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S Abanades

Publications and source records attributed to S Abanades.

7 recordsLinked to original sources
PubMed2005

Development of an inverse method to identify the kinetics of heavy metal release during waste incineration in fluidized bed.

This paper deals with the emission of heavy metals (HM) during the incineration of municipal solid waste in a fluidized bed reactor. This study focused on the development of a general method to identify the kinetics of vaporization of heavy metals from the on-line analysis of exhaust gas. This method is an inverse method, which requires only the time evolution of the HM concentration in exhaust gases (experimental data) and a global bubbling bed model developed for transient conditions at the reactor scale. First, a lab-scale fluidized bed incinerator was set-up to simulate the HM release during the thermal treatment of metal-spiked model wastes. A specific on-line analysis system based on ICP-OES was developed to measure in real time the variation of the relative concentration of HM in exhaust gases. Then, a two-phase flow bubbling bed model was developed and validated to calculate the kinetics of vaporization of HM from its measured concentration time profile in the outlet gas. The technique was first validated with model waste (metal-spiked mineral matrices), thus enabling at each time both solid sampling for measuring the HM vaporization kinetic and on-line analysis for measuring the HM concentration in the outlet gas. The inverse method was then applied to realistic artificial wastes (derived from real wastes) to identify the HM vaporization kinetics from the on-line analysis results.

Aluminum Oxide↗
PubMed2005

[Metamphetamine].

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Amphetamines↗
PubMed2004

Volatilization of heavy metals during incineration of municipal solid wastes.

Incineration experiments with MSW, which had been impregnated with heavy metals, were presented to obtain information on the volatilization behavior of the elements cadmium(Cd), lead (Pb), and zinc (Zn) under different conditions. Experiments were carried out in a bubbling fluid bed system connected to a customized inductively coupled plasma optical emission spectroscopy (ICP-OES) for analyzing metals in the flue gas. The results indicated that the combustion temperature, the gas atmosphere, and the chlorine content in the flue gas could affect the volatilization behavior of heavy metals. In the fluidized bed combustion, a large surface area was provided by the bed sand particles, and they may act as absorbents for the gaseous ash-forming compound. Comparer with the metals Cd and Pb, the vaporization of Zn was low. The formation of stable compounds such as ZnO x Al2O3 could greatly decrease the metals volatilization. The presence of chlorine would enhance the volatilization of heavy metals by increasing the formation of metal chlorides. However, when the oxygen content was high, the chlorinating reaction was kinetically hindered, which heavy metals release would be delayed.

Air Pollutants↗
PubMed2002

Fate of heavy metals during municipal solid waste incineration.

A thermodynamic analysis was performed to determine whether it is suitable to predict the heavy metal (HM) speciation during the Municipal Solid Waste Incineration process. The fate of several selected metals (Cd, Pb, Zn, Cr, Hg, As, Cu, Co, Ni) during incineration was theoretically investigated. The equilibrium analysis predicted the metal partitioning during incineration and determined the impact of operating conditions (temperature and gas composition) on their speciation. The study of the gas composition influence was based on the effects of the contents of oxygen (reducing or oxidising conditions) and chlorine on the HM partitioning. The theoretical HM speciation which was calculated in a complex system representing a burning sample of Municipal Solid Waste can explain the real partitioning (obtained from literature results) of all metals among the various ashes except for Pb. Then, the results of the thermodynamic study were compared with those of characterisation of real incinerator residues, using complementary techniques (chemical extraction series and X-ray micro-analyses). These analysis were performed to determine experimentally the speciation of the three representative metals Cr, Pb, and Zn. The agreement is good for Cr and Zn but not for Pb again, which mainly shows unleachable chemical speciations in the residues. Pb tends to remain in the bottom ash whereas thermodynamics often predicts its complete volatilisation under chlorides, and thus its presence exclusively in fly ash.

Air Pollutants↗
PubMed2001

Modelling of heavy metal vaporisation from a mineral matrix.

This study deals with the fundamental aspects of the volatilisation of heavy metals (HM) during municipal solid waste (MSW) incineration. The thermal treatment of a model waste was theoretically and experimentally studied in a fluid-bed. A mathematical model was developed to predict the fate of metallic species according to the main phenomena controlling the process: heat and mass transfer (transport phenomena), chemical reactions involving HM, and mechanism of vapour metal species sorption inside the porous matrix. The model assumes local thermodynamic equilibrium between the vapour and the metal compound on the substrate in the pores of a particle. This approach permits to predict the extent of HM vaporisation from a mineral porous matrix when its physical properties are known. Experimental data concerning CdCl(2) release from an alumina matrix in a 850 degrees C fluidised bed are in good agreement with theoretical results.

Air Pollutants↗