Efficient EGR technology for future HD diesel engine emission targets

Different systems for achieving short-route cooled EGR on turbocharged and aftercooled heavy-duty diesel engines have been tested on a 12 litre 315 kW engine with 4 valves per cylinder and an electronically controlled unit pump fuel injection system. In all of these systems the exhaust gas was tapped off before the turbine, cooled and mixed with...

Selective catalytic reduction of nitrous oxide with hydrocarbons using a SO2 resistant Fe/zeolite catalyst

Removal of nitrous oxide (N2O) from exhausts of chemical plants andcertain combustion facilities is an effective way for substantial reduction of greenhouse gas emissions from anthropogenic sources. ECN has developed a catalyst for catalytic removal of N2O from various exhaust gases using hydrocarbons (propane or methane) as reducing agent. The...

Use of a detailed model to study the exchange of NO(x) and O3 above and below a deciduous canopy

A 1D deposition model derived from work by Baldocchi, has been used to interpret the exchange of NO, NO2 and O3 measured over an orchard. Where possible, direct measurements from the orchard were used in favour of existing model parameterisations. The model incorporates NO(x)-O3 chemistry and an emission of NO at the air-soil interface. Model...

Biomonitoring human exposure to environmental carcinogenic chemicals

A coordinated study was carried out on the development, evaluation and application of biomonitoring procedures for populations exposed to environmental genotoxic pollutants. The procedures used involved both direct measurement of DNA or protein damage (adducts) and assessment of secondary biological effects (mutation and cytogenetic damage)....

New EGR technology retains HD diesel economy with 21st century emissions

An EGR system for turbocharged (and aftercooled) heavy-duty diesel engines have been demonstrated on a 12 litre 315 kW engine with 4 valves per cyclinder head and high pressure injection system. In the EGR system exhaust gas is tapped of before the turbine, run through a cooler and mixed with the intake air after the compressor and aftercooler....

Exchange of ozone and nitrogen oxides between the atmosphere and coniferous forest

The deposition flux of O3 to a Douglas fir forest in the Netherlands was monitored by eddy correlation during nine months. At the same time the concentration gradients of NO, NO2 and O3 were determined over the forest. The canopy resistance to O3 uptake was calculated from the measurements ant it compared well with model estimates. The...

Modelling land atmosphere exchange of gaseous oxides of nitrogen in Europe

This review outlines current understanding of the exchange processes and methods used to estimate regional NOy deposition. Several methods have been used to measure dry deposition. Measurement artefacts such as non-stationarity caused by local sources, monitors responding to other gases than NO2 and the influence of photochemical reactions have...

Formation of chemical compounds from irradiated mixtures of aromatic hydrocarbons and nitrogen oxides

The paper describes the analysis of products of the photochemical degradation of toluene and toluene-14C in smog chamber experiments. Compounds identified included methylglyoxal, possibly the recently postulated butenedial and other carbonyl compounds. The main product of photochemical degradation of methylglyoxal appeared to be acetaldehyde....

Short term inhalation toxicity studies with peroxyacetyl nitrate in rats

The inhalation toxicity of peroxyacetyl nitrate (PAN) was examined in acute (single exposure), subacute (4-wk repeated exposure) and subchronic (13-wk repeated exposure) studies in rats. The 4-hr LC50 was found to be 95 ppm. In the 4-wk study rats were exposed to 0, 0.9, 4.1 or 11.8 ppm PAN vapor for 6 hr/day, 5 days/wk. Exposure to 11.8 ppm...

Fotochemische smogvorming in Nederland (Photochemical smog formation in the Netherlands)