Algae are defined as any organisms which are plant-like and perform photosynthesis. Based on their morphology and size, algae are typically subdivided into two major categories;macroalgae and microalgae (microphytes). Macroalgae, for example kelps, are composed of multiple cells which organize to structures resembling roots, stems, and leaves of higher plants. Microalgae are commonly microscopic algae found in fresh water and marine systems. Microalgae alarge and diverse group of unicellular are microscopic heterotrophic–autotrophic photosynthesizing organisms that inhabit many different types of environments, including
freshwater, brackish water, and seawater. Alternative biofuel source have gained much attention these days because they have numerous advantages compared with lingo cellulosic feed stocks. Accordingly, microalgae have the potential to synthesize 30fold more oil per hectare than terrestrial plants. They are currently widely used in industry in the synthesis of pigments and additives, as a source of protein, and in biofuel production. Microalgae are sunlight driven cell factories
that convert carbon dioxide to potential biofuels, foods, feeds and high value bio actives and can provide several different
types of renewable biofuels. Microalgae are a diverse group of prokaryotic and eukaryotic photosynthetic microorganisms that grow rapidly due to their simple structure. They can potentially be employed for the production of biofuels in an economically effective and environmentally sustainable manner. Microalgae have been investigated for the production of a number of different bio fuels including biodiesel, bio oil, bio gas, and bio hydrogen. To date, various thermochemical conversion routes of microalgae have been investigated. There are few reports on pyrolysis of microalgae.