Room: Poster Area
Date: Wednesday, 20 May 2026
Time: 16:15 - 17:15 CEST
Session code 4BV.8
Biomass and waste combustion as sustainable strategy for decarbonization
Reduction of Hexavalent Chromium in Ash From Biomass Updraft Gasification Plants
Short Introductive summary
The objective of this work is to reduce hexavalent chromium in ash to levels below the limit (2 mg/kg) set by the European Union regulation for ash to be used as fertilizer. The utilization of biomass ashes on agricultural fields can close mineral cycles and also substitute chemical fertilizers. In this work, different hexavalent chromium reducing agents have been tested: FeCl2, FeSO4 monohydrate and heptahydrate, as well as water only. Different doses of reducing agent have been applied on two ashes with different hexavalent chromium contents, 8 and 44 mg/kg from a commercial and a pilot-scale updraft gasification plant, respectively. The tests have been performed in lab- and pilot-scale. The reducing agents of iron sulphate and iron chloride immediately reduce the Cr VI content significantly. In general, iron sulphate works better than iron chloride. The amount of reducing agent to be added depends on the CrVI content of the ash. The addition of water only has almost no influence on the reduction of Cr VI. Storage time seems to influence the reduction of Cr VI. An increase of Cr VI is observed over time. These results can be explained by means of redox and secondary reactions.
Presenter
Miguel FERNÁNDEZ LLORENTE
CIEMAT, Energy department- CEDER, SPAIN
Presenter's biography
Miguel Fernández Llorente (Master D. in Chemistry and Ph D. in Chemical Engineering) is responsible of Biomass Characterisation Laboratory placed in Soria (CIEMAT) from 1995. He has participated in more than 40 R&D projects and he has written several papers in conferences and international journals.
Biographies and Short introductive summaries are supplied directly by presenters and are published here unedited
Co-authors:
R. Barro, CIEMAT, Soria, SPAIN
K. Supancic, Bios Bioenergiesysteme, Graz, AUSTRIA
I. Obernberger, Bios Bioenergiesysteme, Graz, AUSTRIA
Session reference: 4BV.8.8