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Journal ArticleDOI

Biodiesel from microalgae.

Yusuf Chisti1
01 May 2007-Biotechnology Advances (Elsevier)-Vol. 25, Iss: 3, pp 294-306
TL;DR: As demonstrated here, microalgae appear to be the only source of renewable biodiesel that is capable of meeting the global demand for transport fuels.
About: This article is published in Biotechnology Advances.The article was published on 2007-05-01. It has received 9030 citations till now. The article focuses on the topics: Renewable fuels & Biodiesel.
Citations
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Journal ArticleDOI
TL;DR: The various aspects associated with the design of microalgae production units are described, giving an overview of the current state of development of algae cultivation systems (photo-bioreactors and open ponds).
Abstract: Sustainable production of renewable energy is being hotly debated globally since it is increasingly understood that first generation biofuels, primarily produced from food crops and mostly oil seeds are limited in their ability to achieve targets for biofuel production, climate change mitigation and economic growth. These concerns have increased the interest in developing second generation biofuels produced from non-food feedstocks such as microalgae, which potentially offer greatest opportunities in the longer term. This paper reviews the current status of microalgae use for biodiesel production, including their cultivation, harvesting, and processing. The microalgae species most used for biodiesel production are presented and their main advantages described in comparison with other available biodiesel feedstocks. The various aspects associated with the design of microalgae production units are described, giving an overview of the current state of development of algae cultivation systems (photo-bioreactors and open ponds). Other potential applications and products from microalgae are also presented such as for biological sequestration of CO 2 , wastewater treatment, in human health, as food additive, and for aquaculture.

5,158 citations


Cites background from "Biodiesel from microalgae."

  • ...5 h during the exponential growth phase [21]....

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  • ...The average lipid content varies between 1 and 70% but under certain conditions some species can reach 90% of dry weight [14,15,21,32]....

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  • ...They have much higher growth rates and productivity when compared to conventional forestry, agricultural crops, and other aquatic plants, requiring much less land area than other biodiesel feedstocks of agricultural origin, up to 49 or 132 times less when compared to rapeseed or soybean crops, for a 30% (w/w) of oil content in algae biomass [21]....

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Journal ArticleDOI
TL;DR: In this article, the authors reviewed the technologies underpinning microalgae-to-bio-fuels systems, focusing on the biomass production, harvesting, conversion technologies, and the extraction of useful co-products.
Abstract: Sustainability is a key principle in natural resource management, and it involves operational efficiency, minimisation of environmental impact and socio-economic considerations; all of which are interdependent. It has become increasingly obvious that continued reliance on fossil fuel energy resources is unsustainable, owing to both depleting world reserves and the green house gas emissions associated with their use. Therefore, there are vigorous research initiatives aimed at developing alternative renewable and potentially carbon neutral solid, liquid and gaseous biofuels as alternative energy resources. However, alternate energy resources akin to first generation biofuels derived from terrestrial crops such as sugarcane, sugar beet, maize and rapeseed place an enormous strain on world food markets, contribute to water shortages and precipitate the destruction of the world's forests. Second generation biofuels derived from lignocellulosic agriculture and forest residues and from non-food crop feedstocks address some of the above problems; however there is concern over competing land use or required land use changes. Therefore, based on current knowledge and technology projections, third generation biofuels specifically derived from microalgae are considered to be a technically viable alternative energy resource that is devoid of the major drawbacks associated with first and second generation biofuels. Microalgae are photosynthetic microorganisms with simple growing requirements (light, sugars, CO 2 , N, P, and K) that can produce lipids, proteins and carbohydrates in large amounts over short periods of time. These products can be processed into both biofuels and valuable co-products. This study reviewed the technologies underpinning microalgae-to-biofuels systems, focusing on the biomass production, harvesting, conversion technologies, and the extraction of useful co-products. It also reviewed the synergistic coupling of microalgae propagation with carbon sequestration and wastewater treatment potential for mitigation of environmental impacts associated with energy conversion and utilisation. It was found that, whereas there are outstanding issues related to photosynthetic efficiencies and biomass output, microalgae-derived biofuels could progressively substitute a significant proportion of the fossil fuels required to meet the growing energy demand.

4,432 citations


Cites background from "Biodiesel from microalgae."

  • ...Sustainability is key to natural resource management or exploitation and it involves operational, environmental and socio-economic considerations; all of which are interdependent....

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  • ...Judicious exploitation of microalgae could meet these conditions and therefore make a significant contribution to meeting the primary energy demand, while simultaneously providing environmental benefits [8]....

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  • ...The outlined combination of potential biofuel production, CO2 fixation, biohydrogen production, and bio-treatment of wastewater underscore the potential applications of microalgae....

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  • ...It identifies the knowledge gaps within each area which can be targeted for focused research and innovation aimed at sustainable development of algae-based biofuel technologies....

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  • ...Prokaryotic cells (cyanobacteria) lack membrane-bound organelles (plastids, mitochondria, nuclei, Golgi bodies, and flagella) and are more akin to bacteria rather than algae....

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Journal ArticleDOI
TL;DR: An updated evaluation of potential target structures using similar selection methodology, and an overview of the technology developments that led to the inclusion of a given compound are presented.

3,536 citations

Journal ArticleDOI
TL;DR: The experiments showed that the eustigmatophyte Nannochloropsis sp.
Abstract: Thirty microalgal strains were screened in the laboratory for their biomass productivity and lipid content. Four strains (two marine and two freshwater), selected because robust, highly productive and with a relatively high lipid content, were cultivated under nitrogen deprivation in 0.6-L bubbled tubes. Only the two marine microalgae accumulated lipid under such conditions. One of them, the eustigmatophyte Nannochloropsis sp. FM102: 100–112. © 2008 Wiley Periodicals, Inc.

2,714 citations


Cites background from "Biodiesel from microalgae."

  • ...Today, the potential value of microbial, and particularly microalgal, photosynthesis to produce biofuels is, however, widely recognized (Chisti, 2007; Donohue and Cogdell, 2006; Hu et al., 2008; Huntley and Redalje, 2007; Schenk et al., 2008)....

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  • ...The total content of lipids in microalgae may vary from about 1–85% of the dry weight (Borowitzka, 1988; Chisti, 2007; Spoehr and Milner, 1949), with values higher than 40% being typically achieved under nutrient limitation....

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  • ...Plastic lined, paddle-wheel mixed raceway ponds are much less expensive to build and operate than PBR (but see Chisti, 2007 for a different opinion)....

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  • ...One hectare of sunflower or rapeseed can produce a maximum of about 1,000 L of oil per year, while a hectare of oil palm, currently the best source, yields up to 6,000 L (Chisti, 2007)....

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  • ...For example there is a limit to the extent of total unsaturation (iodine value) and to the content of fatty acids with four and more double bonds (Chisti, 2007)....

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Journal ArticleDOI
TL;DR: A review of second generation biodiesel production systems using microalgae can be found in this paper, where the main advantages of second-generation microalgal systems are that they: (1) have a higher photon conversion efficiency (as evidenced by increased biomass yields per hectare): (2) can be harvested batch-wise nearly all-year-round, providing a reliable and continuous supply of oil: (3) can utilize salt and waste water streams, thereby greatly reducing freshwater use: (4) can couple CO2-neutral fuel production with CO2 sequestration: (
Abstract: The use of fossil fuels is now widely accepted as unsustainable due to depleting resources and the accumulation of greenhouse gases in the environment that have already exceeded the “dangerously high” threshold of 450 ppm CO2-e. To achieve environmental and economic sustainability, fuel production processes are required that are not only renewable, but also capable of sequestering atmospheric CO2. Currently, nearly all renewable energy sources (e.g. hydroelectric, solar, wind, tidal, geothermal) target the electricity market, while fuels make up a much larger share of the global energy demand (∼66%). Biofuels are therefore rapidly being developed. Second generation microalgal systems have the advantage that they can produce a wide range of feedstocks for the production of biodiesel, bioethanol, biomethane and biohydrogen. Biodiesel is currently produced from oil synthesized by conventional fuel crops that harvest the sun’s energy and store it as chemical energy. This presents a route for renewable and carbon-neutral fuel production. However, current supplies from oil crops and animal fats account for only approximately 0.3% of the current demand for transport fuels. Increasing biofuel production on arable land could have severe consequences for global food supply. In contrast, producing biodiesel from algae is widely regarded as one of the most efficient ways of generating biofuels and also appears to represent the only current renewable source of oil that could meet the global demand for transport fuels. The main advantages of second generation microalgal systems are that they: (1) Have a higher photon conversion efficiency (as evidenced by increased biomass yields per hectare): (2) Can be harvested batch-wise nearly all-year-round, providing a reliable and continuous supply of oil: (3) Can utilize salt and waste water streams, thereby greatly reducing freshwater use: (4) Can couple CO2-neutral fuel production with CO2 sequestration: (5) Produce non-toxic and highly biodegradable biofuels. Current limitations exist mainly in the harvesting process and in the supply of CO2 for high efficiency production. This review provides a brief overview of second generation biodiesel production systems using microalgae.

2,254 citations


Cites background from "Biodiesel from microalgae."

  • ...biodiesel production than traditional crops on an area basis (Table 1; [29])....

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  • ...Using highly efficient closed algal bioreactors for biomass feedstock and biomethane production, microalgae can now be grown in large amounts (150–300 tons per ha per year; [29, 138])....

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  • ...Of particular interest are lignocellulosic technologies and microalgae ([29, 76, 96, 155]; Table 1)....

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  • ...Algal production systems are recognized as among the most efficient means of producing biomass for fuel (Table 1; [16, 29, 162]) and further improvements are likely...

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  • ...Presented yields are for peak performing crops [16, 29, 162], although for example, Malaysia’s average oil palm yield is actually about 4 tons/ha [119]....

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References
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Journal ArticleDOI
TL;DR: The first use of microalgae by humans dates back 2000 years to the Chinese, who used Nostoc to survive during famine, while future research should focus on the improvement of production systems and the genetic modification of strains.

3,793 citations


"Biodiesel from microalgae." refers background or methods in this paper

  • ...Oil productivity of many microalgae greatly exceeds the oil productivity of the best producing oil crops....

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  • ...The largest raceway-based biomass production facility occupies an area of 440,000 m2 (Spolaore et al., 2006)....

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  • ...…using photobioreactors and raceway units of dimensions similar to those in Table 3 have indeed been used extensively in commercial operations (Terry and Raymond, 1985; Molina Grima, 1999; Molina Grima et al., 1999; Tredici, 1999; Pulz, 2001; Lorenz and Cysewski, 2003; Spolaore et al., 2006)....

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  • ...Although these fatty acids have much higher oxidative stability compared with DHA and EPA, the European Standard EN 14214 limits linolenic acid methyl ester content in biodiesel for vehicle use to 12% (mol)....

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  • ...Microalgae commonly double their biomass within 24 h. Biomass doubling times during exponential growth are commonly as short as 3.5 h. Oil content in microalgae can exceed 80% by weight of dry biomass (Metting, 1996; Spolaore et al., 2006)....

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Journal ArticleDOI
TL;DR: In this paper, various methods of preparation of biodiesel with different combination of oil and catalysts have been described and technical tools and processes for monitoring the transesterification reactions like TLC, GC, HPLC, GPC, 1H NMR and NIR have also been summarized.
Abstract: Biodiesel is gaining more and more importance as an attractive fuel due to the depleting fossil fuel resources. Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feed stock like vegetable oils and animal fats. It is produced by transesterification in which, oil or fat is reacted with a monohydric alcohol in presence of a catalyst. The process of transesterification is affected by the mode of reaction condition, molar ratio of alcohol to oil, type of alcohol, type and amount of catalysts, reaction time and temperature and purity of reactants. In the present paper various methods of preparation of biodiesel with different combination of oil and catalysts have been described. The technical tools and processes for monitoring the transesterification reactions like TLC, GC, HPLC, GPC, 1H NMR and NIR have also been summarized. In addition, fuel properties and specifications provided by different countries are discussed.

3,232 citations


"Biodiesel from microalgae." refers background in this paper

  • ...Transesterification is catalyzed by acids, alkalis (Fukuda et al., 2001; Meher et al., 2006) and lipase enzymes (Sharma et al., 2001)....

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  • ...Economics of biodiesel production . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....

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  • ...…oil (Roessler et al., 1994; Sawayama et al., 1995; Dunahay et al., 1996; Sheehan et al., 1998; Banerjee et al., 2002; Gavrilescu and Chisti, 2005); and photobiologically produced biohydrogen (Ghirardi et al., 2000; Akkerman et al., 2002; Melis, 2002; Fedorov et al., 2005; Kapdan and Kargi, 2006)....

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  • ...Technology for producing and using biodiesel has been known for more than 50 years (Knothe et al., 1997; Fukuda et al., 2001; Barnwal and Sharma, 2005; Demirbas, 2005; Van Gerpen, 2005; Felizardo et al., 2006; Kulkarni and Dalai, 2006; Meher et al., 2006)....

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Journal ArticleDOI
TL;DR: Economics of monoseptic production of microalgae in photobioreactors and the downstream recovery of metabolites are discussed using eicosapentaenoic acid (EPA) recovery as a representative case study.

2,220 citations


"Biodiesel from microalgae." refers methods in this paper

  • ...The estimation methods used have been described previously (Humphreys, 1991; Molina Grima et al., 2003)....

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  • ...5), centrifugation, and other means (Molina Grima et al., 2003)....

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Journal ArticleDOI
TL;DR: Biodiesel (fatty acid methyl esters), which is derived from triglycerides by transesterification with methanol, has attracted considerable attention during the past decade as a renewable, biodegradable, and nontoxic fuel.

2,185 citations


"Biodiesel from microalgae." refers background or methods in this paper

  • ...This is likely to change as several companies are attempting to commercialize microalgal biodiesel....

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  • ...Technology for producing and using biodiesel has been known for more than 50 years (Knothe et al., 1997; Fukuda et al., 2001; Barnwal and Sharma, 2005; Demirbas, 2005; Van Gerpen, 2005; Felizardo et al., 2006; Kulkarni and Dalai, 2006; Meher et al., 2006)....

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  • ...These include methane produced by anaerobic digestion of the algal biomass (Spolaore et al., 2006); biodiesel derived from microalgal oil (Roessler et al., 1994; Sawayama et al., 1995; Dunahay et al., 1996; Sheehan et al., 1998; Banerjee et al., 2002; Gavrilescu and Chisti, 2005); and…...

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  • ...Alkali-catalyzed transesterification is about 4000 times faster than the acid catalyzed reaction (Fukuda et al., 2001)....

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  • ...Yield of methyl esters exceeds 98% on a weight basis (Fukuda et al., 2001)....

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Journal ArticleDOI
TL;DR: Biodiesel is an alternative diesel fuel that is produced from vegetable oils and animal fats, which consists of the monoalkyl esters formed by a catalyzed reaction of the triglycerides in the oil or fat with a simple monohydric alcohol.

2,164 citations


"Biodiesel from microalgae." refers background in this paper

  • ...Technology for producing and using biodiesel has been known for more than 50 years (Knothe et al., 1997; Fukuda et al., 2001; Barnwal and Sharma, 2005; Demirbas, 2005; Van Gerpen, 2005; Felizardo et al., 2006; Kulkarni and Dalai, 2006; Meher et al., 2006)....

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