Current contributions of microalgae in global biofuel production; cultivation techniques, biofuel varieties and promising industrial ventures

Dwindling fossil fuel supplies and the world's increasing carbon footprint has led to the emergence of biofuels as a solution. However, utilizing conventional plant sources for biofuels require resource-intensive cultivation and pose a food security issue. Microalgae biomass are sustainable alternative over conventional biomass for the generation of biofuels. This review critically analyses current developments in the production of microalgal biofuels, current global production efforts and future prospects in the field. While biodiesel, bioethanol, biogas, biohydrogen and hydrocarbons can be synthesized from the composition of microalgae, strain selection is necessary to identify appropriate species with suitable biochemical compositions. To-date, microalgal biofuel is costly compared to conventional biofuels due to its energy-intensive processing techniques and rigorous cultivation conditions. Future prospects including the usage of nanotechnology during cultivation and novel bioflocculants during harvesting were recommended to reduce the price of biodiesel to be competitive with petroleum prices. Recent microalgal biofuel initiatives in Malaysia, Japan and Turkey have shown great potential, particularly for aviation, however challenges still exist in terms of scalability and reliance on conventional fuel. Although microalgal biofuels currently underperform in terms of engine performance compared to fossil fuels and slight impurities from processing may be present, the advantage of sustainability of biofuel must not be discounted. Nations are already penalizing carbon emissions through carbon taxes and schemes encouraging the use of cleaner energy sources. If stringent policies are introduced to regulate and incentivize the production of microalgae biofuel, widespread adoption of these fuels will soon materialize allowing communities access to cleaner fuels.