Feedstock production is the first step in biofuel supply chain development. Bioenergy feedstocks come from biomass, which we define as renewable, non-food biological materials that can be converted into fuel or other products. BETO is exploring a variety of sustainable biomass resources, including woody biomass (purpose-grown poplar trees, tree trimmings), agricultural residues (corn stover), energy crops (switchgrass, sorghum), algae, and municipal solid waste.
BETO collaborates in developing the technologies and systems needed to produce affordable, consistent, quality-controlled commodity feedstock products that can be efficiently handled, stored, transported, and used by biorefineries. Accomplishing this requires a complementary focus on feedstock supply interfaces at both the production location and the biorefinery, and all logistics involved in between.
BETO's feedstock program is divided into two primary research areas: sustainable feedstock production and feedstock logistics research and development (R&D). Feedstock production is tasked with making affordable, abundant, and high-quality biomass materials accessible for use as bioenergy feedstocks. Feedstock logistics R&D is focused on reducing costs and improving efficiency to harvest, collect, store, handle and deliver affordable, high-quality feedstocks to biorefineries.
Woody biomass feedstocks come from purpose-grown woody crops—such as poplar and southern pine trees—and woody residues that cannot be used to make lumber and other wood-based products—such as forest thinnings, tree limbs, and tops. There are many benefits of using woody biomass to produce renewable energy, including strong new markets for renewable woody resources, reduced risk of forest fires, and healthier forests and woody plantations.
Agricultural biomass feedstocks come from crop residues—such as corn stover—and dedicated energy crops (non-food crops grown specifically for use as fuel)—such as switchgrass, miscanthus, and sorghum. Energy crops are being developed to grow in areas that do not compete with food, feed, and fiber crop production. Ideally, they are fast growing with abundant, aboveground biomass and can be produced in a variety of climates.
Algae feedstocks are produced from algal strains that turn sunlight into energy through photosynthesis—like most land-based plants. Algae are attractive biofuel feedstocks for several reasons: they are capable of extremely high per-acre productivity compared to other feedstocks; they can be grown where agricultural feedstocks cannot; they can grow in a variety of water sources, including brackish, saline, and wastewater; and they can easily be converted to a number of high-quality biofuels including biodiesel, jet fuels, and gasoline. Algae can be grown in open ponds or in enclosed, purpose-designed devices called photobioreactors.
Follow link to learn more about some of the algae technologies BETO is exploring.
Municipal solid waste (MSW) consists of everyday waste items. It is a highly diverse resource that varies regionally, and some sorted portions, such as construction and demolition waste, can be processed into biofuels.
The conversion process focuses on researching and developing technologies that convert biomass feedstocks into commercially viable liquid transportation fuels. There is a multitude of different feedstocks and feedstock blends that can be used with different conversion technologies to produce intermediate products ("intermediates"), which can be further upgraded to form biofuels. These processes generally fall into three pathways: thermochemical, biochemical, or a hybrid process that combines different biochemical and thermochemical technologies.
BETO is focused on several technologies that convert biomass into fuels. Some technologies have been strategically selected for in-depth analysis. Follow the link below to learn more about some of the conversion technologies BETO is exploring.
Thermochemical conversion uses heat as the primary mechanism for converting biomass feedstocks into a gaseous or liquid intermediate. These intermediates are then catalytically upgraded to fuel-blend-quality hydrocarbons (organic compounds that contain only hydrogen and carbon) or other fuels. Examples of thermochemical processes include pyrolysis and gasification.
Pyrolysis uses high temperatures in the absence of oxygen to break feedstocks down into organic vapors. These vapors can then be condensed into bio-oils and upgraded to produce biofuels.
Gasification heats feedstocks to very high temperatures in the presence of oxygen without combustion; this process breaks the feedstocks down into a syngas that can be converted to biofuels and bioproducts with the help of a specialized catalyst.
Biochemical conversion uses mild-heat, mechanical, and chemical processes to break down biomass feedstocks into intermediates, such as carbohydrates. The intermediates are further broken down into sugars, which are the building blocks for biofuels. Catalysts, either biological (enzymes and organisms) or chemical in nature, convert the sugars to liquid fuels or other chemicals.
The demonstration stage of bioenergy development tests the efficiency and cost effectiveness of technologies used to convert feedstocks into biofuels. Hydrocarbon fuels and "drop-in" fuels—fuels that can be used with minimal adaptation of existing tankers, pumps, and vehicles—play a critical role in bioenergy development. Proving the performance of these conversion technologies lowers risk for the private sector, creating a pathway to bring bioenergy to market. BETO validates bioenergy technologies through partnerships with the private sector to build and operate integrated biorefineries.
Integrated biorefineries (IBRs) are the physical facilities that produce commercially viable biofuels and other products using a number of different feedstocks and conversion technologies. BETO-supported IBRs range in scale from pilot plants that verify the performance of a suite of technologies to larger, first-of-a-kind pioneer plants designed to prove economical production at commercial volumes. BETO funds IBRs through public-private partnerships.
After biomass is converted into biofuels, these fuels must be integrated into the transportation system. BETO works with inter- and intra-agency partners to help facilitate a safe and cost-effective biofuel supply network that will meet the Office's strategic goals, and will help achieve the Renewable Fuels Standard (established in the Energy Independence and Security Act of 2007) target for the use of 36 billion gallons of biofuels by 2022.
Biomass feedstocks can be used to create renewable gasoline and renewable diesel, also called hydrocarbon or "drop-in" fuels. These fuels can be upgraded to perform like their petroleum-based counterparts, except they are derived from renewable biomass in processes that produce lower life-cycle greenhouse gas emissions compared to petroleum fuels.
Biobased jet fuels are made to be identical to their petroleum-based counterparts; they help the aviation industry reduce its carbon footprint and insulate it from price swings in the oil market. In addition to commercial airlines, BETO is working closely with the U.S. Departments of Agriculture and the Navy to produce biofuels for use in military applications, such as JP-5, JP-8, and F-76.
The United States currently produces nearly 14 billion gallons of conventional ethanol each year. Most of the gasoline in the United States contains ethanol in blends of up to 10% ethanol by volume (E10). Higher-blended ethanol is available in more than two thousand fueling stations across the nation. It can be used in Flex-Fuel vehicles, which have engines capable of operating on E85.