Algae Oil: a Sustainable Renewable Fuel of Future
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Hindawi Publishing Corporation Biotechnology Research International Volume 2014, Article ID 272814, 8 pages http://dx.doi.org/10.1155/2014/272814 Review Article Algae Oil: A Sustainable Renewable Fuel of Future Monford Paul Abishek, Jay Patel, and Anand Prem Rajan SchoolofBioSciencesandTechnology,VITUniversity,Vellore,TamilNadu632014,India Correspondence should be addressed to Anand Prem Rajan; [email protected] Received 19 February 2014; Accepted 31 March 2014; Published 5 May 2014 Academic Editor: Triantafyllos Roukas Copyright © 2014 Monford Paul Abishek et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A nonrenewable fuel like petroleum has been used from centuries and its usage has kept on increasing day by day. This also contributes to increased production of greenhouse gases contributing towards global issues like global warming. In order to meet environmental and economic sustainability, renewable, carbon neutral transport fuels are necessary. To meet these demands microalgae are the key source for production of biodiesel. These microalgae do produce oil from sunlight like plants but ina much more efficient manner. Biodiesel provides more environmental benefits, and being a renewable resource it has gained lot of attraction. However, the main obstacle to commercialization of biodiesel is its cost and feasibility. Biodiesel is usually used by blending with petro diesel, but it can also be used in pure form. Biodiesel is a sustainable fuel, as it is available throughout the year and can run any engine. It will satisfy the needs of the future generation to come. It will meet the demands of the future generation to come. 1. Introduction In recent years, the use of biofuels has shown manifold global growth in the transport sector due to the policies Oil depletion is the degradation in oil production of a well concentration on achieving energy conservation and the or oil field. A 2010 study published in the journal, Energy avoidance of excess or extremes of GHG (greenhouse gases) Policy by researchers from Oxford University, predicted that emissions [4]. The 1st generation biofuels which are extracted demand would surpass supply by 2015, unless forced by from oil crops like rapeseed oil, sugarcane, sugar beet, and strong recession pressures caused by reduced supply or gov- maize [5] including vegetable oils and animal fat using ernment interference [1]. It relates to long-term degradation conventional technology have attained profitable levels of intheavailabilityofpetroleum.Onanaverage,humanutilizes production [6]. But the use of 1st generation biofuels has fossil fuels which results in the release of 29 gigatonnes raised questions and controversies due to their impact on CO each year. These figures point towards Hubbert’s peak theglobalfoodmarketandfoodsecurity[7]. For example, the demand for biofuels may impose additional pressure on theory according to which peak oil is the point in time when naturalresourcebase,withpotentiallyharmfulsurrounding the maximum rate of petroleum extraction is reached, after and social concerns [8]. which the rateRETRACTED of production is expected to enter terminal Energy shortage refers to the crisis of energy resources decline [2]. This critical situation has led to the emergence to an economy. There has been a massive uplift in the of an eco-friendly, alternative fuel biodiesel. According to global demand for energy in recent years as a result of United States Environmental Protection Agency, the volume industrial development and population growth. Since the requirement of the biomass based diesel in 2013 is 1.28 million early 2000s, the demand for energy, especially from liquid gallons which accounts for 1.13% of the total renewable fuels. fuels, and limits on the rate of fuel production have created This, combined with growing demand, significantly increases such a stage leading to the current energy crisis. The cause the worldwide prices of petroleum derived products. Most maybeoverconsumption,agedinfrastructure,chokepoint important concerns are the availability and price of liquid fuel disruption or crisis at oil refineries, and port facilities that for transportation [3]. confine fuel supply. 2 Biotechnology Research International In this paper, we have focused on addressing the global oil Table 1: Amount of oil produced by various feedstocks [26]. shortage by replacing nonrenewable source of oil reservoir by evergreen renewable natural source, algae oil. Feedstock Liters/hectare Microalgae cover unicellular and simple multicellular Castor 1413 microorganisms, including prokaryotic microalgae that are Sunflower 952 cyanobacteria (chloroxybacteria) and eukaryotic microalgae Palm 5950 for example, green algae (chlorophyta), and diatoms (bacillar- Soya bean 446 iophuta). These microalgae are beneficial as they are capable Coconut 2689 of all year production [9]; they grow in aqueous media and Algae 100000 hence need less water than terrestrial crops [10]; microalgae can be cultivated in brackish water on noncultivated land [11] andtheyhaverapidgrowthpotentialandhaveoilcontent 1.1. Unavailability of Resources. The feedstock is not available up to 20–50% dry weight of biomass [12, 13]. Unlike other for the biodiesel production as it is unethical to use these cash biodeisel corps microalgae does not require herbicides or cropsforfuelwhiletheworldiswitnessingfoodshortage. pesticides [13], microalgae also produce beneficial coproducts Theprimarycauseforglobalfoodshortagemaybedueto such as proteins and residual biomass after oil extraction, overconsumption, overpopulation, and overexploitation. which can be used as feed or fertilizer or can be fermented to produce ethanol or methane [14]; the oil yield, can be signifi- 1.2. Peak Oil. Peak oil is the point where maximum extraction cantly increased by varying growth conditions to modulate of petroleum is reached, after which the rate of production biochemical composition of algal biomass [15]. They also enters decline stage [28]. The invention of new fields, the produce beneficial coproducts such as proteins and residual development of new production techniques, and the misuse biomass after oil extraction, which can be used as feed or of eccentric supplies have resulted in productivity levels, fertilizer or can be fermented to produce ethanol or methane which endure to increase. Peak oil is often confused with oil [16]; the oil yield can be significantly increased by varying depletion; peak oil is the point of maximum extraction, while growth conditions to modulate biochemical composition of depletion indicates the period of falling in production and algal biomass [17]. supply. The algal biofuel technology includes selection of specific species for production and extraction of valuable co-products [18]. The algaes are bioengineered for achieving advanced 2. Sources of Biodiesel photosynthetic efficiencies through continued development Avarietyofoilscanbeusedtoproducebiodiesel.These of production system [19]. Challenges include, only single include the following. species cultivation techniques which are developed so far and are recommended to follow globally, but mixed culture may yield more algae oil than mono culture [20]. Algae oil may 2.1. Virgin Oil Feedstock. Rapeseed and soybean oils are most be less economically which includes techniques such as water commonly used, mostly in U.S [29]. They also can be obtained pumping, CO2 transmission, harvesting and extraction [21]. from Pongamia, field pennycress, Jatropha, and other crops Fatal compounds such as NO and SO are produced in high such as mustard, jojoba, flax, sunflower, palm oil, coconut, concentrations as fuel gases, which are not environmental and hemp. Several companies in various sectors are piloting friendly [22]. research on Jatropha curcas, a poisonous shrub-like tree that Microalgae are sunlight-driven cell factories that trans- produces seeds, considered by many to be a feasible source of form carbon dioxide to potential biofuels, foods, feeds, biodieselfeedstockoil[30]. and high-value bioactive. In addition, these photosynthetic microorganisms are useful in bioremediation applications 2.2. Waste Vegetable Oil (WVO). Vegetable oil is an alterna- and as nitrogen fixing biofertilizers. This review focuses on tive fuel source for diesel engines and for heating oil burners. microalgae as a potential basis of biodiesel. The viscosity of the vegetable oil plays an important role in The idea of using microalgae as a source of fuel is the atomization of fuel for engines designed to burn diesel not novel, but it is now taken seriously because of the fuel;otherwise,itcausesimpropercombustionandcauses increasing price of petroleum and, more significantly, the engine collapse. The most important vegetable oils used as emerging issues about global warming and greenhouse effect fuel are rapeseed oil (also known as canola oil, which is mostly that is associatedRETRACTED with incinerating fossil fuels. Thus, several used in the United States and Canada). In some places of the companies are involved in the production of algal fuel in United States, the use of sunflower oil as fuel tends to increase order to decrease global warming and greenhouse effect. [31]. Some island nations use coconut oil as fuel to lower their Biodiesel is an established fuel. In the United States, biodiesel expenses and their dependence on imported