Christian Bach

Velocity-dependent benzene emission factors of three-way catalyst passenger cars and light duty vehicles from time-resolved exhaust gas analysis

Time-resolved Chemical Ionisation Mass Spectrometry (CI-MS) has been used to investigate the benzene emission profiles in automotive exhaust during transient engine operation. Representative petrol-driven passenger cars and light duty vehicles with model years 1991 to 1996 have been selected from the Swiss car fleet and were measured on the chassis dynamometer at the Swiss Federal Laboratories for Materials Testing and Research (EMPA). The benzene emission characteristics of a fleet of 20 passenger cars (1.3-5.2 l), eight light duty vehicles (2.0-2.4 l) and one conventional vehicle (1.4 l) have been determined. A set of seven driving cycles, including the European Driving Cycle (ECD), the US Urban (FTP 75), the Highway and four additional driving cycles have been investigated by CI-MS. Velocity-dependent emission factors for the individual vehicles as well as for the different vehicle classes were determined by a statistical analysis of the corresponding emission data.

Electro fuels as an alternative to electrification – an energetic and economic analysis

With one third of greenhouse gas emissions and 40% of the CO2 emissions, road transport is responsible for the largest portion of climate gases of all energy sectors in Switzerland. These emissions have actually even slightly increased since 1990, while they decreased for example in the heat production sector. Private motorized road traffic in Switzerland, consisting of 4.5 Mio passenger cars and 0.4 Mio utility vehicles, performed a mileage of approximately 91.0 billion pkm (57.3 billion vehicle-km) and 17.2 billion tkm (6.4 billion vehicle-km), consuming 3.4 billion liters of gasoline and 3.2 billion liters of diesel. Thereby, 16.4 million tons of CO2 were produced, 10.2 million tons from passenger cars and 1.6 million tons from delivery vehicles and trucks.

Diesel and natural gas engines for heavy vehicles

Natural gas is superior to conventional fuels regarding the regulated pollutants, particularly with nitrogen oxides and particulates, as well as concerning the ozone formation and carcinogenicity. However, the CO2 emissions and the efficiency gain on importance, too. The following contribution of Empa (Swiss research institute for materials sciences and technology) presents present and expected tendencies for heavy duty engines.