Andrew Brandess, Catherine Keske and Can Erbil* (email@example.com)
Biofuel policy in the United States has recently been associated with negative connotations due to many struggling economic policies, including the decision of the United States government to protect, through subsidies, domestic corn production for ethanol at the expense of Brazilian sugarcane, a crop with a far superior net energy potential. The Environmental Protection Agency is preparing to release a draft titled, “Biofuels and the Environment: the First Triennial Report to Congress,” which calls into question many of the fundamental problems with the biofuels industry, including the now infamous food for fuel debate. These questions have become exacerbated as biofuels in the United States receive more attention in the wake of increasing crude oil prices.
As the country works towards a more sustainable energy policy, some stopgap solutions have come to light. One potential biofuel feedstock is Camelina Sativa (a.k.a gold-of-pleasure), an oilseed feedstock genetically similar to the common mustard seed. Native to Western Europe, camelina has recently been introduced to the farmlands of the Western United States and Canada.
One of the practices currently being studied at Colorado State University is establishing a market for camelina in eastern Colorado. In the ideal situation, camelina is grown by farmers and brought to a local crushing facility to press the seed and extract oil. This can be used as straight vegetable oil, or transesterfied into biodiesel to be used in the tractors and trucks of farmers. This would displace the need for petroleum-based diesel on the farm.
Camelina is very promising for a myriad of reasons. The crop fits perfectly into common rotation systems native to farmlands in the western United States. Most farmers grow corn, sorghum, sunflowers, or soybeans, followed by a fallow, or a vacancy of the land while it retains moisture. Next a planting of wheat follows the fallow and the rotation begins again. This allows for two crops to be grown in three years. Camelina Sativa fits well into this rotation, having the ability to be grown during the fallow period (Johnson et al., 2008). This allows farmers to grow three crops in three years. It can be successfully integrated due to the very short root system of the crop, which avoids drawing excessive moisture from the ground (Robinson, 1987).
Due to the unique conditions, under which camelina can thrive, it does not enter the food for fuel debate. The crop does not displace farmlands which would have otherwise gone to grow food crops. The residual seeds, after crushing, can also be sold as an animal feed, having recently won F.D.A. approval for that very purpose. Camelina oil is highly rich in Omega-3 fatty acids (Eidhin, Burke, O’Beirne, 2003), allowing for a high protein feed to bring added value to farmers. The crop can also be grown with minimal inputs, including dry-land farming, avoiding the need for irrigated water. The overall water usage of camelina is minimal due to the enhanced drought resistance of the crop. Through personal communications with researchers at Montana State University, it can be derived that two inches of rainfall is necessary for proper plant establishment and a yield of 250 pounds per acre. Each additional inch of rainfall correlates to 125 pounds of additional yield. Using the past 10 years of rainfall data from five weather stations in eastern Colorado, it can be concluded that there is an 87% likelihood of sufficient moisture to cultivate at least 500 pounds of camelina, and a 75% likelihood of enough moisture for at least 625 pounds at harvest.
Fertilizer inputs are also rather minimal. The literature is not consistent with the recommended amount of nitrogen fertilizer needed, ranging from as little as no use, to as much as 80 pounds per acre. The literature average, however, is 35 pounds per acre. In order to find an estimate of the actual cost of fertilizer in 2011, we created a basic forecast, regressing nitrogen fertilizer prices against the price of crude oil and the price of natural gas. There is significant correlation between the price of crude oil and the price of fertilizer. Natural gas was used since it is the main input in ammonia, which in turn is the main input in nitrogen fertilizer. The final estimates indicate that about $10.55 would be spent per acre on nitrogen fertilizer. Similar approaches were used for sulfur, which has a literature average of 5 pounds per acre, phosphate, whose average is 12 pounds per acre, and potassium, at 3.75 pounds per acre. Their costs per acre, when multiplied by the forecasted 2011 fertilizer prices are $1.73, $6.56, and $2.01, respectively.
Camelina is ideal for the Western States, including Montana, Oregon, and Colorado. In just the state of Montana, there are 9,172,222 acres of farm land that currently grows wheat, of which 28%, or about 2,568,222 acres, lay fallow; if this land is used for camelina, using the more conservative estimate of just 50 gallons of biodiesel produced from an acre of camelina, 128,411,111 gallons of biodiesel would be produced. The aggregate potential for the entire United States is about 800 million gallons of biodiesel, assuming camelina is only grown on land otherwise in a fallow period, at a cost of 2.80 $/gallon. While this number is small in comparison to the liquid fuel used annually for transportation in the United States, it is enough to substantially offset on farm fuel requirements, yielding farmers significant independence from the highly volatile diesel prices and serving to stabilize the fluctuations in food and commodity prices that have plagued the markets since 2006.
This production will be net energy positive by 149% (Putnam et al, 1993) and will lead to 67% reductions in greenhouse gas emissions (Shonnard et al., 2010). The graphs from Shonnard et al., 2010 are presented below. They represent net energy and greenhouse gas emissions.
Figure 1. Energy Input/Output of Camelina Compared to Petroleum Based Diesel
Figure 2. Net Greenhouse Gas Emissions of Camelina Compared to Petroleum Based Diesel
Source of graphs: Shonnard,et al.(2010).
There are several flaws with Camelina Sativa at this time. The oil has too high a percentage of linolenic acid (18:3) and total polyunsaturated fatty acids (Pinzi et al., 2009). These high percentages are not ideal for engine performance and shelf life, respectively, of straight vegetable oils. However, the genome has only recently been explored for use a biodiesel, and many studies are optimistic that it can be perfected in the near future. Another issue is the unpredictability of yields at harvest; peer reviewed studies are estimating about 800 pounds per acre on average, with a standard deviation of nearly 400 pounds per acre.
The question of the economic feasibility of camelina as an on-farm energy substitute is being actively studied. Currently, the research is focused around creating a comprehensive enterprise budget needed to grow camelina. Simple forecasting models, along with data supplied from sources such as the USDA, are being employed to value all the inputs, from the cost and quantity of nitrogen fertilizer needed per acre to the expected value of camelina meal at market. Once a satisfactory enterprise budget is created, the results will be run through a simulator, which will add stochastic variables such as rainfall and crude oil prices. The final outcome will demonstrate the probability of economically successful integration of camelina on U.S. farmlands. A comprehensive sensitivity analysis will then be conducted, as economic feasibility can be determined through repeated changes of various variables in the model.
Early simulations have yielded positive results for camelina, with several caveats. The major wildcard at this time is the impact potential impact to wheat crops. While it is most likely that no reduction will be present in the wheat harvest directly following camelina, sources have ranged greatly in this estimate. Shonnard et al. (2010) suggests that there is no loss in yield of the subsequent wheat crop, due to three factors. These include increasing soil moisture due to the short rooted nature of the camelina crop, breaking a crop cycle aids in the prevention of pests and disease, and changing the nutrient profile through complex biochemical mechanisms. This has been disputed, however. It must be acknowledged that personal communications with representatives from the Agricultural Research Service, a division of the United States Department of Agriculture, have suggested that wheat farmers may expect as much as a 33% reduction in wheat yields following a camelina growth rotation. There have been no citations of this figure in any of the literature, however.
It is not known whether following camelina will reduce wheat yields, which is a large uncertainty for farmers given the extraordinarily high prices of wheat per bushel. It is also not known what is the exact reduction in energy efficiency, but estimates suggest that engines will be 78% as efficient when run on straight vegetable oil from camelina compared with diesel. This reduction of efficiency has been considered when factoring the net energy ratio, as camelina has a higher value of thermal energy when burned. It should be noted that this is a conservative estimate, while other sources are suggested the disparity between petroleum and straight vegetable oil to be considerably smaller. It is estimated that between 40 and 60 gallons of fuel can be harvested from an acre of camelina with an average closer to 60 gallons. These rates are derived from personal communications from researchers at Colorado State University that suggest that 7-8 pounds of camelina seed will produce 1 gallon of straight vegetable oil at 100% oil content. Since the seeds of camelina contain about 30-40% oil content, it can be expected that between 20-30 pounds of camelina seed are needed to produce 1 gallon of straight vegetable oil. With overall yields expected between 600 and 1000 pounds per acre, an estimate of 40 to 60 gallons of fuel derived from camelina seed is an appropriate approximation.
The energy input-output ratio of camelina can best be described using the aggregate diesel fuel usage numbers. Through various extension services and published farm surveys, the literature estimates that about 4.2 gallons per acre of diesel fuel are needed to plant, harvest, and transport no-till dryland wheat. While many farms are much bigger, it is easiest to use a 1,000 acre farm as a demonstration. If all the land is being cultivated for wheat, 4,200 gallons of diesel fuel are needed (although this number has a very large variance). Adjusting for the loss of efficiency of straight vegetable oil, it can be estimated that if camelina produces just 40 gallons of straight vegetable oil per acre, a conservative estimate, only 13% of the farmland would need to be devoted to camelina to cover the diesel requirements of the subsequent wheat cultivation. In order to produce enough diesel to cover the wheat rotation and the subsequent camelina rotation, only 17% of the farm would need to be devoted to camelina, the rest can still be in fallow. In the worst-case scenario, given a 33% reduction of wheat yields following a camelina rotation, the overall reduction in the total wheat harvest is only 5.6%, while the actual reduction can be anticipated to be significantly less.
Various sources, including Shonnard et al. (2010), expect reductions in greenhouse gas emissions of straight vegetable oil derived from camelina feedstocks to exceed 85% when compared to current petroleum based diesel fuels. These reductions are seen in primarily in carbon dioxide, methane, and nitrous oxide emissions. The outlook for the crop is promising, but a true sensitivity analysis needs to be conducted to have more certainty regarding the economic viability of Camelina Sativa and whether it has the potential to be next gold-of-pleasure.
Eidhin, D. Ní, J. Burke, and D. O'Beirne. "Oxidative Stability of Ω3-Rich Camelina Oil and Camelina Oil-Based Spread Compared with Plant and Fish Oils and Sunflower Spread." Journal of Food Science 68.1 (2003): 345-53. Print.
Johnson, J., Enjalbert, N., Shay, R., Heng, S., Coonrod, D. 2008. Investigating straight vegetable oil as a diesel fuel substitute. Final Report to Colorado Agricultural Value-Added Development Board.
Pinzi, S., et al. "The Ideal Vegetable Oil-Based Biodiesel Composition: A Review of Social, Economical and Technical Implications." Energy & Fuels 23.5 (2009): 2325-41. Print.
Robinson, Robert G. "Camelina: A Useful Research Crop and a Potential Oilseed Crop." Minnesota Agricultural Research Station Station Bulletin 579-1987 (1987). Print.
Shonnard, David R., Larry Williams, and Tom N. Kalnes. "Camelina-Derived Jet Fuel and Diesel: Sustainable Advanced Biofuels." Environmental Progress & Sustainable Energy 29.3 (2010): 382-92. Print.
U.S. EPA. Biofuels and the Environment: the First Triennial Report to Congress (External Review Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-10/183A, 2011.
* USDA, Colorado State University and Brandeis University, respectively.
 The calculations for the production of camelina based on data from Duane Johnson, Montana State University follow. Seed Cost: $180/ton. Cleaning Cost: $9.17/ton. Expeller Cost: $6.40/ton. Refining Cost: $3.00/ton. These figures lead to an expected total cost of production of $198.57/ton. However, farmers are able to sell the meal, or seed remnants that can be used as animal feed. Camelina meal is especially valuable due to the high Omega-3 fatty acid profile, making it a high quality protein feed. It was assumed farmers would receive $70/ton of camelina produced. Subtracting the returns from selling the meal to the expected total cost of production it can be estimated that camelina costs $128.57/ton. Assuming 34% oil content in the seed, 680 pounds of oil per ton of camelina seed can be produced. Research from Colorado State University is indicating that 7.3 pounds of camelina seed equates to one gallon of biodiesel. This leads to 93 gallons of biodiesel created/ton of camelina seed harvested, at a cost of $128.57/ton. This 93 gallons/ton figure is a different metric than the 50 gallons/acre used in earlier calculations. This yields an estimate of about $1.40/gallon. Given the added transportation costs to a crushing facility, as well as the transesterification process, it is acceptable to double the cost of production, as a rough estimate. This yields a final price of about $2.80/gallon. While this final price per gallon is a considerable over-approximation, it is better to err on the side of caution as opposed to citing overly optimistic but unattainable results.