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Physicist José Goldemberg Discusses Ethanol and Brazil's Short-Lived Nuclear Weapons Program
With easy access to oil unlikely to last much longer, ethanol has the potential to replace a significant part of the world's petroleum-based fuels, says a leader of the push for energy sustainability in Brazil. But José Goldemberg, a physicist at the University of São Paulo, told a 27 June seminar at AAAS that there is considerable "hype" surrounding the recent popularity of ethanol.
While many nations, including the United States, have suitable agricultural conditions to match the Brazilian success in making ethanol from sugarcane, he said, a substantial expansion of global ethanol production will require improvements in present-day technologies, such as more efficient ethanol distilleries, and breakthroughs in methods for converting wood and other forms of biomass into fuel.
During his visit to Washington, Goldemberg—a former president of the Brazilian Association for the Advancement of Science—also told a 25 June briefing on Capitol Hill about his nation's small nuclear energy program and how he had helped persuade his nation's civilian leadership to end its pursuit of nuclear weapons in 1991. Goldemberg served as Brazil's Secretary of State for Science and Technology in the early 1990s. The Capitol Hill briefing was arranged by AAAS's Center for Science, Technology and Security Policy.
Goldemberg's 27 June seminar was co-sponsored by AAAS and the Washington Science Policy Alliance. At that seminar, he described how decisions taken by Brazilian officials during the oil embargo of the 1970s have paid off in a robust ethanol program that has replaced 40% of that nation's gasoline consumption, reduced its dependence on foreign oil, helped improve air quality in major cities and brought international attention to Brazil's energy policies.
The Brazilian government mandated that ethanol be blended into all gasoline and also encouraged automakers to produce engines that could run on pure ethanol. "The government created a guaranteed market" for ethanol, Goldemberg said, and production grew rapidly.
When drivers in Brazil pull into filling stations now, they have a choice of 100% ethanol fuel for cars with suitable engines (flex-fuel engines that can burn fuels with 25 to 100% ethanol) or a blend of gasoline and up to 25% ethanol for cars with standard engines.
Starting in the 1970s, Government subsidies helped cover the price differential at the pump between gasoline and ethanol. In 1980, one liter of ethanol was three times more expensive than a liter of gasoline, Goldemberg said. Subsidies were progressively removed during the 1990s, and by 2005 ethanol had become fully competitive with gasoline. It now costs only about half as much as gasoline, Goldemberg said. At that price, pure ethanol is an attractive option even though the gasoline-ethanol mix gives better mileage.
Brazil now produces about 4.2 billion gallons of ethanol from sugarcane annually. That takes about 2.5 million hectares of agricultural land (or about 6.2 million acres). Goldemberg said that were Brazil to devote about 10 times as much cropland to production of sugarcane ethanol, it could replace about 10% of the world's gasoline consumption.
Brazilian ethanol companies have plans to expand production and would like to open global markets for the fuel. There have been concerns that expanded production might endanger forested areas of the Amazon, but Goldemberg said sugarcane does not prosper in the Amazonian region.
The United States is an obvious potential customer for Brazil's ethanol, but it now imposes a 54-cent-a-gallon tariff on Brazilian ethanol to protect domestic farmers who produce ethanol from corn.
Goldemberg noted that sugarcane ethanol has a much better "energy balance" than corn. It requires less fossil fuel as an input during the growing, trucking and distilling of the product than corn. For each gallon of fossil fuel input, he said, there is about eight to10 gallons of pure ethanol as an output with sugarcane. For corn, he said, the output is more like 1.3 gallons of ethanol for each gallon of fossil fuel used. "It's a positive energy ratio" for corn, Goldemberg said, "But it's not very good. You gain, but you don't gain much."
As Brazil's ethanol program matured, the amount of sugarcane grown per hectare grew remarkably—about 3% a year for two decades, according to Goldemberg. He attributed the strong productivity growth to careful genetic selection of the best seeds for planting each year and improved engineering at the distilleries where the crop is fermented to make ethanol. He said efforts are underway to further improve the efficiency of the Brazilian ethanol distilleries, with hopes of increasing the productivity per hectare by another 50% in the next six to seven years. One promising step: burning the crushed sugarcane stalks, formerly disposed of as waste, to provide heat for distillation and also to generate electricity.
But any effort to dramatically increase the global output of ethanol will probably require new technologies for breaking down the filamentary cellulose molecules in wood and other plant materials so their sugars can be efficiently converted to fuel, Goldemberg said. Existing processes for such conversion are inefficient and expensive.
"Basically, people don't know how to do it in a practical scale, in a commercial scale," he said.
Researchers are looking for ways to change that, including genetically modifying cellulose so it can be more readily broken into its component sugars. They also are exploring ways to genetically engineer microorganisms or enzymes that would be better able to break down the molecules. Goldemberg predicted it could take 10 years or more before such research pays off. "I don't think this will happen shortly," he said, citing what he called "enormous hype" about the prospects for cellulosic ethanol.
But over the long term, Goldemberg said, he is optimistic that "ethanol from any green stuff" will prove to be a reality, a renewable energy resource that will help to preserve the lifestyle that residents of the developed world have come to expect.
In his remarks on Capitol Hill, Goldemberg described Brazil's nuclear energy program and its eventual decision not to pursue nuclear weapons.
In 1975, while under a series of military dictatorships that lasted until 1985, Brazil signed a cooperative agreement with West Germany to build a series of reactors. Dubbed the nuclear "deal of the century," Brazil had plans to construct eight large nuclear reactors by 1990 and more than 50 by 2000.
"Brazil was not immune to the euphoria around the world about the possibilities of nuclear energy," Goldemberg said. "Many in the military in the government felt that a strong program would boost Brazil's international standing to that of a major political actor."
Although the West German agreement crumbled in the 1980s, it did result in one nuclear reactor, the 1,300-megawatt Angra II Nuclear Power Plant, which became operational in the 1990s. The first Brazilian reactor, Angra I, was a 624-megawatt Westinghouse reactor installed much earlier.
Soon after it became apparent that the West German agreement was not going to lead to a robust nuclear energy program, the three military branches started to pursue a path that could lead to weapons. The Brazilian navy was ultimately successful in creating a uranium enrichment program, the first step in developing weapons.
"[United States President] Carter and the United States Congress were putting a lot of pressure on Brazil not to develop a program," Goldemberg said. "This awkward pressure only strengthened the Brazilian resolve to develop a program as it looked like the United States was not allowing the country to express its sovereignty."
But while the Brazilian military and government at that time viewed a nuclear program as a way to obtain energy and international prestige, Goldemberg said that many in the scientific community did not think the program was in Brazil's national interest.
"It just did not make sense to us," Goldemberg said. "In terms of energy production, Brazil has tremendous hydro-electric potential, including the largest hydro-electric dam in the world."
[As of 2007, Brazil has the world's largest hydro-electric dam, Itaipu, which is located on the Paraná River between Brazil and Paraguay. The country also has the third-highest hydro-electric production with 336,800 gigawatt hours produced annually.]
In 1991, Goldemberg was able to successfully convince Fernando Collor de Mello, the first publicly elected president in more than 25 years, to abandon his nation's quest for nuclear weapons.
Earl Lane and Benjamin Somers
3 July 2007