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This is the first in a series of articles on research areas in biomass, and technology associated with producing biofuels, biopower, and bioproducts. The focus of this article will be feedstocks.

What are biomass feedstocks and how are they used?

Biomass feedstocks are any biological materials that can be processed to make fuels, process heat and steam, electricity, chemicals, and other materials. Feedstocks consist of a range of materials, including agriculture (e.g. corn and soybeans), forests, agricultural and forest residues, industrial residues, animal wastes, municipal solid waste, and dedicated energy crops. Energy crops are grown specifically for use as feedstocks, and include cottonwood, hybrid poplar, silver maple, switchgrass, and wheatgrass, among others.

The Roadmap for Agriculture Biomass Feedstock Supply in the United States, released by the U.S. Department of Energy (DOE) in 2003, outlines how these various feedstocks are currently being used in the United States. Wood residues are the most commonly used feedstock, while crop residues, such as corn stover, are the most widely available feedstocks. Research efforts are focusing on the feasibility of growing dedicated energy crops.

What are the benefits of using biomass feedstocks for energy?

Security, Economic, and Environmental Benefits

The use of biomass feedstocks in place of traditional fossil fuel-derived feedstocks to produce fuels, process heat and steam, electricity, chemicals, and other materials will benefit the United States in several ways. Biomass feedstocks increase national security by decreasing dependence on foreign oil and reducing the likelihood of energy supply disruptions. Energy from biomass feedstocks also benefits rural economies where feedstocks are produced and creates local jobs. In addition to increasing national security and economies, the use of biomass feedstocks can have several environmental benefits, including reduced erosion, decreased contaminated wastewater runoff, improved air quality, and land preservation.¹

Technical Benefits

Unlike fossil fuel feedstocks, biomass feedstocks are fairly uniform in their chemical properties, making them interchangeable and more widely available. For example, the heating value of coal ranges from 20-30 GJ/tonne, while the heating value for most biomass feedstocks varies from 15-19 GJ/tonne. Due to higher ignition stability, most biomass materials are also easier to gasify than coal, and are easier to process thermochemically.²

What are the barriers to using biomass feedstocks for energy?

Entering the Present Market System

Fossil fuels are currently a major driver of the U.S. economy. In order for biomass-derived fuels, power, and products to penetrate the market, they must be able to compete with their fossil fuel-derived counterparts, both in performance and cost. In addition to developing enabling biomass technologies, the use of supportive policy and economic incentives are needed for biomass in order to make the transition in the U.S. from a fossil fuel-based economy that is increasingly reliant on imports to an economy based on a more diversified energy supply, including domestically produced renewable energy such as biomass.

Efficiency

Because of the high costs associated with crop production and concerns regarding the energy content of biomass feedstocks, making the shift from fossil fuel-based commodities to biomass-derived fuels, power, and products must be efficient. The production of biomass feedstocks has high cost inputs, such as land, fertilizers, harvesting equipment, transportation and handling equipment, and storage.³ Additionally, the energy density of biomass feedstocks is much lower than that of fossil fuel feedstocks, so it may require more biomass feedstocks to produce the same amount of energy.⁴

What is being done to advance biomass feedstocks?

The current research and development on biomass feedstocks is focused on agricultural and forest residue harvesting, collection, and transport, and other aspects of the feedstock interface between agriculture and forestry and biomass industries. In the future, the research and development focus will begin to shift to the development of a mature biorefinery industry which should spur the growth of dedicated energy crops.

Available Resources

Understanding biomass feedstock availability is essential to assessing the role biomass feedstocks will play in the energy economy. Both DOE and U.S. Department of Agriculture (USDA) R&D efforts focus on determining availabilities, types, and associated costs of biomass feedstocks. The DOE's Biomass Program is working on research to provide credible, transparent, industry-accessible estimates and interpretations of current and future feedstock supplies (quantities, physical characteristics, costs, and geographic distribution) from agricultural residues, forest residues, energy crops, urban wood wastes, industrial wastes, and animal wastes. In the USDA, the Forest Service is investigating ecological management practices including soil sustainability, land use, and water use's impacts on wildlife for short rotation woody crop feedstocks.

Collection, Storage, and Transportation

One of the largest challenges to the use of biomass feedstocks for energy is determining how to cost-effectively collect, store, and transport materials. Research and development is being conducted to identify the most effective and efficient means to conduct these activities. The focus includes developing single-pass multi-component selective harvest capabilities and evaluating the requirements and performance characteristics of bulk processing and storage systems. In addition, the efforts will develop the analytical tools for optimizing overall logistics of the infrastructure system.

Characteristics Assessment

Because the types of biomass feedstocks available vary, identifying the technical characteristics of each is an important part of research and development. Research efforts are focusing on the physical and chemical components of a variety of feedstocks, and on various processing technologies to convert them to energy. The DOE's National Renewable Energy Laboratory (NREL) is currently conducting research using high-powered microscopes to examine, at the cellular level, the makeup of corn stover and enzymes used to break down the feedstock. Through this research, NREL is hoping to be able to increase feedstock yields and create more efficient enzymes.

At the USDA, the Agricultural Research Service is working to improve cereal crops for production of biofuels through an integrated plant molecular biology, genomics, bioinformatics, and plant transformation approach. The Cooperative State Research Education and Extension Service is researching fundamental studies of plant and animal structures/properties to enhance product quality and processing characteristics. The Forest Service is performing research to improve the technical understanding of wood biochemistry and enzymes for conversion of woody biomass to desired energy and pulp products.

For More Information

DOE released the The Roadmap for Agriculture Biomass Feedstock Supply in the United States in November 2003. The Roadmap describes the research and development that is needed to create a biorefinery industry that focuses on the production and processing of biomass feedstocks that can then be distributed in a wide range of markets. Refer to the January 2004 Biomass Research and Development Initiative newsletter for a full story on the Roadmap.

Oak Ridge National Laboratory has conducted extensive research on various biomass feedstocks. The Laboratory has focused on issues surrounding the environmental, economic, and technical analysis of various feedstocks, and on several different conversion technologies. More information can be found at the Laboratory's Bioenergy Information Network.

The U.S. Department of Agriculture's Agricultural Research Service has also conducted extensive research on biomass feedstocks, including research on high-quality products from biomass, hybrid electric generation systems, and development of biofuels from biomass. More information can be found at the Agricultural Research Service Web site.

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The State of South Carolina consumed approximately 1,688 trillion Btus of energy in 2000. The majority of that energy was supplied by nuclear power and petroleum, at 31 percent and 29 percent, respectively. Coal provided 26 percent, followed by natural gas at 9 percent. Biomass supplied five percent or over 75 trillion Btus.¹

Currently, the South Carolina Energy Office, through a partnership with the Environmental Protection Agency (EPA), is promoting the Landfill Methane Outreach Program (LMOP). The LMOP identifies local landfills that would be suitable for landfill gas-to-energy projects. The Program's first success occurred in 2001 when Santee Cooper, a state-owned electricity utility, teamed with the Horry County Solid Waste Authority to convert landfill methane into electricity. The result is a "Green Power" plant that produces 3.3 megawatts of electricity annually. Ten electric cooperatives now participate in the Green Power plant that is supported by the Horry County landfill and Santee Cooper now has three other landfill projects in development.²

The South Carolina Energy Office, with funding from the U.S. Department of Energy's 2003 State Energy Special Projects Grant, also has a Biomass Education program in development. The Program seeks to produce middle school- and high school-level lesson plan booklets integrating academic subject areas such as math, science, and social studies with information and activities about biomass products. All lessons would be aligned with the SC State Department of Education's Learning Standards and with National Learning Standards in each curriculum area. Lesson plans would provide hands-on, cooperative learning activities with accurate and detailed information for both teachers and students. Experienced staff development professionals would train teachers about how best to implement the lessons in the classroom at a week-long Institute offering graduate re-certification credit.³

Incentives to use biomass in South Carolina include the Mainstay Energy Rewards Program's Green Tag Purchase Program. This program is a renewable energy credits program that pays those in both commercial and residential sectors to use a renewable form of energy in their businesses and homes. Biomass is an eligible technology under the program guidelines. The program pays between $1 to $100 per MWh of energy production using a renewable source, depending on the technology used.⁴

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