NEXT STOP: CLEAN DIESEL

摘要

AUTOMOTIVE| Modern diesel engines not only provide stellar fuel economy but are quiet and peppy. Still, despite these improvements in performance, diesels remain nasty polluters. Now some of the black clouds that seem to follow diesel vehicles around could be about to disappear. More-effective diesel-exhaust-cleaning devices are getting tantalizingly close to market. The problem is that diesel exhaust can't be cleaned with conventional catalytic converters because it contains too much oxygen, which destroys the catalysts. Enter plasmas―electrically charged gases. In a chamber attached to the exhaust pipe, rapidly pulsing electrical fields would convert oxygen molecules into ions that help trigger a first round of chemical changes in the exhaust. Then, a bit further along in the exhaust system, a catalytic converter could finish the clean-up job.