Journal of Engineering Science and Technology Review 8 (4) (2015) 1-6 Research Article Biodiesel Production from Selected Microalgae Strains and Determination of its Properties and Combustion Specific Characteristics N. Kokkinos 1,2,* , A. Lazaridou 1 , N. Stamatis 3 , S. Orfanidis 3 , A. Ch. Mitropoulos 1,2 , A. Christoforidis 1,2 and N. Nikolaou 1 1 Eastern Macedonia and Thrace Institute of Technology, Faculty of Engineering, Department of Petroleum & Mechanical Engineering, St. Lucas, 654 04 Kavala, Greece 2 Hephaestus Advanced Research Laboratory, Division of Petroleum Engineering, Ag. Lucas, 654 04 Kavala, Greece 3 Hellenic Agricultural Organization-DEMETER, Fisheries Research Institute, 64 007 Nea Peramos, Kavala, Greece Received 25 October 2015; Accepted 7 November 2015 ___________________________________________________________________________________________ Abstract Biofuels are gaining importance as significant substitutes for the depleting fossil fuels. Recent focus is on microalgae as the third generation feedstock. In the present research work, two indigenous fresh water and two marine Chlorophyte strains have been cultivated successfully under laboratory conditions using commercial fertilizer (Nutrileaf 30-10-10, initial concentration=70 g/m 3 ) as nutrient source. Gas chromatographic analysis data showed that microalgae biodiesel obtained from Chlorophyte strains biomass were composed of fatty acid methyl esters. The produced microalgae biodiesel achieved a range of 2.2 - 10.6 % total lipid content and an unsaturated FAME content between 49 mol% and 59 mol%. The iodine value, the cetane number, the cold filter plugging point, the oxidative stability as well as combustion specific characteristics of the final biodiesels were determined based on the compositions of the four microalgae strains. The calculated biodiesel properties compared then with the corresponding properties of biodiesel from known vegetable oils, from other algae strains and with the specifications in the EU (EN 14214) and US (ASTM D6751) standards. The derived biodiesels from indigenous Chlorophyte algae were significantly comparable in quality with other biodiesels. Keywords: Microalgae, chlorophytes, FAME compositions, empirical models, biodiesel properties __________________________________________________________________________________________ 1. Introduction The demand for alternative fuels has increased in the past several years. Nowadays, biofuels play a leading role in the substitution of the depleting fossil fuels [1,2]. Biofuels derived from biological materials, and this is the main differentiation from other non-fossil fuel energy sources (e.g. wind and wave energy). Biological-based fuels can be solid (e.g. wastes), gaseous (e.g. methane, dymethyl ether, hydrogen) and liquid (e.g. biobutanol, biodiesel). The biggest advantage of biofuels is the environmentally friendliness that they have over fossil fuels. Particularly, biodiesel (from the Greek word βίος: life + diesel from Rudolf Diesel) is a sustainable and renewable fuel, as a result of solar energy conversion into chemical energy. It is biodegradable (degrades about four times faster than petrodiesel) [3], non-toxic and basically free of sulfur and aromatics. The emissions produced by burning of biodiesel are less reactive with sunlight than those produced by burning gasoline; it emits generally less carbon dioxide, carbon monoxide, particulate matter, hydrocarbons, smoke, noxious fumes and odors than mineral diesel fuel. Furthermore, comparing biodiesel with petrodiesel, the former shows higher combustion efficiency, higher cetane number, higher flash point, and inherent luobricity (about 66% better than petrodiesel) [3-5]. On the other hand, biodiesel exhibits higher viscosity, lower energy content, higher cloud point, higher pour point, decreased oxidative stability and slightly increased nitrogen oxide (NOx) emissions compared with petroleum-based diesel fuel [3]. In addition, it is worthy of remark that the first produced biodiesel derived from edible oil seed crops (first generation feedstocks) is lurking a serious risk of disturbing the overall worldwide balance of food reserves and safety. The second generation feedstocks for biodiesel production are obtained from non-edible oil seed crops, waste cooking oil, animal fats, etc. However, these feedstocks are not sufficient to cover the present energy needs. Therefore, recent worldwide attention is on algae, mainly microalgae, as the third generation feedstock [6]. Microalgae are microscopic photosynthetic organisms that are found in both marine and freshwater environments. Bacillariophyceae (diatoms), Chlorophyceae (green algae), and Chrysophyceae (golden algae) are the three most important classes of microalgae in terms of abundance. They do not compete for land; instead they can grow in salty (sea), brackish (lagoons) and fresh (lakes) water. These photosynthetic organisms sequester the atmospheric CO 2 and release oxygen. In spite of the fact that the photosynthetic mechanism of microalgae is similar to land- based plants, the primitive simple cellular structure of microalgae, their large surface-to-volume-body ratio and their efficient access to water, CO 2 , and other nutrients provide them with the ability to grow much faster than terrestrial crops by converting more efficient solar energy into biomass [7,8]. The fact that microalgae can complete an entire growing cycle every few days offer them the potential to produce more oil per acre than any other feedstock being Jestr JOURNAL OF Engineering Science and Technology Review www.jestr.org ______________ * E-mail address: nikokkinos@mwpc.gr ISSN: 1791-2377 © 2015 Kavala Institute of Technology. All rights reserved.