Characterization of Coal Combustion in a Hot and Diluted Environment Using a Surface-Stabilized Gas Natural Flame

摘要

In this study a surface-stabilized flat flame burner has been evaluated for burning pulverized coal samples. The aim of this research was to emulate operating conditions similar-to those usually found in moderate or intense low oxygen dilution (MILD) combustion of coal, including high temperature and low oxygen environment. The iexperimental setup decouples chemical kinetics from complex processes as aerodynamics phenomena. Additionally, it does,not require oxygen nitrogen mixture,preparation or electrical heaters. In a first stage, both simulations and experiments were-done-With natural gas, testing, several lean equivalence ratios and unburned gas velocities in the burner to obtain a hot and diluted environment. Then, in a second stage, the coal was suspended at a fixed distance-from the burner surface in, 4 and 8% v/v oxygen levels. The obtained results show quantitative evolution profiles for CO, CO2, O-2, and NO, as well as, N and C releases during the combustion of coal emulating the MILD Combustion conditions. This approach is an option for tracking combustion products and physicochemical changes of the solid fuel during reactions, such as those that take place in coal MILD combustion.