Influence of limestone addition on the behaviour of NO and N2O during fluidised bed coal combustion

The effect of CaO on emissions of nitric oxide from a fluidised bed combustor

“…reducing or oxidising) are important, particularly with regard to the resulting [CO] in the bed, and also the presence of possible catalytic surfaces. This dependence of [NO x ] on the overall stoichiometry of a fluidised bed combustor has been noted before [46], so that whether the bed is fuel-rich or lean can lead to decreases or increases in the emissions of NO x .…”

“…which seems to be an accepted [44][45][46] reaction, as reviewed by Johnsson [25]. In fact, there is evidence in Fig.…”

Experimental investigations of the conversion of fuel-N, volatile-N and char-N to NOx and N2O during single coal particle fluidized bed combustion

“…Many factors influencing the NOx and the N 2 O emissions have been investigated widely in the past two decades, such as temperature [1e6], operating pressure [1,5], excess combustion air [1e3,7], air staging [1e3, 7,8], reburning [1,9,10], catalyst [9,11,12], limestone [2e4,7], char [9,11,13], coal type [2,6,14], coal particle size [3], co-combustion of coal with other fuel [11,15e18]. The influence of operating parameters of the circulating fluidized bed on the N 2 O emission was studied by [2]; and they found that the relative impact can be given by the relation: temperature > excess air, primary air split > limestone feed.…”

N2O decomposition over the circulating ashes from coal-fired CFB boilers

“…Both carbon or char particles and circulating ashes play catalytic effect on N 2 O decomposition. Nevertheless, N 2 O formation rate is larger than the destruction rate, so the concentration of N 2 O increases with height of furnace [17,27]. It was also found that the flue gas composition such as CO 2 , H 2 O, O 2 , CO and SO 2 are also important for N 2 O homogeneous reaction [27].…”