In situ catalyst-free biodiesel production from partially wet microalgae treated with mixed methanol and castor oil containing pressurized CO2

摘要

The production of microalgae-derived biodiesel without catalyst from partially wet microalgae (Chlorella vulgaris) by in situ cell disruption, extraction, and transesterification using methanol mixed with castor oil containing pressurized CO2 was investigated. The effects of the operating variables on the yield of fatty acid methyl ester (FAME) were systematically examined. The addition of non-edible castor oil was observed to reduce operation pressure and time. Under the most appropriate conditions as a microalgae amount of 10 g containing 20 wt% water, a methanol-to-biomass ratio of 1.5 (g/g), a castor oil amount of 4.5 g, a temperature of 220 degrees C, a pressure of 9.7 MPa and a time of 30 min, the microalgae and castor oil FAME yields were 61.4% and 63.3%, respectively. The obtained results revealed that the proposed means could reduce energy and chemical waste because of higher water tolerance, lower methanol-to-microalgae ratio, lower operation pressure and shorter operation time. (C) 2019 Elsevier B.V. All rights reserved.