Development of Advanced, High-Energy Density Biofuels Based on Algal Feedstocks

As concerns over U.S. energy security and global warming increase, the need to develop alternative and renewable sources of energy is more important than ever before. One promising renewable energy scenario involves the use of microalgal feedstocks. Microalgae are unicellular, photosynthetic microorganisms that are abundant in aquatic and terrestrial environments everywhere on earth. Microalgae have the potential to directly convert sunlight and carbon dioxideinto triacylglycerols (TAGs) that can be converted into a variety of biofuels. The Department of Energy (DOE) supported the Aquatic Species Program (ASP) at the National Renewable Energy Laboratory (NREL) for 18 years. This program was designed to collect and engineer microalgal strains for increased oil production as well as to investigate the biochemical fundamentals of algal oil accumulation and cultivation of select strains of algae in outdoor raceway ponds. Unfortunately, DOE terminated the ASP in 1996 citing reasons of decreasing budgets and the inability of the technology to compete with $20/barrel petroleum oil. Even though recent events in the world energy markets over the last few years have rejuvenated interest in the development of algal-based biofuels, several technical and economic barriers are yet to be overcome in microalgal production of diesel fuel substitutes. This presentation will provide a brief overview of past algal research at NREL and an evaluation of the current potential and challenges of microalgal biofuels production from a federal lab perspective. The presentation will also focus on two specific research initiatives which are part of NREL’s re-established its algal biofuels research program. For example, to identify strains of microalgae exhibiting superior biofuels production, NREL has engaged in a microalgal bioprospecting project that uses Fluorescence Activated Cell Sorting (FACS) as a means to rapidly isolate and identify unique microalgal strains with significant oil production capabilities from a variety of aquatic environments in the Southwestern United States. As part of yet another project, NREL is also developing fast, high-throughput methods to correlate and predict the lipid content in algal biomass based on Near Infrared (NIR) spectroscopy. We are currently developing NIR calibration models for determining the lipid content and composition (neutral versus polar) in microalgal biomass. The ultimate goal of this work is to develop robust prediction models that can then be applied to the rapid assessment of lipid production in microalgae obtained from various sources.