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1 Department of Chemical and Biochemical Engineering, Technical University of Denmark 2 CHEC Research Centre, Department of Chemical and Biochemical Engineering, Technical University of Denmark 3 Ecosystems Programme, Department of Chemical and Biochemical Engineering, Technical University of Denmark 4 Roskilde Universitet
The chemistry taking place in a high temperature char bed used for binding aromatic tar compounds has been studied in detail. 13C labelled tar compounds were used to trace the incorporation into the char bed using isotope ratio mass spectrometry (IRMS) and GC-MS. Furthermore, compounds labelled with 2H (deuterium) were used to support proposed reaction mechanisms. It was found that at 700-800 °C the aromatic tar compounds bind irreversibly to the char by a radical reaction and, hence, become an integrated part of the char. Thermally induced reactions may occur prior to the binding reaction. The findings explain the tar reducing properties of the char bed in two-stage gasifiers. A living char bed for hot gas cleaning is discussed. © 2014 Elsevier B.V.
Journal of Analytical and Applied Pyrolysis, 2014, Vol 107, p. 174-182
Char; Deuterium labelling; Hot gas cleaning; Mass spectrometry; Aromatic compounds; Binding sites; Isotopes; Reaction kinetics; Tar; Isotope ratio mass spectrometry; Reaction mechanism; Thermally induced reactions; Two-stage gasifiers; Deuterium compounds; 13C-labelling
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