The analysis of the current literature on the subject of detailed single-particle measurements revealed that, despite the fact that numerous experimental investigations are reported, the database for the calibration of predictive burnout models is insufficient. To close this gap, a test rig for the optical investigation of the burning behavior of pulverized fuel particles was put into operation and introduced in the first part of this two-article series. In the second part, the results of a measurement campaign, on a high-volatile bituminous coal, and torrefied Miscanthus in eight oxy-fuel atmospheres are presented. The experimental data contains profiles of particle temperature, size, shape, burnout progress over residence time and, thus, provides a sound basis for the calibration of char burnout models. The combination of chosen optical techniques enables distinguishing between burning and cold particles, the latter being non-ignited or already burnt out. This information is important for the analysis of particle size distributions. In addition to optical measurements, partially reacted solid samples were extracted from the reactor. Besides the proximate and elemental analysis, also the porosity of the samples was determined at several burnout levels. Interestingly, the evolution of particle porosity shows atmosphere-independent trends.
展开▼
