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dayton1343404093.pdf (2.07 MB)
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Processing Algal Biomass to Renewable Fuel: Oil Extraction and Hydrothermal Liquefaction
Author Info
Homsy, Sally Louis
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343404093
Abstract Details
Year and Degree
2012, Master of Science (M.S.), University of Dayton, Chemical Engineering.
Abstract
Since the industrial revolution the world’s reliance on fossil fuels has been increasing at an accelerated rate. The negative environmental effects of burning fossil fuels and the demand for energy security have increased interest in renewable fuels technology. Using biomass as a feedstock for energy generation has emerged as an area of interest, and the focus of this study is on the sustainable production of a crude oil from the algal species
Chlorella vulgaris
. The derived crude oil is to serve as a feedstock for renewable diesel production. The constituents of this algae derived oil must be similar in structure and low in impurities, especially nitrogen and sulfur content, to allow for the economical upgrade of this oil to renewable diesel. Two methods for the generation of the crude oil were explored: direct oil extraction from the algal biomass and hydrothermal liquefaction of the algal biomass. Total algal lipid extraction from both dry and wet algal biomass was studied and multiple solvents, procedures and cell pretreatment methods were compared; this includes solvents at ambient conditions, supercritical carbon dioxide, liquefied dimethyl ether, ultrasonication, mechanical disruption and steaming. It was determined that pretreatment of the
Chlorella vulgaris
biomass is not necessary for total oil extraction, that total oil extraction from dry algae can be achieved by using a 95% ethanol solvent and that total oil extraction from wet algae can be achieved by using a 6:77:17 w/w/w ratio of water to ethanol to hexane. The optimal oil extraction procedure was scaled up and a process was developed to fractionate the algal biomass and isolate the lipid fractions conducive to upgrading to renewable diesel. The crude oil produced through this method was analyzed and found to be suitable for economical upgrade to renewable diesel. However biomass conversion to oil was low; only about 13.5% of the biomass could be converted to oil due to the relatively low lipid content of the
Chlorella vulgaris
(about 18% lipids on a dry weight basis). The hydrothermal liquefaction of the Chlorella vulgaris biomass was capable of converting about 44% of the initial
Chlorella vulgaris
biomass to bio-crude. However, the quality of the oil produced was not ideal for upgrading to renewable diesel due to the high nitrogen and sulfur content of the oil and the diverse molecular structures of the oil constituents. In conclusion, it was recommended that a method to enhance
Chlorella vulgaris
lipid content, such as nitrogen starvation or the introduction of sugars in the growth media, should be adopted prior to harvest and that the developed oil extraction procedure should be used to produce a renewable upgradable crude oil.
Committee
Sukh Sidhu, PhD (Committee Chair)
Donald Comfort, PhD (Committee Member)
Matthew Lopper, PhD (Committee Member)
Pages
149 p.
Subject Headings
Alternative Energy
;
Engineering
;
Sustainability
Keywords
Chlorella vulgaris
;
renewable diesel
;
hydrothermal liquefaction
;
oil extraction
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Citations
Homsy, S. L. (2012).
Processing Algal Biomass to Renewable Fuel: Oil Extraction and Hydrothermal Liquefaction
[Master's thesis, University of Dayton]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343404093
APA Style (7th edition)
Homsy, Sally.
Processing Algal Biomass to Renewable Fuel: Oil Extraction and Hydrothermal Liquefaction.
2012. University of Dayton, Master's thesis.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343404093.
MLA Style (8th edition)
Homsy, Sally. "Processing Algal Biomass to Renewable Fuel: Oil Extraction and Hydrothermal Liquefaction." Master's thesis, University of Dayton, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343404093
Chicago Manual of Style (17th edition)
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Document number:
dayton1343404093
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Copyright Info
© 2012, all rights reserved.
This open access ETD is published by University of Dayton and OhioLINK.