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
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
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
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
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. …