Biomass Energy from Agriculture

Texas is the nation’s second-leading agricultural-producing state. Biomass could generate a significant percentage of our energy and fuel while offering rural communities a new economic market.

Dedicated Energy Crops

Energy crops involve a "closed-loop process" in that they grown specifically for their ability to generate energy. Crops such as switchgrass, hybrid poplars (cottonwoods), hybrid willows and sugarcane are being studied for their ability to serve as energy crops for fuel. One of their great advantages is that they are short rotation crops; they re-grow after each harvest, allowing multiple harvests without having to re-plant. Corn and sorghum serve a dual purpose as they can be grown for fuel, with the leftover by-products being used for other purposes, including food.

Texas Possibilities

Texas crops that are being considered for development as energy crops for biofuel potential are sorghum, sugarcane, switchgrass, and canola. The National Commission on Energy Policy estimates that by 2025, producing the crops to make biofuels could provide farmers with profits of more than $5 billion per year. Grains and oilseeds are the primary feedstocks used to produce ethanol and biodiesel fuels. These biomass resources account for about 25 percent of biomass consumption.

Ethanol and biodiesel production offers rural communities the greatest opportunity for economic growth because biorefineries are constructed near the source of the required source of fuel and feedstocks.

Another promising resource for biofuel is Algae.

Biomass Crops

Canola for Biodiesel

Canola is the edible version of rapeseed, the highest yielding oil source in the U.S., at 122 gallons per acre. Soy yields 46 gallons per acre.

Once termed a Cinderella crop, canola, a Texas native plant, is now gaining recognition as a biodiesel fuel, valued for its high oil content, increased lubricity for engines, better fuel pump response, excellent diesel engine wear protection, and low levels of saturated fats which means improved performance in cold climates.

Researchers are currently developing best practices for planting and growing canola and new gene enhancement technology is being developed to increase the yields of canola as well as other energy crops by more than 20 percent.

For more information on canola:

• “Texas Canola Oil May Soon Burn In Engines Rather Than Frying Pans”, A Science Daily Article, November 2005.

Sorghum for Ethanol

Farmers on the hot, dry High Plains in the Texas Panhandle and in the Central Texas “corn belt” grow and use grain sorghum, or milo, like midwest corn belt farmers use corn. It grows well in the Pan Handle because it is drought resistant and a “water-sipping” crop, requiring less intensive irrigation. A prolific producer, sorghum is a short rotation crop, meaning that it can can be harvested multiple times throughout the year.

Though used mainly for livestock feed, 15% of sorghum crops goes to ethanol production. Texas A&M Extension agronomist, Juerg Blumenthal, said at a March 2007 renewable fuels conference that sweet sorghum is a promising crop for Texas’ renewable fuel producers. See these Southwest Farm Press articles:

“Sweet Sorghum: Good Option as Renewable Energy Crop in Texas”, March 2007
“Texas Sorghum Producers Optimistic About Biofuel Potential”, August 2007

Switchgrass for Ethanol & Biodiesel

Switchgrass, a Texas native plant, contains enormous amounts of sugar that can be refined into ethanol. It can be burned to produce electricity or used as a feedstock for cellulosic ethanol. Many farmers already grow switchgrass, either as forage for livestock or as a ground cover to control erosion, so cultivating it as an energy crop would be an easy switch.

As a fast growing energy crop, or closed loop biomass, switchgrass yields over 1,000 gallons per acre, more than 3 times the yield of corn. Switchgrass and sorghum are from the same family; both are short term crops and produce prolifically with limited water, insecticides or fertilizer needs. Switchgrass prevents soil erosion as it restores vital organic nutrients to the soil, so that it can be cultivated repeatedly in the same enriched soil.

Switchgrass has one of the highest potentials for use as a biofuel crop in the United States, mainly because it grows well under a wide range of conditions. The challenge for scientists is in unlocking the sugars held in switchgrass so that it can be converted into cellulosic ethanol.

Finely ground switchgrass is an excellent feedstock to co-fire with coal in a coal-firing energy facility to displace a small amount of coal used.

In his January 28, 2006 State of the Union address, President Bush emphasized that the U.S. must break its addiction to foreign sources of energy and outlined an initiative to make fuel ethanol from renewable energy crops such as switchgrass by 2012.

Some of the current research and development programs are:

• DOE has stepped up its research on the role of switchgrass in biomass production, with the goal of promoting its use in producing ethanol and biodiesel at prices competitive with gasoline and diesel.
• Texas Governor Rick Perry announced the Texas Bioenergy Strategy, and awarded a $5 million Texas Emerging Technology Fund grant to Texas A&M University for research and biofuel advancements. In a four year project, Texas A&M University and the Chevron Corroboration are partnering on research efforts to find ways to speed up harvesting of cellulose crops and turning them into biofuels. The Governor said that Texas will focus on creating biofuels through cellulosic feedstock such as switchgrass, wood chips and corn stems – rather than from corn crops, which are a staple for the Texas cattle industry.
• The Samuel Roberts Noble Foundation scientists are stepping up their exploration of best management practices to establish and grow switchgrass as a crop for a cellulosic ethanol. The foundation now has a switchgrass breeding, production and management program. The foundation is also partnering with Ceres, Inc., a plant biotechnology company for the development and commercialization of new biomass crops for ethanol production.

Other resources on switch grass include:

• “Switchgrass Profile” by David Bransby of Auburn University
• “Biofuels from Switchgrass” from Oak Ridge National Laboratory, Oak Ridge, TN
• “Switchgrass”, University of Iowa
• “Energy Farming With Switchgrass Saves Carbon” U.S. Department of Agriculture, Agricultural Research Service.

Sugarcane for Ethanol

Sugarcane is a tropical crop which is processed into raw sugar and molasses. Because alcohol is created by fermenting sugar, sugar crops like sugarcane and sugar beets are the the easiest to convert into alcohol. According to the U. S. Department of Agriculture (USDA) one acre of sugarcane would yield 665 gallons of ethanol in Texas, corn would yield 370 - 430 gallons, and sorghum would yield about 172 gallons of ethanol.

Texas is the fourth largest sugar cane growing state, with most of it grown in the Lower Rio Grande Valley. Because it is more profitable, sugarcane growers are selling their cane to sugar refineries rather than to ethanol distilleries. Still, sugarcane holds out great promise as an ethanol feedstock, exemplified by Brazil’s fuel self-sufficiency through its use of sugarcane to produce ethanol as the major fuel source.

Currently there are no U.S. plants producing ethanol from sugar feedstocks, but the Energy Policy Act of 2005 created a $36 million Sugar Cane Ethanol Program to study the production of ethanol from sugar cane in Texas.

Sugarcane Bagasse for Ethanol

After sugarcane has been processed into sugar or ethanol, the fibrous material that is left over (bagasse) can be used as fuel, eliminating the need to use fuel from outside sources. The cost of ethanol production from sugarcane would decline if the excess bagasse could also be converted to electricity for sale to the power grid.

In Texas, the Rio Grande Valley Sugar Growers is studying the feasibility of using bagasse as a fuel for ethanol distilleries. Because it contains large quantities of cellulose, Bagasse is also being studied by federal, university and private sector researchers for it’s potential as a cellulosic ethanol feedstock.

For more information on sugarcane and ethanol production, refer to:

• “Ethanol from Sugar – What are the prospects for U.S. sugar co-ops?”, from the USDA (2006)
• “The Economic Feasibility of Ethanol Production from Sugar in the United States” A U.S. Department of Agriculture 2006 report.

Growing Algae for Biofuels

As reported in the Fall 2008 issue of Texas Innovator, researchers at the University of Texas at Austin have developed new strains of cyanobacteria, or blue-green algae, which produce the sugars sucrose and glucose and a form of cellulose that can be converted easily into sugar.

The National Renewable Energy Laboratory (NREL) – a research laboratory in the DOE – has produced algae with a high lipid content that can be used as a source of biodiesel fuel. In October 2007 NREL and Chevron announced that they have entered into a collaborative research and development agreement to produce biofuels from algae. Shell is another oil company that is exploring the potential of algae.

Algae grow rapidly and can have a high percentage of lipids, or oils which conventional petroleum refineries can convert into jet fuel or diesel fuel-a product known as “green diesel.” Algae organisms can double their mass several times a day and produce at least 15 times more oil per acre than alternatives such as rapeseed, palms, soybeans, or jatropha. As the slime grows, it makes a kind of vegetable oil, similar to the oil produced from sunflower seeds or soybeans.

Because algae can grow under severe conditions – extremes of temperature, pH and salinity, algae-growing facilities can be built on arid coastal land unsuitable for conventional agriculture. Key technical challenges include identifying the strains with the highest oil content and growth rates and developing cost-effective growing and harvesting methods.

Other resources on algae for fuel include:

• A 1998 DOE report summarizing research on algae for biodiesel production – “A Look Back at the DOE Aquatic Species Program: Biodiesel from Algae”

Additional Resources

• “Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply”, Departments of Energy and Agriculture.
• Bioenergy Feedstock Characteristics, DOE’s Oak Ridge National Laboratory
• Phyllis is a database, containing information on the composition of biomass and waste.
• The Bioenergy Feedstock Information Network (BFIN) is a gateway to a wealth of biomass feedstock information resources from the U.S. Department of Energy, Oak Ridge National Laboratory, Idaho National Laboratory, National Renewable Energy Laboratory, and other research organizations.