Hydrothermal treatment of lignocellulosic biomass in sub and supercritical water: Product identification

Hydrothermal treatment has been known as one of the most promising techniques to upgrade lignocellulosic biomass via liquefaction process. In this work, Hinoki cypress sawdust as a model lignocellulosic biomass was liquefied by hydrothermal technique at temperatures of 350 to 400 °C for 10 to 30 min reaction time. The liquefaction process was carried out in a batch process, and the Hastelloy tube (5 mL) was employed as a reactor. The gas chromatography mass spectrometer (GC-MS) exhibited that catechol, phenol, guaiacol, and p-cresol existed in water soluble part; whereas the gas chromatography thermal conductivity detector (GC-TCD) apparatus found hydrogen (H2), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), ethene (C2H4), ethane (C2H6), propylene (C3H6), and propane (C3H8) in the gaseous products. Next, although the hydrothermal treatment successfully liquefied the Hinoki cypress sawdust, more research works were entailed that is more appropriate for industrial-scale applications. Nevertheless, according to the results, it can be offered that the technique presented herein is usable technique for advanced lignocellulosic biomass liquefaction using the employing water at sub and supercritical circumstances.