EFFECT OF K3PO4 ON HYDROTHERMAL LIQUEFACTION OF SUGARCANE LEAVES IN ETHANOL-WATER CO-SOLVENT

Abstract

The purpose of this project is to study the production of biocrude derived from hydrothermal liquefaction (HTL) of sugarcane leaves using co-solvent in a semi-continuous flow reactor. Experiments were carried out at a temperature range of 280 - 320 oC with appropriate pressures for 2 hours holding time. The effects of operating parameters, including various flow rates, temperatures, proportion of co-solvent and an addition of alkaline catalyst (K3PO4) on the oil yield were comprehensively investigated. The maximal biocrude1 (dichloromethane-soluble fraction) was roughly 30.63% at a temperature of 300 oC, a flow rate of 0.5 ml/min in mixture of ethanol and water (50/50 v/v) with 1 wt% K3PO4. In contrast, an increase in either catalytic concentration or a flow rate lessened the yield of biocrude1. The similar observation was also recorded in case of pure water with the presence of K3PO4. Besides, the blend of water and ethanol (25/75 v/v) dominated entirely as the most suitable ratio of co-solvent for the HTL in this system, yielding the biocrude1 of 29.47% at 300 oC, a flow rate of 1 ml/min and without the catalyst. As regards the usage of alkaline catalyst, a drastic reduction of acid compounds existed on the ingredient of biocrude1 was also determined by Karl-Fischer titration and total acid number titration. Furthermore, the elemental composition analysis outcomes indicated that the catalyst played a role as the deoxygenating agent, resulting in dwindling the oxygen content and enhancing HHV of the biocrude1. The dispersion of K3PO4 into co-solvent was attributed to both a disappearance of furfural components and an upturn in ester derivatives as apparently depicted by gas chromatography/mass spectroscopy (GC-MS) technique.