Oxy-fuel combustion: The effect of coal rank and the role of char-CO2 reaction

Devolatilization of a single fuel particle in a fluidized bed under oxy-combustion conditions. Part B: Modeling and comparison with measurements

“…Thus, considering the initial stage of char combustion in the period of the devolatilization, the kinetics of char combustion proposed in Ref. [27] is adopted to model the char combustion for all the fuels tested in this work (the chemical kinetics term is retained in Eq. (30), despite its small significance in the present context, in order to keep the integrity of the model).…”

Differences between combustion and oxy-combustion of corn and corn–rape blend using thermogravimetric analysis

“…This is in agreement with Haykiri-Acma et al [45] who reported that oxygen concentration does not influence the mass loss of individual bioresidues if the temperature is under 523 K. The rape DTG profile contains a peak slightly higher than that presented for corn due to its higher moisture content ( Table 1). The difference between combustion and oxy-combustion in this zone is the higher temperature of the process due to the higher energy that must be transported to the combustion chamber because more absorbance of CO 2 (triatomic) than N 2 (diatomic) [6,24,[45][46][47][48][49][50][51][52] revealed higher specific heat of CO 2 than N 2 listed in Table 4. Moreover, peaks observed in the DTG curve are shorter and wider, stating that the process is less favourable and slower.…”

“…Moreover, peaks observed in the DTG curve are shorter and wider, stating that the process is less favourable and slower. It can be assumed that the CO 2 energy absorption reduces flame temperature in the chamber [46][47][48][49][50][51][52][53][54].…”

Investigating the combustion characteristic temperature of 28 kinds of Chinese coal in oxy-fuel conditions

“…An increase in Ca lowered characteristic temperature significantly, which may be related to its strong effect caused by a low temperature and a high content. Moreover, Ca exhibits a good catalytic effect at both high and low temperature [46,51].…”

“…Ca content is higher than those of K and Fe, and it shifts significantly before and after ash formation because of vaporisation [45]. The remaining Ca be sintered during a long period of exposure to a high-temperature environment [46,47].…”