EXPERIMENTAL INVESTIGATION ON THE CHARACTERISTICS OF CO-COMBUSTION OF RICE STRAW WITH STONE COAL

Co-firing rice straw with stone coal, which is a low rank coal with ash content 50-80% and calorific value 3.2-12.93MJ/kg ( on air dry basis), is considered to be a potential method for utilizing 61.87 billions tons of stone coal in China in the near future. In order to understand co-combustion characteristics of rice straw/stone coal blends under different conditions, some experiments were conducted in a thermogravimeter under atmosphere and parameters describing combustion dynamics of the blends, such as activation energy, ignition temperature, burnout characteristics, maximum weight loss rate etc. were obtained. The results show that both of ignition temperature and burnout temperature of the blends decrease promptly when the ratio of rice straw to stone coal increases from 10% to 40%. This implies that co-firing rice straw with stone coal can remarkably improve ignition and burnout performance of stone coals.