Algae for biofuels and energy / Michael A. Borowitzka, Navid R. Moheimani, editors

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The concept of using algae as a source of renewable fuels and energy is quite an old one, dating back at least to 1931, but one which gained much attention during the 1990´s oil crisis and then, once again, more recently interest in algae as a source of biofuels has risen dramatically. The potential attractive features of algae have often been listed, but as yet the high cost of producing algae biomass means that algal biofuels as an economical, renewable and sustainable source of biofuels and bioenergy is still somewhat off in the future. Microalgae are currently probably the most studied potential source of biofuels, and in the US alone there are some 30+ companies working in the area and total investment in R&D is in excess of several bil1ion $US worldwide. This book focuses on microalgae rather than seaweeds, as microalgae are the most attractive for renewable energy production, especial1y the production of biodiesel, although seaweed biomass can also be used. The aim ofthis book is to review in detail the most important aspects of the microalgae-to-bioenergy process, with an emphasis on microalgae as sources of lipids for the production of biodiesel and as potential sources of hydrogen. The book is meant as a guide and resource for both the experienced practitioners in the field and to those newer to this exciting field of research. However, no single book can cover all aspects of the production of bioenergy from algae; for example, we do not cover the fermentation of algal biomass to produce methane, nor the fermentation of algal sugars to ethanol or butanol. This book begins (Chap. 1) with an introduction to the history and developments over the last 80 years or so in the area of large-scale and commercial-scale culture of microalgae and the extensive literature that is available. Much can be leamed from the extensive research that has been carried out, and by knowing this history (some of which is not easily accessible) we can avoid repeating past mistakes. One of the key attractions of microalgae is the high lipid content of some species and the lipid and fatty acid composition and metabolism is covered in Chap. 2 by Guschina and Harwood, and the production and properties of biodiesel from these algal oils is considered in detail by Knothe in Chap. 12, while Chap. 3 by Peters et al. considers hydrogenases, nitroginases and H2 production by water-oxidizing phototrophs (i.e. algae and cyanobacteria). The first step in developing an algae bioenergy process is species and strain selection and this topic is considered in detail in Chap. 4. Chapter 5 by Beardall and Raven focuses on light and inorganic carbon supply as key limiting factors to growth in dense cultures and Chap. 6 by Rasala et al. looks at how genetic engineering may be used to improve and modify algae strains.