Mosaiko

José Goldemberg: Physicist, Environmentalist

• Comments
• Email This Post
• Share on Facebook

José Goldemberg, a prize-winning Brazilian nuclear physicist, wanted a new intellectual challenge. “As a physicist,” he says, “I know how to make calculations. At the time, in 1978, there was great euphoria about ethanol here, but no discussion of it replacing fossil fuels. I decided to make calculations to see how renewable is ethanol? How much oil could we save by converting to liquid ethanol made from sugar cane?”

Brazil was suffering from soaring national debt and serious inflation. Both were due in no small part to the fact that Brazil’s economy ran on oil — 80 percent to 90 percent of it imported at skyrocketing prices. To ease its oil dependency, Brazil’s national government embarked on a program in 1975 to switch the country’s vehicles from gasoline to ethanol, made from fermented sugar cane. In partnership with the sugar industry, the government offered subsidies to growers, loans to build ethanol distilleries, and incentives to purchase ethanol-fueled cars.

But it was not until 1978, when Goldemberg’s calculations were published in Science, a leading scientific journal, that policymakers in Brazil and elsewhere begin to believe that sugar cane could produce a profitable and renewable clean fuel to replace gasoline, and be one key to a renewable energy future. “That [paper] was my contribution,” Goldemberg told Time magazine in 2007. “What I did was make people assured that this [ethanol] was the way to go.”

Goldemberg began to promote the idea that ethanol development was a key to sustainable growth that could also reduce carbon emissions and the threat of global climate change. “What has to be done is produce sugar cane and ethanol in the tropic countries,” he says. “These developing countries need clean industry. Sugar cane-to-ethanol production generates lots of jobs. If the Caribbean countries and Africa started growing sugar cane and producing ethanol for export, it would stimulate development.”

As oil prices stabilized in the 1980s, Brazil’s ethanol development stalled. A partnership of the country’s sugar producers began working to increase agricultural yield from their cane fields, while reducing ethanol production costs. The most significant improvement was the use of sugar cane bagasse, a waste product of cane crushing, to produce energy for the ethanol manufacturing process. Use of bagasse makes fossil fuel use unnecessary when manufacturing ethanol. By contrast, ethanol extracted from corn, a process used in the United States, yields only about 15 to 25 percent more fuel than the fossil fuels used to make it. “That’s why the energy balance for sugar cane ethanol is the best in the world for biofuels,” Goldemberg observes.

In 2000, as oil prices rose and ethanol prices fell, ethanol became Brazil’s fuel of choice. The major auto companies introduced “flex-fuel” cars there in 2003. These vehicles run on either gasoline or nearly 100 percent ethanol. Soon, Brazilian demand for both flex-fuel cars and ethanol exploded. Today, flex-fuel cars comprise about 90 percent of all new cars sold in Brazil, and they are becoming available worldwide.

And none too soon, in Goldemberg’s view. In another paper in Science, published in 2007, he calculated that at the present rates of fossil fuel consumption, known oil reserves will be depleted in 41 years, natural gas in 64 years, and coal in 155 years. “Besides the issue of depletion,” he wrote, “fossil fuel use presents serious environmental problems, particularly global warming.” He sees Brazil’s experience with ethanol as a model that can — and should —be duplicated worldwide. While cutting the nation’s dependence on a disappearing energy source, ethanol use has reduced Brazil’s carbon emissions by about 47 tons annually, 20 percent of its total carbon footprint.

Goldemberg sees even greater promise in “second generation ethanol production” through the use of cellulosic materials — grasses and yard, tree and crop wastes. “Cellulose is everywhere,” he says, “but you have to break the molecule to ferment it.” The technology is still in the development stage. Until it’s commercially viable, he adds, “an alternative already exists.”