Biodiesel Feedstocks: Diverse, Growing, and Potentially Abundant

Posted on April 8th, 2016

Biodiesel can be an elegant way to store solar energy for transportation uses. Biodiesel is nontoxic, biodegradable, reduces emissions, and creates local jobs. With multiple benefits stemming from every gallon of biodiesel used to displace fossil fuels, the big question is: What is the appropriate and achievable rate of growth for this young industry? To answer that question, a diverse group of industry experts were invited to Argonne National Laboratory to talk about biodiesel’s impact on the existing markets for fats and oils and to present on the potential possibilities for producing more oils that could be used to make biodiesel. The presentations from those experts can all be viewed here:

No one presents the facts regarding individual feedstocks better than the market experts and the professionals who are working in the industry to bring new products to market. For an overview of how the US biodiesel industry combines the outlook for these multiple feedstocks, allow me to share the following summary.


The US biodiesel industry was founded in the 1990s in response to the glut of vegetable oil resulting primarily from soy protein production. Soybeans have been steadily growing in popularity as a highly efficient way to grow protein for the food and feed markets. Soybeans are 80 percent protein meal and 20 percent oil. About half of the US soybean crop is exported as whole beans where they meet international demand for protein and oil. Most of remaining crop, which is used stateside is crushed to separate the meal from the oil. Some meal gets exported to Europe, but most is used domestically for livestock feed. Some of the resulting oil is used for food and feed. Because protein demand is strong, more oil is produced than can be used for food. The US biodiesel industry was conceived as a use for this over supply of oil. By creating a value for this excess oil, biodiesel decreases the net cost of producing protein and delivers benefits to the food supply. Major importers of soy products, like China prefer to import whole beans, because they make more money separating the protein and oil in China. They are less interested in our excess oil after the valuable protein has already been stripped away. This is why it was imperative to find a use for soybean oil stranded in the domestic market.

In addition to these synergies with the food system, biodiesel provides other significant benefits such as displacing imported crude oil, supporting local jobs, and reducing greenhouse gases. With these benefits in mind, the National Biodiesel Board has sought to increase the impact of these benefits by using any sustainable feedstocks that can be produced in North America. As the biodiesel industry grows, it continues to become more diverse. Today, slightly less than half of the biomass based diesel used under the federal Renewable Fuel Standard (RFS) is made from soybean oil. The remaining half is made from relatively equal portions of used cooking oil, animal fats, and distillers corn oil (approximately 15 percent each) and between 5 and 10 percent from canola. Historical data shows that when the biodiesel industry grows, use of wastes, recycled grease, and fats grows at a faster rate than use of traditional vegetable oils. This may indicate that while use of veg oils for biodiesel is driven primarily by protein demand from oilseeds, the conversion of wastes is driven by growth in biodiesel use.

The production of waste grease will not increase in response to biodiesel demand. However, there exists the potential for nearly 500 million gallons of existing waste grease that could be turned into biodiesel if the biodiesel market was sufficiently strong to encourage the technological innovation and adoption to convert these low quality feedstocks. While this potential source has not been factored into NBB’s projections for biodiesel growth through 2018, the technology being developed by Novozymes and others suggest that this could be a commercial reality if demand for biodiesel justified the investment in technology.

nbb_blog_biodiesel-feedstocks-dgpa-oil_215x300_01There is an example of previously underutilized oil that has already responded to the growth in biodiesel demand. This is oil extracted from the distillers grain byproduct of ethanol production. Distillers corn oil can add 3 billion pounds (enough to make 400 million gallons of biodiesel) to the fats and oils market with current yields and technology, yet none of this volume was being extracted prior to biodiesel growth under the RFS. When the soluble carbohydrates in corn kernels are fermented to make ethanol, the protein, fat, and insoluble carbohydrates (fiber) remain. This protein and fiber byproduct know as distillers grain is used to feed livestock. The fat content of distillers grains posed a limit to how much distillers grains could be fed to ruminant animals like beef and dairy cattle. The ratio of fat can be too high for proper animal nutrition. The technology to extract oil from distillers grains existed before biodiesel, but there was no economic incentive to install extraction equipment. Biodiesel changed that. Growth of biodiesel fostered by the RFS encouraged the extraction of distillers corn oil from the left over distillers grains. Once again, biodiesel can be produced from the byproduct of protein. If demand for protein and ethanol increase, or if yields and extraction technology improve, even more oil can be produced. Biodiesel policy encourages the optimization of existing systems to deliver nutritional, economic, and environmental benefits. This is a formula we would like to replicate.

Algae has been recognized as a frontier of research that could result in large quantities of renewable oil. The Department of Energy estimates that algae could produce 5 billion gallons of renewable fuel each year pending development of sustainable and economic pathways. Wide-spread, commercial production is yet too far away to be included in the short term growth goals for the National Biodiesel Board, but the potential emphasizes the need to steadily grow biodiesel volumes under the RFS based on already existing feedstocks. The biodiesel industry has proven a pathway exists to bring renewable oils at nearly any scale into the fungible fuel market. This is a key step in supporting algae research. When researchers find the economic formula for producing oil form algae, the pathway to bring it to market is ready and waiting. The more we encourage market growth for renewable fuels today, the more rapidly we are likely to discover the formulas that are key to unlocking the solar energy stored by algae.

nbb_blog_biodiesel-feedstocks-dgpa-field_250x350_01Between the immediate growth in distillers corn oil and long term development of algal biofuel, there are also a growing number feedstock development programs that could produce addition volumes of oil in just a few years’ time. These include a number of different oilseed crops with a few strategies in common. What is common between these crops is their aim to make better use of existing land. Examples covered in the workshop include canola, camelina, and pennycress.

While canola is already a significant feedstock for biodiesel eclipsing 100 million gallons of US biodiesel each year, significant growth potential exists to increase canola production in the US as a winter annual crop. The US currently plants 1.8 million acres of Canola in North Dakota and the Columbia Plateau compared to Canada’s 19 million acres. Growing Canola in the winter could support 2-5 million acres of Canola on the Southern Great Plains and several million more acres in southeastern states from Kentucky to South Carolina.

Camelina has been suggested as a new rotation crop primarily with wheat, but not exclusively. Potential acres exist in Montana, Washington, Oregon, and California. In these regions, much emphasis is placed on allocating water resources. Existing rotations include extended fallow periods which allow soil moisture to be built up for subsequent seasons of wheat production. The low water needs and root structure of camelina may allow for one fallow period to be replaced with a camelina crop every 3 or 4 years. This agronomic approach to optimization of land and water resources could result in over 100 million gallons of biodiesel each year. Some estimates even go as high as 1.5 billion gallons of annual potential from camelina broadly adopted across the potential regions.

Reducing fallow periods has the desirable effect of reducing soil erosion, increasing biodiversity, and improving soil health. Farmers are beginning to adopt winter cover crops for these gains, and may soon increase the adoption of winter cover crops that could be harvested as biodiesel feedstock. Pennycress is an example of an oilseed that is being developed as a commercial crop with the agronomic benefits of a cover crop to enhance the rotation between corn and soy. Thirty million acres of winter fallow land has been identified for pennycress planting. Plant breeding development is well underway targeted at yields of 1,500 pounds per acre. This could equate to 1.2 billion gallons of biodiesel.

nbb_blog_biodiesel-feedstocks-dgpa-plant_300x420_01The potential for some of these new rotational crops and conversion of existing wastes and byproducts to bring hundreds or even billions of gallons of annual capacity for increased biodiesel production is very exciting, and it should provide motivation to keep the momentum going when it comes to growing biodiesel demand through policy. However, the National Biodiesel Board maintains a highly conservative approach toward quantifying the short term volume requirements under the RFS. By relying only on commercially proven feedstocks that are in use today, we demonstrate the impact of 2.3 billion gallons of US biodiesel production by 2017. These projections are informed by the World Agricultural, Economic, and Environmental Services modeling which include consideration of international production and demand for agricultural commodities, policies, population growth, inflation, exchange rates, and crude oil prices. Under these scenarios, the cost of biodiesel feedstocks and biodiesel production is estimated to decline. This means, as we make more biodiesel, it will get less expensive. While this will be good for consumers and generally good for the environment as we displace fossil fuel, we will need to maintain the incentives that are creating real breakthroughs in feedstock production.

The potential exists to grow the biodiesel industry, and with it improve our food supply, increase biodiversity, support local jobs, and reduce greenhouse gases.

I would like to again thank all of the presenters and attendees who participated in this feedstock workshop, as well as the organizing committee for the Coordinating Research Council Workshop on Life Cycle Analysis of Transportation Fuels who encouraged us to bring this information together.

Don Scott serves as the Director of Sustainability for the National Biodiesel Board.

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