摘要: |
Diesel engines are now responsible for half or more of the total nitrogen oxide(NOx) and exhaust particulate matter (PM) emissions from on-road vehicles nationally There has been recent progress in developing control technologies such as selective catalytic reduction, lean NOx traps, NOx storage catalysts, and diesel particulate filters. Although these technologies have not yet been widely deployed in on-road vehicles, their use will soon be required due to new heavy-duty engine emissions standards that will take effect in the U.S. starting with the 2007 model year. This research will review control technologies available for future use, assess control efficiency, cost, durability and robustness in service, and the potential for undesirable side-effects on exhaust emissions. Emissions estimates will be developed for historical, current and future year scenarios that span a 20-year time period. We will use a 3-D photochemical model to predict the effects of changes in vehicle emissions on air pollution levels in the Los Angeles area. |