Simulation of mercury capture by activated carbon injection in incineratorflue gas. 1. In-duct removal

Authors
Citation
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
Journal title
ENVIRONMENTAL SCIENCE & TECHNOLOGY
ISSN journal
0013936X → ACNP
Volume
35
Issue
21
Year of publication
2001
Pages
4367 - 4372
Database
ISI
SICI code
0013-936X(20011101)35:21<4367:SOMCBA>2.0.ZU;2-Z
Abstract
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.