Diesel fumes have long been a major contributor to urban smog. Now, a Shell Oil Co. researcher says he has come up with a way to dramatically reduce sulfur and other diesel emissions. At a meeting of the American Institute of Chemical Engineers, Stanley N. Milam, a research chemist with Shell Development Co. in Houston, reported that the process utilizes a new low-pressure catalyst that, through chemical reactions, lowers aromatic levels in diesel. Aromatics, which add octane to a fuel, often escape through the exhaust system and react in sunlight to form smog.
A Shell joint venture--Zeolyst Enterprises--will license the process, which is expected to be ready in time to meet Uncle Sam's strict new clean-air laws that take effect in 1993.