EXPERIMENTAL STUDY ON THERMAL BEHAVIOR OF COAL AND MINERAL IN O2/CO2 COMBUSTION

摘要

O2/CO2 recycle combustion (oxy-fuel combustion) is one of several promising new technologies associated with mitigating the CO2 rise in the atmosphere. This paper presents an experimental study on the thermal behavior of three coals and their low temperature ash (LTA) in air and O2/CO2 mixture atmospheres with focus on the inorganic mineral element vaporization. The thermal behavior of the coal and LTA samples exhibit typical four weight loss stages obviously, including: the elimination of physically adsorbed water, releasing of volatile matter, combustion of the carbonaceous materials, transformation of mineral and vaporization of mineral elements. The mineral element vaporization amount increases with the increasing temperature. The carbon in coal has little effect on mineral elements vaporization comparing with LTA. The total mineral element vaporization amount is higher in O2/N2 atmosphere than in O2/CO2 atmosphere. with the increase of heating-up rate from 20°C/min to 50°C/min, the total vaporization amount also exhibit an obviously increase.