skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Evaluation of lipid extractability after flash hydrolysis of algae

Abstract

Microalgae is identified as a promising feedstock for producing renewable liquid transportation fuels; however, lipids extraction from microalgae for downstream processing to biofuels is one of the important challenges for algal based biorefineries. This work aims at evaluating the potential of applying flash hydrolysis (FH) as a chemical-free technique to increase the lipids extractability of algal biomass as well as its integration with the hydrothermal liquefaction (HTL) of microalgae to enhance the biocrude yields and characteristics for fuel production. To this aim, the FH process was performed on three different algal species (Scenedesmus sp., Nannochloropsis sp., and Chlorella vulgaris) at 280 degrees C and 10 s of residence time. Following FH, in addition to the nutrients rich hydrolysate, approximately, 40 wt% of solids containing almost all (>90 wt%) the lipids termed as biofuels intermediates (BI), were recovered. Kinetics study on lipids extractability from the BI and their lipid profile analyses were conducted for each algal species. The results showed that the FH process had significantly enhanced the lipids extractability. For all three algae species, lipid yields from BI were higher than that of the raw algae. Lipid yields of Chlorella vulgaris in the first 15 min were more than fivemore » times higher (52.3 +/- 0.8 vs. 10.7 +/- 0.9 wt%) than that of raw algae during n-hexane based solvent extraction. The kinetics of lipids extractability followed a zero-order reaction rate for all wet raw microalgae and the BI of Scenedesmus sp., while the BI recovered from the other two algal species were determined as a second-order reaction. Comparison of fatty acids profiles indicated the contribution of the FH process in saturating fatty acids. Subsequent to lipids extraction, a conventional hydrothermal liquefaction was performed at 350 degrees C and 1 h to compare the biocrude yields from raw versus BI of Chlorella vulgaris microalgae. The results showed that the biocrude yields from the BI and its quality was significantly enhanced post FH than that of raw algae. The FH process was proven to be a viable option for lipid extraction by increasing the extent of recovery and decreasing the extraction time. Its integration with HTL notably impact the biocrude yields and characteristics for fuel production.« less

Authors:
 [1];  [1];  [2];  [1]
  1. Old Dominion Univ., Norfolk, VA (United States)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1431040
Report Number(s):
NREL/JA-5100-71235
Journal ID: ISSN 0016-2361
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Accepted Manuscript
Journal Name:
Fuel
Additional Journal Information:
Journal Volume: 224; Journal Issue: C; Journal ID: ISSN 0016-2361
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; microalgae; flash hydrolysis; lipid analysis; oil extraction; kinetics study; hydrothermal liquefaction

Citation Formats

Teymouri, Ali, Adams, Kameron J., Dong, Tao, and Kumar, Sandeep. Evaluation of lipid extractability after flash hydrolysis of algae. United States: N. p., 2018. Web. doi:10.1016/j.fuel.2018.03.044.
Teymouri, Ali, Adams, Kameron J., Dong, Tao, & Kumar, Sandeep. Evaluation of lipid extractability after flash hydrolysis of algae. United States. doi:10.1016/j.fuel.2018.03.044.
Teymouri, Ali, Adams, Kameron J., Dong, Tao, and Kumar, Sandeep. Sun . "Evaluation of lipid extractability after flash hydrolysis of algae". United States. doi:10.1016/j.fuel.2018.03.044. https://www.osti.gov/servlets/purl/1431040.
@article{osti_1431040,
title = {Evaluation of lipid extractability after flash hydrolysis of algae},
author = {Teymouri, Ali and Adams, Kameron J. and Dong, Tao and Kumar, Sandeep},
abstractNote = {Microalgae is identified as a promising feedstock for producing renewable liquid transportation fuels; however, lipids extraction from microalgae for downstream processing to biofuels is one of the important challenges for algal based biorefineries. This work aims at evaluating the potential of applying flash hydrolysis (FH) as a chemical-free technique to increase the lipids extractability of algal biomass as well as its integration with the hydrothermal liquefaction (HTL) of microalgae to enhance the biocrude yields and characteristics for fuel production. To this aim, the FH process was performed on three different algal species (Scenedesmus sp., Nannochloropsis sp., and Chlorella vulgaris) at 280 degrees C and 10 s of residence time. Following FH, in addition to the nutrients rich hydrolysate, approximately, 40 wt% of solids containing almost all (>90 wt%) the lipids termed as biofuels intermediates (BI), were recovered. Kinetics study on lipids extractability from the BI and their lipid profile analyses were conducted for each algal species. The results showed that the FH process had significantly enhanced the lipids extractability. For all three algae species, lipid yields from BI were higher than that of the raw algae. Lipid yields of Chlorella vulgaris in the first 15 min were more than five times higher (52.3 +/- 0.8 vs. 10.7 +/- 0.9 wt%) than that of raw algae during n-hexane based solvent extraction. The kinetics of lipids extractability followed a zero-order reaction rate for all wet raw microalgae and the BI of Scenedesmus sp., while the BI recovered from the other two algal species were determined as a second-order reaction. Comparison of fatty acids profiles indicated the contribution of the FH process in saturating fatty acids. Subsequent to lipids extraction, a conventional hydrothermal liquefaction was performed at 350 degrees C and 1 h to compare the biocrude yields from raw versus BI of Chlorella vulgaris microalgae. The results showed that the biocrude yields from the BI and its quality was significantly enhanced post FH than that of raw algae. The FH process was proven to be a viable option for lipid extraction by increasing the extent of recovery and decreasing the extraction time. Its integration with HTL notably impact the biocrude yields and characteristics for fuel production.},
doi = {10.1016/j.fuel.2018.03.044},
journal = {Fuel},
number = C,
volume = 224,
place = {United States},
year = {2018},
month = {7}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Save / Share: