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In this study torrefied feedstocks, consisting of mixed wood and wood residues torrefied at 300°C and ash wood torrefied at 250 and 265°C, were pyrolyzed in a pyroprobe at five pyrolysis temperatures (600-1000°C) and a fast heating rate (600°C•s −1) to investigate the effect of torrefaction on the formation of volatiles and their evolution in a 100 kW circulating fluidized bed gasifier. Results showed that torrefaction converted mostly the hemicellulose content of feedstocks. Furthermore, torrefaction resulted in decreasing the bio-oil and gas yields, increasing the char and phenol yields and not affecting the polyaromatic hydrocarbons yield. Phenol and naphthalene showed the largest yield at 600-700°C and 800-1000°C, respectively. At such high temperatures, the rest polyaromatic hydrocarbons showed yields similar to phenol's. At 900°C torrefaction affected mainly the phenolic species, with 4-propyl-phenol being the dominant species of its group for mixed wood and wood residues feedstock. In the gasifier, H 2 and CO 2 yields increased, CH 4 yield remained constant, and CO yield depended on tar conversion and oxidation and steam reactions. The phenol and naphthalene yields further decreased and increased, respectively, whereas, polyaromatic hydrocarbons did not change in the gasifier.

Furfural is a very promising product of lignocellulosic biomass‐based biorefineries and has the potential to become a useful resource for further conversion and utilization. Aquatic plants show an enormous potential as feedstock since they do not compete for land use, and they require minimal water consumption in a biorefinery concept due to their very high water content. This work is focused on experimental studies of furfural production from water hyacinth (Eichhornia crassipes) by means of aqueous, acid‐catalyzed dehydration. The temperature range of the process, and the acid and seawater presence were chosen based on the previous relevant studies. The aim of the study was to determine whether water hyacinth is suitable for furfural production. The experiments were performed between 160°C and 200°C with a water hyacinth concentration of 2 wt%. The results suggest that the effects of acid catalyst presence on biomass dehydration are similar to the case of pure pentose dehydration. Furthermore, the addition of seawater did not have a positive catalytic effect in terms of the furfural yield. The maximum yield was 53.2 mol% based on the C5 sugar content in the original biomass. The furfural yield of 7.9 wt% of water hyacinth input was comparable to the yield of feedstocks such as corn cob, bagasse, and oat's residue and higher than the cases of rice straw or hulls. Thanks to the comparatively high pentose potential, water hyacinth shows promising results as a candidate feedstock for furfural production. A certain variability of pentosan should be taken into account, as the chemical composition of the plant depends on the source and harvesting seasons.

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