Influence of gas-staging on pollutant emissions from fluidized bed oxy-firing

A review of oxy-fuel combustion in fluidized bed reactors

“…Stream staging was reported to be an effective way for NO emission control in a CFB unit. Similar result was observed for oxy‐BFB reactors by Lupiáñez et al , but the flow rate of the secondary gas was lower.…”

“…Also, the addition of limestone (L2) leads to a significant increase in NOx emission; these findings were reported to be similar to those of de Diego et al who observed that the addition of limestone in an FB boiler significantly reduces SO 2 and N 2 O while increasing NOx emission. More recently, the same authors reported the effect of gas‐staging on CO, NOx and SO 2 emissions in air combustion and oxy‐combustion conditions for lignite and anthracite .…”

“…Air‐staging was reported to influence the fluid dynamics and other combustion characteristics, such as combustion efficiency and/or desulfurization. Lupiáñez et al observed staged air to have no influence on unburned carbon rates in the solid residues, which were successively taken in a fall chamber, a cyclone and a bag filter. In their air staging evaluations where two secondary gas inlets were introduced at different heights.…”

NOx and SO2 emissions of coals, biomass and their blends under different oxy-fuel atmospheres

“…Fuel-NO is formed from the oxidation of molecular nitrogen organically bound within the fuel mass (Lupi añez et al, 2014). Fuelbound nitrogen can either be released during devolatilisation (referred to as volatile-N), or can remain in the char (referred to as char-N) (Shaddix and Molina, 2011).…”

Study on the combustion and NOx emission characteristics of low rank coal in a circulating fluidized bed with post‐combustion

“…Conventional methods for regulating NO x emission generated from combustion primarily involve the reduction of combustion temperature, enhancement of secondary air staging, and control of the air stoichiometric ratio ( λ ) in the furnace . These methods, however, are not equipped to establish the CFB boiler's capability of meeting the new standard with respect to NO x emission.…”