Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. ...

Joint Research Centre

The effect of lubricants on nanoparticle formation in heavy-duty diesel exhaust with and without a continuously regenerating diesel particulate filter (CRDPF) is studied. A partial flow sampling system with a particle size distribution measurement starting from 3 nm, approximately, is used. Tests are conducted using four different lubricant formulations, a very low sulfur content fuel, and four steady-state driving modes. A well-documented test procedure was followed for each test. Two different kinds of nanoparticle formation were observed, and both were found to be affected bythe lubricant but in differentway. Without CRDPF, nanoparticles were observed at low loads. No correlation between lubricant sulfur and these nanoparticles was found. These nanoparticles are suggested to form mainly from hydrocarbons. With CRDPF, installed nanoparticles were formed only at high load. The formation correlated positively with the lubricant (and fuel) sulfur level, suggesting that sulfuric compounds are the main nucleating species in this situation. Storage effects of CRDPF had an effect on nanoparticle concentration as the emissions of nanoparticles decreased over time.

Effect of lubricant on the formation of heavy-duty diesel exhaust nanoparticles.

The effect of a conventional oxidation catalyst and a novel particle oxidation catalyst (POC) on diesel particles is studied using identical methodology. Regulated particulate matter emission measurement is followed by analyzing soluble organic fraction. In addition, size distributions are measured using a partial flow sampling system with a thermodenuder as an option. A parallel ELPI-SMPS method is used to study the particle effective density and, further, the mass. Tests are conducted using a heavy duty diesel engine with a very low sulfur fuel. A decrease in particle mass was observed when using a catalyst. When using a conventional catalyst the decrease was attributed to the decrease of soluble organic fraction, while using POC the nonsoluble fraction was also found to decrease, by 8-38%. This observation is confirmed by particle number measurement, and POC was found to decrease the dry particle number concentration measured downstream of a thermodenuder by 13-28%. Further particle structure analysis indicated lower density values when using conventional catalyst or POC. The physical size of the particles was not changed noticeably over either catalyst--implying the soluble organic fraction was condensed onto the soot, filling the voids in the porous structure of soot agglomerates, when no catalyst is used.

Effect of oxidation catalysts on diesel soot particles.

Traffic-related emissions of fine particles represent one of the main sources of air pollution especially in urban areas. In particular, diesel engines are blamed as one of the main contributors for their inherent high particulate emissions. In order to reduce the impact on human health of particulate emissions from vehicles, new stricter emission standards were considered necessary for Europe. The introduction of very low particulate emission limits has required the development of an improved measurement procedure for particulate mass and a new measurement procedure for particle number. The Particle Measurement Programme (PMP) was established in 2001 on the initiative of some European states to achieve this target. The interlaboratory comparison exercise for light duty vehicles, co-managed by the Joint Research Centre (JRC) of the European Commission and the UK Department of Transport, was completed in 2007, and the results have provided the scientific basis for the new Euro 5/6 limits for particle number and particulate mass. The heavy-duty interlaboratory exercise was started in the second half of 2007 with an exploratory work carried out at the JRC and is still on-going.

Future European emission standards for vehicles: the importance of the UN-ECE Particle Measurement Programme.

The introduction of selective catalytic reduction (SCR) aftertreatment to meet stringent diesel NOx emission standards around the world increases exhaust ammonia. Further to the direct air quality and health implications of ammonia, this may also lead to particle formation in the exhaust. In this study, an ammonia SCR system was examined with respect to its impact on both solid and total exhaust particle number and size distribution, downstream of a diesel particulate filter (DPF). Fuel post-injection was conducted in some tests to investigate the effect of ammonia during active DPF regeneration. On average, the post-DPF solid >23 nm and total <23 nm particle number emissions were increased by 129% (range 80-193%) and by 67% (range 26-136%), respectively, when 100 ppm ammonia level was induced downstream of the SCR catalyst. This is a typical level during ammonia overdosing, often practiced for efficient NOx control. Ammonia did not have a significant additional effect on the high particle concentrations measured during DPF regeneration. Based on species availability and formation conditions, sulfate, nitrate, and chloride salts with ammonium are possible sources of the new particles formed. Ammonia-induced particle formation corresponds to an environmental problem which is not adequately addressed by current regulations.

Barouch Giechaskiel

Sustainable Transport Unit,
Institute for Energy,
Transport and Climate,
Sustainable Transport Unit, Institute for Energy, Transport and Climate

Joint Research Centre

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

Barouch Giechaskiel

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Sustainable Transport Unit,Institute for Energy,Transport and Climate,Sustainable Transport Unit, Institute for Energy, Transport and Climate

Joint Research Centre

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

Sustainable Transport Unit,
Institute for Energy,
Transport and Climate,
Sustainable Transport Unit, Institute for Energy, Transport and Climate