For all practical purposes the word “biofuels” is currently synonymous with ethanol made from corn or sugarcane. To a lesser extent, biofuels are also seen to include a type of “biodiesel” made from vegetable fats and oils. Thus our public discourse, especially in the U.S., concerning biofuels largely revolves around topics related to using large amounts of corn ethanol and the effects that may have on food and feed prices, land use, and agricultural practices. But increasingly—and importantly—not all biofuels are ethanol or today’s biodiesel. As new kinds of advanced biofuels are developed from a variety of non-food, non-feed sources and for new uses, more nuanced language could help create wider public understanding and a refined discourse.
Ethanol itself has variations that would benefit from greater understanding. In 2012, by blending gasoline with 10 percent ethanol (E10, as the blend is called), ethanol will displace about 10 percent of the roughly 140 billion gallons of gasoline used in the U.S. each year.
Even though the U.S .Environmental Protection Agency has approved
the use of fuels containing up to 15 percent ethanol (E15) for vehicles
manufactured after 2001, few cars in the U.S. are certified to use it and it
is uncertain whether fuel retailers will install E15 pumps for such a small
portion of the market. It seems more likely that we may eventually see the
proliferation of E85 pumps.
Although only about 10 million vehicles in the U.S. can run on ethanol blends higher than 15 percent, providing light-duty cars and trucks with flex-fuel capability reportedly adds less than $80 to the vehicle cost. In Brazil more than 80 percent of light-duty vehicles are flex-fuel vehicles capable of using either all gasoline, all ethanol, or any mixture of both depending on consumer desire. To create future options for ethanol, it is to be hoped that we will soon see legislation that requires all light-duty vehicles sold in the U.S. to have flex-fuel capability.
The meaning of the word biofuels is expected to soon undergo an expansion that will further muddy the public discourse about the topic. First, we
will soon see the commercial production of ethanol made from lignocellulose, the inedible parts of plants. The issues concerning production of lignocellulosic ethanol are very different than those associated with corn ethanol. Thus, it will be useful to have new words to clearly and quickly distinguish ethanol made from food crops from ethanol made from corn cobs, energy grasses, municipal waste, and other sources of lignocellulose.
I think that “cellulosic fuels” might be a suitable description. However, another pending development will further complicate the issue – the production of new biofuels that are neither ethanol nor today’s biodiesel. In general, these fuels are currently called “drop-in” fuels inasmuch as they are designed to more closely mimic the chemical composition and performance of existing petroleum-derived fuels. We will soon see drop-in fuels made from corn or from lignocellulose. Additionally, some will be suitable for blending with gasoline and others will be suitable for blending with diesel or jet fuels. Thus, the word biodiesel may also need some variants.
An excellent overview of the topic of drop-in fuels by our contributor Steve Pietsch is a highlight of this issue of Bioenergy Connection. The pending proliferation of new types of biofuels will complicate the ways that biofuels are distributed and used by various sectors of society. Consumers are unlikely to be willing to make complex choices at the pump. Thus, it seems likely that as new types of biofuels, including newcomers such as butanol, enter the retail market, they will either be invisible to consumers or described with catchy brand names that lack technical meaning. By contrast, large-scale users such as transportation companies and airlines would be expected to take a more nuanced approach.
The largest user of fuels in the U.S. is the military and so it is not surprising that the military has begun testing various types of drop-in
and other next-generation biofuels. As a mostly locally-produced and
renewable resource, biofuels have potential strategic value to military
planners who must consider the impact of disruptions in petroleum
supplies. Also, as a technically savvy organization that can make decisions based on price and performance, military use of biofuels provides
a possible route to market for new types of fuels with good performance
characteristics that might otherwise encounter long delays in consumer
acceptance that limit the ability of companies to achieve economy of
scale in ramping up production of next-generation biofuels.
In effect, military use of next-generation fuels can accelerate scale-up while also providing opportunities for testing new fuels under a wide variety of distribution and operating conditions. The article in this issue by Ellyn Kerr on the U.S. military interest and activity in alternative fuels describes some aspects of this evolving development.
This is the third issue of Bioenergy Connection. We have sincerely appreciated the support expressed and the comments provided following our first two issues. We continue to seek feedback and invite your suggestions about issues to cover, science to explore, and people to profile. Write us at www.bioenergyconnection.org.