13. Liquid Fuels Production from Algal Biomass

Energy crisis is looming the global economy and environment. The rate at which fossil fuels are depleting, a necessity of alternate fuel has been gaining importance. The use of fossil fuels for energy is unsustainable and causes build up of greenhouse gases in the atmosphere leading to global warming. Biofuels store energy chemically that can be harnessed easily. It can also be used in existing combustion engines after blending with petroleum diesel to various degrees. No separate transportation infrastructures would be required for such fuels (Amaro et al., Appl Energy 88:3402–3410, 2011). In biorefinery concept, every component of the biomass material would be used to produce commercially important products. At present, first generation biofuels are produced using sucrose and starch crops. Second generation biofuels are produced using lignocellulosic biomass. Lignocellulosic biomass gained importance because of their abundant availability but need of pretreatment and saccharification processes has hindered their usage as feedstock. Moreover, bioenergy production using agricultural crops or agricultural wastes as feedstock is disadvantageous as resources for water and agriculture lands are limited (Li et al., Appl Microbiol Biotechnol 81:629–636, 2008). Algal biomass has been considered as third generation feedstock for biofuel production (Metzger and Largeau, Appl Microbiol Biotechnol 66:486–496, 2005). Many algal species having high lipid content thus could be explored for oleo-fuel generation. Similarly, algal species having high carbohydrate content can be exploited for bioethanol or biogas production.