It's gasoline, but not as we know it. The fuel isn't refined from crude oil, but from coal, and one day it could end U.S. reliance on foreign oil.

"We have enough coal to replace substantially all of the hydro-carbons used for transportation in America today," FBR Senior Analyst Kevin Book said.

The world's leader in the field is SASOL, a South African corporation that operates this vast facility outside Johannesburg.

This plant, which covers 10 square miles and sits atop one of the largest coal mines in the world, right now produces 28 percent of all of South Africa's gasoline, diesel and jet fuel. Invented in the 1920s, the process was developed by pariah states with no oil, Nazi Germany then apartheid South Africa.

"It's a much, much cleaner fuel," SASOL Group General Manager Lean Strauss said.

Cleaner to burn, yes, but not cleaner to produce: Plants spew twice as much carbon than oil refineries.

"We have to find solutions for CO2. But again, the United States do have some interesting options there," Strauss said.

The solution most talked about is pumping CO2 back into the earth, but some environmentalists say it will never work on this scale. Also, these plants are very expensive to build.

But with oil now over $145 a barrel, they just might make economic sense.

And SASOL engineers believe the greatest potential lies in the U.S.

"The U.S. have got the biggest coal reserves, so the biggest opportunity lies there," Strauss said. "They've got more oil stored in the form of coal than there are oil reserves in the Middle East."

A small coal to liquid plant is planned for Gilberton, Pa., but there's strong opposition because of the carbon emissions issue. Also, the Air Force plans to convert coal into jet fuel at a base in Montana.

There's enough coal in the U.S. to last an estimated 250 years. And once a plant is built, it's cheap energy. In South Africa, they produce gasoline from coal for just $25 a barrel.