Biobutanol: Friend or Foe?

Given the immense challenges faced by the ethanol industry over the past 18 months, it isn't surprising that some may be inclined to view biobutanol as competition. However, future biobutanol producers adamantly describe themselves as allies of ethanol production.
By Erin Voegele | February 09, 2010
Those working to develop U.S. biobutanol production stress that they should not be seen as competitors to the existing ethanol industry any more than cellulosic ethanol should be seen as a competitor to corn ethanol. Rather, they note that producers of all biofuels share the same goals, and will be valuable allies in meeting the second stage of the renewable fuel standard (RFS2) requirements, limiting U.S. dependence on foreign oil, and furthering the political initiatives of the renewable fuels industry.

The RFS2 requires 36 billion gallons of renewable fuel be blended into the transportation fuel supply by 2022. The U.S. Energy Information Administration estimates that slightly more than 9 billion gallons of ethanol were produced in the U.S. during 2008. This means that in order to meet the targets of the RFS2, the U.S. biofuels industry will essentially need to quadruple production capacity in a little more than a decade. In addition to setting these high blending goals, the RFS2 stipulates that the vast majority of this growth in the biofuels industry will need to stem from advanced production technologies that drastically reduce greenhouse gas (GHG) emissions. In other words, the RFS2 has created a huge market opportunity for renewable fuels that comply with the regulation's definition of advanced biofuel, cellulosic biofuel, and biomass-based diesel. This includes not only advanced ethanol technologies, but other alcohol-based fuels as well.

What is Biobutanol?
Like ethanol, biobutanol is an alcohol-based biofuel. Both products are manufactured through fermentation and can be used as a fuel additive. While both ethanol and biobutanol share favorable environmental characteristics relative to gasoline, butanol can be blended into gasoline without increasing the vapor pressure and is more resistant to water absorption. The production processes to make each fuel are also similar and use the same feedstocks. Although slight differences are employed in the fermentation and distillation processes, these differences are small enough to allow butanol technology to be retrofitted in existing ethanol plants.

While current U.S. regulations allow transportation fuel to contain a maximum of 10 percent ethanol, similar regulations currently allow biobutanol to comprise approximately 16 percent of a fuel blend. Since it is possible to blend both ethanol and biobutanol into the same batch of gasoline, biobutanol could be part of the solution in overcoming the blend wall and allowing more renewable content in transportation fuel.

Although biobutanol is not currently produced on a commercial scale in the U.S., at least two companies are working to swiftly bring the fuel to market. Butamax Advanced Biofuels LLC, which is a joint venture between parent companies BP plc and DuPont, is currently building a demonstration scale facility in the United Kingdom and is expected to establish a commercial-scale facility by late 2012 or early 2013. Colorado-based Gevo Inc. is also working to commercialize biobutanol production. Gevo began to produce biobutanol on a demonstration-scale in the second half of 2009, and is expected to complete its first retrofit of an existing ethanol plant to biobutanol production by 2011.

Competition Versus Collaboration
"To meet the 36 billion gallon renewable fuel standard, I think all renewable fuel producers need to work together— and there is certainly enough volume opportunity for all of us," says Jack Huttner, Gevo's executive vice president of commercial and public affairs. "Really, I don't see any competition between the two biofuels. We want the ethanol industry to look favorably on the biobutanol industry. We are not a competitor. We are part of the biofuels industry, and we are not looking to replace ethanol."

Butamax CEO Tim Potter agrees that it is important that ethanol producers and biobutanol producers work together. "They are in the same industry, likely with the same producers," he says. "They are two different molecules that are accomplishing the same goal. They use the same feedstocks and similar processing, and they are both entering the transportation fuel network as a biofuel. Biobutanol is a molecule that enables higher levels of renewables to be blended into gasoline within existing specifications, and as such, it is valuable to help biofuel producers increase their contribution to transportation fuels. We are all working towards meeting the goal of 36 billion gallons by 2022, and we should be working hand in hand to educate, influence and guide policies that enable those goals to be met."

Potter also notes that biobutanol possesses some unique characteristics that are complementary to blending with ethanol. "One of the challenges we have with ethanol is that the vapor pressure increase limits the blend volume," he says. "You can think about butanol in an ethanol/gasoline blend as reducing that vapor pressure, so butanol can help get more renewables into the gallon of fuel." In other words, when all three fuels are blended together, biobutanol can significantly increase the renewable portion of the existing fuel.

This could offer one path in overcoming the blend wall currently faced by the biofuels industry. "Really, what biobutanol is going to do for us is increase the amount of biofuels that can be blended within the transportation fuel supply," Potter says. "And act as an enabler in overcoming the existing blend wall." Even though the U.S. EPA is currently expected to approve a fuel waiver request allowing E15 to be used in standard vehicles, moving to an E15 blend would only delay the blend wall for a few years. In order to meet the RFS2 requirements, transportation fuel is going to have to contain a much higher portion of renewable fuel.

Under current regulations, Potter says that it is possible to blend 16 percent biobutanol into gasoline, which would nearly double the renewable energy content of the gasoline. Combinations of E10 and 16 percent biobutanol are also permissible under current regulations and offer opportunities for economic synergies, he continues. Potter adds that Butamax's research indicates biobutanol could be blended into gasoline at higher percentages than the current 16 percent limit and be technically effective. However, the higher blend would need EPA evaluation and approval similar to the current process underway to get an E15 waiver approved.

Chris Ryan, Gevo's executive vice president of business development, points out that butanol offers the potential to increase the renewable portion of transportation fuel in another way. In addition to being used as a blendstock for gasoline, Ryan says biobutanol can be converted into hydrocarbons in existing refineries. This means that rather than being employed as a biofuel additive, the product can essentially be transformed into a renewable gasoline product, which negates the issue of allowable blend percentages. "If you look at what you can do with butanol and ethanol together, not only are you outlining the options to blend the two as a gasoline blendstock, but there are various ways to combine these two products to serve the gasoline market needs, the refinery needs, and address some chemical market opportunities as well."

Parallel Goals, Parallel Processes
According to Potter, ethanol producers and biobutanol producers share many of the same goals. "I see them as one industry," he says. "There are not separate industries. We're in the biofuels industry to increase the amount of biofuel within the transportation fuel supply, reduce our demand on imported oil and sustain agriculture—and both molecules help us to do that."

Potter also says that biobutanol can play an important role in the continued buildup of the biofuels industry. "We saw a complete collapse of the industry as far as being able to get funding and being able to continue the build out, but this new molecule can be retrofitted to existing ethanol facilities, giving producers access to a range of added value fuel properties. It will allow us to think about how we start to grow the biofuels industry again," he says.

Although both biofuel products are manufactured from the same feedstocks, Potter notes that it is important to understand that rather than competing for existing feedstock, producers of both biofuels can build on the research of the other when it comes to developing advanced feedstocks, such as cellulosics.

Ryan emphasizes that Gevo's ultimate goal is to move to cellulosic feedstocks. "Our intention is to have the fermentation technology that will enable us to use mixed sugars from cellulosic feedstocks to make butanol, while continuing to evaluate ways to reduce the carbon footprint of our process," he says.

Growing the Industry
One primary challenge facing biobutanol is a lack of public familiarity with the product, which can lead to misinformation. Potter says there are several specific misconceptions his company is currently working to address.

"The first thing is [the belief] that biobutanol is a threat to the existing ethanol industry," he says. "We know that is not true—biobutanol is a value-adder for the existing industry and existing producers. It's really about advancing biofuels in transportation fuel. We are both sustainable and sustaining agriculture, and we are both looking to accomplish more biofuels in the transportation fuel network." He says other misconceptions have to do with concerns about scale up and commercial competitiveness. "This product has to be competitive to succeed in the market," Potter says. "We believe that we have the right skills and expertise to understand, develop, market and distribute biobutanol."

As future biobutanol producers work to address these issues, Huttner and Potter agree that the future outlook for the biofuels industry is good. Potter expects to see rapid growth in biobutanol production over the next decade, particularly in areas of the world where government mandates have been established. "I think both ethanol and butanol will be growing rapidly as we start to see all the different feedstocks that are capable of making biofuel— both will be enabled, both will be working in that area and I believe we will see a global expansion," he continues.

"I think that we will be able to step in and contribute a significant portion of the RFS mandates," Huttner says. "[Over the] next decade, I think we will be there to participate with our ethanol friends, our algae friends, and others." EP

Erin Voegele is a BBI International associate editor. Reach her at (701) 850-2551or