Production of Biodiesel Fuel from the MicroalgaSchizochytrium limacinumby Direct Transesterification of Algal Biomass

Abstract

Producing biofuel from microalgae has gained renewed interest recently. Schizochytrium limacinum is a heterotrophic microalga that is capable of producing high levels of biomass and total fatty acid. The objective of this work is to explore the potential of producing biodiesel fuel from this alga using different biodiesel preparation methods, including oil extraction followed by transesterification (a two-stage method) or direction transesterification of algal biomass (a one-stage method). When freeze-dried biomass was used as feedstock, the two-stage method resulted in 57% of crude biodiesel yield (based on algal biomass) with a fatty acid methyl ester (FAME) content of 66.37%. The one-stage method (with chloroform, hexane, or petroleum ether used in transesterification) led to a high yield of crude biodiesel, whereas only chloroform-based transesterification led to a high FAME content. When wet biomass was used as feedstock, the one-stage method resulted in a much-lower biodiesel yield. The biodiesel prepared via the direct transesterification of dry biomass was subjected to ASTM standard tests. Parameters such as free glycerol, total glycerol, acid number, soap content, corrosiveness to copper, flash point, viscosity, and particulate matter met the ASTM standards, while the water and sediment content, as well as the sulfur content did not pass the standard. Collectively, the results indicate the alga S. limanicum is a suitable feedstock for producing biodiesel via the direct transesterification method.

Cultivation of Microalgae in Medium Containing Palm Oil Mill Effluent and Its Conversion Into Biofuel

“…The FAME produced had 69.9% ester content. This purity was comparable with those deriving from the same algae species by Velasques-Orta et al (2012), 71.0%; Johnson andWen (2009), 66.0% andEhimen et al (2010), 88.0%, respectively.…”

Use of Anion Exchange Resins for One-Step Processing of Algae from Harvest to Biofuel

“…The transesterification reaction is sensitive to water [10][11][12][13][14] but this is not normally a problem since oils, such as would be obtained by hexane extraction, normally contain little water. When the entire processes is analyzed for cost and energy expenditure, some current projections suggest that the energy spent in the cultivation, harvest, and extraction of oil from algae could be greater than that gained from the product [5] along with the possibility of significant environmental impact [15].…”

“…Previous studies have shown that algal lipids can be transesterified in situ by adding reagents to a dried sample of algae [11,[16][17][18][19]. One study examined a two-step procedure where the acyl groups of component lipids were hydrolyzed with base and then re-esterified in excess sulfuric acid/methanol [20].…”

“…This procedure gave greater amounts FAME than obtained by lipid extraction followed by transesterification. Another study showed that direct acid-catalyzed transesterification of wet biomass can produce FAME yields similar to that of dried biomass, although FAME compositions differed [11].…”

Cultivation of algae in photobioreator and obtention of biodiesel

“…Also, C. vulgaris shows promises as a biomass fuel and as a natural food coloring agent (Lourenço, 2007;Terãn, 1989;Rocha et al, 2007). Because algae grows rapidly in light and dark places with a minimum of nutrients, large amounts of flammable when dried C. vulgaris can be produced at low cost (Johnson et al, 2009). Another property of C. vulgaris its ability to produce natural colorants and fatty acids (Lourenço, 2007).…”