In search of the FUEL OF THE FUTURE

While Congress heaps lavish attention and money on corn ethanol as the fuel of America’s future, ethanol from a local plant has proven to be more efficient and better for the environment: sugarcane.

According to the Department of Energy, sugarcane ethanol could reduce greenhouse gas (GHG) emissions by 87 percent, compared to an 18 percent to 28 percent reduction from corn ethanol.

“The energy output is a little bit better than gasoline because it is 100 percent burning. There’s no admission [of greenhouse gases] at all,” according to Dr. Raj Boopathy, an associate professor at Nicholls State University.

Sugarcane requires few chemicals to grow, does not erode topsoil and generates eight times more energy output than energy input. Because plant residue can be used to operate processing facilities, making sugarcane ethanol requires one-fifth the petroleum used to make fuel than from other crops.

Despite these advantages, there are no sugarcane ethanol plants in the United States. The possibility of Americans powering automobiles solely on sugarcane (or any type of) ethanol seems highly unlikely anytime soon. The most important reason is the United States does not have the permissible climate or available farmland to harvest enough sugarcane to wean Americans off oil.

Sugarcane is only grown in the southern portions of Louisiana, Florida, Texas and Hawaii. To produce enough ethanol to kick America’s 21-million-barrel-a-day oil addiction, acreage equal to all four states combined would have to be planted with sugarcane.

Another key factor is the American government heavily subsidizes the corn ethanol industry: It receives 51 cents per gallon produced. Also, ethanol only generates two-thirds the energy of gasoline, according to numerous scientific reports.

Ethanol is 180-proof grain alcohol that has been denatured with chemical additives. For sugarcane, the juice is extracted, and then fermented with yeast to produce alcohol. “Corn grain is made of starch. The starch is broken down into sugar, and the sugar is converted into ethanol. Sugarcane is a much simpler plant to use,” said Dr. Edward P. Richard Jr., research leader at the USDA Sugarcane Research Unit in Houma.

Environmentalists proclaim sugarcane is a superior option to corn for producing ethanol. To support their argument, they look toward Brazil to serve as the template for America’s future energy independence.

In 2006, Brazil produced 4.4 billion gallons of sugarcane ethanol and is the world’s leading ethanol exporter. The Washington Post reported, “The pressed sugarcane juice can either go to huge fermentation vats to make alcohol or be spun in centrifuges to produce sugar and molasses, depending on which product is priced more favorably on any given day.” Ethanol plants supply their own electricity by burning bagasse, the outer stalk of the cane. Some plants produce so much electricity that they sell their excess to the national grid.

Brazil spent billions of dollars in ethanol incentives over the past three decades, but today no longer pays subsidies. “They (Brazilians) can make ethanol from sugar cheaper than (Americans) can make ethanol from corn,” Boopathy said.

Eighty percent of Brazil’s new cars have flex-fuel engines that burn gasoline blended with ethanol, pure ethanol, or any combination of the two.

Brazilian sugarcane researchers report for every unit of energy expended to turn cane into ethanol, 8.3 times as much energy is created, compared with 5.0 for gasoline and 1.3 times for corn. “There’s no reason why we shouldn’t be able to improve that ratio to 10 to one,” said Suani Teixeira Coelho, director of the National Center for Biomass at the University of Sao Paulo.

So, can Brazil’s model for energy independence be replicated in the United States? Maybe not.

Put both nations’ energy consumption into perspective. United States gasoline demand is more than 20 times that of Brazil. Even though ethanol production levels are similar in both countries, Brazil’s output meets 40 percent of its gasoline demand, while America’s ethanol production satisfies only about two percent of its gasoline demand, according to an ExxonMobil Energy Outlook analysis.

Newsweek reports, “To replace just one percent of U.S. gasoline consumption would require a staggering additional eight billion liters of ethanol.” That is about double the amount both nations produce, combined.

Last year, the United States imported about 500 million gallons of ethanol from Brazil. This occurred despite a 54-cent-per-gallon tariff on imported ethanol on top the 51-cent-per-gallon subsidy paid to American corn ethanol producers. America also imposes a seven percent maximum on imported Brazilian ethanol. This means that Brazil cannot import more than seven percent of the ethanol that was produced in America the previous year.

Sugarcane is a $1.5 billion industry that employs 27,000 workers in Louisiana, according to the American Sugar Cane League. Despite being home to nearly half this country’s sugar production, Louisiana has had an on-again, off-again relationship with ethanol.

According to Alan A. Troy, a former senior energy engineer for the Louisiana Department of Natural Resources, from 1984 through 1990, ethanol was Louisiana’s alternative fuel of choice. The ethanol was blended with gasoline to form gasohol (gasoline containing 10 percent ethanol). Eighteen ethanol plants were planned in Louisiana at one time or another. Nine plants were built, but the maximum number operating at any one time was six. After the 1989 Legislature repealed state ethanol subsidies, production ceased and all plants shut down by December 1990.

In the United States, the sugar-cane industry has had little incentive to diversify into ethanol production because import quotas keep American sugar prices far above world levels. “Right now, it’s more profitable for our growers to grow sugarcane for sugar production, than to grow sugarcane for fuel production,” said Windell Jackson, senior agronomist at the American Sugar Cane League.

Today, Louisiana’s brightest minds are at the forefront of turning sugar into an economically viable alternative to corn as the nation’s feedstock for ethanol production. The goal is not only for ethanol to use the raw sugar, but also the waste byproduct of the cane.

Boopathy and graduate assistant Letha Dawson have produced sugarcane ethanol from its residues: leaf litter, bagasse, and sugar top. Boopathy and Dawson use sulfuric acid to remove lignin from the cellulose in cane waste. The cellulose allows yeast to convert the glucose into ethanol during fermentation. Theoretically, the discharged lignin would be burnt to produce heat needed to process ethanol or used to generate electricity to run the facility and excess electricity could be sold to utility companies, Richard said.

Unlike Brazilian mills that use cane waste to power its facilities, future American mills would use the cane waste to make ethanol.

Boopathy and Dawson’s research have produced one liter of fuel-grade ethanol in the lab. The next step is to produce 50 liters and prove the economic viability of their process. “We’re not actually increasing sugarcane production, but we’re making better use of the waste material that comes from the crop,” Boopathy said.

“The potential for sugar ethanol is vast if it can be developed on a commercial scale,” Richard added.

The Department of Energy estimates that one ton of dry biomass produces 60 to 80 gallons of ethanol. USDA researchers indicate that the average sugarcane farm generates per acre 6.3 tons of bagasse plus three tons of leaf litter, which could yield 558 gallons of ethanol per acre. In addition, the average sugarcane farm yields 31 tons of sugar per acre, equaling 512 gallons of ethanol per acre. That is 1,070 gallons of ethanol per acre of sugarcane – more than triple the amount corn can produce.

Richard has even grander plans expanding sugar production. Because most sugarcane varieties have bagasse than sugar and needs 10 to 11 months to reach full maturation, Louisiana growers have only one harvest a year. (Brazilian sugar is harvested three-to-four times a year.)

“The next generation of sugarcane varieties needs to mature in about 8 months… and produce as much or more sugar than bagasse,” he said.

South Louisiana is the northernmost location where sugarcane is grown in the world. Richard said his research team is “crossbreeding wild Asian sugarcane weed from the Himalayas with native commercial sugarcane varieties to increase cold tolerance” and hopes to expand where it can be harvested. Seedlings have already been sent as far away as California to study its feasibility.

He reasons sugarcane ethanol may not be the perfect solution to the dependence on foreign oil, but it can play a role in transitioning the nation to a cleaner, environmentally-friendly energy supply.

Anna Hale, research geneticist at the Sugarcane Research Unit in Houma, sets to work in a row of sugarcane. * Photo by CHRIS SCARNATI