By Charles Creekmore

The million-dollar word these days is biofuel—fuel made from renewable plant material, called biomass. Because of its potential as a renewable energy source, biofuel has become the Holy Grail for many engineers questing
after solutions to such global problems as our dependence on fossil fuels and the challenges of climate change.

One leading biofuel researcher works in UMass Amherst’s Chemical Engineering Department. George Huber’s specialty is chemical catalysis—increasing the rate of a chemical reaction by the introduction of a catalyst—as applied to the conversion of plant material into fuels and chemicals. Says Huber, “The focus of my research is breaking the chemical and engineering barriers to lignocellulosic biofuels.”

Lignocellulosic biomass is the nonedible portion of biomass, such as wood residues (including sawmill and paper mill discards), municipal paper waste, agricultural residues (from corn and sugarcane production), and dedicated energy crops, which are mostly composed of tall, woody grasses.

Huber is the newly appointed John and Elizabeth Armstrong Professional Development Professor. In recommending Huber for the professorship, the Chemical Engineering Department personnel committee characterized his work as “a timely area of research that could potentially shape the world’s energy economy for years to come.”

In effect, Huber’s work is figuring out how to turn waste into fuel. Massachusetts alone deals with 5,000 to 7,000 metric tons of waste wood a year. All of this deadwood—wood that the forestry service culls from forests to make them healthier and less fire-prone—with the proper technology could be converted into energy. What’s more, growing biomass as an energy crop could double the national farm income, from $3 billion to $6 billion per year.
Biofuel has a marvelous upside. At $10 to $30 per barrel, the oil energy equivalent is significantly cheaper than crude oil, currently selling for upwards of $90 a barrel. Potentially the United States could produce about 1.3 billion dry tons of cellulosic biomass per year, or enough to replace four billion barrels of crude oil—more than half the amount Americans burn annually.

Best of all, biofuel is also clean. Huber says, “These fuels are, in effect, carbon-dioxide-free. What CO2 is emitted by burning biofuel would later be consumed by further biomass regrowth. So it’s a net-zero emission when you consider the whole life cycle of the process.” Consequently, biofuel could reduce domestic carbon-dioxide emissions by 85 percent.

The water-into-wine quality of Huber’s work sounds almost too good to be true. But for Huber, it’s all in a day’s work. “Chemical engineers are taught how to take inexpensive raw material and convert it into something that’s more valuable,” he explains. “We do this with petroleum products, we do this in the semiconductor industry, we do this with pharmaceuticals. That’s the whole chemical engineering profession.”

In this sense, chemical engineers are the alchemists of the 21st century, metaphorically turning waste into gold. To illustrate this point, Huber presents a jar of sludge giving off a smoky campfire aroma. This is Bio Oil, manufactured by Renewable Oil International in Fitchburg, Massachusetts. Huber is studying how to convert this product, which can be made from trees, grass, or other biomass, into sustainable diesel fuel, home-heating oil, and gasoline.

“One problem with Bio Oil in its present form,” says Huber, “is that it’s acidic and therefore corrosive, so your engine or furnace won’t last very long while burning it. The other problem is that this stuff has half the energy density per volume of gasoline and diesel fuel.” One of Huber’s goals, using a $100,000 grant from the U.S. Department of Energy, is to make Bio Oil less corrosive and more efficient.

Bio Oil is just one of Huber’s current projects. He’s also working to help shape national policy on biofuel, consulting with private companies to bring technologies to market, and teaching a graduate course in Chemical Reaction Engineering and Materials and Energy Balance for
first-year graduate students.

Huber traveled to Washington, D.C. last June and led a workshop,“Breaking the Chemical and Engineering Barriers to Lignocellulosic Biofuels,” sponsored by the National Science Foundation and the Department of Energy. The workshop brought together academia, industry, and government to create a roadmap for making lignocellulosic biofuels a practical reality. On a return visit, Huber presented that roadmap to Congress, accompanied by other UMass Amherst experts, including Michael F. Malone, dean of the College of Engineering, Professor Curt Conner from Chemical Engineering, and emeritus chemistry professor Richard Stein.

Huber also consults on biofuel technologies with a variety of companies, including Conoco-Phillips, Khosla Ventures, and United Technologies. His past research is being commercialized by two start-up companies, Virent Energy Systems and Bio-e-con.
“I’m really fortunate to have Professor Huber as my mentor,” says Tushar P. Vispute, a chemical engineering graduate student at UMass Amherst. “He is very motivated and passionate about our work. Successful completion of this project will alleviate our energy crisis and be a step towards a greener earth.”

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Reservoir of Hope
The Q microbe is a strain of the soil-dwelling bacterium Clostridium phytofermentans, which was isolated in the lab from forest soil collected near the Quabbin Reservoir. Amherst biofuels technology company SunEthanol has invested in Q microbe’s ability to convert plant matter into ethanol, and has attracted millions of dollars in funding from venture capitalists and others. UMass Amherst microbiologist and professor Susan Leschine, chief scientist at SunEthanol, studies the bacterium. It has a voracious appetite for cellulose, found in switch grass, wood pulp, corn plant waste, and other plant materials, and is efficient in converting biomass to ethanol. Leschine says that the Q microbe is also important to alternative fuel technology because the process by which it makes ethanol is carbon-neutral and can be carbon-negative, depending on the biomass being used.

Hot Stuff
Professor James Holden, a microbiologist, has been awarded a three-year, $601,000 grant from the National Science Foundation along with researchers from the University of Washington in Seattle. The grant funds research of microorganisms from deep-sea volcanic environments that have optimum growth at temperatures of around 200°F. Holden’s research focuses on the cultivation of this newly discovered species of hyperthermophilic microorganisms and models their impact on the ecology of volcanic environments. With a $28,000 grant from the U.S. Department of Transportation’s Northeast SunTrust, Holden also studies whether certain hyperthermophiles can be used for the production
of biofuels.