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Biomass Energy

Biomass from local sources can be key to a campus climate action plan by providing a long-term, low-cost fuel source.

The following links go to sections that outline how biomass may fit into your campus climate action plan.

Photo of a pair of hands holding a small pile of oat hulls

Biomass is plant matter from trees, grasses, or other crops. The most common sources of biomass fuels are wood chips and agricultural residues, such as these oat hulls that were discarded during cereal production.
Credit: Tom Jorgensen, University of Iowa

Under the carbon accounting protocol of the Intergovernmental Panel on Climate Change, use of biomass fuels for energy does not add to the net amount of carbon in the atmosphere. This is because the same amount of carbon that is released during combustion of biomass fuels is absorbed from the atmosphere by the plants while they grow.

Campus Biomass Energy Options

A research campus could use biomass in several ways:

  • Cofiring with coal: Biomass can often be substituted for as much as 50% of the fuel for a coal-fired boiler with minimum modifications. This capability depends greatly on boiler configuration and design. The most commonly used biomass fuels for cofiring are wood chips and grasses; however, other biomass fuels might also be used. Suitable fuel handling equipment and storage for the biomass fuel are required.

  • New biomass boiler: The technology for biomass combustion is well understood, and modern biomass boilers are efficient and have low emission rates. A new biomass boiler can connect directly into a district heating or combined heat and power system.

  • Gasification: Although biomass gasifiers represent an emerging technology, gas fuels are easier to handle and result in fewer emissions than do solid or liquid fuels. And because they have the potential for using two thermodynamic process in one combined cycle power plant for producing electricity, gas fuels have the potential to greatly increase system efficiencies over systems that use solid or liquid fuels. Finally, biomass is more chemically reactive than solid fossil fuels such as coal, which makes it more amenable for use in gasifiers. As a result, biomass gasifiers will likely see a lot of activity in the coming years.

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Considerations for Campus Biomass Installations

Is biomass right for your campus?
  • Does it combust coal?
  • Does it have a district heating system?
  • Is there a local source of biomass fuels?
  • Do you have staffs to operate and maintain a biomass facility?

Research campuses should consider the following before undertaking an assessment or biomass energy installation.

Substitute for Coal

Coal has a higher rate of carbon dioxide (CO2) emissions per British thermal unit than any other boiler fuel. Therefore, substituting renewable biomass for some or all of your current coal consumption greatly reduces carbon emissions. The material handling and combustion systems used for coal are often suitable for at least partial biomass mix with little modification.

District Heating

Biomass is not generally suitable for boilers for individual buildings because of its handling and storage requirements, but it is well suited to operations that support larger central boilers.

Local Resource

Low fuel cost is a major advantage for biomass energy. To warrant building or converting a power or heating systems for biomass, a large, dependable source of inexpensive biomass needs to be available locally. Transporting biomass any significant distance can quickly erode its cost advantage and sustainability benefits.

The U.S. Department of Energy (DOE) Alternative Fuels & Advance Vehicles Data Center provides state biomass resource maps that indicate local availability of forest residues, mill and urban wastes, and agricultural residues, as well as energy crop potential.

Staffing Capability

The operation of a solid-fuel central plant is an around-the-clock effort that requires a staff of plant managers, operators, and mechanics. If you currently operate a solid fuel plant, this is nothing new. If you are considering a solid fuel plant or a gasification plant for the first time, you must consider the cost and logistics of staffing such a plant.

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Leading Example: University of Iowa Biomass Cofiring Project

Photo of a large power plant with a smokestack on the banks of a river.

The University of Iowa is cofiring discarded oat hulls from a nearby cereal producer with coal at the UI Power Plant on the banks of the Iowa River in Iowa City. Ultimately, the university plans to combust 50,000 tons of oat hulls per year, which would reduce coal consumption by 25%.
Credit: University of Iowa

The use of biomass at the University of Iowa is an excellent example of partnering with industry to turn a by-product into a valuable fuel. For the last five years, the university has burned oat hulls from the local Quaker Oats plant. With no technical precedent, this practice required experimentation, boiler modifications, and considerable material handling challenges. The result has been a great success for the University of Iowa, for Quaker Oats, and for the environment.

Steam produced by the boilers is used for heating, electrical generation, and chilled water production. A general description is available, as is a technical description of the project in a report titled, The University of Iowa Biomass Fuel Project Supporting Materials.

The successful experience with the main utility plant led to a vision for a climate-neutral heating, cooling, and electrical generation facility for a developing Oakdale campus for the university. The envisioned facility is proposed to be fueled by biomass gasification and by methane from a landfill. View a presentation titled, Oakdale Renewable Energy Plant: Getting Ahead of the Curve on the proposed facility.

Additional examples of research campus biomass projects include:

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Here you will find links to technology basics and biomass organizations.

Technology Basics

The following resources explain the fundamentals of biomass energy technologies:

  • Biomass Energy Basics: NREL publishes this overview of biomass for consumers in its Learning About Renewable Energy section.

  • ABC's of Biopower: DOE publishes this online resource for students.

  • Biomass Combined Heat and Power Catalog of Technologies: The U.S. Environmental Protection Agency publishes this catalog describing various technologies for using biomass for heat and power generation.

  • UK Biomass Case Studies: Includes summary details on several commercially developed biomass energy generation facilities including those that run on agricultural waste byproducts such as poultry and equine bedding.

Biomass Organizations

Detailed information about biomass is available from the following organizations.

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