TG-FTIR analysis of co-combustion characteristics of oil shale semi-coke and corn straw

摘要

TGA/DSC1 thermogravimetric analyzer and Fourier infrared spectrometric analyzer (FTIR) were used to conduct a series of combustion experiments using oil shale semi-coke, corn straw, and blends of the two. The results showed that the volatile initial precipitation temperature and ignition temperature of mixed samples are much lower than oil shale semi-coke, but it slightly higher than corn straw. The volatile initial precipitation temperature and ignition temperature of the mixed sample are increased with the increase in heating rate. When the heating rate is constant, the combustion process presents the trend to the low temperature; the peak value of the low-temperature section is high and intense release of volatile, thus improved combustion characteristics of the mixtures. Infrared spectral results are that: with increasing proportion of corn straw, A (CO)/ decreases gradually; the utilization rate of mixtures is improved. The value of A (CO)/ is minimum at the heating rate of 20 K min(-1), combustion effect of mixtures is best, and the burnout rate is highest. RMS and MR values are used to evaluate the mutual influence of the co-combustion process and the study showed that main effects of the interaction occurred in second, third and fourth stages, the second and third stages are the favorable effects, and the fourth stage is the adverse effect and when the mass ratio of the semi-coke and the corn straw is 7:3, the mutual influence is the largest and the beneficial effects. The model of distributed activation energy is applied to analyze co-combustion kinetics of the blends. The results show that activation energy presents a rising tendency during the impelling of reaction, which is unanimous to the change law of DTG and FTIR curves. The results can provide reference for efficient combustion of oil shale semi-coke and corn straw.