Blatant Reality

National Alliance for Advanced Biofuels and Bioproducts (NAABB) and the Center for Advanced Biofuels Systems (DOE-EFRC) released a statement yesterday further refuting the recent study by UVA researching concerning algae biofuels.

Here is their statement:

View point of the National Alliance for Advanced Biofuels and Bioproducts (NAABB) And the Center for Advanced Biofuels Systems (DOE-EFRC)

March 9, 2010

The recently published article “Environmental Life Cycle Comparison of Algae to Other Bioenergy Feedstocks” by Clarens et al. in the journal of Environmental Science & Technology (2010) provides a number of conclusions that are worth noting, discussing further, and in many cases refuting due to the choice of data inputs. The important conclusion this paper makes is for the need to design algal systems that capture waste streams for CO2 and nutrients in order to create sustainable algal production systems. These conclusions are consistent with the draft Algal Roadmap (US DOE 2009), and are the guiding principles behind well established research and development investments in algal fuels. In this document we expand on eight other key areas that we feel compelled to discuss further and provide a different point of view than that shared by Clarens et. Al.

Unfortunately, in the Clarens article the negative lifecycle analysis for algal fuel is directly determined by the choice of input values and assumptions–which is to say, the results are a priori determined by the choice of assumptions. The choice of metrics, inputs for production, limits of the analysis, and system design features bias the results against algae relative to corn, canola, and switchgrass.

Furthermore, the stochastic model is a useful way to derive confidence intervals around estimates, but is valid only so far that the underlying distributions are understood and the [min, max, likeliest] are well documented. The choice of the boundary points on the distribution will affect the calculation of the confidence intervals, and if those boundary points from which that distribution is drawn are poorly known (as is the case for algae) then the confidence interval information can lead to greater variability in the mean estimate than is justified by the available data.

There are number of specific areas worth noting and refuting for this article:

Geographic Areas for Production: Clarens et al. determined viability of geographic production areas as delimited by precipitation and water evaporation rates. This effectively eliminates many locales that have natural resource endowments useful for large scale algal cultivation. In this article other critical resources necessary for algal production are ignored, e.g., large expanses of under-utilized flat land; sufficient solar insolation; sufficient average temperatures; large quantities of saline water; sufficient sources of effluent from industrial, municipal, and animal production; and sources of waste CO2 streams from coal-fired power plants or other industrial activities.

By utilizing currently cultivated land in their model, the authors note that large indirect negative effects will be created which further drive the sustainability of algae below that of other terrestrial crops. One of the key benefits of algae as a fuel source is the ability to use water and land that is not used for other economic purposes (draft DOE Algal Roadmap, pp. 5-6).

CO2 Management: The choice of CO2 and production technology significantly affects the results and will determine the ultimate environmental and economic sustainability of an algal fuel industry. The Clarens et al. result that using steam reformed CO2 for algae production is not environmentally or economically viable has been well known for years and the recommendation from researchers has been to use waste streams of CO2 for algal production (Brown et al. 1994; Sheehan et al. 1998; Draft DOE Algal Roadmap 2009).

Fossil Fuel Based Fertilizers: It is important to note that Clarens et al. (2010) conclude that the energy and GHG profile of algae changes substantially when municipal waste sources are utilized. This conclusion has been reached by many researchers in algae, and was a prominent feature of the ABO summit in October 2009, with multiple presentations on the topic.

Recycling: An important element of second generation algal production systems currently being developed is the re-use and recycling of many of the nutrients required to produce algae. There is significant effort underway to design “closed loop” systems that minimize discharges to the environment and minimize energy and nutrient inputs.

Use of Waste Waters: The community has accepted the use of municipal waste waters as a possible source of water and nutrients (see ABO conference presentations). Other sources of water that are being actively investigated for algal production include non-potable saline waters and waste waters from industrial production and oil and gas extraction.

Flocculation and Centrifugation: It is well-known that using centrifugation will result in an algal system that is not economically feasible and unsustainable. This is a key area where excellent innovation and major breakthroughs in technology are currently being achieved showing significant decrease in energy utilization and increase in economic feasibility.

Energy Content of Algae: Clarens et al. use whole algae in their model and assign a value of 24 GJ/Mg. The use of the whole algae for the calculation of Higher Heating Values (HHV), and no breakdown or discussion of the lipid energy content versus the residual biomass, and the use of the residual biomass for additional HHV is a serious issue in the methodology. Further, for corn and canola the authors compute a mass-weighted average HHV, but do not do this for algae.

Energy of Fuel Conversion: Clarens et al. chose to end their model at cultivation and harvesting of the feedstocks, arguing that the upstream impacts associated with algae will swamp whatever benefits it may have in conversion relative to the fermentation of grain into ethanol. Given the choices of first generation technology based data, the negative energy balance outcome is predetermined. This would not be the case if second generation technologies were utilized and downstream fuel conversion effects and energy density of algal fuels in comparison to ethanol will be much more favorable.

Algal investigators are addressing the key barriers highlighted by Clarens et al and these research paths are clearly documented in the draft US DOE Algal Roadmap (2009). We believe that the current generation of algal fuel production system research is addressing the issues of nutrient source, energy inputs, water, and land use that drive the study by Clarens et al. Furthermore, gathering of reliable and acceptable algal production and harvesting data will result in greater confidence in predictive and comparative models such as presented by Clarens et al.

Authored by:

Jose Olivares, Ph.D, Executive Director, The National Alliance for Advanced Biofuels and Bioproducts (NAABB), The Donald Plant Science Center; Deputy Division Leader, Bioscience Division, Los Alamos National Laboratory

Richard R. Sayre, Ph.D, Scientific Director NAABB; Director Enterprise Rent-A-Car Institute for Renewable Fuels, The Donald Danforth Plant Science Center

Meghan Starbuck, Ph.D, Chief Economist NAABB; Assistant Professor, Economics and International Business at New Mexico State University

About the National Alliance for Advanced Biofuels and Bioproducts (NAABB)

The National Alliance for Advanced Biofuels and Bioproducts (NAABB) Plant Science Center was recently selected to receive $44 million from the U.S. Department of Energy under the American Recovery and Reinvestment Act as announced today by Energy Secretary Steven Chu. The consortium will conduct advanced biofuels research to support the development of a clean sustainable transportation sector and will develop technologies and the scientific foundation needed to quickly establish a viable algal biofuels industry that can provide sufficient fuel to dramatically reduce US dependence on imported oil.

Consortium partner organizations include, The Donald Danforth Plant Science Center, the Los Alamos National Laboratory, Pacific Northwest National Laboratory, University of Arizona, Brooklyn College, Colorado State University, New Mexico State University, Texas AgriLife Research -Texas A&M University System, University of California Los Angeles, University of California San Diego, University of Washington, Washington University in St. Louis, Washington State University, AXI, Catalin, Diversified Energy, Eldorado Biofuels, Genifuel, HR Biopetroleum, Inventure, Kai BioEnergy, Palmer Labs, Solix Biofuels, Targeted Growth, Terrabon, and UOP.