Jacob Almén

Cold start emissions at +22, −7 and −20°C ambient temperatures from a three-way catalyst (TWC) car: regulated and unregulated exhaust components

A project initiated by the Swedish Environmental Protection Agency (SEPA) concerning cold start driving conditions is partially reported in the present paper. A three-way catalyst car was run in accordance with the European driving cycle (EDC) at 22°C, −7°C and −20°C ambient temperatures. The diluted exhaust was analyzed for: Carbon monoxide (CO), unburned fuel hydrocarbons (HC), oxides of nitrogen (NOx), particulates, light aromatics, alkenes, green house gases, aldehydes and polycyclic aromatic hydrocarbons (PAH) in particles and in the gaseous phase. As expected, the emission factors of both regulated and unregulated exhaust components increased at lower ambient temperatures. However, the emissions did not increase uniformly. The mutagenic/carcinogenic compound benz[a]pyrene for example, increased more than 100 times while CO and HC only increased 5–20 times at the lowest ambient temperature studied.

Exhaust emissions from gasoline-fuelled light duty vehicles operated in different driving conditions: A chemical and biological characterization

Abstract Chemical analysis and mutagenicity tests on Salmonella typtimurium strains TA 98 and TA 100 (Ames test) of exhaust emissions from five passengers vehicles, with or without a three-way catalyst, have been carried out to obtain emission factors and to characterize exhaust emissions. Both constant cruising speeds and transient driving conditions were investigated, regulated CO, HC, NOx and particulates, as well as unregulated pollutants, were analysed. The following unregulated pollutants were measured: particle-associated polycyclic aromatic hydrocarbons (PAH), 1-nitropyrene, light aromatics and light oxygenates. In total, 39 individual compounds were assayed. Emissions from catalyst-equipped vehicles showed a dramatic decrease compared with those from the vehicle without a catalyst. An emission dependency of both regulated and unregulated pollutants and biological activity on driving conditions were determined. An increased emission of PAH, 1-nitropyrene, particulates and mutagenic activity was found with a higher cruising speed.

Estimation of aliphatic amine emissions in automobile exhausts

An analytical method for the determination of aliphatic amines ranging from C3 to C10, C12 and two diamines i.e. putrescine (C4) and cadaverine (C5), has been developed. The reagents 9-fluorenylmethyl-chloroformate (FMOC-C1) or 2-(9-anthryl)ethyl chloroformate (AEOC) weres used in pre-column derivatization of the amines investigated. The amino derivatives were separated using high performance liquid chromatography (HPLC) in conjunction with fluorescence detection. For standard compounds investigated the detection limit is < 0.3 ng. This method has been used for examination of exhaust emissions from both gasoline fueled cars and a diesel fueled engine with respect to amine emissions. The results obtained indicate that the emission of amines (present in the standard mixture used) was, for a US FTP-75 transient test, less than 1 μg/km, if any of them exist in the exhaust emission. Further, fuels (gasoline and diesel) spiked with amines (standard mixture) showed no significant difference in comparison with the emissions originating from the un-spiked fuel investigated.

Chemical characterization of exhaust emissions originating from the regeneration mode of a diesel particulate trap

The chemical characterization of exhaust emissions originating from the regeneration mode of a diesel particulate trap was achieved. The regeneration process was carried out by heating the particulate trap to 700 °C for 208 min with an air stream passing through. Emissions of carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), particulates, chemical compounds present in the particulate and the semi-volatile phase were identified and quantified. The n-alkanes with carbon number ranging from C15 to C35, 15 polycyclic aromatic hydrocarbons (PAH) and 1-nitropyrene have been identified. Results obtained for a full regeneration mode were: CO, 200 mg; HC, 30 mg; NOx, 500 mg; particulates, 5.5 mg; aliphatic hydrocarbons, 90 μg; sum of 22 PAH, < 3 μg and 1-nitropyrene, < 0.02 μg respectively. A white residue obtained in the sampling device was identified as calcium sulfate hydrate. The emission factors determined show that the amount of pollutants emitted during the regeneration mode is negligible compared to emissions during the accumulation mode.

Chemical analysis and biological testing of exhaust emissions from two catalyst equipped light duty vehicles operated at constant cruising speeds 70 and 90 km/h and during acceleration conditions from idling up to 70 and 90 km/h

Abstract Exhaust emissions from catalyst equipped passenger cars have been analysed chemically and in conjunction with bioassay tests. Transient driving conditions investigated include acceleration from 0 to 70 and 90 km/h and subsequent deceleration. Cruising conditions were investigated at 70 and 90 km/h. Both regulated (CO, HC and NOx) and un-regulated pollutants were analysed. The un-regulated pollutants measured were particulate, particle-associated polycyclic aromatic hydrocarbons (PAH), light aromatics and light oxygenates. The emission dependency of both regulated and un-regulated pollutants as well as biological activity (Ames test) was found to be due to driving condition differences.