Qi BioEnergy

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Grain-based ethanol production is expanding rapidly and is the primary factor leading to major increases in the amount of corn grown in the USA and elsewhere. Increased corn acreage and fertilizer application rates due to corn prices will increase N and P losses to streams, rivers, lakes, and coastal waters, particularly the Northern Gulf of Mexico and Atlantic coastal waters downstream of expanding production areas. Harvest of corn stover for cellulosic ethanol production would likely increase erosion (sedimentation) and nutrient loads, which will adversely affect these already nutrient-stressed waters. It is critical that a broad suite of conservation measures, particularly nutrient management, are rigorously implemented on new or more intensively managed corn lands, particularly under continuous corn production to partially offset an increased potential for nutrient loss; for example, the use of precision and variable-rate applications of fertilizers and the Late Spring Nitrate Test. Additional measures include interseeding corn with cover crops and the inclusion of buffers or riparian filter strips to minimize edge-of-field runoff of N and P.

Dried distiller’s grain from fermentation is rapidly becoming available for use in animal rations, particularly for beef and dairy cattle. Due to the high P content of DDGs, the P content of manures will increase, which will further enhance the mobility in runoff of P applied in these manures. The use of DDGs in animal rations should not be done at such a level as to increase N and P contents of feeds above nutritional requirements. Otherwise, N and P contents of manure will be greater than using current feed management practices, enhancing the potential for nutrient enrichment of runoff. The likely concentration of animal facilities near ethanol production plants must be accompanied by sound nutrient management planning and other conservation measures to avoid the soil and water-quality consequences of N and P accumulation in areas used to land apply manures.

The development of efficient and competitive fermentation technologies and supporting infrastructure to allow development of a perennial grass or waste-based cellulosic ethanol industry could provide a long-term sustainable approach to ethanol production. A cellulosic renewable energy approach could provide multiple ecosystem services including energy, C sequestration, improved water quality and fisheries habitat, and improved soil quality and productivity. As markets develop for each of these services/products, perennial grass production for ethanol generation may become economically competitive with, or even superior to, grain or crop residue fuel-stocks for ethanol production. Any alternative fuel production technology may have impacts on water quality. As a result, it is important to make policy and programmatic and scientific decisions that avoid or mitigate the unintended environmental consequences of biofuel production during development of the industry to avoid the much higher costs of remediation and ecosystem restoration at a later date.

We are proposing a new cropland reserve program, operating in parallel to but not within the Conservation Reserve Program. The Renewable Energy Reserve Program (RERP) would require a ten- to fifteen-year commitment from the landowner, along with the establishment of perennial crops suitable for biomass production, in order to receive program benefits. Benefits would include one-time reimbursement of up to 50% of crop establishment costs and an annual payment to the landowner modeled on CRP land rents for the first three years of program participation (five years for a woody biomass crop), extendible at a reduced rate through subsequent years for any producer who can document annual crop sales to an energy user (ethanol plant, pelletizing company, co-firing electricity plant, etc.) Phasing out land rental payments after three years (five years for woody crops) will discourage signup in locations where potential user industries are unlikely to emerge, or on land more appropriate for participation in CRP. Landowners who sign up for the RERP could withdraw after five years, but only after reimbursing the Federal government, with interest, for all benefits received prior to contract termination.

Sponsored by U.S. Dep. Energy’s Biomass Program through contracts with Oak Ridge National Laboratory and the Great Plains Institute of Sustainable Development and in collaboration with the Energy & Environmental Research Center

Although switchgrass (Panicum virgatum L.) has been used as a model biomass energy crop, other species and/or mixtures of species may improve overall performance and sustainability of biomass production systems. Our objectives were to compare biomass production potential of switchgrass monocultures to native warm-season grass mixtures at multiple locations in the northern Great Plains. Switchgrass, big bluestem (Andropogon gerardii Vitman), and indiangrass [Sorghastrum nutans (L.) Nash] were planted as monocultures and in 2- and 3- way mixtures using a no-till drill during May 2002 at four locations (one at Brookings, SD; one near Pierre, SD; and two near Morris, MN). Due to establishment failure, the Pierre site was replanted successfully during November 2002. Harvests were made at each site during late autumn 2003-2005, respectively. One of the sites at Morris, MN was discarded after the 2003 harvest because of inadvertent early harvest in 2004 and destruction from construction traffic in 2005.

Averaged across years, switchgrass monocultures or mixtures including switchgrass were the highest yielding treatments at both SD locations. While there was a similar trend at Morris, MN, yields were not significantly different among treatments. However, big bluestem tended to dominate stands at Brookings, SD and Morris, MN, thus demonstrating the importance of big bluestem in filling areas perhaps underutilized by other species. Big bluestem did not achieve the same composition level at Pierre which is a much drier site and beyond the western edge of the tall grass prairie region.

Switchgrass could be a new crop for   farmers.   Photo: Warren Gretz, NREL

Tripling U.S. use of biomass for energy could provide as much as $20 billion in new income for farmers and rural communities and reduce global warming emissions by the same amount as taking 70 million cars off the road.

Many farmers already produce biomass energy by growing corn to make ethanol. But biomass energy comes in many forms. Virtually all plants and organic wastes can be used to produce heat, power, or fuel.

Biomass energy has the potential to supply a significant portion of America’s energy needs, while revitalizing rural economies, increasing energy independence, and reducing pollution. Farmers would gain a valuable new outlet for their products. Rural communities could become entirely self-sufficient when it comes to energy, using locally grown crops and residues to fuel cars and tractors and to heat and power homes and buildings.

Opportunities for biomass energy are growing. For example, several million dollars of federal incentives are available through the 2002 Farm Bill to develop advanced technologies and crops to produce energy, chemicals, and other products from biomass. A number of states also provide incentives for biomass energy.

Biomass Energy Sources on the Farm

Biomass Residues

Agricultural activities generate large amounts of biomass residues. While most crop residues are left in the field to reduce erosion and recycle nutrients back into the soil, some could be used to produce energy without harming the soil. Other wastes such as whey from cheese production and manure from livestock operations can also be profitably used to produce energy while reducing disposal costs and pollution.

Energy Crops

Crops grown for energy could be produced in large quantities, just as food crops are. While corn is currently the most widely used energy crop, native trees and grasses are likely to become the most popular in the future. These perennial crops require less maintenance and fewer inputs than do annual row crops, so they are cheaper and more sustainable to produce.

Grasses. Switchgrass appears to be the most promising herbaceous energy crop. It produces high yields and can be harvested annually for several years before replanting. Other native varieties that grow quickly, such as big bluestem, reed canarygrass, and wheat grass, could also be profitable.

Trees. Some fast-growing trees make excellent energy crops, since they grow back repeatedly after being cut off close to the ground. These short-rotation woody crops can grow to 40 feet in less than eight years and can be harvested for 10 to 20 years before replanting. In cool, wet regions, the best choices are poplar and willow. In warmer areas, sycamore, sweetgum, and cottonwood are best.

Oil plants. Oil from plants such as soybeans and sunflowers can be used to make fuel. Like corn, however, these plants require more intensive management than other energy crops.

Protecting the Land

With thoughtful practice and management, perennial energy crops can improve the soil quality of land that has been overused for annual row crops. The deep roots of energy crops enhance the structure of the soil and increase its organic content. Since tilling occurs infrequently, the soil suffers little physical damage from machinery. One study estimates that converting a corn farm of average size to switchgrass could save 66 truckloads of soil from erosion each year.

Perennial energy crops need considerably less fertilizer, pesticide, herbicide, and fungicide than annual row crops. Reduced chemical use helps protect ground and surface water from poisons and excessive aquatic plant growth. Furthermore, deep-rooted energy crops can serve as filters to protect waterways from chemical runoff from other fields and prevent sedimentation caused by erosion.

Finally, perennial energy crops can create more diverse habitats than annual row crops, attracting a wider variety of species such as birds, pollinators, and other beneficial insects, and supporting larger populations. Furthermore, the long harvest window for energy crops enables farmers to avoid nesting or breeding seasons.

Converting Biomass to Energy

Most biomass is converted to energy the same way it always has been—by burning it. The heat can be used directly for heating buildings, crop drying, dairy operations, and industrial processes. It can also be used to produce steam and generate electricity. For example, many electric generators and businesses burn biomass by itself or with other fuels in conventional power plants.

This 50 MW biomass power plant runs on residues produced by the nearby forest products industry. Photo: Warren Gretz, NREL

Biomass can also be converted into liquids or gases to produce electricity or transportation fuels. Ethanol is typically produced through fermentation and distillation, in a process much like that used to make beer. Soybean and canola oils can be chemically converted into a liquid fuel called biodiesel. These fuels can be used in conventional engines with little, if any, modification.

Biomass can be converted into a gas by heating it under pressure and without oxygen in a “gasifier.” Manure too can be converted using a digester. The gas can then be burned to produce heat, steam, or electricity.

Other biogas applications are still in development, but show great potential. One promising technology is direct combustion in an advanced gas turbine to run a generator and produce electricity. This process is twice as efficient as simply burning raw biomass to produce electricity from steam. Researchers are also developing small, high-speed generators to run on biogas. These “microturbines” have no more than three moving parts and generate as little as 30 kilowatts, which could power a medium-sized farm. Several companies are also considering converting gasified biomass into ethanol as a less expensive alternative to fermentation.

Alternatively, biogas can be processed into hydrogen or methanol, which can then be chemically converted to electricity in a highly efficient fuel cell. Fuel cells can be large enough to power an entire farm or small enough to power a car or tractor.

An innovative experiment in Missouri provides one example of the possibilities. Corn is used to produce ethanol, and the waste from the process is fed to cows for dairy production. Cow manure fertilizes the corn and is also run through a digester to produce biogas. A fuel cell efficiently converts the biogas into electricity to run the operation. The end products are ethanol, electricity, and milk. All the waste products are used within the project to lower costs.

Potential

Biomass currently provides about two percent of America’s electricity, one percent of the fuel used in cars and trucks, and some of the heat and steam used by homes and businesses. With more energy crops and better conversion technology, it could gain a much larger portion of the market. Energy crops and crop residues could provide 14 percent of U.S. electricity use or 13 percent of the nation’s motor fuel.

An Oak Ridge National Laboratory (ORNL) study found that farmers could grow 188 million dry tons of switchgrass on 42 million acres of cropland in the United States at a price of less than $50 per dry ton delivered (see map below). This level of production would increase total U.S. net farm income by nearly $6 billion. ORNL also estimates that about 150 million dry tons of corn stover and wheat straw are available annually in the United States at the same price, which could increase farm income by another $2 billion. This assumes about 40 percent of the total residue is collected and the rest is left to maintain soil quality.

Opportunities

One opportunity for energy crop development is to use land that is currently idle or poorly suited for food crops, such as that in the Conservation Reserve Program (CRP). This program encourages farmers and ranchers to adopt long-term conservation practices on environmentally sensitive land. In 2000, more than 34 million acres were enrolled in the CRP. Much of this land is already planted in native grasses and trees to help reduce erosion, protect water quality, and provide wildlife habitat. With careful management, farmers could harvest energy crops on some of this land. This would allow them to earn an income and reduce subsidy payments, while still maintaining the environmental benefits of the program.

A co-op in Iowa is testing this concept. In the Chariton Valley, farmers have planted 5,500 acres of CRP land with switchgrass to be burned with coal in a large utility power plant near Ottumwa. If successful, the project will scale up to 50,000 acres, producing 200,000 tons of switchgrass each year and supplying five percent of the plant’s fuel.

This example also shows that selling biomass feedstocks as a commodity to energy producers may be a more attractive option than producing biomass energy on the farm. Energy producers have greater access to capital and energy markets, can typically produce energy at a lower cost in larger facilities, and have the expertise to operate and maintain these facilities.

Since establishing an energy crop takes time and harvesting occurs over a number of years, long-term contracts with energy producers are likely to be necessary to make a profit. Long-term contracts also offer greater income stability by allowing farmers to avoid some of the fluctuations of commodity markets.

Another option is for farmers to form a local co-op to produce energy and other value-added products in jointly owned facilities. This approach can increase profits by achieving economies of scale and scope in production and by gaining access to low-cost financing. It can also help improve the viability of family farms and strengthen rural communities by creating new jobs and keeping money in the local economy. This approach has been particularly successful in Minnesota, which provides incentives for small community-based ethanol plants.

For More Information

U.S. Department of Energy
Biopower and Biofuels Programs
www.eren.doe.gov

Institute for Local Self-Reliance
1313 5th Street SE
Minneapolis, MN 55414-1546
(612) 379-3815
www.carbohydrateeconomy.org

National Renewable Energy Laboratory
1617 Cole Boulevard
Golden, CO 80401
(303) 384-6979
www.nrel.gov/biomass

U.S. Department of Agriculture
2002 Farm Bill Renewable Energy Incentives
www.rurdev.usda.gov/rd/farmbill/9006resources.html

Regional Biomass Energy Program
www.ott.doe.gov/rbep/

American Bioenergy Association
209 Pennsylvania Avenue SE
Washington, DC 20003

Center for the Analysis and Dissemination
of Demonstrated Energy Technologies
www.caddet-re.org/technologies/search.php?id=12

BIOMASS is a renewable resource that can be used to generate electricity, heat, or liquid fuels such as ethanol. A successful perennial grass-based bioenergy system requires reliable establishment and persistence, knowledge of optimum cultural and production practices, high yielding cultivars, and appropriate conversion technology. The Conservation Reserve Program (CRP) is a land retirement program established by the Food Security Act of 1985. The main objectives of this program are to reduce soil erosion, reduce commodity surpluses, and to supplement farm income (Jewett et al., 1996). Native warm-season grasses such as switchgrass are permitted for use as permanent vegetation on CRP land. Rather than losing the environmental benefits and converting switchgrass CRP land to traditional crops when contracts expire, the herbaceous material could be used as a biomass feedstock.

The primary objective of this research was to determine the biomass/bioenergy yield and economic value of typical CRP land in northwestern Oklahoma.

When the supply estimate is presented in terms of total acreage in a region, the scenarios with increased yields move the supply prices downward, i.e. they lower supply costs. Improved yields in 2005 with a modest research program lower costs at the line shown Figure 3 from $47.60 per ton to $42.48, a reduction of $5.12 per dry ton or 11 percent. By 2020 with a long term research program, the costs are lowered to $35.74 per ton, down $11.86 or 25 percent from the costs projected in 2000.

The Conservation Reserve Program is the largest environmental program administered by the U.S. Department of Agriculture , with enrollment exceeding 34 million acres across all 50 states. In Wyoming, 281,116 acres on 739 farms are in the CRP. Based on average rental payments, the CRP brings in more than $7.7 million per year to Wyoming’s farm economy. Improvement in program performance is an enduring goal of CRP administrators. For the past 9 years and continuing today, scientists from the Fort Collins Science Center have been working in partnership with the USDA Farm Service Agency to help improve the program evaluating program performance both socially (how is it working for CRP contractees) and ecologically (how is wildlife habitat improved?). In June 2004, FORT and the FSA sponsored a national meeting for more than 200 participants and presenters to address and present research on these issues as well as future CRP directions. The proceedings, The Conservation Reserve Program: Planting for the Future, as published in 2006.

According to the U.S. Department of Agriculture, Nebraska has more than 1.2 million acres of CRP land.