|WANG, WEI-CHENG - North Carolina State University|
|ALLEN, ELLE - North Carolina State University|
|CAMPOS, ANDREW - North Carolina State University|
|CADE, RUSHYANNAH - North Carolina State University|
|IMMER, JEREMY - North Carolina State University|
|MIXSON, STEPHANIE - North Carolina State University|
|SRIRANGAN, SOUNDARYA - North Carolina State University|
|SCHRECK, STEVEN - North Carolina State University|
|SUN, KEYI - North Carolina State University|
|THAPALIYA, NIRAJAN - North Carolina State University|
|BURKHOLDER, JOANN - North Carolina State University|
|GRUDEN, AMY - North Carolina State University|
|LAMB, H - North Carolina State University|
|SEDEROFF, HEIKE - North Carolina State University|
|STIKELEATHER, LARRY - North Carolina State University|
|ROBERTS, WILLIAM - North Carolina State University|
Submitted to: Journal of Environmental Progress and Sustainable Energy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2013
Publication Date: 9/11/2013
Citation: Wang, W., Allen, E.M., Campos, A.A., Cade, R.K., Dean, L.L., Immer, J.G., Mixson, S.M., Srirangan, S., Schreck, S., Sun, K., Thapaliya, N., Burkholder, J., Gruden, A.M., Lamb, H.H., Sederoff, H., Stikeleather, L.F., Roberts, W.L. 2013. ASI: Dunaliella Marine Microalgae to Drop-In Replacement Liquid Transportation Fuel. Journal of Environmental Progress and Sustainable Energy. Vol. 32 (4):916-925.
Interpretive Summary: A type of salt water algae know as Dunaliella is known to be high in fat and grows very fast. It is being produced in large cultures using salt water. The fat can be easily removed because it does not have a cell wall like other types of algae. This study examined 14 different varieties of Dunaliella to determined how it could best be grown. Four of the varieties were selected and genetically modified to increased their production of carbon. After breaking the membranes, an electrostatic form of collection was found to be the most economical way of harvesting the fat. A type of catalytic conversion was designed to effective convert the collected fat from the algae in to fuel for different engines. The resulting fuel components can also be converted to diesel. This complete process is a presented as a method to convert a renewal resource (algae) into a fuel to replace petroleum.
Technical Abstract: Microalgae are a promising biofuels feedstock, theoretically yielding concentrations of triacylglycerides (TAGs) per unit area far higher than traditional feedstocks due to their rapid growth. Dunaliella is particularly advantageous as a feedstock because it is currently commercially mass cultured, thrives in salt water, and has no cell wall. Fourteen strains of Dunaliella have been investigated for growth rates and lipid production in mass culture and tested for enhanced lipid production under a range of environmental stressors including salinity, pH, nitrogen and phosphorus limitation, and light regime. The nuclear genome has been sequenced for four of these strains, with the objective of increasing carbon flux through genetic engineering. Electroflocculation followed by osmotic membrane rupturing may be a very energy and cost efficient means of harvesting the lipid bodies from Dunaliella. A technically feasible and scalable thermo-catalytic process to convert the lipids into replacements for liquid transportation fuels has been developed. The lipids were converted into long-chain alkanes through continuous thermal hydrolysis followed by fed-batch thermo-catalytic decarboxylation. These alkanes can be reformed into the renewable diesel via conventional catalytic hydrocarbon isomerization reactions to improve the cold flow properties if desired.