RESEARCH METHOD OF RELATIVE CONTRIBUTION OF VOLATILE N AND CHAR N TO N_2O FORMATION BASED ON COAL/CHAR RESPECTIVE COMBUSTION EXPERIMENT:DISCUSSION ON EXPERIMENT AND CALCULATION

During fluidized bed combustion of coal,nitrogen in coal (coal N) is divided into two parts:volatile N and char N,which both make a contribution to N 2O formation.“Coal/Char respective combustion experiment” is one of methods researching the relative contribution of volatile N and char N.But for this method,there are some shortcomings in experimental technique and calculation of relative contribution. It is pointed out that the temperature for char preparation should be the same as that for coal/char combustion experiment and the equipment for coal/char combustion experiment should be exactly the same one as that for char preparation.It is demonstrated that the difference between percent conversion of coal N and that of char N could not be regarded as that of volatile N .For the experimental cases in which more than 90% of N in coal remains in char,the percent conversion and converted amount of N in char formed during coal combustion are larger than those of N in char prepared by coal pyrolysis and the latter char cannot be representative of the former one.