Effect of O2/CO2 concentration on characteristics of four bituminite char gasification reaction

The article chooses 3 kinds of high ash fusion coal and one kind of low ash fusion coal for exploring the technology of entrained flow coal gasifieres dry ash out. Isothermal thermogravimetry is used for experiment to study the characteristics of combustion and gasification reaction of coal char-O-2 and coal char-CO2. Effect of concentration alternation of O-2 and CO2 on combustion and gasification reaction velocity, rate of C conversion and kinetic parameters of 4 kinds of coal has been studied. The results show that apparent activation energy is influenced by lots of factors, all of which are good for forward reactor between coal chars and gasifying agents can decrease apparent activation energy of coal char. Bituminous coal is used in experiment. HN coal char-CO2 gasification reaction transition temperature from dynamical area to diffusion area is 1100 degrees C. Effect of O-2 and CO2 concentration on apparent activation energy is larger when the temperature is over 1200 degrees C, which is the higher concentration of O-2 and CO2 the lower of apparent activation energy. It is the same effect of concentration on coal char frequency factor. Combustion reaction velocity of O-2 is higher than gasification reaction velocity of CO2 for 4 kinds of coal char when the temperature is 1200 degrees C. Coal char combustion and gasification reaction velocity is increasing along with the increase of O-2 and CO2 concentration.