SUNY-ESF Produces ‘Next Generation of Biofuels’

Researchers in the college’s Department of Paper and Bioprocess Engineering are experimenting with different strains of bacteria that can ferment sugars extracted from wood into biobutanol that can be pumped into automobile gas tanks.

Researchers believe biobutanol — more efficient than ethanol in producing energy and easier to add to the existing gasoline distribution infrastructure — could be the emerging biofuel of the future.

“Biobutanol is one of the next generation of biofuels,” said Dr. Timothy Volk of ESF's Department of Forest and Natural Resources Management. “Every day in the United States, two-thirds of the oil we use comes from outside this country. We can see the results of this in the increase in oil and gas prices.

“ESF is working on producing alternative biofuels from locally produced resources. We use wood,” he said. “New York state has abundant wood. The forest is growing three times faster than it is being harvested. It can also be grown in the form of shrub willow as an agricultural crop on marginal agricultural land. So we are focused on using woody biomass from willow and natural forests as a feedstock, but other regions will use agricultural crop residuals or perennial grasses.”

Volk, who leads the college’s Willow Biomass Project that is developing shrub willow as a renewable energy source, said biobutanol offers several advantages over the ethanol that is commonly mixed with gasoline in a mixture known as E10 (10 percent ethanol, 90 percent gasoline).

“Butanol has a higher energy density than ethanol and it can be pumped right into the existing gas pipeline. Going to a higher percentage of ethanol means a new delivery system,” Volk said. “Ethanol is less efficient and harder to mix with regular gas.”

Biobutanol is one of a handful of fuels that can be produced from wood sugars; the specific fuel that is produced depends on what kind of organism is used to ferment the sugar. Butanol, in addition to being a more efficient fuel than ethanol, also has the advantate of serving as a platform chemical for other purposes, including jet fuel.

The biobutanol research happens in a laboratory in Walters Hall on the ESF campus. Dr. Shijie Liu and his research team are experimenting with different strains of bacteria to see which can most effectively ferment the mixed sugars, including glucose and xylose, that have been obtained from wood through a process developed at the college several years ago into biobutanol.

In Liu’s lab, woody biomass such as willow cuttings and wood chips are processed with water to obtain those sugars. A strain of bacterium such as Clostridium acetobutylicum, a microorganism frequently used by industry in fermentation processes, is used to ferment the mixed sugars to butanol.

Liu and his students work in laboratories outfitted with an anaerobic chamber, used to fine tune the selection of microorganisms used in the fermentation process, and a bioreactor, in which the fermentation process occurs.

Liu’s research is supported by a $400,000 grant from the U.S. Department of Energy and $75,000 from the New York State Energy Research and Development Authority.