Production of Bio-Crude Oil from Microalgae Chlorella sp. Using Hydrothermal Liquefaction Process

Currently, microalgae have attracted as potential feedstock for biofuel production. Hydrothermal liquefaction was proposed as technology to convert microalgae into bio-crude oil. Microalgae used in this study was Indonesia-cultivated Chlorella sp., This work investigated the effect of temperature (200°C, 225°C, 250°C), biomass weight-water ratio (1:20, 2:20, 3:20), and residence time (10, 20, 30 minutes) on bio-crude oil yield of non-catalytic hydrothermal liquefaction. The highest bio-crude oil yield was 2.25%, obtained at temperature of 250°C biomass weight-water ratio of 1:20, and residence time of 10 minutes. The highest component of bio-crude oil was alcohols. The low bio-crude oil yield was caused by the longer residence time of cooling step (driving gas conversion), low amount of carbon-hydrogen content and high amount of oxygen-ash content in biomass. Furthermore, the highest component of bio-crude oil was alcohols, stimulated by low carbon content coupled with high oxygen content in Chlorella sp.