The present work investigated the synergetic effect of pyrolysis-derived char

tar and gas (py-gas) on NO reduction

which may occur in circulating fluidized-bed decoupling combustion (CFBDC) system treating N-rich fuel. Experiments were carried out in a lab-scale drop-tube reactor for NO reduction by some binary mixtures of reagents including char/py-gas

tar/py-gas and tar/char. At a specified total mass rate of 0.15 g·min

-1

for NO-reduction reagent

the char/py-gas (binary reagent) enabled the best synergetic NO reduction in comparison with the others. There existed effective interactions between char and some species in py-gas (

i.e

.

H

2

C

x

H

y

) during NO reduction by pyrolysis products

meanwhile the tar/py-gas or tar/char mixture only caused a positive effect when tar proportion was necessarily lowered to about 26%. On the other hand

the synergetic effects were not improved for all tested binary reagents by increasing the reaction temperature and residence time.