Microalgae as Biofuels Feedstocks: An Assessment of the Yields and Fuel Quality

We need to move away from our dependence on fossil fuels as an energy source but there is a general reluctance to abandon liquid hydrocarbons as transportation fuels. This opens up a large market that can be addressed by renewable and sustainably produced biofuels. Algae are considered important contributors to feedstocks for future biofuels production. The high biomass productivity and associated high lipid yields make algae an attractive option. With the high oil yields, algae address the energydense fuels market, which is a niche market segment not fully addressed by other biofuels without encroaching on valuable crop land and affecting food commodity prices. We illustrate the theoretical maximum conversion efficiency of solar energy into organic products and the pathways of converting these products into fuel precursors. One of the main questions we aim to answer is how algal fuels compare to traditional biodiesel fuels, with regards to fuel quality and processing parameters. We present data on the oil yields and lipid profile of algae and extrapolate to the fuel quality of biofuels. We are also using fermentable carbohydrates present in the non-lipid portion of algae to address additional biofuels markets such as ethanol or other advanced biofuels. Our data indicate that algal fuels compare favorably to traditional biofuels, and we illustrate that algae have great potential as biofuels feedstocks, but there are a number of challenges associated with reducing the uncertainties around the overall production process.