Dioxins and furans in biochars, hydrochars and torrefcates produced by thermochemical conversion of biomass: a review

0574070 - ÚCHP 2024 RIV DE eng J - Journal Article
Sobol, L. - Dyjakon, A. - Soukup, Karel
Dioxins and furans in biochars, hydrochars and torrefcates produced by thermochemical conversion of biomass: a review.
Environmental Chemistry Letters. Roč. 21, č. 4 (2023), s. 2225-2249. ISSN 1610-3653. E-ISSN 1610-3661
Institutional support: RVO:67985858
Keywords : hydrothermal carbonization * torrefaction * pyrolysis
OECD category: Environmental sciences (social aspects to be 5.7)
Impact factor: 15.7, year: 2022
Method of publishing: Open access
https://link.springer.com/article/10.1007/s10311-023-01600-7

Converting raw biomass into valuable products protects the environment, improves economics, and helps tackle climate change by cutting resource demand and waste production. Thermochemical treatment is a common method for producing biochars, hydrochars and torreficates from biomass and organic wastes, which can also generate dioxins and furans and consequently limit the use of thermochemically converted chars. Here we review the presence of dioxins and furans in chars produced by hydrothermal carbonization, torrefaction, and pyrolysis processes under the influence of temperature, residence time, heating rate, pressure, and feedstock type. Dioxins and furans were mostly below 20 ng total toxic equivalence per
kilogram (TEQ kg −1 ), with the highest level of 113 ng TEQ kg −1 found in over 100 samples of different char types. The most toxic products were hydrochars produced from sewage sludge. Processing temperature and feedstock type were key factors resulting in high dioxin levels in chars, and care should be taken when producing chars at temperatures up to 300 °C or using feedstocks previously contaminated with dioxins or preservatives.
Permanent Link: https://hdl.handle.net/11104/0344439