Spring 1999
U.S. Department of Energy
Bioenergy Feedstock Development Program at
Oak Ridge National Laboratory
Energy Crops Forum was published periodically by the Bioenergy
Feedstock Development Program, Environmental Sciences Division, Oak Ridge
National Laboratory, managed by UT-Battelle, LLC., for the U.S. Department of
Energy under Contract No. DE-AC05-00OR22725.
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Table of Contents
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News, announcements, and electronic versions of many of our handouts, brochures,
and publications go up on BIN (http://bioenergy.ornl.gov/)
quite often so be sure to bookmark it.
As a matter of fact, the Image Gallery, a self-service 'mall' that contains
publication-quality digital images that can be downloaded, was recently
expanded to include new pictures of commercial short rotation forestry
operations in the Pacific Northwest, equipment, and miscanthus.
And speaking of miscanthus and BIN, the full text of a Miscanthus: a review of
European experience with a novel energy crop and a fact sheet based on
that report are now available online.
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8MW gasifier fueled with willow:
In December 1998, the UK Government's Energy Minister, John Battle,
placed the foundation stone for Europe's first commercial "clean and green"
power station. The 8-MW, wood-fueled plant in the Vale of York should become
operational in 1999, producing electricity from forest wood chips and specially
grown willow. A number of partners are involved in development of the plant,
with Yorkshire Water taking the lead. About 1/3 of the power station's funding
will come from a European Union program, known as THERMIE. The project also
benefits financially from inclusion in the UK Government's Non Fossil Fuel
Obligation program. The plant has a 15-year contract to supply the local grid
with enough electricity to satisfy the daily demands of over 18,000 people.
The UK Government sees the project as both economically viable and
environmentally sustainable, while Yorkshire Water and its Dutch and Swedish
partners see a future moneymaker that will help reduce the harmful greenhouse
gases produced by traditional fossil fuel power stations. This project will be
one of the first in Europe to rely primarily on farm-grown biomass.
The project is using an atmospheric circulating fluidized bed gasification
process developed by Termiska Processer AB (TPS) of Sweden. During the first 5
years of operation, most of the biomass fuel will come from forestry wastes.
The project will work with local farmers to establish 2000 hectares (4920
acres) of willow coppice which will eventually supply up to 80% of the facility
demand for wood fuel. The willows will be harvested on a 3-year rotation cycle.
A portion of the willows will be grown using treated sewage sludge as the
fertilizer in order to both increase yields and to demonstrate a
environmentally acceptable and secure disposal route for the sludges. About 200
hectares (492 acres) have already been planted; 300 hectares (738) are
scheduled for planting in the spring of 1999.
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Minnesota leads the U.S. in new biomass power
projects: In December 1998, Minnesota's
Northern States Power (NSP) Co. signed power purchase agreements with St. Paul
Cogeneration, LLC, and EPS/Beck Power, LLC. Each will supply 25 megawatts (MW)
of biomass-generated power to the NSP system. The 20-year agreements fill part
of a state mandate requiring NSP to contract for 125 MW of electric generating
capacity fueled by biomass energy, according to Audrey Zibelman, president of
NSP Energy Marketing. In 1997, NSP announced a 75-MW agreement with Minnesota
Valley Alfalfa Producers. The agreements signed last month with EPS/Beck Power
and St. Paul Cogeneration bring the total biomass megawatts to 125. The
contracts are subject to the review and approval of the Minnesota Public
Utilities Commission. St. Paul Cogeneration, LLC, is a partnership of District
Energy St. Paul, Inc., and Trigen-Cinergy Solutions of Cincinnati. EPS/Beck
Power is owned by Energy Performance Systems of Minneapolis and R.W. Beck, an
engineering consulting firm with extensive experience in the independent power
industry.
NSP supplies electricity to 1.4 million customers in portions of Minnesota,
Wisconsin, Upper Michigan, South Dakota, and North Dakota. It also has natural
gas operations, serving more than 400,000 customers.
The St. Paul Cogeneration biomass project plans to use clean wood waste from
the Minneapolis-St. Paul area to fuel an expansion of its cogeneration facility
in downtown St. Paul. The wood waste will include such items as tree trimmings,
wood chips, and demolition waste wood. The cogeneration facility provides
district heating and district cooling to citizens of St. Paul, Minnesota.
The EPS/Beck Power project calls for a new generating facility near St. Peter.
The power production technology will use Whole-Tree EnergyTM , a
high-efficiency combustion and steam turbine system. In compliance with a state
law requiring a renewable fuel source, tree farms will be developed in
cooperation with landowners near the generating facility. Hybrid poplar trees
will serve as the primary fuel source for the generating plant, though forest
wastes and thinnings will be needed during the first 2-3 years of operation.
About 27,000 acres will be required for the facility. This project will be the
first in the U.S. to demonstrate the costs and feasibility of using
closed-loop, farm-grown woody crops to supply the majority of the biomass
feedstock requirements for a biomass project.
The short-rotation hybrid poplar technology to be used by EPS/Beck Power was
first tested by researchers in the U.S. Forest Service in the late 1960s and
early 1970s and further developed by the U.S. Department of Energy (DOE) since
1978 in collaboration with the Forest Service and many universities. The Forest
Service's North Central Station, including researchers in Minnesota and
Wisconsin, were among the earliest groups involved in development and testing
of hybrid poplars. Other universities in the region that have conducted
breeding, physiology, agronomic, and environmental research on poplars (with
DOE support) include Iowa State University, Michigan State University,
University of Minnesota and University of Wisconsin. Pulp and paper companies
in the North Central region are planting hybrid poplars commercially and are
cost-sharing research and development with the government. The success of the
EPS/Beck Power Project will not only benefit Minnesota by creating jobs and
reducing fossil carbon emissions, but it will also be an example of the
positive benefit of the federally funded hybrid poplar research in the region.
The 75-MW agreement with the Minnesota Valley Producers involves the supply of
alfalfa stems for production of electricity in a gasification/combined cycle
power plant. 700,000 tons per year of alfalfa will be produced on 180,000
acres. Co-products will include livestock feed pellets. The project is
currently preparing an Environmental Impact Statement and undergoing public
review.
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Switchgrass co-firing project
launched in Alabama : On October 28, 1998, a
kickoff meeting was held in Birmingham, Alabama, to launch a research
partnership formed to study ways to grow and harvest switchgrass to blend with
coal as a fuel for power generation. Building on the many years of switchgrass
research by Dr. David Bransby of Auburn University, the unique public and
private research partnership consists of Southern Research Institute, Southern
Company, Auburn University, the Electric Power Research Institute (EPRI), the
Alabama Department of Economic and Community Affairs (ADECA) and the U.S.
Department of Energy (DOE). If successful, the switchgrass project could result
in a cleaner environment and provide a new cash crop for Alabama's farmers.
Additional information about the partnership can be on the Internet:
http://www.sri.org/nrswitchgrass1.html.
Dr. Bransby began involvement in switchgrass research in an energy crop
screening project initiated by Auburn University in 1985 with funding from the
U.S. Department of Energy's Bioenergy Feedstock Development Program. The goal
of the original project was to select new herbaceous crops that could be
economically produced on a wide variety of sites, be incorporated into
conventional farming operations and be sustainable for production of
transportation fuels and electric power generation. Switchgrass (Panicum
virgatum) clearly fits that description. It's a rugged native grass
that can be grown in the southeastern U.S. on marginal land with very little
fertilization and herbicide. Dr. Bransby, a forage scientist from South Africa
who joined the Auburn University staff in 1987, was intrigued by the growth
characteristics of switchgrass. He identified the variety, Alamo, as being
particularly well adapted to Alabama climates and soils. Alamo has shown
maximum heights of up to 12 feet and growth rates of 10 dry tons per acre in
experimental plots. Commercial yields are expected in the range of 6 to 8 dry
tons per acre in Alabama.
The current project involves several distinct activities. Production studies,
by Dr. Bransby in collaboration with a private farmer, will evaluate
establishment success and growth of switchgrass on 300 acres of typical pasture
land in central Alabama. Handling studies by Dr. Bransby will evaluate the
merits of field chopping versus baling, and various storage and transportation
options. Processing studies, by Southern Research Institute, will determine the
sensitivity of milling operations ( fuel preparation, blending, and
pulverizing) to switchgrass particle size, percentages in blend, and coal
types. Data on combustion, slagging and fouling, and emissions from co-fired
switchgrass and coal will be collected at Southern Research Institute's
pilot-scale power plant. A full-scale, 2-week co-firing demonstration by
Southern Company will provide information about fuel blending, heat rate and
efficiency effects, boiler slagging and fouling, and overall performance.
Southern Company, an independent power producer and the parent company of
Alabama Power, Georgia Power, Gulf Power, Mississippi Power, and Savannah
Electric, sees itself as an industry leader in finding cleaner ways to produce
electricity. The company is hopeful that mixing switchgrass with coal will be
both effective and economically promising because it won't require any changes
in existing technology at power plants. Instead of retrofitting plants, which
would ultimately result in higher costs to the consumer, they are working to
change the fuel blend. Since switchgrass uses carbon dioxide for growth, the
combustion of switchgrass will not increase atmospheric levels of CO2.
The testing will help verify if switchgrass is a reasonable low-cost option
that could help the utility industry meet environmental requirements and
increasing demands for electricity. Southern Company, which accounts for 30,000
megawatts of capacity in the Southeast, could provide a significant demand for
switchgrass supplies if the project is successful.
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Gregory J. Harvey, Certified Industrial Hygienist, Co-Chair of the EPA
Remedial Technology, Development Forum TCE Working Group, Wright-Patterson Air
Force Base
For decades, various industries used trichloroethylene (TCE) in industrial
cleaning processes as a safer way to clean metal parts prior to plating or
painting. Past operating and disposal practices resulted in TCE contamination
in groundwater at thousands of sites across the country. Communities near a
number of sites focus on these TCE plumes because natural attenuation of TCE in
groundwater has proven problematic. High levels of dissolved oxygen that
promote the intrinsic bioremediation of petroleum hydrocarbons can cause TCE to
persist for decades in the subsurface. It is not unusual for plumes of TCE to
have moved miles from their point of origin.
At the majority of TCE clean up sites, investigations and feasibility studies
conducted by and for government and industry have championed traditional
remedies such as pump and treat systems. Pump and treat systems, however, are
energy and capital intensive endeavors. Alternative clean up technologies are
needed.
While plants have often been noticed at sites with shallow TCE contamination,
they were only recently considered to play any significant role in the
remediation of the solvent. Research in various university labs, such as the
University of Georgia-Athens, Kansas State, Iowa State, and the University of
Washington, have found that several plants possess the enzymatic capability to
degrade TCE and its decomposition products such as dichloroethylene.
Currently there are several field demonstrations investigating the role plants
may play in promoting the remediation of halogenated hydrocarbons such as TCE.
Trees under consideration are hybrid poplars and cottonwoods. Field trials are
under way at sites in Florida, Maryland, New Jersey, Texas, and Utah. These
trials demonstrate various planting techniques (e.g., auguring down to the
water table or employing methods developed to plant short-rotation woody crops)
involving a range of TCE concentrations from 1 to 200 parts per million, and in
a variety of climates and hydraulic regimes.
The Air Force's Aeronautical Systems Center Environmental Management Directorate
is leading a multi-agency demonstration project in Fort Worth, Texas. The
project studies the efficacy and cost of phytoremediation in shallow
groundwater contaminated with trichloroethylene (TCE). The DOD's Environmental
Security Technology Certification Program and the U.S. EPA's SITE Program are
also involved in the project. Planting and cultivation of eastern cottonwood
(poplar) trees above a dissolved TCE plume in a shallow (< 12 feet) aerobic
aquifer took place in spring 1996. A year later, NATO's Committee on the
Challenges of Modern Society accepted the project as part of an ongoing
technology transfer process within the NATO scientific community. Data are
being collected to determine the ability of the trees, planted as a
short-rotation woody crop, to perform as a natural pump and treat system.
Seventeen months after the trees were planted, when it was determined that the
tree roots had reached the water table approximately 10 feet below the surface,
several trenches were dug adjacent to selected trees (R.L. Hendrick, Univ. of
Georgia, oral commun., 1997). Transpiration measurements indicated that the
largest planted trees transpired approximately 3.75 gallons per day during the
summer of 1997; whereas a nearby 19-year-old cottonwood tree was determined to
transpire approximately 350 gallons per day (J.M. Vose, U.S. Forest Service,
oral commun., 1997). Although the trees were transpiring water from the
contaminated aquifer, they were not hydraulically controlling the plume.
Project plans include predicting hydraulic control of the plume by combining
results of a transpiration model (PROSPER) and a groundwater flow model
(MODFLOW).
Laboratory experiments conducted on root samples from the site show the
disappearance of tetrachloroethylene (PCE) in the presence of roots from the
cottonwood trees. Other than a trace of TCE, there were no detectable
dehalogenated by-products in the cottonwood roots at the end of these
experiments. The disappearance of PCE in the presence of willow tree roots near
the site was even more remarkable (L.M. Wolfe, USEPA, oral commun., 1997).
These experiments indicate that tree enzymes will likely contribute to
attenuation of TCE.
TCE concentrations in groundwater samples collected beneath the 19-year-old
cottonwood tree during summer 1997 were about 80 percent less than
concentrations in ground water beneath the planted trees, and concentrations of
a TCE degradation by-product (cis-1,2-dichloroethylene) were about 100 percent
greater. These data, along with additional geochemical data from the site --
such as dissolved oxygen, bicarbonate, iron, hydrogen, and dissolved organic
carbon data -- are consistent with microbial degradation of TCE beneath the
mature tree (R.W. Lee, USGS, oral commun., 1997). Microbes with the ability to
readily degrade TCE require an environment that is low in dissolved oxygen and
high in an appropriate source of organic carbon. These conditions, which are
often lacking at sites contaminated with TCE, exist in the aquifer under the
mature tree and are likely due to the introduction of organic matter from
tree-root activity. Once the planted cottonwood trees have established more
mature root systems, a similar environment will likely develop in the aquifer
beneath the trees and result in an additional mechanism for attenuation of TCE
at the site.
By employing short-rotation woody crop technologies to clean up shallow
groundwater, researchers hope to use this project to leverage the knowledge
obtained by the DOE during the last twent-five years in the search for
sustainable sources of fiber and fuel. For further information about this
project or to obtain a copy of the Technology Demonstration Plan, arrange a
visit to the site or receive the final report due in the spring of 1999 by
contacting Gregory J. Harvey at (937) 255-7716 ext. 302 or email
Gregory.Harvey@wpafb.af.mil.
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Working with Patrick Girouard, REAP-Canada, Marie Walsh and Denny Becker, BFDP,
Oak Ridge National Laboratory, have modified BIOCOST, an EXCEL-based model, for
use in Canada. BIOCOST has a graphical interface that lets the user select a
region and then specify values for several variables including expected yields,
land rents, labor costs, and chemical, fertilizer, fuel, and planting stock
prices.
For information about the U.S. version of BIOCOST, contact Marie Walsh, Oak
Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6205,
(865)576-5607 (voice),(865)574-8884 (fax), email:
walshme@ornl.gov. For information about the Canadian version, contact
Patrick Girouard, Resource Efficient Agricultural Production (REAP) - Canada,
Box 125, Maison Glenaladale, Ste. Anne de Bellevue, Qc, H9X 3V9, (514)398-7743
(voice), (514)398-7972 (fax), email: reap@interlink.net
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