Biodisel a Partir De Algas

Energy Conversion and Management 52 (2011) 163–170

Contents lists available at ScienceDirect

Energy Conversion and Management
journal homepage: www.elsevier.com/locate/enconman

Importance of algae oil as a source of biodiesel
Ayhan Demirbas a,*, M. Fatih Demirbas b
a b

Sirnak University, Dean of Engineering Faculty, Sirnak, Turkey Sila Science, University Mah., Mekan Sok No. 24,Trabzon, Turkey

a r t i c l e

i n f o

a b s t r a c t
Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae are very important as a biomass source. Algae will some day be competitive as a source for biofuel. Different species of algae may be better suited for different types of fuel. Algae can begrown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Algae can be a replacement for oil based fuels, one that is more effective and has no disadvantages. Algae are among the fastest-growing plants in the world, and about 50% of their weight is oil. This lipid oil can be used to makebiodiesel for cars, trucks, and airplanes. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,000 l per acre, per year; this is 7–31 times greater than the next best crop, palm oil. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. Most current research on oil extractionis focused on microalgae to produce biodiesel from algal oil. Algal-oil processes into biodiesel as easily as oil derived from land-based crops. Ó 2010 Elsevier Ltd. All rights reserved.

Article history: Received 1 November 2009 Accepted 22 June 2010 Available online 16 July 2010 Keywords: Algae Algal oil Biodiesel Economy

1. Introduction Primary energy sources can be divided intonon-renewables and renewables. The reality shows that the energy availability from the non-renewable sources is limited, and beyond that, the exploration, the processing and the use of energy impose considerable impacts on the environment [1–3]. Fossil fuels were formed a great many years ago and are not renewable. Infact today, over 80% of the energy we use comes from three fossil fuels: petroleum, coal,and natural gas. About 98% of carbon emissions result from fossil fuel combustion. Reducing the use of fossil fuels would considerably reduce the amount of carbon dioxide and other pollutants produced [4]. This can be achieved by either using less energy altogether or by replacing fossil fuel by renewable fuels. Hence, the future trend is towards using alternate energy sources. Fortunately,technological developments are making the transition possible [5]. Since fossil fuel has become a finite energy source, in the last decades many efforts have been put into the production of renewable alternative energy sources. Among the existing renewable alternatives to fossil fuels, algae have raised great interest. Another problem with petroleum fuels is their uneven distribution in the world; forexample, the Middle East has 63% of the global reserves and is the dominant supplier of petroleum [6]. This energy system is unsustainable because of equity issues as well
* Corresponding author. Tel.: +90 462 230 7831; fax: +90 462 248 8508. E-mail address: ayhandemirbas@hotmail.com (A. Demirbas). 0196-8904/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.doi:10.1016/j.enconman.2010.06.055

as environmental, economic, and geopolitical concerns that have far reaching implications. Interestingly, the renewable energy resources are more evenly distributed than fossil or nuclear resources. Today’s energy system is unsustainable because of equity issues as well as environmental, economic, and geopolitical concerns that will have implications far into the future. Hence,...