Elaboration of new formulations to remove micropollutants in MSWI flue gas

This study consists in identifying and testing potential inorganic substitutes to carbon based materials commonly used as adsorbents for the removal of organic pollutants such as dioxins and furans released from Municipal Solid Waste Incinerators (MSWI). Although carbon materials enable to reach the current regulation in terms of dioxins and furans emissions, they exhibit a potential auto ignition risk when present in hot flue gases. Here, the adsorption potential of carbon based products is compared to the one of some inorganic materials. Chlorobenzene was chosen as a reference molecule to compare the removal performance of the different adsorbents. This comparison was based on the determination of the adsorption energies derived from temperature programmed desorption (TPD) experiments. In the first part of this study, five inorganic materials were selected according to their chlorobenzene adsorption performance compared to those of carbon based products currently used to remove micropollutants from MSWI flue gases. In the second part of the study, the influence of the inlet concentration of adsorbate on the adsorption potential of sorbents is investigated. Actually, the organic compound concentration was decreased in order to be closer to those met in MSWI. Furthermore, the adsorption experiments were performed with other adsorbates whose molecular mass or chlorine content are higher. Thanks to these adsorption results a new organic free formulation has been proposed for the removal of micropollutants. Tests carried out on an industrial scale, demonstrated that this product enables to reach the current norm concerning dioxins and furans emissions. (C) 2004 Elsevier Ltd. All rights reserved.