Estimation of Flame Temperature and Alkali Emission During the Combustion of Sugarcane Bagasse in Laboratory in Combustion Chamber Type Grate Using Spectroscopy Method

Knowing the temperature of the combustion of solid biomass residues and how alkaline gases must be supplied during combustion is an area currently under study in the international community. The correlation between temperature and concentration of alkaline gases in the combustion phases is an open research for some types of biomass, among which sugarcane bagasse. This information optimizes the operation of thermoelectric boilers that use solid biomass waste as fuel, improving its efficiency and maintenance costs. The aim of the study was to estimate the temperature of the flame during the combustion of sugarcane bagasse in a pilot chamber that simulates burning in a grid, as well as an estimate of the potassium concentration in the flue gases. Temperature estimates were made using the two-color spectrometry technique in the visible light range. The potassium concentrations in the flue gases were estimated through analysis of the emission lines present in the electromagnetic spectra collected by a spectrometer for different combustion temperatures. In the experiments, the biomass flame was of the diffusion flame type. Considered the combustion phases - devolatilization, char combustion and ash formation - temperature were varying in the range of 1000 K to 1700 K. The average emission of potassium in the flue gases was evaluated in the range of 0.126 ppm to 0.631 ppm, considering the combustion phases. For the combustion conditions, no alkaline sodium gases were detected.