Research of the ultimate cleanness of internal combustion engine and the application for mass production vehicles

The needs of the non-internal combustion engine for the automobile have been increasingly emphasized due to the seriousness of the air pollution in major cities and the global warming. However, such power plant technologies are generally considered to be still far away from the full commercialization as technical issues including infrastructure and cost are still remaining to be solved, so the substantial emission cleanup through the market penetration requires a long time for the realization. For the mean time, attempts are made to investigate the maximum potential of the internal combustion engine for reduction of both exhaust emissions and CO₂ focusing on Honda''s near-zero emission Zero Level Emission Vehicle (ZLEV) technology. The authors conducted research to achieve almost complete elimination of the noxious components in gasoline engine exhaust gas, and these efforts were rewarded in the form of basic technologies with the potential to realize ultimate low emission levels equivalent of 1/10 or less of ULEV standards. This vehicle was named ZLEV, because emission levels are almost same as which produced by a relatively clean power plant that generates power required to operate an electric vehicle which does not emit any exhaust gases. This was accomplished by applying the Three- Stage Emission Management System, utilizing ultra-precise combustion and exhaust gas conversion control technology, and dividing the operation into three stages of just after engine start, the warm-up stage, and normal running. In this paper, technologies of this system are described. Using a Fourier Transform Infrared (FTIR)-based, on-board measurement system which Honda developed for investigating ZLEV performance and ambient pollutants, on-road test results are presented for vehicle emissions and ambient/roadway pollution concentrations while operating in the Tokyo area. Further, the application of emission technologies for mass production vehicles is mentioned.