Small scale biodiesel production from <em>Sargassum</em> sp and optimization of conditions for yield enhancement

Abstract

Production of biofuel from excessive natural resources and underutilized plant materials has drawn global attention due to its cost effectiveness, eco friendliness and sustainability compared to the conventional fossil fuels. This work was aimed to select the best marine flora available in the Northern Sri Lankan sea to produce biodiesel and to optimize the conditions to enhance the yield. Sargassum sp., Ulva fasciata, Turbinaria ornata, Gelidium sp. and Thalassia sp. were collected from the coastal region of the Jaffna peninsula and washed thoroughly sun-dried. The organic solvents used to extract oil from these algal and sea grass species were n-hexane and di-ethyl ether, while alkaline catalysts were used to convert the extracted oil into biodiesel via transesterification reaction. When the oil extraction was done separately from the five dried marine plant species using n-Hexane and Di-ethyl ether as solvents, significantly higher quantity of oil was obtained from Sargassum sp. than the other tested algal and plant species, hence Sargassum sp. was selected for further studies. When the conditions for the extraction of oil from Sargassum sp. such as Sargassum to solvent(n-Hexane: Di-ethylether) ratio (0:200), amount of algal biomass (100 g), longer contact time (24h), molar ratio (4:1), catalyst amount (0.6 %), temperature (60 o C), reaction time (25min) were optimized before the conversion of oil into biodiesel via transesterification reaction, there was a significant increase in the quantity of extracted oil by 11.7 times than the non-optimized conditions. Since the density of the biodiesel (867.3 kg/m 3) meets the international standards, the quality of the biodiesel produced from Sargassum sp. could be recommended as satisfactory. Large scale multicenter studies need to be done in order to confirm and implement this finding.

Biodiesel production from aquatic vegetation

“…Quantity of the Biodiesel from Sargassum sp. was significantly increased by more than 11 times, after transesterification conditions were optimized and the higher density of the biodiesel (867 Kgm -3 ) from this marine algal species matched the international standards (Fernando and Kapilan, 2020).…”

“…and Thalassia sp. The organic solvents n-hexane and di-ethyl ether were used extract oil from these marine plant species, whereas the bioconvertion of the oil into biodiesel was done via transesterification reaction facilitated by alkaline catalysts (Fernando and Kapilan, 2020).…”

Bioethanol production from Palmyrah (Borassus flabellifer) wastes using yeast

“…Then the acetaldehyde produced will be reduced by nicotinamide adenine dinucleotide (NAD) to form ethyl alcohol (Singh et al, 2003). Metabolic activities of yeasts that produce the ethanol and other metabolic by-products such as esters, ketones and higher alcohols are due to the efficient fermentation mechanism (Hansen, 1999;Piškur et al, 2006;Fernando & Kapilan, 2019). During prolonged fermentation of the pulp, the amount of alcohol and acid produced showed a decrease, and this may be due to the formation of esters and higher alcohols.…”