An evaluation of thermal resistance as a measure of black carbon content in diesel soot, wood char, and sediment

The time dependence and efficacy of pretreatment by chemothermal oxidation for estimating black carbon (BC) content was evaluated using 28 samples of wood char, soot, activated carbon, and sediment. For 19 wood chars, 24-h carbon survival under air (at 375 °C) varied between 0 and 44%, with no survival in any char formed at 850 °C and even in some low H/C chars formed at 1000 °C. Results depended not only on extent of carbonization, but also on physical attributes of particles. Because not all environmentally relevant BC is detected, the method is perhaps best considered as a semi-quantitative measure of soot content.