Effect of Extractive Solvents on Bio – Oil Production From Microalgae via Hydrothermal Liquefaction

Abstract

Bio–oil from spirulina sp. is complicated mixture with valued chemicals. The hydrothermal liquefaction (HTL) converts directly the spirulina microalgae into liquid oil at reaction temperature 300°C with heating rate 10°C /min,100 bars pressure and 30 min. reaction time eight different organic solvents with different polarities were applied to extract the bio – oil from these chemicals. The order of bio–oil extraction yield of the eight solvents from high to low were as follow tetrahydrofuran (THF) ˃ dichloromethane (DCM) ˃ acetone (ACE) ˃ chloroform (CHL) ˃ methanol (MeOH)˃ ethyl-acetate (EAC) ˃ hexane (HEX) ˃toluene (TOL).The results obtained from single stage extraction process showed that maximum percentage oil yield was (26.55%). with rather high heating value (HHV ≈ 30 MJ/kg). The combination of THF, EAC and n-hexane was selected to extract and separate the bio – oil into three fraction heavy oil (48.9%) mid weight oil (37.8%) and light oil (62.2%). These three oils were characterized using gas chromatography mass spectrum (GC – mass).

Keywords:- Bio–oil , extractives, hydrothermal , liquefaction, micro- algae.