Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of\r\nhigh temperature gradient of order 200?C�·s-1 by a CO2 gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser\r\nheating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize\r\neffects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experimental results\r\nindicated that coal weight reduction ratio to gases followed the Arrhenius equation with increasing coal temperature; further which\r\nwere increased around 5% with adding H2O in CO2-rich atmosphere. In addition, coal-water mixtures with different water/coal\r\nmass ratio were used in order to investigate roles of water vapor in the process of coal gasification and combustion. Furthermore,\r\nchar-water mixtures with different water/char mass ratio were also measured in order to discuss the generation ratio of CO/CO2,\r\nand specified that the source of Hydrocarbons is volatile matter from coal.Moreover, it was confirmed that generations of CO and\r\nHydrocarbons gases are mainly dependent on coal temperature and O2 concentration, and they are stimulated at temperature over\r\n1000?C in the CO2-rich atmosphere.
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