NaB[H.sub.4] + 2[H.sub.2]O [right arrow] 4[H.sub.2] NaB[O.sub.2].

Little did we know when watching the television show Death Valley Days just how much it would predict the Future. Host Ronald Reagan became the 40th president, and the main ingredient in "20 Mule Team Borax"--the show's sponsor--is a prime contender For powering automotive Fuel cells. Who knew?

"The main question concerning Fuel cells has been, 'Where do you get the hydrogen?'," says Tom Moore, vice president of DaimlerChrysler's Liberty Technical Affairs. Where indeed, and at what cost? Gasoline reformer Fuel cells have start-up emissions. Methanol reformers are subject to corrosion, and the fuel burns with an invisible Flame. Storing hydrogen under pressure requires a large tank which places limits on vehicle range.

Sodium borohydride, on the other hand, is non-toxic, comes in powder form, and Forms a non-combustible slurry when mixed with water. Passing this mixture through a ruthenium catalyst Frees the hydrogen to run the fuel cell, and leaves a hydrogendepleted borax slurry as its "waste" product. This remnant can be re-hydrogenated [currently via a natural gas-powered process] to turn it into fuel again.

Millennium Cell, Inc. (Eatontown, N.J.).) is working with Moore's group to perfect this "hydrogen on demand" process For automotive use. Rex Luzader, v.p. of Business Development--Transportation at Millennium says recyclability is just one advantage sodium borohydride has over its competitors. "The reaction is easily controlled through the catalyst and reactor configuration," he says. Turning the pump off isolates the fuel From the catalyst. And the catalyst can be used many, many times. Plus, the storage tank doesn't require any special materials, and doesn't have to contain high pressures." The tank is unique, however.

"We developed a dual-bladder fuel tank," says Moore, "to hold the residue created by this process." Refueling pushes the filtrate out of the second bladder and into a collection tank, where it is held until returned for reprocessing. "Unlike gasoline, the tankers won't return to the refinery empty," says Moore, "so the trip back is value-added." And vehicle dynamics are more consistent due to the retention of the residue. There is no dramatic weight variation between "Full" and "empty".

The technology currently is undergoing testing in a Chrysler minivan. "Technically, the vehicle is a hybrid," says Moore, "because the fuel cell recharges a lithium-ion battery pack that provides power for the wheels." Early testing has shown the van to be capable of 0-60 mph in 16 sec., the equivalent of 30 mpg, and of 300 miles on a tank of, well, slush. That tank, by the way, holds 54 gallons of new fuel, up to 40 gallons of residue, and is located between the rear axle and bumper under the van floor.

Ironically, U.S. Borax, Former sponsor of Death Valley Days, owns most of the borax reserves in the world. There are 600 million metric tons of known borax reserves (dry lake beds are the greatest source), and estimates predict the 50 million vehicles currently on the road would use 20 million tons of borax each year, most of which would be recycled.