Three Sustainability Tools Are Enhancing Environmental Benefits of Biofuels

October 28, 2015

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by Kristen Johnson and Alicia Moulton (U.S. Department of Energy) At the Energy Department’s Bioenergy Technologies Office, we’re actively working to develop the advanced biofuels industry in a way that leads to positive impacts and that demonstrates responsible stewardship of the environment. Biofuel production is closely tied to the environment—for example, energy crops can affect soil and water resources as well as wildlife populations, and water and energy are required to convert energy crops to fuel at a biorefinery. To help make sure that biofuel production has a positive impact on factors such as the quality of water, soil, and air, we need data and tools to understand how biofuels do and can affect the environment. Three tools—WATER, LEAF, and GREET—are helping scientists, landowners, and technology developers enhance the environmental benefits of biofuels.

1. WATER

As with most refined products, biofuel production requires some amount of water. Biomass needs water to grow, and water is used in the conversion process to make the fuel. The Water Assessment for Transportation Energy Resources (WATER), developed at Argonne National Laboratory, is a tool to estimate the water consumption of biofuel production as well as its impact on water quality. For example, biofuel made from agricultural residue–which is plant material left over from a harvest–will require a different amount of water intake than biofuel produced from grasses or from fast-growing trees. This tool can help bioenergy developers determine which energy crops are best suited to different geographic locations and make wise decisions in relation to water quality and supply. Argonne released a new version of WATER (version 3.0) in January 2015 and will continue to develop and update the tool to include more types of biomass and conversion technologies.

2. LEAF

Idaho National Laboratory developed the Landscape Environmental Assessment Framework (LEAF) to explore how cellulosic biomass can be produced in a way that is profitable to a farmer while also considering soil and water resources. For example, LEAF can help estimate what percentage of corn stover—the leftover corn husks, stalks, and stems—can be harvested from a farmer’s corn field while maintaining optimum soil conditions. Farmers can potentially increase their income by selling their corn stover to a cellulosic ethanol biorefinery; at the same time, removing too much from the field could reduce the amount of carbon and nutrients in the soil over time. LEAF can aid farmers and scientists in determining the right amount of corn stover to remove. LEAF can also be used by farmers and scientists to explore how energy crops, like switchgrass, can be grown in certain parts of a field in a way that increases profit while also reducing erosion and nutrient runoff, which improves the health of the soil, streams, and rivers.

3. GREET

Argonne National Laboratory’s Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model gives researchers a way to evaluate the total greenhouse gas emission impacts of transportation fuels from their production to end use. Biofuels offer significant potential to reduce life-cycle greenhouse gas emissions relative to fossil fuels because the plants used for biofuel absorb carbon dioxide from the atmosphere as they grow; and since this carbon comes from the atmosphere instead of from resources sequestered deep in the earth, it results in lower net emissions of carbon to the atmosphere.

However, biofuels do emit greenhouse gases when we use them. Greenhouse gases are also emitted by the vehicles harvesting and transporting biofuel crops and by the biorefinery where biofuels are produced. GREET combines data on all of these to assess the total impact associated with biofuel production. Researchers and companies are using GREET to develop biofuels from agricultural residues, forestry residues, energy crops, and algae that have greater greenhouse gas reduction benefits compared to petroleum fuels and even compared to other biofuels on the market. READ MORE