title: A comparison of devices using thermal desorption for mercury speciation in solids.
abstract: The goal of this work is to emphasize the reliability of the thermal desorption technique in identifying mercury species. The analysis of mercury species in solids is essential for assessing the risk of disposal or re-use of mercury-contaminated materials. This study evaluates the accuracy and reliability of thermal desorption as a technique for identifying mercury species by means of different thermo-desorption devices. For this purpose, mercury species present in samples related with coal utilization processes were identified. Three devices were compared for analyzing samples free of carbon or with a low carbon content (fly ashes, gypsums and soils), and a new equipment was developed to analyze samples with a high carbon content (coal). In spite of the fact that the first three devices employ different experimental conditions (i.e., heating rate, gas flow and carrier gas), the mercury species identified in the samples were comparable in all cases. The need for new equipment for mercury speciation in materials containing carbon was a consequence of interferences produced from the pyrolysis products of the organic matter. The new device consists of two furnaces and two gas inlets to allow thermal oxidation of organic pyrolysis products and the identification of mercury species in carbonaceous samples. This new approach offers the application of thermal desorption to mercury speciation in all types of materials contaminated with mercury.
authors.affiliation: Instituto Nacional del Carbón (CSIC), Francisco Pintado Fe, 26, 33011 Oviedo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Rumayor
authors.affiliation: Instituto Nacional del Carbón (CSIC), Francisco Pintado Fe, 26, 33011 Oviedo, Spain. Electronic address: marian@incar.csic.es.
authors.forename: M A
authors.initials: MA
authors.lastname: Lopez-Anton
authors.affiliation: Instituto Nacional del Carbón (CSIC), Francisco Pintado Fe, 26, 33011 Oviedo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Díaz-Somoano
authors.affiliation: Centre for Innovation in Carbon Capture and Storage (CICCS), School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom.
authors.forename: M M
authors.initials: MM
authors.lastname: Maroto-Valer
authors.affiliation: Technische Universität Braunschweig, Institut für Geoökologie, Langer Kamp 19c, 38106 Braunschweig, Germany.
authors.forename: J-H
authors.initials: JH
authors.lastname: Richard
authors.affiliation: Technische Universität Braunschweig, Institut für Geoökologie, Langer Kamp 19c, 38106 Braunschweig, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Biester
authors.affiliation: Instituto Nacional del Carbón (CSIC), Francisco Pintado Fe, 26, 33011 Oviedo, Spain.
authors.forename: M R
authors.initials: MR
authors.lastname: Martínez-Tarazona
keywords: Coal; Mercury; Speciation; Thermal desorption