The composition of VOC (volatile organic compounds) emissions from in-use passenger cars with different engine types, ie cars with diesel engines, cars with petrol engines equipped with three-way-catalysts, and cars with petrol engines without catalysts was determined. Five cars of each engine type have been measured on a chassis dynamometer under conditions of the US FTP 75 test procedure and the "Autobahn" test developed by TUV Rheinland. Measurements of C2 and C10 hydrocarbons were made with a GC-FID system. In addition, samples on DNPH cartridges were taken and analysed by means of a HPLC-system for the determination of aldehydes and ketones. The influence of cold/warm-conditions on the VOC composition was determined. In the case of cars with diesel engines as well as for the petrol driven cars without exhaust treatment, the effect caused by the cold start only led to minor changes in the VOC composition. A similar behaviour was observed for these car types at higher speeds. In contrast to the cars without catalysts the cars with three-way-catalysts showed a great variability of the VOC composition. During the cold start phase the aromatic compounds and the alkanes yielded the main fraction of the VOC. During the warm phase the less reactive alkanes were predominant. With increasing mean velocities the VOC composition changed in favour of the more reactive compounds. (A) For the covering abstract see IRRD E101903.

Determination of voc-components in the exhaust of gasoline and diesel passenger cars

The requirements of the Texas State Implementation Plan of the U.S. Clean Air Act for the Houston-Galveston Ozone Nonattainment Area stipulate large reductions in oxides of nitrogen (NOx ) emissions. A large number of sources at Dow Chemical Co. sites within the nonattainment area may require the addition of continuous emission monitoring systems (CEMS) for online analysis of NOx , CO, and O2 . At the outset of this work, it was not known whether the analyzers could accurately measure NOx as low as 2 ppm. Therefore, NOx CEMS analyzers from ﬁve different companies were evaluated for their ability to reliably measure NOx in the 2–20 ppm range. Testing was performed with a laboratory apparatus that accurately simulated different mixtures of ﬂue gas and, on a limited basis, simulated a dual-train sampling system on a gas turbine. The results indicate that this method is a reasonable approach for analyzer testing and reveal important technical performance aspects for accurate NOx measurements. Several...

https://www.tandfonline.com/doi/pdf/10.1080/10473289.2003.10466208

Evaluation of NO(x) flue gas analyzers for accuracy and their applicability for low-concentration measurements.

This study contributes to the topic of nitrogen oxide (NOx) formation at the level of single droplet and droplet array combustion The results show that the trade-off between ambient temperature and available oxygen determines the NOx formation of droplets burning in hot exhaust gas The degree of droplet vaporization has an effect on flame stabilization around the droplet and on NOx formation In the ignition model, the NOx production rate turns out to be very sensitive against the ignition position

On the Formation of Nitrogen Oxides During the Combustion of Partially Pre-Vaporized Droplets

Testing of Volatile and Nonvolatile Emissions from Advanced Technology Natural Gas Vehicles

This article by the Technical University of Darmstadt and by Umicore, ABB APR and AVL List describes a new measuring system for optimising the performance of SCR systems by analysing the exhaust gas components NH3, NO, NO2 and N2O. A newly developed UV photometer that is able to simultaneously measure NH3, NO and NO2 was used. In addition, N2O was measured by an improved NDIR. Both analysers used a specially configured sampling method. The performance of this measuring system was evaluated on a heavy-duty diesel engine test bench equipped with a state-of-the-art SCR catalyst system.

John L. Snyder

Papers

Quantification of uncertainties in continuous measurement systems for low-no x emissions from stationary sources