Qi BioEnergy

Coskata, a startup that says it can make ethanol from almost any carbon-rich source—including old tires—for less than $1 a gallon. That’s about half as expensive as making gasoline, and much cheaper than other next-generation biofuels. General Motors bought the buzz—literally, announcing last month an investment and partnership with the biofuel company, which now plans to build a plant that can output 100 million gallons per year by 2011 to join its existing pilot facility. Click here to read the full article

The Syntec Process focuses on an entirely different ethanol production methodology from today’s conventional method that relies on the fermentation of food chain feedstocks (i.e. corn or sugar cane). Syntec uses source feedstocks from renewable waste materials including wood waste, crop residues including sugar cane bagasse and corn stover, organic waste, manure, sewage digester gas or landfill gas.

Technically speaking, the Syntec Process is a BTL (biomass-to-liquid) conversion path quite similar to modern day methanol or GTL (gas-to-liquid) production processes used commercially. The key differentiating factors are the feedstocks, catalysts and operating parameters.

There are 3 basic steps in the Syntec Process:

The Syntec Process has the potential to revolutionize the ethanol industry with higher ethanol yields and lower production costs per ton of feedstock than any other ethanol production path in use today. Furthermore, it is anticipated that the Syntec Process will enable the conventional ethanol industry to value add by using these well established chemical processes (via the DOE’s integrated biorefinery program) to obtain production and efficiency metrics beyond which traditional grain based fermentation processes can offer.

Perhaps the most important aspect of the Syntec Process is the ability to convert abundant, low cost (sometimes negative cost) waste products into ethanol and bio-alcohols without harming the agricultural land base or competing with consumable food stocks. These green biofuels significantly reduce green house gas emission. Moreover, enough biomass exists and is renewed every year in North America, and other parts of the world, to significantly reduce a country’s dependence on imported oil required for petroleum derived fuels.

Affordable, available, and easy to work with, corn is the main feedstock for ethanol in the United States. As ethanol production increases—USDA chief economist Keith Collins estimates that our country could produce 12-13 billion gallons in 2009—so does the demand for suitable feedstocks.

To avoid overburdening the corn market, ethanol producers have two options: increase conversion efficiency or use an alternative crop. Several ERRC research projects have demonstrated how these can be done.

Food technologist David Johnston is investigating new processes using protease enzymes from microbial and fungal sources to produce ethanol more efficiently. In trials, Johnston found that adding enzymes during fermentation sped up the process and increased ethanol yields.

“The enzymes make more nutrients available for the yeast. They expedite the fermentation process and can also make it easier to separate liquid from solids after the ethanol has been removed,” Johnston says. “This is important because the more efficiently you separate the free liquid from the solids, the more energy efficient the process can be.”

Engineers Andrew McAloon (left) and Winnie Yee (right) explain the economic advantages of a new fuel ethanol process to ERRC director John Cherry. (D771-1)

Corn isn’t the only available feedstock for ethanol. Research leader Kevin Hicks is collaborating with biotechnology company Genencor International; Virginia Tech, in Blacksburg, Virginia; and members of the barley industry to explore barley’s potential as a feedstock in regions of the United States where corn is not the principal crop.

Hicks estimates that barley grown in North America could supply about 1 billion gallons of ethanol per year. The crop is well suited to the Mid-Atlantic, where it could be grown as a winter crop in rotation with soybeans and corn in 2-year cycles.

Currently, barley yields less ethanol than corn does, and the ethanol from barley is more expensive. Barley’s physical properties—an abrasive hull and low starch content—impede production efficiency. But Hicks and his colleagues are overcoming these hurdles with research.

With Genencor, the researchers are developing new enzyme technology that could improve the speed, efficiency, and cost of barley-based ethanol production.

They also collaborated with Virginia Tech researchers to develop barley varieties with higher starch content and a loose hull that generally falls off during harvest or grain cleaning. Initial studies suggest that such varieties have promise as a feedstock. In one study, for example, a hull-less barley produced 2.27 gallons of ethanol per bushel, whereas hulled barley produced 1.64 gallons per bushel.

The scientists are now studying which conditions will promote the most cost-effective production of barley-based ethanol.

Breaking Down the Biomass

There are two main processes, or “platforms,” for making fuels from biomass: sugar and thermochemical conversion. The sugar platform involves breaking down complex carbohydrates in the biomass—materials such as sawmill waste, straw, and cornstalks (stover). Then, yeasts metabolize, or consume, the simple sugars to make alcohol.

Breaking down those complex carbohydrates requires a lot of energy, Hicks says, and special microorganisms are required to convert some sugars into ethanol. And, ironically, the process creates a lot of carbon dioxide—the greenhouse gas that’s helping to spur the biofuels movement.

The thermochemical platform involves heating the biomass in a reactor and converting it into liquid (bio-oil) and synthetic gas (gaseous fuels comprising carbon monoxide, hydrogen, and low-molecular-weight hydrocarbon gases such as methane and ethane). Chemical engineer Akwasi Boateng has led much of the ERRC research on this process.

In a study with research leader Gary Banowetz and colleagues in Corvallis, Oregon, Boateng converted grass seed straw into synthetic gas using small-scale gasification reactors. Built to serve a farm or small community, these reactors could provide an environmentally friendly and economic use for the 7 million tons of straw produced by the grass seed industry every year in the Pacific Northwest.

Neither the sugar platform nor the thermochemical platform has been perfected yet, Hicks cautions.

“Each one has technical and economic hurdles that must be solved through research,” he says. “We’re trying to compare the processes and determine which, if perfected, would give the most useful energy from a given amount of biomass. We’re working with international experts to make intelligent decisions on where to focus our efforts.”

A Model Approach: Cost Analysis

Price is one of the major factors inhibiting the spread of biofuels. Reducing production costs would make them more competitive with petroleum-based fuels—but where can scientists cut costs?

Engineers Winnie Yee and Andy McAloon create technical models to guide research efforts toward economically feasible processes. With the models, they analyze every aspect of a biofuel production process and determine where cost-cutting would be most effective. This allows researchers to pinpoint the exact steps in the process that need to be modified.

“It’s important to know that our research makes economic sense, that these processes will be competitive enough for industry to accept them,” McAloon says.

Haas used one of McAloon’s models to analyze his efforts to create biodiesel from soy flakes. The model estimated that by first drying out the moist flakes, Haas could reduce the amount of methanol required later, thereby reducing the cost per gallon from $2.83 to $2.66. Haas and his colleagues are currently working to reduce that cost even further to a point of commercial competitiveness.

For about 10 years, ERRC has been providing these technical models for ARS scientists. Developing a model from the ground up is time-consuming, McAloon says, but once developed it can be modified to meet the needs of a specific product or process. Within the past year alone, he estimates, ERRC has produced several hundred copies of their models for researchers within ARS and around the world.

“Our scientists are approaching biofuels research from many different angles that allow us to come up with comprehensive solutions,” Cherry says. “We’ve made some great discoveries here at ERRC that have helped improve biofuel production, and I’m confident that we’ll see even more improvements in the future.”—By Laura McGinnis, Agricultural Research Service Information Staff.

On a blackboard, it looks so simple: Take a plant and extract the cellulose. Add some enzymes and convert the cellulose molecules into sugars. Ferment the sugar into alcohol. Then distill the alcohol into fuel. One, two, three, four — and we’re powering our cars with lawn cuttings, wood chips, and prairie grasses instead of Middle East oil.

Unfortunately, passing chemistry class doesn’t mean acing economics. Scientists have long known how to turn trees into ethanol, but doing it profitably is another matter. We can run our cars on lawn cuttings today; we just can’t do it at a price people are willing to pay.

The problem is cellulose. Found in plant cell walls, it’s the most abundant naturally occurring organic molecule on the planet, a potentially limitless source of energy. But it’s a tough molecule to break down. Bacteria and other microorganisms use specialized enzymes to do the job, scouring lawns, fields, and forest floors, hunting out cellulose and dining on it. Evolution has given other animals elegant ways to do the same: Cows, goats, and deer maintain a special stomach full of bugs to digest the molecule; termites harbor hundreds of unique microorganisms in their guts that help them process it. For scientists, though, figuring out how to convert cellulose into a usable form on a budget driven by gas-pump prices has been neither elegant nor easy. To tap that potential energy, they’re harnessing nature’s tools, tweaking them in the lab to make them work much faster than nature intended. Click here to read the full article on Wired