Sterling Ethanol

Source: Energy Digital

Date :8/7/2007 10:49:51 AM

By working to increase its plant’s efficiency, Sterling Ethanol is showing that ethanol can be produced cost effectively and with little to no carbon footprint

Written and produced by Andrea Orr & Nick Ledue

As Americans look for affordable and environmentally-friendly alternatives to oil produced overseas, they are increasingly receptive to the use of ethanol, a home-grown fuel produced from agricultural products, most often corn.

But ethanol has long been dogged by critics who claim it is not so environmentally friendly after all, once you factor in the large amounts of fuel required to make it, the large quantity of waste created in the production process, and the conventional fossil fuels required to ship it to end users.

Because ethanol is made from corn or other crops, it is usually manufactured in farming centers in the Midwestern U.S. from which it must travel to refineries around the country.

Sterling Ethanol LLC says those criticisms are often not accurate and it is working to reverse that negative perception by example.

Sterling, which in 2005 built the first ethanol plant in the state of Colorado, and today produces 50 million gallons of ethanol a year from that plant, is continuously working to improve efficiencies to minimize the fuel it consumes and the waste it produces.

Dave Kramer, president and general manager of Sterling Ethanol, says Sterling has fine-tuned its production process so that virtually all of the by-product created in production is converted into cattle feed and that all the fuel emitted during production is recycled.

The corn that enters its plant as a raw material gets converted to ethanol, while the byproduct is a distillers’ grain that’s a better animal feed than corn, Kramer says.

While corn typically has an 11 percent protein content, and a 4 percent fat content, the distillers’ grain coming out of the plant is approximately 30 percent protein and 12 percent fat.

The nutritional value of the byproducts created in ethanol production is often overlooked by the energy industry, which is more focused on the value of the fuel itself. But Kramer stresses that the ability to convert what might normally be viewed as a waste product into a valuable commodity for farmers is a critical factor keeping ethanol plants efficient and successful.

“We were built strictly for the cattle industry,” he jokes, to make the point that the plant views animal feed as more than just a byproduct.

In the two years since the first Sterling Ethanol plant was opened in Sterling, Colo., in the northeastern corner of the state, the company has increased production from 40 million gallons of ethanol a year to 50 million a year. Looking forward, Sterling is in the process of expanding capacity to 60 million gallons a year. It has also opened a second plant in Yuma, Colo., and is in the process of building a third in the city of Bridgeport, Neb. Business is brisk and demand is growing, says Kramer.

Sterling ships most of the fuel it produces to communities around Denver, which also contributes to the fuel’s environmentally-friendly reputation by minimizing transport distances.

Kramer maintains that much of the criticism leveled at the ethanol industry has been unjust and that some of it is the result of fuel efficiency studies that are at least 30 years old. While he declines to disclose the exact amount of power the Sterling plant consumes, he says it is the equivalent of about 40 cars on the road, an amount that he argues is not a lot given the fuel it produces.

Thanks to newer technologies installed at the plant to capture emissions and put them back into production, fuel consumption is much less than it would otherwise be.

“We produce 40 percent of our electricity with excess steam,” says Kramer. “We’re really, really efficient.”

More importantly, he notes that Sterling is now a zero discharge plant, thanks to those technologies that enable it to recycle emissions.

The process of making ethanol involves milling, cooling and fermenting corn, which results in a product that has a high-oxygen content allowing automobile engines to combust fuel more efficiently resulting in reduced tailpipe emissions.

In recent years, ethanol production has surged around much of the U.S., particularly in the Midwest. The Renewable Fuels Association says that last year there were some 110 ethanol-producing refineries — also known as biorefineries in the U.S. — which produced 4.9 billion gallons of ethanol. Another 73 plants were under construction, offering the potential to add another 6 billion gallons to the country’s supply.

The Sterling plant is owned by 26 local business people, many of them farmers. It has 30 employees, runs 24 hours a day, and consumes 50,000 bushels of corn per day. Each bushel of corn is converted into 2.9 gallons of ethanol, and the cattle feed that is also created during production, is highly sought after by local cattle farmers.

Because it has become such a competitive business, Kramer is reluctant to disclose all the specifics of his plant’s efficiency profile, but says his goal is to be the most efficient plant in the U.S.

To that end, Sterling Ethanol is currently looking into a new technology known as fractionalization that should further improve plant efficiencies by separating the corn germ before the fermentation process. When corn is partially broken down before fermentation, the power requirements to produce ethanol are further reduced.

Long term, the goal is to bring plant fuel consumption down to zero.

“I want to be able to build a plant that consumes no outside fuel,” says Kramer.