PROJECTING THE ENVIRONMENTAL IMPACT OF DIESEL CARS ON GASEOUS POLLUTANTS, PM_(2.5) AND CO_2 IN A METROPOLITAN AREA

摘要

Almost all passenger cars (PC) in Brazil are flex fuel (can run any proportion of petrol and ethanol) and diesel fuel is prohibited to these cars; diesel is available for vans and pickup trucks, as well petrol and ethanol. However, there is a proposal under discussion to introduce diesel PC in Brazilian market, arguing that they have better autonomy and emit less CO_2 and pollutants. The goal of this paper is to show the impact on pollutants and CO_2 emissions from diesel PC being offered as a main option; it will be discussed also an alternative scenario, the environmental impact if Internal Engine Combustion (ICE) vehicles are banned in favor of electric ones. Data analysis was performed on type-approval tests of petrol / flexfuel light duty vehicles (LDV). For the first case, the projection for introducing PC diesel in SPMR market shows a significant increase in NO_x emission, small rise for fine particulate matter (PM_(2.5)) and little reduction for HC, CO and total CO_2, although with significant rise for fossil CO_2. The alternative scenario, replacing ICE PC with electrics, shows high reduction for NO_x, some gain for CO_2 and PM_(2.5) and small decrease for CO and HC. Thus, the use of diesel PC will lead to NO_x increase; by other hand, biofuels can reduce CO2 but will increase NMHC and CO emissions. Electric PC may be a good option but requires time to replace ICE vehicles and bringing effective environmental gain.