Steam explosion pretreatment of willow grown on phytomanaged soils for bioethanol production

•The steam explosion of phytoremediation metal-rich willow was studied.•The heavy metals distribution in the fractions of the process was examined.•The impact of the metals on the enzymatic hydrolysis and fermentation into ethanol was studied. A steam explosion (SE) process was evaluated as a pretreatment method to achieve simultaneously the pretreatment and the decontamination of trace elements (TE) from woody biomass for bioethanol applications. The willow biomass used in this study was obtained from short rotation coppice phyto-managed plots harvested on a TE-contaminated soils (Zn, Mn). The influence of the SE reaction severity on the composition of the cellulosic pulp and on the TE extraction in the water effluent was investigated. SE performed at 220 °C after a 2% sulfuric acid presoaking allowed an extraction of ̴ 80% of Mn and Zn in the water effluent. The enzymatic hydrolysis of the resulting pulps was examined. A cellulose-to-glucose conversion of ˜80% was obtained after 75 h of incubation of the pulp obtained after a SE treatment performed at 180 °C. The subsequent fermentation into ethanol using Saccharomyces cerevisiae was successfully performed. No significant influence of TEs on the action of the biocatalysts (enzymes and yeast) was observed.