comprehensive study was carried out on the effects of pyrolysisconditions on structure of chars prepared from an Argentine asphaltite. Thestudy comprised qualitative and quantitative analyses of char structures byX-ray diffraction, complemented with the characterization of physical morphologyof char particles by scanning electronic microscopy and high-resolutiontransmission electronic microscopy. Effects of pyrolysis temperature, heatingrate and holding time at the peak temperature were investigated separately in afixed bed tubular reactor. Additionally, the overall effect of variations intime-temperature history of individual char particles was evaluated using adrop tube furnace reactor. Experimental results have shown that pyrolysisconditions have a strong influence on the asphaltite-derived char structure,producing a significant reordering of the carbonaceous matrix at high heattreatment temperatures that is evidenced by increments in aromaticity andcrystalline carbon fraction. The resulting physical morphology ofasphaltite-derived char particles was found to be profoundly influenced by theheating rate at which the volatile matter is released, due to the appearance ofa liquid phase during the heating process.