Andrew Lee

Master of Engineering Science Candidate

B.E. (Chem), Adelaide

Location: Room A210 Engineering Annex
Email: alee@chemeng.adelaide.edu.au
Phone: + 61 8 8303 3093
FAX: + 61 8 8303 4373

Supervisors

Dr Peter Ashman
Dr David Lewis

Research Topic

Large Scale Harvesting and Extraction of Algal Lipids for Biofuels

Research Abstract

As a feedstock for biodiesel, the marine microalgae Pleurochrysis carterae offers advantages such as a high growth rate, high lipid content, the ability to grow in arid areas not suitable for farming, and a high range of pH tolerance (7 to 11). However, the small size of the microalgae, low concentration and their ability to remain in suspension make harvesting one of the most difficult areas for commercial application. Traditional separation methods such as centrifugation, filtration or flocculation, are either too expensive to compete with plantation products or ineffective under a marine environment. While bioflocculation, which is induced by environmental stress, (e.g. extreme pH, temperature), may cause cell damages or composition changes and is not economically viable on a commercial scale.

Microbial bioflocculation is based on the principle that by introducing and encouraging the growth of flocculating microbes in situ, Pleurochrysis carterae can be flocculated and settled under gravity, making other secondary separation methods more efficient. Under a range of experimental variables, an average recovery efficiency of 72.4% (standard deviation 18.5%) and a concentration factor of 223 (standard deviation 73.3) were achieved. As no inorganic flocculants were used, flocs were free from metallic contaminants. The microalgae were not under stress and remained viable; culture media could be reused; the process was simple and could be continuous.

Interests

• Bioengineering, Biodiesel, microalgae separation

Awards

• Andrew Lee was awarded the Australian Academy of Technological Science and Engineering (ATSE) "Early Career Symposium Fellowship" to attend the "2008 National Symposium on Alternative Transport Fuel for Australia" in Melbourne, 16-18 November 2008. "to assist the Facilitator and Chair of the workshop to identify recommendations to be presented to the Government".
• Andrew Lee was awarded the AIE state sponsorship to attend the 2008 Australian Institute of Energy, "National Postgraduate Students Energy Award" in Sydney on Tuesday 18 November 2008

Conference Attendance

• Andrew Lee presented his research paper orally in the 3rd Congress of the International Society for Applied Phycology and the 11th International Conference on Applied Phycology, 21-27 June 2008, National University of Ireland, Galway, Ireland. The paper is entitled "Microbial flocculation of Pleurochrysis carterae, the primary stage for commercial harvesting".

Publications

• A.K. Lee, D.M. Lewis, P.J. Ashman, "Microbial flocculation, a potentially low-cost harvesting technique for marine microalgae for the production of biodiesel". J Applied Phycology (in press).