This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”) for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl ester (FAME)...This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”) for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl ester (FAME) production. ZDS produced a significantly higher FAME yield in N. occulata than in C. vulgaris (p = 0.008). The varying performance of ZDS in the two species could be due to their different cell wall chemistries. Sodium dodecyl sulphate (SDS) in H2SO4 for FAME enhancement from the two species was also studied. Treatment with SDS in H2SO4 increased the FAME production rate in both species. Residual protein content after the in situ transesterification in C. vulgaris and N. occulata reduced respectively by 6.5% and 10%. The carbohydrate content was reduced by 71% in C. vulgaris and 65% in N. occulata. The water tolerance of the process when using H2SO4, with or without SDS, was evaluated by hydrating the two species with 10% - 30% distilled water (w/w dry algae). The FAME concentration began to diminish only at 30% water content in both species. Furthermore, the presence of a small amount of water in the biomass or methanol increased the lipid extraction efficiency, improving the FAME yield, rather than inhibiting the reaction.展开更多
Microalgal phospholipid bilayer contributes to the molar excesses of methanol and high acid concentration required in reactive extraction to achieve high fatty acid methyl ester (FAME) yield. This study reports an inv...Microalgal phospholipid bilayer contributes to the molar excesses of methanol and high acid concentration required in reactive extraction to achieve high fatty acid methyl ester (FAME) yield. This study reports an investigation into the effects of pre-soaking Nannochloropsis occulata in methanol at 600:1 and 1000:1 methanol to oil molar ratios prior to acid-catalyzed in situ transesterification at 8.5:1 and 15:1 H2SO4 to oil molar ratios on the FAME yield. The results showed that the pre-soaked Nannochloropsis occulata produced a higher FAME yield at the two tested methanol to oil molar ratios and acid concentrations than the un-soaked, resulting in a reduction in methanol volume and acid concentration. A maximum FAME yield of 98.4% ± 1.3% was obtained for the pre-soaked Nannochloropsis occulata at 1000:1 methanol to oil molar ratio and 15:1 H2SO4 to oil molar ratio. Both the phosphorus mass balance and conversion of the isolated phospholipids into FAME revealed that pre-soaking solubilizes the phospholipid bilayer to some degree, and contributes to an increased FAME yield.展开更多
文摘This article reports a high yielding technique of synthesizing zirconium dodecyl sulphate (“ZDS”) for in situ transesterification of Nannochloropsis occulata and Chlorella vulgaris for fatty acid methyl ester (FAME) production. ZDS produced a significantly higher FAME yield in N. occulata than in C. vulgaris (p = 0.008). The varying performance of ZDS in the two species could be due to their different cell wall chemistries. Sodium dodecyl sulphate (SDS) in H2SO4 for FAME enhancement from the two species was also studied. Treatment with SDS in H2SO4 increased the FAME production rate in both species. Residual protein content after the in situ transesterification in C. vulgaris and N. occulata reduced respectively by 6.5% and 10%. The carbohydrate content was reduced by 71% in C. vulgaris and 65% in N. occulata. The water tolerance of the process when using H2SO4, with or without SDS, was evaluated by hydrating the two species with 10% - 30% distilled water (w/w dry algae). The FAME concentration began to diminish only at 30% water content in both species. Furthermore, the presence of a small amount of water in the biomass or methanol increased the lipid extraction efficiency, improving the FAME yield, rather than inhibiting the reaction.
文摘Microalgal phospholipid bilayer contributes to the molar excesses of methanol and high acid concentration required in reactive extraction to achieve high fatty acid methyl ester (FAME) yield. This study reports an investigation into the effects of pre-soaking Nannochloropsis occulata in methanol at 600:1 and 1000:1 methanol to oil molar ratios prior to acid-catalyzed in situ transesterification at 8.5:1 and 15:1 H2SO4 to oil molar ratios on the FAME yield. The results showed that the pre-soaked Nannochloropsis occulata produced a higher FAME yield at the two tested methanol to oil molar ratios and acid concentrations than the un-soaked, resulting in a reduction in methanol volume and acid concentration. A maximum FAME yield of 98.4% ± 1.3% was obtained for the pre-soaked Nannochloropsis occulata at 1000:1 methanol to oil molar ratio and 15:1 H2SO4 to oil molar ratio. Both the phosphorus mass balance and conversion of the isolated phospholipids into FAME revealed that pre-soaking solubilizes the phospholipid bilayer to some degree, and contributes to an increased FAME yield.
