11 research outputs found
Hydrotreatment of Supercritical Carbon Dioxide Extracts of Hydrothermal Liquefaction Lignocellulosic Biocrude
Raw lignocellulosic biocrude produced by hydrothermal
liquefaction
and its supercritical carbon dioxide extract (SE) were hydrotreated
at 350–405 °C and for 2–6 h utilizing commercial
CoMo and NiMo catalysts. The hydrotreatment reduced the oxygen content
of the SE down to 1.6 wt %, while the minimum oxygen content of the
hydrotreated biocrude (HBC) was 3.1 wt %. No coke formation was observed
in the hydrotreatment of the SE, while the yield of coke was 13 wt
% when processing the raw biocrude. The hydrotreated SE (HSE) samples
exhibited molecular weights 24–61% lower than that of the HBC
samples, with larger low-boiling fractions (up to diesel). The better
quality of the HSE and the absence of coke, together with the lower
metal content of SE (0.2 g/kg) versus BC (8.5 g/kg), suggest that
the implementation of hydrotreatment on SEs, instead of raw lignocellulosic
biocrude, is a promising option