International Journal of Engineering and Technical Research (IJETR) ISSN: 2321-0869, Volume-2, Issue-11, November 2014 8 www.erpublication.org Abstract— The increase in petroleum-based aviation fuel consumption, the decrease in petroleum resources, the fluctuation of the crude oil price, the increase in greenhouse gas emission and the need for energy security are motivating the development of Bio-jet fuel, an alternate jet fuel. Bio-jet fuel has been produced by blending petro-based jet fuel with Chlorella vulgaris biodiesel (Fatty Acid Methyl Ester, or simply FAME). Microalgae lipids extraction and transesterification to biodiesel are energy and time-consuming (roughly 5 hours in the lab). This study investigated the integrated one-step extraction/ transesterification of freeze dried Chlorella vulgaris to produce biodiesel for blending with jet fuel. The one step or “in-situ” transesterification reaction was run in methanol assisted by ultrasonication, and was completed in 30 minutes. The FAMEs produced were identified using a gas chromatograph. Yields up to 56.82 mg FAME/g dry algae were obtained. Predicted physical properties of in-situ FAME satisfied European and American standards confirming its quality. Index Terms— Chlorella vulgaris, microalgae, biodiesel, in-situ, Oil Extraction, Ultrasound, Fatty Acid Profiles. I. INTRODUCTION A. Airline Industry Challenges. The airline industry enjoys a yearly passenger ridership of over 2.2 billion and delivers over 30% of all international material. Estimates are that over 32 million jobs are directly related to the US$3.5 billion airline industry. However, the industry is confronted with environmental and financial challenges. These include increasing petroleum-based jet fuel price (which tripled in the last 7 years), dependency on imported petroleum oil and deteriorating climate due to global anthropogenic greenhouse gas (GHG) emission. The industry currently generates about 2% of the GHG. This is estimated to reach about 3% by 2050. It is highly desirable to reach a carbon-free airline industry. B. Bio-Jet Fuel. The airline Renewable aviation fuel, also known as bio-jet fuel is the most desired alternative to replacing carbon-intensive petro-based jet fuel. Bio-jet fuel is a drop-in alternative fuel; less dependent on and greener than petroleum-based jet fuel; has low volume per unit energy (i.e., has a low gallon per Btu); and could reduce flight-related GHG emissions by over 60% compared to petroleum-based jet fuel. The renewable aviation fuel can be produced Manuscript received October 28, 2014. Marian Elmoraghy, Chemical Engineering Department, University of New Hampshire, Durham, New Hampshire, USA, Ihab H. Farag, Chemical Engineering Department, University of New Hampshire, Durham, New Hampshire, USA, +1-603-767-4442. domestically from local resources, thus, it provides the airline industry a secure supply of liquid fuel. In addition, bio-jet fuel is produced from sustainable biomass like microalgae. Algae are aquatic organisms that contain green pigments (chlorophyll) in the cells. The chlorophyll uses photonic energy (light), carbon dioxide (CO2) and water to synthesize a number of chemicals, e.g., lipids. They do not compete for arable land and can be produced year round. Microalgae are small microscopic aquatic photosynthetic plants (around micrometers). They are single celled that grow quickly in water suspension. They use light energy to obtain their inorganic compound’s nutritional needs. Some microalgae contain large amounts of lipids within their cells. The ideal natural oil feedstock for biodiesel and bio-jet production are of triacylglycerides (TAGs), [1], [2], [3]. Figure 1, shows the structure of a TAG. Fig. 1 Structure of triacylglyceride (TAG). R1-COOH, R2-COOH and R3-COOH in the TAGs are saturated and unsaturated fatty acids. These could be short or long chains hydrocarbons. Shorter chain length fatty acids (16-21 carbon atoms) are ideal for making biodiesel The lipids (TAGs) content of microalgae is usually between 10-50 g per 100 g dry algae. Table 1 gives a list of some saturated (S) and unsaturated (U) FAs found in algal cells. The labels S and U are listed in the first column. The second column contains the name of each fatty acid (FA) is followed by the total number of carbon, and total number of double bonds; for instance, (16:1) indicates FA (palmitoleic or sapienic) of 16 carbons with one double bond. The chemical abstract service registry (CAS) number is listed in the third column. The formula is given in column 4. Algae cells of each strain do not contain every single fatty acid displayed in Table I. The lipids FAs should contain 16 – 21 carbons for biodiesel production. The resulting biodiesel will have flash point range of 120°C to 150°C. This satisfies the European standards of biodiesel flash point greater than 101°C (the flash point range of petroleum diesel is 60°C to 90°C). The flash point is the temperature at which a vapor can be ignited in air. Hence, biodiesel has lower fire risk than petroleum diesel. In-situ Transesterification of Chlorella vulgaris towards Bio-Jet Fuel Production Marian Elmoraghy, Ihab H. Farag