Algal biorefinery for sustainable development and the challenges

Microalgae are a promising biofuel feedstock, since they can mitigate carbon dioxide through photosynthesis and may not compete with food production for farmland. A lot of research has been done in microalgal biology, culture, harvest, biofuel conversion and so forth. However, both academia and industry suggest that microalgae-based biofuel production is still in its infancy due to a lack of economic efficiency. Microalgae contain lipids, carbohydrates (starch and cellulose), proteins and a wide range of inorganic and organic molecules. These components can be converted into biofuels, feed, food and other high-value products such as cosmetics, fine chemicals and pharmaceuticals. Through microalgal biorefinery, multiple products (low-volume high-value bio-products and low-value high-volume biofuels) can be produced, thus maximising the value derived from microalgal biomass. However, some uncertainties with risks also exist during the process, and should be forecast well in advance and then minimised or even eliminated. The main challenges during microalgal biorefinery include water footprint, energy balance, production costs, market potential and policy influence. In an effort to mitigate these uncertainties, further research and development in the field is still required.