Can Butanol Be the New Ethanol?
Even as the ethanol industry is wobbling over the Environmental Protection Agency’s decision to cut back on the ethanol mandate in 2014, a new candidate has emerged as an additive to gasoline – butanol.
Virgin Airways founder and CEO Richard Branson has announced that his Virgin Green Fund will be cosponsoring a groundbreaking butanol manufacturing plant in Luverne, Minnesota. “Butanol is the future of renewable fuel,” said Branson, who is already using renewable jet fuel for his airline. “It’s hugely versatile and can be used to produce gasoline fuel blends, rubbers, solvents, and plastics, which gives us scope to enter a range of markets,” he said in an interview with Bloomberg.
Corn ethanol now dominates the $26 billion gasoline additive market, drawing the glucose content out of 45 percent of the nation’s corn crop (the protein is fed to animals). Branson’s butanol would use a similar feedstock – corn, sugar cane or cellulosic biomass – but would produce a fuel that has 84 percent of gasoline’s fuel density compared to ethanol’s 66 percent, although ethanol has a higher octane rating. The implication is that butanol could be mixed at higher blends, giving it almost the same range as gasoline.
Both butanol and ethanol are made through a process that employs yeasts to ferments the glucose from organic material into alcohols. Methanol, the simplest alcohol, has one carbon joined to a hydroxyl ion while ethanol has two carbons and butanol has four. Octane, the principal ingredient in gasoline, has eight carbons without the hydroxyl ion.
As far a butanol is concerned, it’s not as if people haven’t tried this before. Both BP and Royals Dutch Shell have experimented with producing butanol from organic material but have found the process harder than they anticipated. “There is certainly a potential, but there have been quite considerable problems with the technology,” Clare Wenner, of the London-based Renewable Energy Association, told Bloomberg. “It’s taking a lot longer than anybody thought years ago.”
Gevo’s plant in Minnesota, for instance, has been running at only two-thirds of its 18 million gallon-a-year capacity because of a contamination in its yeast fermenting facility in September 2012. Similar instabilities in the microbial-based process have dogged the efforts to break down cellulose into simple molecules. There operations can often be performed in the laboratory but become much more difficult when moved up to a commercial scale.
Branson is confident these obstacles can be overcome. He’s already got Silicon Valley investor Vinod Khosla on board in Gevo and Total, the French oil company, has also taken a stake. Together they have enlisted big ethanol producers such as Big River Resources and Siouxland Ethanol to commit to switching their manufacturing process to butanol. Butamax Advanced Biofuel, another Minnesota refiner funded by Dupont and BP, is also in the process of retrofitting its ethanol plant to butanol. Taken together, these facilities would be able replace 1 billion of the 14 billion gallons of ethanol now being produced every year.
Whether this would be enough to make a bigger dent in America’s oil import budget remains to be seen. The 14 billion gallons of ethanol currently substitutes for 10 percent of our gasoline and about 6 percent of our total oil consumption. The Environmental Protection Agency has limited ethanol additives to 15 percent of the blend, mainly to protect older cars. (In Iowa, newer cars are running on an 85 percent blend.) Now the reduction in the 2014 mandate is making the ethanol industry nervous about overcapacity. Butanol is less corrosive of engines and the 16 percent blend could give it an edge.
On another front, T. Boone Pickens’ Clean Energy Fuels announced this week that it may turn a profit for the first time since its founding in 1997. Clean Fuels is concentrating on supplying compressed natural gas for trucks, signing major contracts with Frito-Lay, Proctor & Gamble, United Parcel Service and Ryder. It is also attempting to set up a series of filling stations on the Interstate Highway System. The use of CNG requires an entirely new infrastructure, however, rather than the easy substitution of liquid and butanol.
The dark horse here is methanol, which is liquid and fits easily into our present infrastructure but would be synthesized from natural gas. Somehow, methanol has not attracted the attention of Branson’s biofuels and Pickens’ CNG. All of these efforts hold promise, however, and would make a huge dent in our annual $350 billion bill for oil imports, which constitutes the bulk of our $450 billion trade deficit. So good luck to all and may the best fuel win – or all of them, for that matter.
