Modeling of entrained flow mercury adsorption on sorbents

With the recent regulations regarding mercury emissions, many power plants have begun investigating sorbent injection as means of mercury removal. A computer program has been developed to investigate elemental mercury adsorption in an entrained flow scenario. Input parameters include: sorbent particle radius, feeding rate, reactor residence time, porosity, average pore diameter, and adsorption/desorption constants. The model employs a central differencing method of lines to generate spatial discretized concentrations. These results allow external and internal mass transfer effects to be determined along with total mercury adsorption. This paper will discuss the estimated effects of internal vs. external particle mass transfer as a function of the sorbent and reactor conditions.