Oxy-combustion of low-volatility fuel with high water content

Fundamental study on oxy-combustion of high water content fuels is continued from our previous work. In this study, the investigation focuses on low-volatility fuel. Glycerol is chosen as the candidate. It is found that self-sustained flame can only be obtained for glycerol solution with concentrations as high as 60 wt%, even burned in pure oxygen. However, the flame is lifted away from the nozzle. t-Butanol and ethanol, as high-volatility fuels, were added into low-concentration glycerol solutions to assist the combustion. Experiments showed that attached flame can be obtained by burning the mixture containing 8.3 wt% t-butanol, 30 wt% glycerol and 61.7 wt% water (B8.3/G30) or 10 wt% ethanol, 30 wt% glycerol and 60 wt% water (E10/G30) under oxy-fired condition. The flame stability for B8.3/G30 and E10/G30 was characterized under 100% and 85% swirl flow conditions. Temperature measurements were conducted for stable flames under 4 different conditions and temperature contours were generated. For stable flames, a hot zone exists in near burner region, which provides heat to robustly vaporize the high water content fuels in order to stabilize the flame..