[en] Highlights: • None of the additives show the tendency to As, Ni, Sb and Zn capture in the ash. • Ammonium sulphate captures and immobilises Cr and Cu in the bottom ash. • Halloysite is effective in Cd, Co, V and Mn capture in the bottom ash. • Kaolinite is the most effective in Pb capture. -- Abstract: Up to now, a few studies on the efficiency of heavy metal(-oid)s capture by a sorbent directly mixed with fuel, have been performed. For this reason, the main objective of the study is to determine whether or not such a solution is effective when RDF is incinerated. The paper presents a two-step analysis of the impact of three sorbents (ammonium sulphate, kaolinite and halloysite) in three dosages (2, 4 and 8 wt%) on heavy metal(-oid)s retention in the bottom ash. 12 heavy metal(-oid)s were taken into consideration - As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, V and Zn. Samples were incinerated in a lab-scale tubular reactor at two temperatures - 900 °C and 1100 °C. The first step of investigation constitutes ICP analysis of heavy metal(-oid)s content in the bottom ash, coupled with SEM/EDS analysis. Afterwards, the second step was to determine the stability of formed additive-heavy metal(-oid)s complexes via leachability tests in neutral and acid environments. The performed research has shown that ammonium sulphate is effective in Cr, Cu and Hg capture, halloysite – in Cd, Co, V and Mn capture, whereas kaolinite – in Pb capture.

[en] Highlights: • The higher temperature, the more diverse condensates composition. • The condensates contain phenols, furans and LCFA, considered to be toxic or/and inhibitory for anaerobic bacteria. • Regardless of the torrefaction temperature, the condensates appear to be highly toxic for the tested organisms. • The assessment of the condensate's toxicity only on the basis of the furans and phenols contents is unlikely to be accurate. -- Abstract: Until now, few studies on the valorisation of torrefaction condensable volatiles (condensates) have been performed. The composition and toxicity of torrefaction condensable volatiles determine their possible applications. Therefore, a study on the composition of wheat-barley straw torrefaction condensates, combined with toxicity tests, was performed. This analysis was mainly aimed at the utilisation of these condensates as an anaerobic digestion substrate. The torrefaction process was performed in a batch-scale reactor at temperatures from 240 °C to 320 °C. The condensates were analysed using GC/MS, and quantitative analysis was based on the calibration curves (external standard method). Toxicity tests were performed for vascular plants (Lemna sp. Growth Inhibition Test), saltwater bacteria (Microtox® bioassay) and freshwater crustaceans (Daphtoxkit F magna® survival bioassay). The condensates were classified as highly toxic for the tested organisms. Compounds that are inhibitory and/or toxic to anaerobic bacteria were detected in the samples, e.g. furfural, guaiacol, palmitic acid and oleic acid. Taking into account the condensates’ high toxicity for the tested organisms and the presence of anaerobic digestion process inhibitors, there is a significant likelihood that prior detoxification of the condensates is necessary before they can be utilised as anaerobic digestion substrates.