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Rapid transesterification of micro-amount of lipids from microalgae via a micro-mixer reactor.

Liu J, Chu Y, Cao X, Zhao Y, Xie H, Xue S - Biotechnol Biofuels (2015)

Bottom Line: The minimum amount of sample was decreased to 30 µg lipids.The new approach was successfully applied to the fatty acid composition analysis of soybean oil and microalgal lipids.The micro-mixer reactor has great potential for applications not only in large-scale biodiesel production but also for the micro-scale analysis of microalgae fatty acid compositions.

View Article: PubMed Central - PubMed

Affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 16023 China ; University of Chinese Academy of Sciences, Beijing, 100049 China.

ABSTRACT

Background: Fatty acid composition is an important physiological parameter of microalgae, which is taken as the third generation alternative resource of biodiesel. To boost microalgal research and applications, a convenient, rapid, and acid-catalyzed transesterification procedure that satisfies the demand for the analysis of the fatty acid composition of lipids with micro-scale samples in the high-throughput screening of microalgal strains is needed, along with the evaluation of the physiological status of microalgae in response to nutrient stress.

Results: The reaction conditions of transesterification via a micro-mixer reactor were optimized as follows: 90 °C reaction temperature, 20 min reaction time, 6:1 volume ratio of H2SO4-methanol to lipid-in-hexane, and a Y-type micro-mixer with a 20-m-long extended loop that has a 0.3 mm diameter. The minimum amount of sample was decreased to 30 µg lipids. The new approach was successfully applied to the fatty acid composition analysis of soybean oil and microalgal lipids. Definitely, it could be applied to acyl related oils from different sources.

Conclusion: Here, we have developed a simple and rapid method for the analysis of the fatty acid composition of lipids. The new method requires less than 20 min for transesterification and a minimum of only 30 µg lipid sample. Furthermore, a high-throughput process can be easily realized by numbering up the micro-mixer reactors. The micro-mixer reactor has great potential for applications not only in large-scale biodiesel production but also for the micro-scale analysis of microalgae fatty acid compositions.

No MeSH data available.


Related in: MedlinePlus

FAME yield obtained under different reaction times and ratios of the two inlet flows
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Fig4: FAME yield obtained under different reaction times and ratios of the two inlet flows

Mentions: The effects of the volume ratio of the two inlet flows and the reaction time on the FAME yield were investigated by varying the flow velocity. The results in Fig. 4 show that the FAME yield increased as the ratio of the two inlet flows increased. When the ratio was 1:1, the FAME yield was very low; even after prolonging the reaction time from 14 to 35 min, there was no increase in the FAME yield as expected. By increasing the ratio to 3:1, the FAME yield increased from 23.2 to 86.3 % dramatically for the 20 min reaction time. Increased FAME yields were also observed at the 14 and 35 min reaction times. The FAME yield reached 98.1 and 97.8 % when the ratio was 6:1 and 9:1 at the 35 min reaction time, respectively. A two-phase plug-flow of the immiscible solvents after pumping a 1:1 ratio of methanol and hexane into the MR and the slow mass transfer between the two-phase plug-flow resulted a low FAME yield consequently. When the ratio was increased to 6:1 and 9:1, a homogeneous phase flow was generated after pumping into the MR. Therefore, the mass transfer limitation of the two immiscible phases was significantly reduced. This result explains why the FAME yield dramatically increases as the ratio of the two phases increases. Compared with a BR, the enhancement of transesterification in the MR by adding hexane into the reaction system is more apparent. In the BR, for the 30 min reaction, the FAME yield increased from 80.7 to 82.2 % by adding hexane at one-sixth of the methanol volume. While in the MR, the FAME yield increased from 23.2 to 90.1 % for a reaction time of only 20 min by increasing the ratio from 1:1 to 6:1, as seen in Fig. 4. In addition to the ratio of the two immiscible phases, increasing the methanol-to-oil ratio was another factor that increased the FAME yield [14, 28].Fig. 4


Rapid transesterification of micro-amount of lipids from microalgae via a micro-mixer reactor.

Liu J, Chu Y, Cao X, Zhao Y, Xie H, Xue S - Biotechnol Biofuels (2015)

FAME yield obtained under different reaction times and ratios of the two inlet flows
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4696256&req=5

Fig4: FAME yield obtained under different reaction times and ratios of the two inlet flows
Mentions: The effects of the volume ratio of the two inlet flows and the reaction time on the FAME yield were investigated by varying the flow velocity. The results in Fig. 4 show that the FAME yield increased as the ratio of the two inlet flows increased. When the ratio was 1:1, the FAME yield was very low; even after prolonging the reaction time from 14 to 35 min, there was no increase in the FAME yield as expected. By increasing the ratio to 3:1, the FAME yield increased from 23.2 to 86.3 % dramatically for the 20 min reaction time. Increased FAME yields were also observed at the 14 and 35 min reaction times. The FAME yield reached 98.1 and 97.8 % when the ratio was 6:1 and 9:1 at the 35 min reaction time, respectively. A two-phase plug-flow of the immiscible solvents after pumping a 1:1 ratio of methanol and hexane into the MR and the slow mass transfer between the two-phase plug-flow resulted a low FAME yield consequently. When the ratio was increased to 6:1 and 9:1, a homogeneous phase flow was generated after pumping into the MR. Therefore, the mass transfer limitation of the two immiscible phases was significantly reduced. This result explains why the FAME yield dramatically increases as the ratio of the two phases increases. Compared with a BR, the enhancement of transesterification in the MR by adding hexane into the reaction system is more apparent. In the BR, for the 30 min reaction, the FAME yield increased from 80.7 to 82.2 % by adding hexane at one-sixth of the methanol volume. While in the MR, the FAME yield increased from 23.2 to 90.1 % for a reaction time of only 20 min by increasing the ratio from 1:1 to 6:1, as seen in Fig. 4. In addition to the ratio of the two immiscible phases, increasing the methanol-to-oil ratio was another factor that increased the FAME yield [14, 28].Fig. 4

Bottom Line: The minimum amount of sample was decreased to 30 µg lipids.The new approach was successfully applied to the fatty acid composition analysis of soybean oil and microalgal lipids.The micro-mixer reactor has great potential for applications not only in large-scale biodiesel production but also for the micro-scale analysis of microalgae fatty acid compositions.

View Article: PubMed Central - PubMed

Affiliation: Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 16023 China ; University of Chinese Academy of Sciences, Beijing, 100049 China.

ABSTRACT

Background: Fatty acid composition is an important physiological parameter of microalgae, which is taken as the third generation alternative resource of biodiesel. To boost microalgal research and applications, a convenient, rapid, and acid-catalyzed transesterification procedure that satisfies the demand for the analysis of the fatty acid composition of lipids with micro-scale samples in the high-throughput screening of microalgal strains is needed, along with the evaluation of the physiological status of microalgae in response to nutrient stress.

Results: The reaction conditions of transesterification via a micro-mixer reactor were optimized as follows: 90 °C reaction temperature, 20 min reaction time, 6:1 volume ratio of H2SO4-methanol to lipid-in-hexane, and a Y-type micro-mixer with a 20-m-long extended loop that has a 0.3 mm diameter. The minimum amount of sample was decreased to 30 µg lipids. The new approach was successfully applied to the fatty acid composition analysis of soybean oil and microalgal lipids. Definitely, it could be applied to acyl related oils from different sources.

Conclusion: Here, we have developed a simple and rapid method for the analysis of the fatty acid composition of lipids. The new method requires less than 20 min for transesterification and a minimum of only 30 µg lipid sample. Furthermore, a high-throughput process can be easily realized by numbering up the micro-mixer reactors. The micro-mixer reactor has great potential for applications not only in large-scale biodiesel production but also for the micro-scale analysis of microalgae fatty acid compositions.

No MeSH data available.


Related in: MedlinePlus