Technology Trends and Regulations Driving Reduction in Vehicular Emissions

摘要

In the "State of Global Air" report published earlier this year, exposure to ambient particulate matter < 2.5 microns (PM_(2.5)) was identified as the 5th largest risk factor to health, accounting for 4.2 million deaths across the globe. The report highlights measurements which show that 92% of the world's population lives in areas that exceeded the 10 ug/m~3 guideline recommendation by the World Health Organization (WHO). The poor air quality is also associated with some of the most densely populated and rapidly growing economies of the world. Accordingly, measures are being taken across several developing countries to adopt and enforce tighter vehicular emission regulations to minimize tailpipe unburned hydrocarbons, NO_x and particulates. The societal needs for lower greenhouse gas (GHG) emissions have also increased focus on improvements in vehicle fuel economy and powertrain electrification. This has led to the adoption of fuel efficiency and/or tailpipe CO_2 targets by several countries. Moreover, the emphasis on reduced emissions has shifted worldwide from lab-based certification cycles to real-world driving conditions. Much thought has been put into developing testing procedures to measure real-driving emissions (RDE). This triple confluence of reduced tailpipe emissions of criteria pollutants, improving fuel economy and achieving these under a wide range of real-world driving conditions is a significant challenge facing the automotive industry. This paper describes recent advances in both the regulations across the world as well as engine and after-treatment technologies.