By Robert C. Brown and Tristan Brown
In the face of criticism about ethanol, delays in the commercialization of advanced biofuels and the recent development of domestic supplies of fracked gas and petroleum, some people are asking, “Why are we producing biofuels?”
The answer, quite simply, is that we have few other options for achieving a sustainable energy future. Besides quality and cost, future fuels will have to meet additional metrics including environmental, social and political sustainability.
Biofuels are transportation fuels produced from biomass, which is the generic term for any kind of plant material used as an energy source. Corn ethanol and soy biodiesel were the first to emerge. The first decade of the 21st century witnessed an unprecedented boom in the U.S. biofuels industry with fuel ethanol production increasing by a factor of 10.
This was only the beginning of a national effort to substitute domestically produced biofuels for petroleum-based fuels. Recognizing that even the entire U.S. corn crop converted to ethanol would replace only about 20 to 25 percent of national gasoline consumption, agronomists have been developing alternative crops for biofuels. These include trees and tall prairie grasses, residues from traditional crop production, municipal wastes and even microalgae.
Encouraged by federal mandates for the production of advanced biofuels, venture capitalists, corporations and governments have invested billions of dollars in startup companies with business models built around cellulosic ethanol and drop-in biofuels. These investments are starting to bear fruit, with several advanced biofuels companies currently building commercial-scale plants.
Conversion of biomass into biofuels is the best option for reducing use of petroleum and other fossil fuels. Why? Except for biofuels, none of the other fossil-fuel alternatives — coal, natural gas, tar sands, oil shale — has prospects for long-term sustainability as evaluated in terms of production costs, greenhouse gas emissions, water demand, impact on local communities or infrastructure investment.
Although other kinds of renewable energy can be converted into fuels, most are more costly and less infrastructure-compatible than biofuels.
Some critics of biofuels are calling for an overthrow of the legislation that made possible the successful introduction of alternative fuels into the U.S. energy infrastructure. Instead, we should be charting a path to sustainable energy that incorporates lessons learned in commercializing first-generation biofuels.
What did we learn?
We demonstrated that it is possible to produce renewable fuels at commercial scale — 14 billion gallons of ethanol per year is, after all, a lot of fuel. We discovered that increasing domestic fuel production, even though displacing only 10 percent of gasoline supply, could shake up the energy industry, with gasoline refining in the United States now facing a long decline and oil-producing nations realizing they are not the only players in fuel markets.
We recognize that the first generation of biofuels is not the last. This in no way denigrates the existing ethanol and biodiesel industries, whose leaders understand that innovation is critical to the future success of their technology-driven enterprises. Biofuels need to be improved in terms of infrastructure compatibility; optimal use of land to supply both food and fuel security; increasing the energy efficiency of biomass agriculture and biofuels production and utilization in vehicles; and achieving prices that are competitive with other fuels.
Besides recognizing our profligacy in energy consumption, we need to acknowledge the grand challenge that lies ahead for future societies: harnessing solar energy. Nature already has it figured out, turning sunlight, carbon dioxide and water into energy-rich carbohydrates, lipids and proteins, which were universally used by humans for both food and energy before the coming of the Petroleum Age.
The U.S. Department of Energy has aspirations of not only emulating photosynthesis, but doing it more efficiently. In the meantime, nature goes about capturing solar energy in the form of biomass at a rate six times faster than modern societies consume all forms of energy.
Those who argue that solar energy is not sufficiently efficient or economic should remember one thing: Fossil energy that we exploit today is solar energy captured by photosynthesis eons ago. Undoubtedly, we would declare fossil energy to be inefficient and uneconomic if nature had not done the hard work for us.
Robert C. Brown is director of the Bioeconomy Institute and the Anson Marston Distinguished Professor of Engineering at Iowa State University.
Tristan Brown is research associate at the Bioeconomy Institute. Comments: email@example.com