It's called a 'corona discharge device.' It looks and acts like a giant spark plug. And nobody knows exactly why, but it cuts tailpipe emissions.
Its maker, Litex Inc. of Sherman Oaks, Calif., says that inserting the plug into an exhaust pipe will make a smaller catalytic converter do the job of a larger one, or reinvigorate a converter that has been contaminated by sulfur.
But neither the company's scientists nor those of its intended customers at exhaust system suppliers can explain precisely why the fiery blue plasma generated by the device improves the performance of a catalytic converter.
'Magic,' suggests Barry Cooper, vice president of technology at catalyst supplier Johnson Matthey Catalytic Systems Division in Wayne, Pa.
'They do seem to do something to the exhaust chemistry. As an emissions-control chemist, I'll be fascinated to see what,' he says.
NO COMMITMENTS YET
So far, neither Johnson Matthey nor anyone else has been willing to put the corona discharge device into production. But Cooper, who is routinely approached by small firms peddling new technology, has purchased one of Litex's plugs for testing. Assuming the system lives up to its advertising, it would be at least four years before one appeared on any of his customers' vehicles, Cooper said.
Litex is a 3-year-old company founded by former executives of original patent-holder Lockheed Corp., which receives 2 percent of sales. Litex says the plug will boost the performance of a gasoline catalytic converter while potentially cutting in half a supplier's outlays for the expensive precious metals that make catalytic converters work.
Those claims are tantalizing to an industry hungry for inexpensive catalyst technology.
Without catalytic converters, even the cleanest engines today would fail federal emissions standards. Converters use precious metals such as palladium, platinum and rhodium to break down unburned gasoline, oxides of nitrogen and carbon monoxide in raw engine exhaust into benign carbon dioxide and nitrogen.
MANNA FROM HEAVEN
As emissions regulations tighten under the Federal Tier II mandate, automakers are relying more and more on catalytic converters to meet them. But catalysts have one notable drawback: cost.
The metals that produce the electrochemical reaction cost $400 to $500 per ounce. A typical passenger car catalyst uses 0.1 to 0.2 ounces, or $40 to $80 worth, and a light truck's catalytic elements can cost up to $150.
'Taking precious metal out is like manna from heaven for a car company that fights for nickels and dimes,' says Cooper.
Also, the performance of a catalyst begins to deteriorate when exposed to the high levels of sulfur common in North American gasoline.
Litex's device plays into those concerns. It is inserted into the exhaust pipe upstream of the catalyst. There, a portion of the exhaust gasses pass through its blanket of blue plasma. The toxic molecules are stripped of electrons by the plasma's nonthermal magnetic fields.
These ions - or 'radicals'- flow into the catalyst and 'work on the precious metal sites to enhance catalyst activity,' says Leon Ekchian, Litex's CEO.
Exactly why this happens remains to be discovered, the executive admits.
'It's a very complicated chemical reaction. Our focus so far has been empirical, and we're only now working on a theory to explain it.'
Ekchian says the company's test data shows the device will cut hydrocarbons by 26 percent, carbon monoxide by 40 percent, and oxides of nitrogen by 22 percent when run on pump gasoline with an average sulfur level of around 300 parts per million. The cuts are even higher when fuel sulfur levels are lower, he says. The system will also help a catalyst contaminated with sulfur to purge itself and run cleaner.
In mass production, says Litex, the system will cost about $70 per unit. Prototypes have cost about $5,000 each to make.
However, it is the system's low power consumption of only 25 watts and the potential to save on precious metals that has suppliers interested. Figuring out how those feats are being achieved is the next task, says Cooper.
'It's difficult to judge based on the information we've been given,' he says. Litex has 'showed us results that demonstrated that it improved the performance of the catalyst, but what the root cause of the advantages remains to be seen.'