Mercury emissions are major environmental and regulatory concerns due to the toxic. nature of mercury and the significant ever increasing amounts of this pollutant released into. the atmosphere by various natural and anthropogenic sources. Cleanup technologies available. to control mercury emissions include wet scrubbing and adsorption on dry sorbents. The latter. does not pose any problem of treating and inertizing liquid waste streams thus being very. attractive for both small and large combustors such as those used for the incineration of. hospital wastes or urban wastes, respectively. Particularly, activated carbon adsorption is a. technology that offers a great potential for the control of gas-phase mercury emissions. This. research group has already carried out several studies on mercury adsorption, both in metallic. and divalent form, on a laboratory scale apparatus, by using activated carbon, even. impregnated. This time a new pilot-scale apparatus, in which a spray-dryer reactor, used in. this research as a column with cyclone effect, is used to adsorb metallic mercury. The. simulated flue gas is obtained by evaporating liquid mercury (reagent grade Hg0 from BDH). contained in a thermostated glass saturator into an air stream. The solid sorbent is powdered. activated carbon, injected in column to be available for the gas phase. The exhaust gas exiting. from the reactor is then forced to pass through a fabric filter.. The main purpose of the present paper is the study of metallic mercury adsorption. phenomena by using a commercially available activated carbon (Norit DARCO FGD). The. experimental results have been obtained by varying the following parameters in the indicated. range: reactor temperature (Tr, 80 to 120°C); initial mercury concentration (cHg. in, 100 to 200. ��g\\\/m3); carbon flowrate (Mc, 15.5 to 110.0 g\\\/h) while the initial total gas flowrate was kept. constant (Qt= 52.30 m3\\\/h).. The main results obtained in this study show that mercury adsorption efficiency is higher. at lower temperature, and that mercury removal efficiency up to 80% can be obtained for. carbon concentrations in the range 0.3 to 2.1 g\\\/m3. Moreover, the exhaust gas flowrate after. fabric filter crossing, reaches mercury concentrations close to zero, in any case below the law. imposed emission limits.
A pilot scale plant application for the removal of elemental mercury by activated carbon
MUSMARRA, Dino;
2011
Abstract
Mercury emissions are major environmental and regulatory concerns due to the toxic. nature of mercury and the significant ever increasing amounts of this pollutant released into. the atmosphere by various natural and anthropogenic sources. Cleanup technologies available. to control mercury emissions include wet scrubbing and adsorption on dry sorbents. The latter. does not pose any problem of treating and inertizing liquid waste streams thus being very. attractive for both small and large combustors such as those used for the incineration of. hospital wastes or urban wastes, respectively. Particularly, activated carbon adsorption is a. technology that offers a great potential for the control of gas-phase mercury emissions. This. research group has already carried out several studies on mercury adsorption, both in metallic. and divalent form, on a laboratory scale apparatus, by using activated carbon, even. impregnated. This time a new pilot-scale apparatus, in which a spray-dryer reactor, used in. this research as a column with cyclone effect, is used to adsorb metallic mercury. The. simulated flue gas is obtained by evaporating liquid mercury (reagent grade Hg0 from BDH). contained in a thermostated glass saturator into an air stream. The solid sorbent is powdered. activated carbon, injected in column to be available for the gas phase. The exhaust gas exiting. from the reactor is then forced to pass through a fabric filter.. The main purpose of the present paper is the study of metallic mercury adsorption. phenomena by using a commercially available activated carbon (Norit DARCO FGD). The. experimental results have been obtained by varying the following parameters in the indicated. range: reactor temperature (Tr, 80 to 120°C); initial mercury concentration (cHg. in, 100 to 200. ��g\\\/m3); carbon flowrate (Mc, 15.5 to 110.0 g\\\/h) while the initial total gas flowrate was kept. constant (Qt= 52.30 m3\\\/h).. The main results obtained in this study show that mercury adsorption efficiency is higher. at lower temperature, and that mercury removal efficiency up to 80% can be obtained for. carbon concentrations in the range 0.3 to 2.1 g\\\/m3. Moreover, the exhaust gas flowrate after. fabric filter crossing, reaches mercury concentrations close to zero, in any case below the law. imposed emission limits.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
