Physical characterization of the cigarette coal: part 1—smolder burn

Oxidative pyrolysis of solid fuels

“…Past literature has extensively addressed thermochemical degradation and combustion of carbon rich solid materials (solid fuels), including coals [1][2][3][4][5][6][7][8][9][10], biomass [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and polymers [26][27][28][29][30][31][32][33][34][35][36][37], as a possible route to the production of energy and/or of valuable chemicals. As a matter of fact most studies are focused on pyrolysis under inert conditions and on combustion of the residual char, although in practical applications thermal degradation of solid fuels often occurs in presence of oxygen.…”

Physical characterization of the cigarette coal

“…Notice the uneven char line in slices 5-8. the cigarette coal from a smoked cigarette that was stopped 1.5 s into a 2 s puff. This is unlike the flat profile that was observed for the smoldering cigarette coal [7,8].…”

“…5, consisted of shreds that exhibited three regions that differed in color from yellow non-scorched, to brown marginally scorched, to black charred tobacco. The method of sample dissection has been documented previously [7]. Briefly, the dissection of the ash sample from the coal was carried out by carefully scraping the ash layer from the outer layer of the cigarette coal with the edge of a razor blade and placing the ash in a sample vial.…”

“…Temperature range from charred tobacco behind the coal. Temperatures associated with shred color were discussed previously [7]. in front of the char line and placed into a sample vial.…”

“…Until recently, very little was known about the morphology of the tobacco within the cigarette coal. Baliga et al [7] have shown that the cigarette coal during the smolder burn contains four distinct regions with unique morphologies to each region. Baker has provided considerable information on the thermal and chemical events that occur during the puff and smolder burn modes in the smoked cigarette [8][9][10].…”