Autotrophic algae capture energy from the sun to synthesize their own food
Research demonstrates that some species of algae could be utilized as biomass in biorefineries to yield ethanol (Efremenko et al., 2012). Ethanol is a source of energy for domestic and industrial uses. There have been issues that limited research exists in the utilization of microalgae in ethanol production, and more research is needed to fully utilize the benefits of algae in biorefineries (Parmar, Singh, Pandey, Gnansounou & Madamwar, 2011).
Algae are either autotrophic or heterotrophic. Autotrophic algae capture energy from the sun to synthesize their own food through photosynthesis. The food manufactured by the autotrophic algae is stored in the form of carbohydrates. On the other hand, heterotrophic algae obtain small molecules from the environment and convert them to fat, oil or proteins. Algae are either microalgae (microscopic) or macroalgae (macroscopic). Microalgae have high ability for converting photons, and this implies that they could produce a lot of carbohydrates needed in a biorefinery over a short period of time (Chen et al., 2011; Chen et al., 2013; John, Anisha, Nampoothiri & Pandey, 2011). Some biorefineries could use petroleum as the source of energy for heating biomass. Microalgae have been confirmed to withstand high levels of carbon dioxide from petroleum-based sources of energy (Demirbas, 2011).
