National Association of Conservation Districts

National Association of Conservation Districts

NACD's mission is to serve conservation districts by providing national leadership and a unified voice for natural resource conservation.

Bioenergy: Power for Agriculture and Conservation

 

What is biomass?

Biomass is the feedstock to generate fuels, electricity, chemicals, materials and other products. Biomass is any organic material produced by photosynthesis and is available on a renewable basis. Think of it as “stored solar energy.” Examples of agricultural biomass feedstocks for bioenergy production are:

Bioproducts use biomass to replace petroleum- based products. Virtually any product made from petroleum can now be made from biomass. Basic industrial and household products such as plastics, lubricants, solvents, resins, thickeners and urethane foam can all be bioproducts.

There will be a need for all of the above as demand increases for environmentally friendly energy sources and bioproducts. The beauty of potential and inexpensive feedstock from material that is considered a waste today (and in some cases, a source of pollution, like mishandled animal waste), is that tomorrow, it could put money in farmers’ pockets, reduce greenhouse gases and also solve water quality problems while it is generating clean, domestic power or used to produce bioproducts.

Why is bioenergy important?

Bioenergy and bioproducts replace fossil fuel that emits excess greenhouse gases into the atmosphere. Biomass supplies sustainable energy in power production, transportation and manufacturing processes. It supports national energy security and improves the international balance of payments. It opens new markets for farmers and improves rural economies. In addition to farmers providing the biomass feedstock for bioenergy production, in many cases, individual farmers and farmer cooperatives own the energy production operations.

Reduces Greenhouse Effects
Bioenergy and bioproducts will help the United States reduce its world-leading pace of greenhouse gas emissions, the prime source of global climate change. The carbon dioxide (CO2) emitted from burning biomass returns it to the current carbon cycle. Growing plants take in CO2 from the atmosphere during photosynthesis, a process that releases oxygen and retains carbon in plant tissues, and then is subsequently returned to the global pool of CO2 in the atmosphere when the plant is burned, decomposed or digested. As a result, biomass does not contribute to increased concentrations of CO2 in the atmosphere. Its use replaces the use of fossil fuels that emit CO2 that was removed from the atmosphere during prehistoric times.

The world’s mass of vegetation relies on an adequate concentration of CO2 in the air; however, that concentration has been seriously increased since the advent of the Industrial Revolution. Fossil fuels–coal and oil–were selected as primary energy sources and have been consumed in ever-increasing volumes for the last 150 years. The CO2 released from fossil fuel is drawing on an ancient carbon cycle that was essentially closed millions of years ago. The growing consumption of fossil fuel produces CO2 and other greenhouse gases far in excess of that required for plant growth and the maintenance of our present climate and are now starting to have a major impact.

Greenhouse gases reflect back some of the heat emanating from Earth in a similar fashion to heat reflected back by the glass in a greenhouse; hence, the “greenhouse effect.” Human activities and fossil fuel consumption have caused the greenhouse effect to change world climate; and as a result, changes in the natural cycles of plants, animals and water. Increased use of bioenergy and bioproducts can help reduce emissions from non-renewable fossil fuels by working within the currently active carbon cycle.

A Matter of National Security
Every gallon of ethanol and biodiesel fuel and every bioproduct that replaces petroleum- based products that are produced in this country reduce our reliance on foreign fossil fuel. At this point approximately 60 percent of America’s consumption of oil comes from foreign sources and costs $80 billion a year. In the last 30 years, the United States has experienced an OPEC (Organization of Petroleum Exporting Countries) engineered “gas crisis” that created long lines at gas stations and a sharp increase in prices, a war with Iraq that threatened the U.S. oil supply lines and cost $1 billion a day and the beginning of a war against terrorists that may again threaten our extended supply lines to Mid Eastern oil. Any domestic alternative through bioenergy and bioproducts that reduces our need to use foreign fossil fuel pays substantial dividends: increasing our control over our own energy source; improving the environment in the process; and, providing agriculture with lucrative new markets.

Senator Tom Harkin, Chairman of the Senate Agriculture Committee, said recently,

“…We have only scratched the surface of developing farm-based sources of renewable energy – ethanol, biodiesel, biomass, wind, methane, hydrogen… Anything we can produce from a barrel of oil, we can also produce on our farms. We do not have to drill for oil in environmentally pristine areas, nor do we have to be at the mercy of foreign oil producers…”

Building Up the Base
In August 1999, President Clinton issued an executive order that created the Biobased Products and Bioenergy Initiative with a general mission to triple the use of bioenergy by 2010 through a combined effort led by the U.S. Departments of Agriculture and Energy (USDA, DOE). The next year, Senator Richard Lugar, then- Chairman of the Senate Agriculture Committee, outlined similar goals in the Biomass Research and Development Act, which was passed into law as part of the Crop Insurance Bill.

A permanent body, the Biomass Research and Development Board, cochaired by USDA and DOE, meets quarterly to create measures that will encourage the substantial growth of the bioenergy and bioproducts industries. Its goals include: reducing technology costs; providing demonstrations of bioenergy and bioproducts; monitoring and evaluating environmental impacts; increasing research; and, coordinating policies to encourage early market adoption of bioenergy and bioproducts. For example, the Board has recommended that the federal government be a major consumer of bioenergy and that incentives should be provided to boost production in the private sector. Efforts are also underway to encourage federal procurement officers to purchase more bioproducts. Although procurement regulations may not guarantee an automatic response, an effort is being made to provide product information to procurement officers to raise their awareness.

USDA expects to double its annual use of 80,000 gallons of biodiesel by 2002 and to be using 360,000 gallons a year by 2005. The entire USDA fleet of vehicles currently totals nearly 36,000. USDA started the Bioenergy Program in 2000 through which the Farm Services Agency (FSA) provides up to $150 million per year in payments to commercial bioenergy producers in the United States that increase their bioenergy production from eligible commodities. As a result of the first year’s program, ethanol producers committed to expanding production by 246 million gallons, and biodiesel producers by 36 million gallons.

USDA also started the Biomass Pilot Project in 2000 to encourage biomass development projects on up to 250,000 acres of land enrolled in the Conservation Reserve Program (CRP). The approved pilot projects must use a vegetative cover that, in addition to producing biomass, would ensure the environmental integrity of the CRP provisions, operate for a minimum period of 10 years and the total acreage per project may not exceed 50,000 acres. The first four approved projects will use switchgrass in Iowa and Pennsylvania, hybrid poplars in Minnesota and willows and switchgrass in New York.

Forms of Bioenergy From Agricultural Feedstock

Transportation Fuels – Ethanol
Ethanol is produced by converting biomass into alcohol. The process involves fermentation of the sugars in the biomass using enzymes, yeasts and bacteria. As a process, producing ethanol is not far removed from producing moonshine! The traditional feedstock for ethanol has been crops with high sugar content such as corn or sugar cane; however, some industries have optimized the use of manufacturing wastes by producing ethanol from cheese whey, brewery and beverage wastes, potato wastes, paper wastes and excess sugars and starches. As of September 2001, 46 of the 57 existing ethanol operations in the U.S. use corn as a feedstock. In addition, there are 13 new plants being planned and 11 of those will also use corn as the primary feedstock. Of the 57 existing operations, 19 (one third) are owned by farmers’ cooperatives.

The ethanol industry began in 1978 during the Carter Administration as a response to the Gas Crisis of 1973. As an attempt to make ethanol cost competitive with gasoline, Congress passed the Energy Tax Act of 1978 that exempted ethanol blends from federal highway taxes. A common blend is “E-10,” 10 percent ethanol, 90 percent gasoline, which can be used in vehicles without major adjustments. A growing number of vehicles are being adjusted for E-85, a blend that is 85 percent ethanol.

Ethanol is a much cleaner fuel than petroleum products. It boosts octane and, in California and several other states, will soon replace methyl tert-butyl ether (MTBE), a synthetic chemical oxygenate that has been found to pollute groundwater. An article coauthored by Senator Richard, Lugar R. James Woolsey, former CIA Director in 1999, provided the following example to demonstrate the impact of ethanol on the environment:

“…Cellulosic ethanol is a first-class transportation fuel, able to power the cars of today as well as tomorrow…If a second Exxon Valdez filled with ethanol ran aground off Alaska, it would produce a lot of evaporation and some drunk seals…”/1

Biodiesel Fuel
A biobased version of diesel fuel, which requires no adjustment of diesel engines, is derived from oilseed products such as soybean, sunflower or canola oil or animal fats such as tallow or even waste grease from restaurants. It is also an excellent lubricant. Compared with diesel exhaust, biodiesel emits less black smoke, odor, greenhouse gases, air toxics and particulates. It contains no sulfur dioxide, the major constituent of acid rain.

Methane Capture
Methane is a greenhouse gas that is 21 times more potent than carbon dioxide in its warming effect. Technology that has significantly improved over the last 20 years allow livestock operators to capture the methane from animal manure and use it to fuel generators that can not only provide all the electrical power needed by the farm, but also produce an excess that, as required by the Energy Policy Act of 1992, must be purchased by the local utility. Of the few in operation today, many claim that the odor and fly control provided by covering manure facilities is almost as valuable to them as the energy savings. Methane performs the same as natural gas; it could also be burned and used for heating or grain drying.

Depending on the size of the operation, the return could be as much as $10,000 - $20,000 in savings each year by self-generated energy plus the added revenue of selling excess power. After this process, the manure becomes a more effective fertilizer because the process converts organic nitrogen into a mineralized form that can be taken up more quickly and predictably by plants than raw manure.

The production of methane is through anaerobic digestion, i.e. biological decomposition by bacteria without the presence of oxygen. Although the current applications of this process are predominantly with animal manure, it is possible to produce methane with any biomass in an anaerobic digester. State of the art biorefineries can incorporate this process with any biomass feedstock as a by-product of an ethanol operation.

The downside is that the system is expensive, although depending on the scale of the operation, the rate received for selling to the local utility and some other key factors, an economic analysis usually shows an investment return in 5–10 years. If, however, a viable carbon credit market existed, credits would be traded for all the greenhouse gases. A methane credit would likely be more valuable than a carbon credit because it is more potent (and should be valued as such in the market), it can be measured precisely in units of cubic feet and it is a direct reduction of a greenhouse gas, not an offset. If a well-defined and established carbon market existed, the ability to sell methane credits would be a significant additional incentive to invest in such as system.

Biomass Conversion to Electricity
Power generation stations can use biomass to produce electricity as the exclusive feedstock or co-fired with fossil fuel such as coal. Co-firing would result in a reduction of a power plant’s overall greenhouse gas emissions from fossil fuel, a portion of which is replaced with emissions from biomass returning CO2 to the current carbon cycle. One essential requirement is that the biomass can be provided in sufficient quantity to keep a power generation station operating 24 hours a day. There are currently 350 power plants using biomass as feedstock, collectively producing 7,500 megawatts of power. In some cases, the feedstock is sawmill wastes.

Burning biomass in a low-pressure gasifier is a more efficient system, capable of extracting twice as many BTU’s from feedstock and producing a clean, fuel gas (similar to propane) that can then be burned to produce power.

Other Forms of Clean Energy
Tremendous advances in various forms of clean energy sources make them viable components of the nation’s overall energy inventory. Wind power, for example, has more than doubled in capacity over the last five years. Modern windmills are being constructed in the major windsheds of the world and are compatible with agriculture, with a relatively small footprint and lucrative annual rental fees paid to farmers.

Similar advances are being made with photovoltaic (solar battery) energy and geothermal energy where heat from the earth’s core provides the energy source. The future could also hold the potential commercial development of hydrogen fuel cells, which emit oxygen and water. These cells can replace the internal combustion engine to power the vehicles of tomorrow.

The Concept of an Energy Budget

In order for bioenergy or any energy source to be a viable component of the nation’s inventory, one must calculate how much energy is consumed to produce it and compare it to its energy output. Consider for example, using corn to produce ethanol. To figure the energy life cycle of corn, one must consider not only the energy consumed in planting and harvesting the corn, but also the energy involved in manufacturing the fertilizer, chemicals and farm equipment itself.

Calculating the totals in terms of an energy and economic comparison with the cost of producing gasoline, ethanol made from corn has been costly to produce. However, that comparison improves when adding in several valuable by-products that can be utilized from corn after ethanol has been produced. One by-product is gluten or dry miller’s grain, used as high quality cattle feed. Corn and soybeans can also be basic components in a number of bioproducts such as plastic, lubricants, solvents, urethane foam, resins, thickeners and just about any product currently made with petroleum. A study conducted by USDA-Economic Research Service in 1995/2 determined that using corn as a feedstock to produce ethanol with modern technology, a “net energy value” of 16,193 Btu per gallon of ethanol is achieved with an energy ratio of 1.24. That means that the energy produced from burning a gallon of ethanol provides a 24 percent gain over the energy it took to produce that gallon of ethanol from corn.

A Major Breakthrough
Advances in biotechnology have developed enzymes and other biocatalysts that can now use virtually any plant material to produce ethanol, instead of just those of high sugar content like corn or sugar cane. Senator Lugar reported on this breakthrough in the article he coauthored in 1999:

“…Recent and prospective breakthroughs in genetic engineering and processing… are radically changing the viability of ethanol as a transportation fuel. New biocatalysts—genetically engineered enzymes, yeasts and bacteria— are making it possible to use virtually any plant or plant product (known as cellulosic biomass) to produce ethanol…”/3

Producing ethanol from biomass that is less energy-intensive to grow could make it more cost competitive with gasoline. More research is needed over the next several years to perfect the bioengineered enzymes before the new process is production-ready. With this new technology, switchgrass is a promising biocrop. It is a very high yielding native perennial grass with a deep, extensive root system (which sequesters considerable amounts of carbon below ground) that requires minimal fertilizer inputs. The energy budget of a plant like switchgrass is even more favorable than corn. As Dr. Sandy McLaughlin reports after several years of research on switchgrass at Oak Ridge National Laboratory:

“…Ethanol from switchgrass can produce about five times more energy than you put in. When you factor in the energy required to make tractors, transport farm equipment, plant and harvest, and so on, the net energy output of switchgrass is about 20 times better than corn’s…”/4

Crop residues are also promising as inexpensive feedstocks in ready supply. Corn stover, rice and wheat straw are examples of materials under research for full-scale ethanol production. Materials currently considered waste products also have great potential use as feedstock. Forestry waste, including excess forest floor litter that has contributed to devastating wildfire damage in recent years, could be gathered and utilized. The harvest of crop residues and forest litter must, however, be controlled so that a sufficient amount is retained (at least 30 percent) to ensure adequate erosion control, as well as restoration of soil nutrients and carbon from sufficient organic matter decomposition at the soil surface. The organic component of municipal waste, the landfilling of which is a serious and growing urban problem, could be used to produce ethanol and methane.

Ethanol might even be produced in the future from manure. In many areas of the U.S., regional concentrations of livestock and poultry produce more manure than can be applied to nearby cropfields without exceeding nutrient management guidelines and transportation costs to move it to other areas are too high. If an ethanol operation in the midst of such an area accepted all the excess manure in that area, it would help to solve a major water quality problem in addition to providing cleaner energy.

Research is still needed in order to perfect the technology and production efficiency of using cellulosic biomass for ethanol. Corn is currently the feedstock of 46 of 57 existing ethanol operations, all of which use material with high sugar content. The potential future demand for ethanol to replace MTBE as the oxygenate in gasoline as well as higher mixtures like E-85, and other forms of bioenergy and bioproducts could require full production of all the various feedstocks. In the future, corn ethanol operations may add facilities onsite to handle other biomass feedstocks to ensure flexibility in ethanol production that is not just dependent on the price of corn.

Putting it All Together—Biorefineries Under Design

Combining Operations for Maximum Efficiency
The bioenergy operation of the near future will utilize the full energy potential of its feedstock because biomass can maximize energy efficiency by producing several forms of bioenergy in sequence before it is totally consumed. The ultimate biorefinery, with variations depending on feedstock, may produce:

One example of a modern biorefinery under design is PRIME Technologies, a $40 million facility to be built near Pierre, South Dakota. It will use corn to produce ethanol. The residue of that process is high quality animal feed that every other ethanol operation utilizes but has to expend tremendous energy to dry it adequately for shipment. PRIME Technologies intends to make livestock a part of the operation, feeding the wet material to 60,000 cows per year directly. The livestock manure will be collected in an anaerobic digester where captured methane will be converted to electricity that will run the entire operation. Excess power will be sold and manure residues will be composted, bagged and sold as commercial organic fertilizer.

Another example of a biorefinery that is currently operating is a joint venture of Cargill and Dow Chemical in Blair, Nebraska. It uses corn to produce ethanol and gluten, which is dried and shipped. But what makes it unique is that it also produces biodegradable plastic from corn. Cargill Dow expects to produce nine million pounds of plastic this year and estimate that they will produce one billion pounds by 2010.

In Louisiana, Ensyn Technologies and Louisiana-Pacific Corporation are building a plant that would use a “fast pyrolysis process,” superheating and liquefying biomass in the absence of oxygen, to convert bark and wood waste into bio-oil. The biooil will be transformed into a resin for structural building products such as plywood and oriented strand board. The waste product, called char, will be used as a filtering agent and as a heat source for the plant.

Opportunities for Agriculture

Bioenergy’s tremendous need for growth provides agriculture with a huge new market opportunity. It gives agriculture the chance to produce the feedstock for fuel, chemicals, materials and electricity to help the nation become more self-reliant. The selection of feedstock could be a common organic material that is currently considered to be of little or no value making waste a major asset. Farmers can also be owners of the new power centers.

When a farm installs methane capture equipment, it becomes its own utility. It increases farm profits by supplying its own electrical needs and thereby saving what would have been spent in energy costs. It also establishes a new revenue stream through the sale of excess power to the local utility.

When a farm grows a biocrop or uses crop residue to provide a local biorefinery or power plant with feedstock, it adds more options for new markets and a profitable operation.

Opportunities for the Conservation Partnership

The nation’s conservation districts and their partners could be the catalyst to establish new bioenergy/bioproducts operations by linking biomass feedstock plant managers to the community of farmers that will be their suppliers. Bioenergy and bioproduct production are positive steps for the local and global environment. Biocrops, such as switchgrass, are sustainable with a minimum of inputs. They also can improve soil and water quality and provide excellent wildlife habitat.

Conservation partners have a critical role in ensuring that biomass production and harvest are sustainable and that adequate natural resource conservation systems are in place. They can also help to expand conservation opportunities through this new market. For example, if the feedstock were corn stover or other crop residues, cooperation is needed from all parties to leave a significant portion on the field in order to maintain erosion control and increase soil organic carbon. Biomass demand could also supply the impetus to introduce and expand conserving grass-based rotations to traditional grain rotations, grass contour strips, perennial buffers and agroforestry practices. Innovation and opportunities will need to be explored and developed locally.

Getting involved in bioenergy and bioproducts presents the chance to establish new partnerships, find new funding pools for conservation and the opportunity to take a local leadership role in pilot and demonstration projects to ground-truth research. Seeing the opportunities that bioenergy can provide for agriculture and conservation could also inspire a proactive political approach that increases governmental support for the substantial growth of all forms of bioenergy.

This article was written by Gerald F. Talbert, an independent consultant working with the National Association of Conservation Districts on a grant from the Turner Foundation. It is dedicated to the memory of Denis Nickel, NRCS Global Climate Change Team, Davis California. “Global climate change provides the greatest opportunity since the Dust Bowl to advance conservation goals.”

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Citations:

  1. Senator Richard Lugar and R. James Woolsey, The New Petroleum, Foreign Affairs Magazine, Vol. 78, #1, January, 1999
  2. Hosein Shapouri, James A. Duffield, Michael S. Graboski, Estimating the Net Energy Balance of Corn Ethanol, USDA-Economic Research Service, Agricultural Economic Report Number 721, Washington, DC, July 1995
  3. Senator Richard Lugar and R. James Woolsey, The New Petroleum, Foreign Affairs Magazine, Vol. 78, #1, January, 1999
  4. Oak Ridge National Laboratory, Biofuels from Switchgrass: Greener Energy Pastures, http://bioenergy.ornl.gov/papers/misc/switgrs.html