Results of pilot experiments are presented on the extraction of microalgae with supercritical CO2.The chromatographic analysis of the extract samples have been conducted. Valuable components have been found in the algae extract.
Synthesis of methyl and ethyl esters of fatty acids via transesterification of vegetable oils in supercritical methanol and ethanol is carried out on a pilot installation with a continuous flow reactor. The corresponding procedures are described, and the results are analyzed. The effect of preliminary ultrasonic treatment of the initial mixture on the product yield is studied, and the correlation between the stability of the obtained emulsions and the composition of the initial mixture, as well as the intensity of the ultrasonic treatment, are determined. The isobaric heat capacity of the supercritical alcohol (methanol, ethanol) — vegetable oil mixtures is measured.
The results of the rapeseed and palm oils transesterification with supercritical methanol and ethanol were presented. The studies were performed using the experimental setups which are working in batch and continuous regimes. The effect of reaction conditions (temperature, pressure, oil to alcohol ratio, reaction time) on the biodiesel production (conversion yield) was studied. Also the effect of preliminary ultrasonic treatment (ultrasonic irradiation, emulsification of immiscible oil and alcohol mixture) of the initial reagents (emulsion preparation) on the stage before transesterification reaction conduction on the conversion yield was studied. We found that the preliminary ultrasonic treatment of the initial reagents increases considerably the conversion yield. Optimal technological conditions were determined to be as follows: pressure within 20-30 MPa, temperature within 573-623 K. The optimal values of the oil to alcohol ratio strongly depend on preliminary treatment of the reaction mixture. The study showed that the conversion yield at the same temperature with 96 wt.% of ethanol is higher than with 100 wt.% of methanol. (C) 2011 Elsevier Ltd. All rights reserved.
