Date of Award

2012-01-01

Degree Name

Master of Science

Department

Mechanical Engineering

Advisor(s)

Russell Chianelli

Abstract

Lipid containing biomass from microalgae has received recent research interest as a renewable and sustainable feedstock for biofuel production. Algae is known to offer as much as 30 times the energy density than corn based ethanol, the current world standard for biomass based liquid transportation fuels. The development of large scale systems and methods of extracting lipids from microalgae is still in the early stages of development and significant increases in efficiency and reduction in costs are necessary to substantiate algae as a feasible alternative source of fuel. Traditional conversion of algae feedstock into a refineable feedstock for biofuel can be divided into three primary steps: growth and cultivation, biomass concentration, and lipid extraction and separation. This study focuses on the extraction and separation stage where cells must be lysed and lipids separated from other cell matter before further conversion can take place. Current methods of lipid extraction include mechanical methods, solvent methods, and sonication methods. The focus of this work is the development of a low energy method of disrupting lipid containing biomass to facilitate the extraction of intracellular matter from microalgae biomass in its wet form, before any concentration or other processing has occurred. Cavitation offers a potential mechanism to be an effective means of releasing intracellular matter; however traditional ultrasound cavitation reaction systems suffer from the scale up problems. A novel reaction system was developed consisting of a flat plate reactor and a Terfenol-D transducer operating within the audible range. The ability of the reaction system to produce cavitation condition was verified through iodine dosimetry and the Weissler reaction. Sonication of 200 ml samples of KI solution was performed at various frequencies and power levels, samples were examined spectrophotometrically at 355nm. Further, samples of algae were irradiated under similar conditions. The samples are examined visually under magnification to validate the efficacy of the system in disrupting the cell wall and releasing intracellular matter. A summary of the efficiency and efficacy of the reaction system is reported as well as future directives for continued research in low energy methods of lipid extraction from microalgae biomass.

Language

en

Provenance

Received from ProQuest

File Size

59 pages

File Format

application/pdf

Rights Holder

Joaquin Rodriguez

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