Assessing biodiesel quality parameters for wastewater grown Chlorella sp

Area of Science:

• Biotechnology
• Renewable Energy
• Environmental Science

Background:

• Microalgae are a promising source for renewable biodiesel, capable of meeting global transport fuel demands.
• Wastewater cultivation of microalgae offers a sustainable approach to biofuel production, reducing reliance on freshwater resources.

Purpose of the Study:

• To assess the fuel quality parameters of biodiesel derived from indigenous microalga Chlorella sp. grown in wastewater.
• To evaluate the potential of Chlorella sp. as a viable source for sustainable biodiesel production.

Main Methods:

• Cultivation of Chlorella sp. in secondary treated wastewater diluted with tap water.
• Determination of microalgal dry weight and lipid content.
• Transesterification of lipids to fatty acid methyl ester (biodiesel).
• Analysis of biodiesel yield and fatty acid profile.
• Prediction of physical and chemical fuel properties using empirical equations and spectroscopic methods (FTIR, NMR).

Main Results:

• Chlorella sp. achieved a dry weight of 0.849 g L^-1 with 27.1% lipid content.
• Biodiesel yield was 80.64%, with major fatty acids including palmitic, linoleic, oleic, and linolenic acids.
• Predicted fuel properties (cetane number 56.5, iodine value 75.5, heating value 40.1 MJ kg^-1, flash point 135 °C, kinematic viscosity 4.05 mm² s^-1, density 0.86 g cm³, cold filter plugging point 0.7 °C) largely met ASTM standards.
• FTIR and NMR analyses confirmed the chemical structure of the biodiesel.

Conclusions:

• Wastewater-grown Chlorella sp. is a promising source for biodiesel production.
• The resulting biodiesel quality is comparable to established standards, indicating its suitability for use as a transport fuel.
• This study highlights the potential of utilizing microalgae cultivated in wastewater for sustainable energy solutions.