The Quest for Biofuels: Issues and Concerns

Biofuels have been billed as an important component in the United States bid to become less dependent on foreign energy. As the price of crude oil continues to increase, and as the country sets its sights on becoming less dependent on foreign oil the pressure is mounting to increase the production of biofuels. In addition, the global energy demand is continuing to increase and known petroleum supplies are decreasing (CAST II, 2007); the need for a sustainable substitute for current fossil fuels has become more evident than ever. The rise in costs of traditional energy sources has raised this issue to prominence in many American households as well. Several government agencies and working groups have set goals, targets, and timelines for reducing the use of fossil fuels and the substitution of biofuels to fill the energy demand. This push for the use of biofuels will have dramatic effects on many sectors of the American economy and many new problems and issues will arise that need to be considered. Currently grain-based ethanol production is the primary means by which biofuels are produced in the United States. Corn is the grain of choice in this production system. The annual production capacity of ethanol has increased rapidly in recent years, from 1.7 billion gallons in 2000 to 4.3 billion gallons in 2006 (CAST, 2006). It is also projected that the annual production capacity will increase to 7 billion gallons by 2008 (CAST, 2006). This use of corn has necessitated cause for concern with many people in the agriculture industry. The primary concern is the impact of ethanol production on the price of corn and on the availability of corn for traditional uses, such as livestock feed. In the 2004/2005 marketing year 11.2% of the corn crop was used in the production of ethanol. This number is projected to increase to 27.6% in the 2010/2011 marketing year (CAST, 2006). The discussion on the effect of this demand on corn availability for other uses and price is quite vague. Many unknowns exist in this equation. The ability of corn yield to increase is part of the unknown. Corn yields have increased annually at an average of 1.8 bu per acre over the last 40 years. In order for the corn producers to surpass the projected annual production capacity in the 2010/2011 marketing year the 1.8 bu average will have to increase. A severe negative effect will occur on the national and global corn markets if this yield increase doesn’t occur. Ethanol, under this situation, will take corn needed for other uses and/or intended for foreign markets. The demand will greatly outweigh the supply and prices will be driven up. In addition to the effect of ethanol production on corn prices and availability, ethanol also produces many coproducts that need to be used or disposed of. One of the major coproducts produced is distillers grains. Distillers grains can be used to supplement 35 to 40% of the total diet for feedlot cattle and much less for dairy cattle. Swine and poultry can have up to 20% and 10% distillers grains as a substitute, respectively (CAST, 2006). For swine and poultry the distillers grains must be in the dry form (drying accounts for nearly 1/3 of the energy costs at the average ethanol plant) (CAST, 2006). It is projected that the production of coproducts will increase past the demand for them. Possible uses for the remaining distillers grains have been explored. Burning them as a fuel source is one option that the plants are exploring as well as exporting them to foreign markets, but again the burning and export of distillers grain depends on them being dried. CAST Commentary (2006) ultimately concedes that the ability of all the coproducts to be used depends on their use in animal production systems (as wet distillers grains) and other value added uses, such as use as a fuel source. The environmental impact of grain ethanol production is also an issue that needs to be considered. With the growing demand on corn, and the rise in corn prices that will follow as a result, more corn acreage is estimated to be put into production. This increase in corn acreage will most likely cause marginal land to be placed into production as well as corn after corn rotations to become more prominent. As more acreage is brought into tillage this can increase the amount of CO2 released into the atmosphere. Nitrogen use also represents a major concern on the environment. In rain-fed corn nitrogen use represents roughly one half of the energy input; this is due to the high amount of energy required to make nitrogen (CAST, 2006). As more corn is planted, and as higher yields per acre are sought, nitrogen use will only increase. The corn after corn rotations will also lead to additional nitrogen use, as soil fertility will quickly be drained. As the push for biofuels has increased over recent years so has the search for dedicated feedstock crops for the production of biofuels. These crops, unlike crops grown for grain-based ethanol, don’t require high inputs of fertilizers and pesticides and aren’t grown on high value agricultural land. Instead, these dedicated feedstock crops are harvested for total aboveground biomass and are referred to as lignocellulose-based crops. These crops require few economic or environmental inputs and can be grown on marginal, lower productivity land (CAST, 2007). Because of these advantages there has been great interest in lignocellulose-based ethanol production. However, with this method of ethanol production there is also new concerns that need to be addressed. One of the foremost concerns with lignocellulose-based ethanol production is the introduction of the crops that will be used as dedicated feedstock for production. Many of these crops have rapid growth rates, high production of biomass, and perform well on marginal land (CAST, 2007). These characteristics make them both the ideal feedstock crop and a risk to become highly invasive. Many of the suggested feedstock crops are nonnative species that cause economic and/or environmental damage and that is a major concern. CAST Commentary asserts that their life history characteristics, rapid growth rate, nonnative status, and their potential scale of cultivation present a significant risk that these biofuel feedstocks will escape cultivation cause damage to surrounding ecosystems. The attempts at breeding and genetic engineering for drought tolerance, increased biomass production, and lower lignin content may also have unforeseen consequences on the invasive risk of these crops (CAST, 2007). A major component of this risk is the similarity between the desirable agronomic traits of a lignocellulose-based ethanol feedstock and the traits of a successful invasive species. Currently the desired feedstocks being sought for the production of lignocellulose-based ethanol have characteristics such as being a C4 (high rate of photosynthesis), having a rapid establishment rate and long canopy duration with high density growth, being drought tolerant, and tolerant of low soil fertility (CAST, 2007). These characteristics result in a crop that is low input, high yielding and able to be cultivated on marginal, low productivity land. CAST Commentary (2007) suggests that because of the growing demand for lignocellulose-based ethanol feedstocks the introduction of nonnative species and genetically engineered species is unavoidable. Instead they suggest that the introduction of these feedstocks must be done in a responsible manner that will mitigate the risks associated with potential invasive species. Ideally these crops would grow well in managed cultivation but would be unable to survive without managed cultivation. As discussed earlier, grain-based ethanol production, is the primary means of producing biofuel currently, however, large-scale biofuel production will require much more feedstock than offered by corn grain alone (CAST II, 2007). Lignocellulosic feedstocks will fill this gap in ethanol demand and the supply that grain-based ethanol production can fill. Several organization and government sectors have devised goals for biofuel production. One such goal is the one set by the Bush administration in 2007 to have 250 million tons a year of biomass converted to ethanol by 2017 (CAST II, 2007). Many reports indicate that these goals are possible, but use bold and optimistic figures. CAST commentary asserts simply that at this point the ethanol to biomass production process is too immature and inefficient to meet these goals (CAST II, 2007). They continue, “if biofuels technology is not mature in all aspects from supply to end product distribution, it will be only partially able to accommodate the higher feedstock prices that are caused by supply/demand effects.” Gasoline and grain-based ethanol, which are mature technologies, have feedstock costs that are greater than 50% of the total cost of production. It is estimated that the first commercial lignocellulosic biorefineries will only be able to devote 40% of total costs to feedstock. This poses a problem because at the moment it is estimated that producing and delivering large quantities of dedicated feedstock will exceed 40% of the total costs of production (CAST II, 2007). This problem has to be addressed on several fronts including resource availability (to insure that sufficient lignocellulosic biomass can be produced), agronomic systems information (technical production data and cost reduction research), crop development (enhanced yield and stress tolerance; and research on new crops), feedstock supply logistics (development of low cost harvest and handling technologies), and education/extension (education and support for growers and workers). Biofuel demand will continue to surge with the given oil prices and government goals set for the production and use of biofuels as a substitute for oil derived energy. This demand, and the pressure it will put on producers to and biorefineries is now become clearer than ever. Many new problems will arise that have to be solved in order for biofuel production to be a viable option for the United States to become less dependent on fossil fuels. These problems include the negative effects of grain-based production on national and global corn markets and the other agriculture sectors, in addition to the price volatility that will result. The environmentally sound use of grain-based ethanol coproduts, and the pressure on marginal land from an increased need for corn acreage is also an issue. This will also lead to an effect on energy use by corn producers, since additional nitrogen will be needed to meet the higher demand for corn. Lignocellulose-based ethanol production also raises areas of concern. The ability of these feedstocks to become invasive species and cause economic and ecological damage is one such problem. The other major concern is the immaturity of the lignocellulosic ethanol production technologies. There are inefficiencies in all areas of this production method of ethanol. In short, a great deal of research must be done in order for biofuel production to meet the intended goals in a economical and environmentally responsible manner by the deadlines set. It seems that with some research and development breakthroughs that these goals can be met in a responsible manner.

References

Cassmann, K., V. Eidman, and E. Simpson. Nov. 2006. Convergence of Agriculture and Energy: Implications for Research and Policy. CAST Commentary, QTA2006-3.

DiTomaso, J.M., J.N. Barney, and A.M. Fox. Nov. 2007. Biofuel Feedstocks: The risk of Future Invasions. CAST Commentary, QTA2007-1.

Fales, S.L., J.R. Hess, and W.W. Wihelm. Nov. 2007. Convergence of Agriculture and Energy: II. Producing Cellulosic Biomass for Biofuels. CAST Commentary, QTA2007-2