SUSTAINABLE ENERGY PRODUCTION USING DUCKWEED BIOMASS THROUGH OPTIMIZED WASTE-TO-FUEL TECHNOLOGIES

The quest for renewable energy alternatives to fossil fuels that have low carbon footprints has become a global priority. In response to the urgent call for significant decreases in Greenhouse Gas (GHG) emission, the Renewable Fuel Standard provision of the Federal Energy Independence and Security Act of 2007 requires 36 billion gallons of biofuels to be used in our nation's transportation fuel supply by the year 2022. Of these, 21 billion gallons are expected to derive from cellulosic and other 'second generation (i.e. non-corn starch-based)' biofuels. Two major alternative biofuel strategies are being pursued worldwide. In the so-called second generation biofuels, technologies are being optimized for conversion of cellulosic feedstock materials into sugars for subsequent fermentation. However, cellulose is heavily fortified in plant-based feedstocks and requires significant energy input and enzyme pretreatments to aide its transformation into fermentable sugars with current technologies. With current estimated production cost of cellulosic ethanol at about 3 times that of corn-starch ethanol, it is unclear if and when cellulosic bioethanol will become economically viable. The situation with algal biodiesel, also called third generation biofuel, is perhaps even a bit worse since the scale-up of this approach has been particularly problematic. One of the major issues, for example, is the economical separation of algal biomass from the aqueous medium in which it has been growing. A recent life cycle analyses of these different biofuel feedstocks have raised significant concerns over their true environmental impact, especially for algal biofuels. In our consideration of alternative sources of renewable biomass that can be 'domesticated' for energy production, we believe the Lemnaceae family of aquatic plants, commonly called duckweeds, holds great potential for the development of a commercially viable feedstock as a micro-crop for fuel production. The chief characteristics that make duckweeds ideal for waste-to-energy conversion are their rapid growth rate, easy harvesting potential, and ability to grow directly on existing wastewater sites. To realize these advantages of this micro-crop system, my laboratory will carry out research to develop new aquatic agronomic methods for deploying selected duckweed strains as a waste-to-fuel platform on local sites in New Jersey. In the next five years, we endeavor to 1) create a functional and sustainable pilot pipeline in which bioethanol can be produced from duckweed harvested from wastewater sites, 2) optimization of the harvesting and processing methods to improve the economic output of the system, 3) carry out a full Life-Cycle-Analysis of the completed demonstration pipleline by the end of the 5 year project, and 4) educating the public and relevant agencies on the potential of this novel micro-crop and facilitating research on this aquatic plant model as well as its applications.