F. Scala, Simulation of mercury capture by activated carbon injection in incineratorflue gas. 1. In-duct removal, ENV SCI TEC, 35(21), 2001, pp. 4367-4372
Citations number
33
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
A detailed model for the in-duct mercury capture in incinerator flue gas by
powdered activated carbon injection is presented. Material balances on mer
cury in both gaseous and adsorbed phases are carried out along the duct len
gth and inside the activated carbon particles, taking into account mass tra
nsfer resistances and adsorption kinetics. The set of the coupled partial d
ifferential equations is transformed by means of an orthogonal collocation
technique and integrated using a Runge-Kutta method with adaptive stepsize
control. The model has been applied to several sorbents of practical intere
st, whose parameters have been evaluated from available literature data. Th
e values and range of the operating variables have been chosen in order to
simulate typical incinerators operating conditions. Results of simulations
indicate that large sorbent loadings in the duct are needed to obtain high
mercury removal efficiencies, due to the short residence times. As a conseq
uence very low utilization of the sorbents is achieved in any case. To mini
mize the sorbent feed rate it is particularly advisable to use a reactive s
orbent and to lower the operating temperature as much as possible. Improvem
ents in the mercury capture performance can be obtained also by increasing
the in-duct particles residence time and by decreasing the sorbent particle
s size. Model results are compared with available relevant full scale data.