Tires Possible Solution to Energy Woes

Article excerpt

By Matthew L. Wald

N.Y. Times News Service

HARRISON, N.Y. _ Oil companies think of automobile tires as a petrochemical product, but earlier this month, Texaco Inc. tested a process using tires as a feedstock, in a multistage process for making electricity cleanly.

The process, which Texaco says is technically viable and, it believes, economically viable as well, recasts tires as an interim stage between crude oil and useful energy. It also gives a starring role to worn-out lubricating oil, thus addressing two headaches.

Texaco is one of the last oil companies that maintains a substantial alternative energy program. Much of the effort, including this new machine, is built around gasification.

The idea is that cooking hydrocarbon fuels into a gas before burning them results in far cleaner combustion and far more energy than is possible in traditional combustion.

The burning takes place in gas turbine engines, which resemble jet-airplane engines, only bolted to the ground. Most gas turbines today run on methane gas or burn diesel oil, which vaporizes easily.

But Texaco has been commercially successful in gasifying less valuable hydrocarbons, notably heavy crude oil that is generally difficult to burn because of its high sulfur content. The company has 40 gasifiers and has sold licenses for 100 more.

With government subsidies, Texaco has also shown promising results in gasifying high-sulfur coal. Now, making gasification technology more valuable, the company is moving to less attractive fuels.

Recently it signed an agreement with Petroleos de Venezuela, General Electric Co. and Teco Power Service Co., a corporate cousin of Tampa Electric, to build a 250-megawatt power station in Puerto Rico that will gasify Orimulsion, one of the most abundant and promising fuel resources in this hemisphere, if only someone could figure out how to use it.

"It's perfect for us," said David C. Crikelair, a Texaco vice president who heads the company's alternate energy department.

Orimulsion comes from the Orinoco tar deposit, which is more like asphalt than oil. Drillers push water into the ground so they can pump the material to the surface. The product is 28 percent water, which is acceptable, and 8 percent sulfur, which can present difficulties.

Texaco also recently signed a major gasification deal with China, to provide gas for domestic and industrial use in Shanghai.

The tire project is a concatenation of technologies, building a system to produce fuel for the gasifier, which in turn produces fuel for the turbine, which makes electricity.

This chain of processes took a new twist in early December when Texaco successfully tested a device that cooks old tires into a liquid. It does so in a bath of waste oil, like old lubricating or transmission oil or even antifreeze from cars.

At a laboratory in Montebello, Calif., in Los Angeles County (and, appropriately enough, overlooking a landfill), the company built a processing unit that takes chunks of tires and cooks them at 700 degrees Fahrenheit, for half an hour.

The system, which the company hopes to sell for about $2 million, handles 1,000 to 2,000 tires a day, the number produced daily by a city of 250,000 to 500,000 people. The machine also requires an equal amount of waste oil, by weight.

The tires have an energy content of about 15,000 British Thermal Units per pound, nearly 80 percent as much as crude oil. …