Kinetics of coal oxy-combustion by means of different experimental techniques

A large number of papers reported measures of coal char conversion rate under combustion and gasifi- 30 cation conditions carried. Measures involved a variety of coal and char types, as well as different exper- 31 imental techniques, ranging from TGA to wire mesh reactors and drop tube furnaces. For oxy-combustion 32 with flue gas recirculation the impact of CO2 on the rate of combustion of char combustion is still con- 33 troversial. 34 In the present paper the rate of carbon conversion in O2/CO2 mixtures typical of oxyfuel conditions has 35 been investigated by conventional as well as innovative experimental techniques, respectively isothermal 36 and non-isothermal thermogravimetric analysis and reaction in an aerodynamic levitator particle reactor 37 (ALPR). 38 Results show that the ALPR provides reliable results also at values of temperature and oxygen concen- 39 tration where thermogravimetric analysis fails. Experimental results have been worked out to obtain 40 simple rate expressions for oxy-fuel combustion. Commonly used kinetic laws, however, proved unable 41 to fit experimental results in the whole range of operating conditions