From Pond Scum to Fuel
The National Alliance for Advanced Biofuels and Bioproducts (NAABB) was formed in 2009 to vie for funding from the Department of Energy’s Office of Biomass Program to work on development of technologies for algal biofuels commercialization. Last year DOE Secretary Steven Chu announced NAABB’s award in which, as a public-private partnership, the NAABB will devote $49 million of federal funds along with about $20 million of cost-share commitments from its partners to the development of these objectives. The NAABB framework for a sustainable algal biofuels industry includes a research program in algal biology, cultivation, harvesting and lipid extraction, conversion into fuels and coproducts, enveloped by a sustainability modeling and analysis program.
The NAABB program has focused on developing technologies and proving the viability of algae as a biofuel feedstock across six primary areas that include algal strain development, cultivation methodology, harvesting and extraction systems, lipid and biomass conversion to fuels and power, agricultural and chemical coproduct development, and understanding the economic, energetic and environmental sustainability of these processes
Scientists believe that there are over 50,000 species of algae in the world with a very broad diversity. These organisms range from the macroalgae, which make up many of the “sea weeds” in our oceans, to unicellular microalgae, many of which are invisible to the naked eye. There is very little known about most of these species, specifically on their ability to accumulate lipids. Therefore, prospecting nature for strains that have high biomass and lipid productivity has been one of NAABB’s goals. To date, NAABB investigators from Brooklyn College and the University of Washington have isolated over 800 strains of algae and screened over 400 of these for productivity. About 60 of these strains look to be promising candidates for further evaluation, characterization and testing in outdoor environments.
Similarly, little is known about the genome and metabolic regulation process of most algae. In fact, only a few algal genomes have been fully sequenced. The NAABB consortium is working with two model microalgal organisms that were chosen because one has a fully characterized genome and the tools for genetically manipulating this organism are quite extensive. NAABB investigators are already working through sections of genomic data combing for important genes that regulate the metabolic processes regulating hydrocarbon biosynthesis. Additionally, work at Los Alamos National Laboratory and the Donald Danforth Plant Science Center is generating the genomic sequence for a fresh water organism and a saltwater organism, which are being used by the consortium as major production organisms.
The consortium has a number of outdoor test bed facilities. As an example, a new innovative raceway design for cultivation is being developed at the University of Arizona, called the ARID (Arid Raceway Integrated Design) system. The water temperatures in the southwest regions of the United States can swing as much as 15 degrees centigrade during the course of the day. In extreme cases, experienced this winter, even Tucson will see deep freezes halting culture growth and productivity. The ARID system uses a unique design that cascades water into different depth ponds during the day and night. Therefore, the earth mass around the pond acts as an insulator and heat exchanger to control the temperature of the water for algal cultivation.
If one looks at a pond containing microalgae cultures, 99.9 percent of the culture is water. So separating this quantity of water from the microalgae that contain the oils and biomass of interest consumes much energy. Most commercial systems, available for harvesting algae and extracting lipids (e.g., centrifuges), consume much more energy than can be returned by the collected product. Thus, NAABB is developing a number of technologies that it hopes will lower this energy demand. One such technology is an electrocoagulation system being developed by researchers at Texas A&M University. This device concentrates the algae in the water, making it easier to collect through filtration or decantation. These types of technologies, typically used for high volume water treatment systems, are now being modified and applied to algal harvesting.
Other, more developmental systems, such as LANL’s acoustic harvester, use sound waves to concentrate algal particles in a standing wave created in a fluid flow-through cavity. When the acoustic waves are turned on, the algal particles coagulate. After sufficient biomass is concentrated the acoustic waves are turned off and the algae falls out of solution. This technology received an R&D 100 award. The device is being developed in conjunction with Solix Biosystems. The goal of the NAABB consortium is to show that these technologies can produce liquid transportation fuels—biodiesel, diesel, jet fuel and gasoline. NAABB announced last year that Catilin Inc., an industry member of the consortium recently acquired by Albermarle Corporation, successfully used its proprietary catalyst developed with partner Iowa State University to produce the consortium's first batch of biodiesel from algal oil. Catilin’s T300 catalyst is a mesoporous material that is not caustic or hazardous, unlike the sodium hydroxide traditionally used and has proven to be more economical. “We knew our process would work, but the scarcity of algal oil has prevented this type of testing,” said Dave Sams, vice presidfent of business development for Catilin. “If it weren't for our affiliation with NAABB, it would be extremely difficult for us to access this amount of oil from algae.” Eldorado Biofuels, an NAABB partner operating in Jal, New Mexico, provided the algal oil. Eldorado is developing water purification technologies for the cleanup of produced waters from oil drilling and utilizing these for algal cultivation.
The ultimate goal of the consortium is to understand the sustainability of any algal biofuels process that it implements. In order to understand energy balances, economic and market impacts, and environmental impacts (e.g., green house gas emissions), a number of analyses and underlying models are being developed and used for algae. These include analytical systems such as life cycle analysis (LCA), which accounts for the energy and material balance in any process from “cradle to grave.” The NAABB sustainability team, led by investigators at New Mexico State University, Texas A&M and Pacific Northwest National Laboratory, are using information from the LCA, techno-economic modeling, geospatial information systems, along with global market analysis to model and understand the impacts of algal biofuels and coproducts on future markets.
This is a sampling of the achievements over the past year by some 250 investigators, students, postdocs and support staff associated with the NAABB partnership. Although many challenges are still to be undertaken, this first year has already seen a resurgence of excellent work, which promises to be multiplicative in the coming years. As our goals are set to help the algal biofuels industry be successful through the development of technologies that are economical and profitable, we hope that policy and investment (both public and private) will keep pace in lowering the commercialization risk and provide the stability that this nascent industry will require.
José A. Olivares is the biofuels program lead at Los Alamos National Laboratory and NAABB executive director.