Extraction Technique for Lipid from Microalgae for Biodiesel

A study on the technique of lipid extraction from microalgae for the biodiesel
production is performed, in which the author has narrowed down the research to the
microalgae cultivation method, harvesting technique, lipid extraction of microalgae
and also transesterification. At the early stage of the research, the author has batchcultivated
the Nannochloropsis sp and Chiarella sp to conduct the growth evaluation
by using the cell count method. The microalgae are then harvested by centrifugal
separation. The project work continued with the sample collection of the mixedculture
of microalgae from the pond for the extraction of lipid. For this project, the
author has selected the solvent extraction method continued with the rotary
evaporator to extract the lipid from microalgae. The solvent systems used for the
extraction are n-hexane, methanol and the mixture of chloroform/methanol. The
result from the extraction has shown that methanol is the best solvent to extract lipid
from the mixed-culture of microalgae. The selection of this technique is made based
on the ease of application and low cost consumption. Transesterification is also
performed in order to convert the oil which is in the form of lipid to methyl ester.
The alkali catalyzed process is applied in transeterification which is by using sodium
hydroxide. Lastly, the pH measurement of the esterified product is conducted and
analysis by using Thin Layer Chromatography is performed.