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The search for substitutes for modern fossil fuels incentivises the use of new propulsion systems (hybrid or electric) and the use of new fuels (gaseous, mainly hydrogen). The article discusses the basic issues related to hydrogen fuel: from its extraction, through the discussion of its properties to its use and applications. Analyzes of the energy consumption involved in its extraction or production were presented, classifying hydrogen in those terms. Great emphasis was placed on design solutions for the use of hydrogen in internal combustion engines, together with discussing the concept of its combustion. The methods of storing hydrogen in a condensed and compressed form were also presented, indicating at the same time the most modern solutions available, such as mixed systems – storage in cryo-compressed form. It has been shown that the combustion of hydrogen in internal combustion engines increases their efficiency, and at the same time significantly reduces the exhaust emissions of toxic gases – including the emission of nitrogen oxides.

Testing of real driving emissions (RDE) offers the opportunity to collect the data about the emissions in special driving, or non-driving situations. These situations are: cold start, warm-up of the engine, stop & go and idling. In the present work, the definitions of the special driving situations were proposed, the emissions of 7 passenger cars (gasoline & Diesel) were extracted from the present RDE data and some special driving situations, particularly the stop & go operation with varying share of idling were reproduced on chassis dynamometer. As expected, the emissions of CO, NOx and PN are in the cold start and in the first part of the warm-up phase (c.a. 25s) considerably higher than in the rest of the investigated urban phase. The singular emitting situations like “stop & go” or idling occur frequently in the warm-up phase, i.e. in the city operation when the engine and the exhaust system are still not warm enough.

Biofuels represent one of the alternatives to obtain the CO2-neutral propulsion of IC-engines. Butanol, which can be produced from biomass, is considered and was investigated in the last years due to the very advantageous characteristics of this alternative fuel. Butanol can be easily and irreversibly blended both with light (gasoline) and heavier (Diesel) fuels. Comparing with ethanol it has the advantages of: higher calorific value, lower hygroscopicity and lower corrosivity. It can replace the aviation fuels. This paper presents the emission results obtained on two Diesel passenger cars with different technology (Euro2 and Euro6c) and with addition of Butanol to Diesel fuel, as a part of the research project DiBut (Diesel and Butanol). Interesting results are given about some non-legislated (non-regulated) components, Acetaldehyde (MeCHO) and Formaldehyde (HCHO) and about the PN-emissions with/without DPF.

Gasoline direct injection (GDI) vehicles have recently been identified as a significant source of carbonaceous aerosol, of both primary and secondary origin. Here we investigated primary emissions and secondary organic aerosol (SOA) from four GDI vehicles, two of which were also retrofitted with a prototype gasoline particulate filter (GPF). We studied two driving test cycles under cold- and hot-engine conditions. Emissions were characterized by proton transfer reaction time-of-flight mass spectrometry (gaseous non-methane organic compounds, NMOCs), aerosol mass spectrometry (sub-micron non-refractory particles) and light attenuation measurements (equivalent black carbon (eBC) determination using Aethalometers) together with supporting instrumentation. Atmospheric processing was simulated using the PSI mobile smog chamber (SC) and the potential aerosol mass oxidation flow reactor (OFR). Overall, primary and secondary particulate matter (PM) and NMOC emissions were dominated by the engine cold start, i.e., before thermal activation of the catalytic after-treatment system. Trends in the SOA oxygen to carbon ratio (O : C) for OFR and SC were related to different OH exposures, but divergences in the H : C remained unexplained. SOA yields agreed within experimental variability between the two systems, with a tendency for higher values in the OFR than in the SC (or, vice versa, lower values in the SC). A few aromatic compounds dominated the NMOC emissions, primarily benzene, toluene, xylene isomers/ethylbenzene and C3-benzene. A significant fraction of the SOA was explained by those compounds, based on comparison of effective SOA yield curves with those of toluene, o-xylene and 1,2,4-trimethylbenzene determined in our OFR, as well as others from literature. Remaining discrepancies, which were smaller in the SC and larger in the OFR, were up to a factor of 2 and may have resulted from diverse reasons including unaccounted precursors and matrix effects. GPF retrofitting significantly reduced primary PM through removal of refractory eBC and partially removed the minor POA fraction. At cold-started conditions it did not affect hydrocarbon emission factors, relative chemical composition of NMOCs or SOA formation, and likewise SOA yields and bulk composition remained unaffected. GPF-induced effects at hot-engine conditions deserve attention in further studies.

Testing of real driving emissions (RDE) with portable emission measuring system (PEMS) in an appropriate road circuit became an obligatory element of new type approval of passenger cars since September 2017. In several projects the Laboratory for Exhaust Emissions Control (AFHB) of the Berne University of Applied Sciences (BFH) performed comparisons on passenger cars with different PEMS’s on chassis dynamometer and on road, considering the quality and the correlations of results. Particle number measuring systems (PN PEMS) were also included in the tests. The present paper informs about influences of E85 on RDE on two flex-fuel-vehicles, discusses some aspects of different ways of evaluation with different programs, shows comparison of different types of PN PEMS and represents the effects of simulation of slope on the chassis dynamometer.

Gasoline direct injection (GDI) vehicles quickly replace traditional port-fuel injection (PFI) vehicles in Europe reaching about 50 million vehicles on roads in 2020. GDI vehicles release large numbers of soot nanoparticles similar to conventional diesel vehicles without particle filters. These exhausts will increasingly affect air quality in European cities. We hypothesized that such particles are released together with polycyclic aromatic hydrocarbons (PAHs) formed under the same combustion conditions. Emission data of a fleet of 7 GDI vehicles (1.2–1.8 L) including Euro-3,-4,-5 and -6 technologies revealed substantial particle emissions on average of 2.5 × 1012 particles km−1 in the cold worldwide harmonized light vehicle test cycle (cWLTC), the future European legislative driving cycle. Particle emissions increased 2–3 orders of magnitude during acceleration like CO, indicating that transient driving produces fuel-rich conditions with intense particle formation. For comparison, an Euro-5 diesel vehicle (1.6 L) equipped with a particle filter released 3.9 × 1010 particles km−1 (cWLTC), clearly within the Euro-5/6 limit value of 6.0 × 1011 particles km−1 and 64-fold below the GDI fleet average. PAH and alkyl-PAH emissions of the GDI vehicles also exceeded those of the diesel vehicle. Mean GDI emissions of 2-, 3-, 4-, 5- and 6-ring PAHs in the cWLTC were 240, 44, 5.8, 0.5 and 0.4 μg km−1, those of the diesel vehicle were only 8.8, 7.1, 8.6, 0.02 and 0.02 μg km−1, respectively. Thus mean PAH emissions of the GDI fleet were 2 orders of magnitude higher than the bench mark diesel vehicle. A comparison of the toxicity equivalent concentrations (TEQ) in the cWLTC of the GDI fleet and the diesel vehicle revealed that GDI vehicles released 200–1700 ng TEQ m−3 genotoxic PAHs, being 6–40 times higher than the diesel vehicle with 45 ng TEQ km−1. The co-release of genotoxic PAHs adsorbed on numerous soot nanoparticles is critical due to the Trojan horse effect describing the property of sub-200 nm particles being deposited in the alveoli transporting genotoxic compounds into the lung. These nanoparticles are persistent and may eventually penetrate the alveolar membrane reaching the blood circulation system. We showed that all GDI vehicles tested released large numbers of nanoparticles carrying substantial loads of genotoxic PAHs. If non-treated diesel exhaust is considered as class-1 carcinogen by the WHO inducing lung cancer in humans, these GDI vehicle exhausts may be a major health risk too for those exposed to them corroborating the progress achieved with current diesel vehicles, now equipped with efficient particle filters.

Air pollution exposure, including passenger car emissions, may cause substantial respiratory health effects and cancer death. In western countries, the majority of passenger cars are driven by gasoline fuel. Recently, new motor technologies and ethanol fuels have been introduced to the market, but potential health effects have not been thoroughly investigated. We developed and verified a coculture model composed of bronchial epithelial cells (ECs) and natural killer cells (NKs) mimicking the human airways to compare toxic effects between pure gasoline (E0) and ethanol-gasoline-blend (E85, 85% ethanol, 15% gasoline) exhaust emitted from a flexfuel gasoline car. We drove a steady state cycle, exposed ECs for 6h and added NKs. We assessed exhaust effects in ECs alone and in cocultures by RT-PCR, flow cytometry, and oxidative stress assay. We found no toxic effects after exposure to E0 or E85 compared to air controls. Comparison between E0 and E85 exposure showed a weak association for less oxidative DNA damage after E85 exposure compared to E0. Our results indicate that short-term exposure to gasoline exhaust may have no major toxic effects in ECs and NKs and that ethanol as part of fuel for gasoline cars may be favorable.

The real driving emission (RDE) testing for certification of vehicles is performed in conditions that are well defined in legislation. For emissions inventories and for research, the influences of some extended driving conditions on emissions are an interesting issue. In the present work, some examples of RDE results from two common passenger cars with gasoline and diesel propulsion are given. The varying driving conditions were “winter/summer”, “mild/aggressive”, and “higher altitude/slop”. The driving conditions: “winter”, “aggressive”, and “higher slope/altitude” generally require more energy, cause higher fuel consumption, and therefore, higher CO2-emissions. The condition of “winter driving”, especially in the urban type of operation, may cause some longer phases with not enough warmed-up exhaust aftertreatment and consequently some increased gaseous emissions. The DPF eliminates the nanoparticles (PN) independently on the driving conditions. Nevertheless, the DPF regeneration has an influence on the CO2-normality of the trip. The CO2-normality primary tolerance range can also be exceeded with aggressive driving. The elaborated results confirm the usefulness of the existing legal limits for the driving conditions of RDE homologation tests.

The nanoparticles (NP) count concentrations are limited in EU for all Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. For the particle number (PN) of MPI gasoline cars there are still no legal limitations. In the present paper some results of investigations of nanoparticles from five DI and four MPI gasoline cars are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. Moreover, five variants of “vehicle – GPF” were investigated. The PN-emission level of the investigated GDI cars in WLTC without GPF is in the same range of magnitude very near to the actual limit value of 6.0 × 10^12 1/km. With the GPF’s with better filtration quality, it is possible to lower the emissions below the future limit value of 6.0 × 10^11 1/km. The modern MPI vehicles also emit a considerable amount of PN, which in some cases can attain the level of Diesel exhaust gas without DPF and can pass over the actual limit value for GDI (6.0 × 10^12 1/km). The GPF-technology offers in this respect further potentials to reduce the PN-emissions of traffic.

Ethanol can be produced from biomass and as such is renewable, unlike petroleum-based fuel. Almost all gasoline cars can drive with fuel containing 10% ethanol (E10), flex-fuel cars can even use 85% ethanol (E85). Brazil and the USA already include 10–27% ethanol in their standard fuel by law. Most health effect studies on car emissions are however performed with diesel exhausts, and only few data exists for other fuels. In this work we investigated possible toxic effects of exhaust aerosols from ethanol-gasoline blends using a multi-cellular model of the human lung. A flex-fuel passenger car was driven on a chassis dynamometer and fueled with E10, E85, or pure gasoline (E0). Exhausts obtained from a steady state cycle were directly applied for 6 h at a dilution of 1:10 onto a multi-cellular human lung model mimicking the bronchial compartment composed of human bronchial cells (16HBE14o-), supplemented with human monocyte-derived dendritic cells and monocyte-derived macrophages, cultured at the air-liquid interface. Biological endpoints were assessed after 6 h post incubation and included cytotoxicity, pro-inflammation, oxidative stress, and DNA damage. Filtered air was applied to control cells in parallel to the different exhausts; for comparison an exposure to diesel exhaust was also included in the study. No differences were measured for the volatile compounds, i.e. CO, NOx, and T.HC for the different ethanol supplemented exhausts. Average particle number were 6×102 #/cm3 (E0), 1×105 #/cm3 (E10), 3×103 #/cm3 (E85), and 2.8×106 #/cm3 (diesel). In ethanol-gasoline exposure conditions no cytotoxicity and no morphological changes were observed in the lung cell cultures, in addition no oxidative stress - as analyzed with the glutathione assay - was measured. Gene expression analysis also shows no induction in any of the tested genes, including mRNA levels of genes related to oxidative stress and pro-inflammation, as well as indoleamine 2,3-dioxygenase 1 (IDO-1), transcription factor NFE2-related factor 2 (NFE2L2), and NAD(P)H dehydrogenase [quinone] 1 (NQO1). Finally, no DNA damage was observed with the OxyDNA assay. On the other hand, cell death, oxidative stress, as well as an increase in pro-inflammatory cytokines was observed for cells exposed to diesel exhaust, confirming the results of other studies and the applicability of our exposure system. In conclusion, the tested exhausts from a flex-fuel gasoline vehicle using different ethanol-gasoline blends did not induce adverse cell responses in this acute exposure. So far ethanol-gasoline blends can promptly be used, though further studies, e.g. chronic and in vivo studies, are needed.

Bioethanol as an alternative fuel is widely used as a substitute for gasoline and also in gasoline direct injection (GDI) vehicles, which are quickly replacing traditional port-fuel injection (PFI) vehicles. Better fuel efficiency and increased engine power are reported advantages of GDI vehicles. However, increased emissions of soot-like nanoparticles are also associated with GDI technology with yet unknown health impacts. In this study, we compare emissions of a flex-fuel Euro-5 GDI vehicle operated with gasoline (E0) and two ethanol/gasoline blends (E10 and E85) under transient and steady driving conditions and report effects on particle, polycyclic aromatic hydrocarbon (PAH), and alkyl- and nitro-PAH emissions and assess their genotoxic potential. Particle number emissions when operating the vehicle in the hWLTC (hot started worldwide harmonized light-duty vehicle test cycle) with E10 and E85 were lowered by 97 and 96% compared with that of E0. CO emissions dropped by 81 and 87%, while CO2 emissions w...

Ethanol as an engine fuel emits less pollutants than gasoline, is a completely renewable product with good ecological implications, and has the potential to reduce greenhouse gas emissions. However, ethanol–gasoline blends present a multitude of technical challenges to engine operation, including the creation of adverse engine deposits, especially on inlet valves and injector tips. Special detergent–dispersant additives in ethanol–gasoline blends are the most effective way of bypassing these technical challenges. In the present work, two detergent–dispersant additives, developed by the Oil and Gas Institute, National Research Institute, were used and investigated on a flex-fuel direct-injection vehicle with ethanol–gasoline blend fuels containing 10 and 85% ethanol with special consideration of nanoparticle and non-legislated gaseous emissions. These researchers, among others, stated that, at cold start, particle count emissions are significantly reduced with ethanol blend fuels under all operating condit...

In the present paper, the results and experiences of testing different PEMS on the chassis dynamometer and on-road are presented. In the first part of work the measuring systems were installed on the same vehicle (Seat Leon 1.4 TSI ST) and the results were compared on the chassis dynamometer in the standard test cycles: NEDC, WLTC and CADC. In the second part of work the nanoparticle emissions of three Diesel cars were measured with PN-PEMS. PN-PEMS showed an excellent correlations with CPC in the tests on chassis dynamometer and it indicated very well the efficiency of DPF in eliminating the nanoparticles in real world driving.

The fast replacement of traditional gasoline port-fuel injection technology with gasoline direct-injection (GDI) vehicles is expected to have a substantial impact on urban air quality. Herein we report on effects of four prototype gasoline particle filters (GPFs) on exhausts of a 1.6 L Euro-5 GDI vehicle. Two noncoated and two filters with catalytic coatings were investigated. These filters, on average, lowered PN emissions 4–7-fold to 4.0–6.8 × 1011 particles/km. Genotoxic PAHs were lowered 2–5-fold too with GPF-1–3, with GPF-1 having the highest efficiency, 79% and resulting in 45 ng toxic equivalent concentration (TEQ)/km. Thus, particle filtration efficiencies and reduction of the genotoxic potentials are correlated. GPF-4 showing the poorest particle filtration efficiency (66–78%) also released exhausts with highest genotoxic potential of 240–530 ng TEQ/km. We recently reported particle-number (PN) emissions of four generations of GDI vehicles (Euro-3 to Euro-6) which released, on average, 2.5 × 1012...

Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited. The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm2 and 0.39 ± 0.09 μg/cm2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO2). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses. Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of volcanic ash and gasoline vehicle exhaust has a limited short-term biological impact to an advanced lung cell in vitro model.

The present paper informs about some results obtained with selective catalytic reduction (SCR) and with SDPF (a diesel particle filter (DPF) with SCR coating) on a medium duty research engine Iveco F1C. This work is a first attempt at evaluating the effects of a SDPF on non-legislated gaseous emissions and on secondary nanoparticles. Beside the limited gaseous emission components, NH3, NO2, and N2O were measured with FTIR, and the analysis of nanoparticle emissions was performed with Scanning Mobility Particle Sizer (SMPS) and condensation particle counter (CPC). The integration of functions of filtration and NOx reduction in one element of exhaust aftertreatment system offers several advantages and is widely investigated and considered as a market solution. The most important technical statements of the research are as follows: Further developments of those aftertreatment systems, concerning substrates, coatings, and reduction agent control, open further potentials of improvements.

Ultrafine particles (UFP) are major contributors to air pollution due to their easy gas-like penetration into the human organism, causing adverse health effects. This study analyzes UFP emissions by buses of different technologies (from Euro II till Euro V EEV – Enhanced Environmentally-friendly Vehicle) at low-load regimes. Additionally, the emission-reduction potential of retrofitting with a diesel particle filter (DPF) is demonstrated. A comparison of the measured, engine-out, particle number concentrations (PNC) for buses of different technological generations shows that no substantial reduction of engine-out emissions at low-load operating modes is observed for newer bus generations. Retrofitting the in-use urban and interurban buses of Euro II till Euro IV technologies by the VERT-certified DPF confirmed its high efficiency in reduction of UFP emissions. Particle-count filtration efficiency values of the retrofit DPF were found to be extremely high – greater than 99.8%, similar to that of the OEM filter in the Euro V bus.

Nanoparticles from a HD-Diesel engine and their composition were investigated in the present paper. Three variants of fuel additivities were applied to allow the balances of certain tracer-substances after the tests: 2% of additives-free lube oil; 2% of market lube oil with additive package and Fe-based regeneration additive (FBC) with 40 ppm Fe. The analysed SMPS particle size distributions indicated that by blending of the market lube oil to the fuel the combined effects of metals or metal oxides from the additive packages and of the heavy HC’s from the lube oil matrix contribute the most to the increase of nuclei mode. From the masses of Fe, Zn and Ca, which were introduced with the fuel, only parts were found as integral masses at all ELPI-stages – Fe 43.5%, Zn 36.6%, Ca 65.5%. The majority of mass of some metals, or metal oxides emissions on ELPI-stages (up to 80%) is in the size ranges below 100 nm.

Nanoparticle emissions of two 2-stroke scooters were investigated along the exhaust- and CVS-system (Constant Volume Sampling) with closed and with open line (cone). Due to their technology, the scooters produce different kind of aerosol (state of oxidation & SOF-content) and in addition to that they were operated with and without oxidation catalyst. The scooters represent a modern technology with direct injection TSDI* ) (two stroke direct injection) and with carburettor.

The invisible nanoparticles (NP) from combustion processes penetrate easily into the human body through the respiratory and olfactory ways and carry numerous harmful health effects potentials. NP count concentrations are limited in EU for Diesel passenger cars since 2013 and for gasoline cars with direct injection (GDI) since 2014. The limit for GDI was temporary extended to 6 x 1012 #/km. Nuclei of metals as well as organics are suspected to significantly contribute especially to the ultrafine particle size fractions, and thus to the particle number concentration. In the present paper, some results of investigations of nanoparticles from four gasoline cars – an older one with MPI and three never with DI – are represented. The measurements were performed at vehicle tailpipe and in CVS-tunnel. The results show that the older vehicle with MPI emits high particle count concentrations. The size distributions of this vehicle are decisively bimodal with high numbers in nuclei mode. The emissions of the newer vehicles with DI show sometimes no typical uniform shape of particle size distributions and are at lower level, than for the older vehicle. There is no visible nuclei mode and the ultrafine particle concentrations below 10 nm are insignificant. Some of the newer, low-emitting vehicles show at constant speed operation a periodical fluctuation of the NPemissions. Increased NP-emissions at cold start were confirmed.

Gasoline direct injection (GDI) vehicles have recently been identified as a significant source of carbonaceous aerosol, of both primary and secondary origin. Here we investigated primary emissions and secondary organic aerosol (SOA) formation from GDI vehicle exhaust for multiple vehicles and driving test cycles, and novel GDI after-treatment systems. Emissions were characterized by proton transfer reaction time-of-flight mass spectrometry (gaseous non-methane organic compounds, NMOCs), aerosol mass spectrometry (sub-micron non-refractory particles), and light attenuation measurements (equivalent black carbon (eBC) determination using Aethalometer measurements) together with supporting instrumentation. We evaluated the effect of retrofitted prototype gasoline particle filters (GPFs) on primary eBC, organic aerosol (OA), NMOCs, as well as SOA formation. Two regulatory driving test cycles were investigated, and the importance of distinct phases within these cycles (e.g. cold engine start, hot engine start, high speed driving) to primary emissions and secondary products was evaluated. Atmospheric processing was simulated using both the PSI mobile smog chamber (SC) and the potential aerosol mass oxidation flow reactor (OFR). GPF retrofitting was found to greatly decrease primary particulate matter (PM) through removal of eBC, but showed limited partial removal of the minor POA fraction, and had no detectable effect on either NMOC emissions (absolute emission factors or relative composition) or SOA production. In all tests, overall primary and secondary PM and NMOC emissions were dominated by the engine cold start, i.e. before thermal activation of the catalytic after-treatment system. Differences were found in the bulk compositional properties of SOA produced by the OFR and the SC (O : C and H : C ratios), while the SOA yields agree within our uncertainties, with a tendency for lower SOA yields in SC experiments. A few aromatic compounds are found to dominate the NMOC emissions (primarily benzene, toluene, xylene isomers and C3-benzenes). A large fraction (> 0.5) of the SOA production was explained by those compounds, based on investigation of reacted NMOC mass and comparison with SOA yield curves of toluene, o-xylene and 1,2,4-trimethylbenzene determined in our OFR within this study. Remaining differences in the obtained SOA yields may result from diverse reasons including aging conditions, unaccounted-for precursors and differences in SOA yields of aromatic hydrocarbons with different degrees of substitution, as well as experimental uncertainties in the assessment of particle and vapor wall losses.

Adverse effect studies of gasoline exhaust are scarce, even though gasoline direct injection (GDI) vehicles can emit a high number of particles. The aim of this study was to conduct an in vitro hazard assessment of different GDI exhausts using two different cell culture models mimicking the human airway. In addition to gasoline particle filters (GPF), the effects of two lubrication oils with low and high ash content were assessed, since it is known that oils are important contributors to exhaust emissions. Complete exhausts from two gasoline driven cars (GDI1 and GDI2) were applied for 6 h (acute exposure) to a multi-cellular human lung model (16HBE14o-cell line, macrophages, and dendritic cells) and a primary human airway model (MucilAir™). GDI1 vehicle was driven unfiltered and filtered with an uncoated and a coated GPF. GDI2 vehicle was driven under four settings with different fuels: normal unleaded gasoline, 2% high and low ash oil in gasoline, and 2% high ash oil in gasoline with a GPF. GDI1 unfiltered was also used for a repeated exposure (3 times 6 h) to assess possible adverse effects. After 6 h exposure, no genes or proteins for oxidative stress or pro- inflammation were upregulated compared to the filtered air control in both cell systems, neither in GDI1 with GPFs nor in GDI2 with the different fuels. However, the repeated exposure led to a significant increase in HMOX1 and TNFa gene expression in the multi-cellular model, showing the responsiveness of the system towards gasoline engine exhaust upon prolonged exposure. The reduction of particles by GPFs is significant and no adverse effects were observed in vitro during a short-term exposure. On the other hand, more data comparing different lubrication oils and their possible adverse effects are needed. Future experiments also should, as shown here, focus on repeated exposures.

A substantial amount of traffic-related particle emissions is released by gasoline cars, since most diesel cars are now equipped with particle filters that reduce particle emissions. Little is known about adverse health effects of gasoline particles, and particularly, whether a gasoline particle filter (GPF) influences the toxicity of gasoline exhaust emissions. We drove a dynamic test cycle with a gasoline car and studied the effect of a GPF on exhaust composition and airway toxicity. We exposed human bronchial epithelial cells (ECs) for 6 hours, and compared results with and without GPF. Two hours later, primary human natural killer cells (NKs) were added to ECs to form cocultures, while some ECs were grown as monocultures. The following day, cells were analyzed for cytotoxicity, cell surface receptor expression, intracellular markers, oxidative DNA damage, gene expression, and oxidative stress. The particle amount was significantly reduced due to GPF application. While most biological endpoints did not differ, oxidative DNA damage was significantly reduced in EC monocultures exposed to GPF compared to reference exhaust. Our findings indicate that a GPF has beneficial effects on exhaust composition and airway toxicity. Further studies are needed to assess long-term effects, also in other cell types of the lung.

Retrofitting older vehicles with diesel particulate filter (DPF) is a cost-effective measure to quickly and efficiently reduce particulate matter emissions. This study experimentally analyzes real-world performance of buses retrofitted with CRT DPFs. 18 in-use Euro III technology urban and intercity buses were investigated for a period of 12 months. The influence of the DPF and of the vehicle natural aging on buses fuel economy are analyzed and discussed. While the effect of natural deterioration is about 1.2%–1.3%, DPF contribution to fuel economy penalty is found to be 0.6% to 1.8%, depending on the bus type. DPF filtration efficiency is analyzed throughout the study and found to be in average 96% in the size range of 23–560 nm. Four different load and non-load engine operating modes are investigated on their appropriateness for roadworthiness tests. High idle is found to be the most suitable regime for PN diagnostics considering particle number filtration efficiency.

Using bioalcohols as a renewable energy source to substitute a part of fossil energy traffic and increasing the sustainability of individual transportation are important objectives in several countries. The global share of Bioethanol used for transportation is continuously increasing. Ethanol is a biomass-based renewable fuel that can be produced by alcoholic fermentation of sugar beet, sugar can, corn, and wheat (bio-ethanol), although petro-ethanol also exists, i.e., ethanol produced from fossil fuels. In the present tests we performed repeated cold starts performed with all investigated fuels, in two temperature ranges approaching 0ºC and 20ºC and with online measurement of different legislated and non-legislated emission components. The investigated fuel contained ethanol (E), in the portions of 10% and 85% by volume. The investigated vehicle represented a newer state of technology and an emission level of Euro 5. The engine works with homogenous GDI concept and with 3-W-catalyst (3WC). Since there is a special concern about the particle emissions of gasoline cars with direct injection, the nanoparticle counts measurements were systematically performed. The non-legislated gaseous emissions were tested at the tailpipe with FTIR, this with special focus on NH3, HCHO (formaldehyde), and MeCHO (acetaldehyde).

EU directives promoting the measures of biofuels and advanced exhaust aftertreatment systems aim to mitigate global warming and air pollution, respectively; however, in addition to these claimed benefits, what trade-off effects arise from combining these measures? Based on new-vehicle emissions data for EU road-freight transport combining RME biodiesel, selective catalytic reduction (SCR), and diesel particulate filter (DPF), we determine well-to-wheel (WTW), tank-to-wheel (TTW), and well-to-tank (WTT) greenhouse gas (GHG) emissions as well as the regulated emissions of NOx, PM, CO, and NMHC. In comparing results, we draw three conclusions: First, vehicles fuelled by RME biodiesel have reduced WTW GHG emissions and NMHC emissions, but have slight increases in WTW emissions of NOx, PM, and CO. Second, vehicles fitted with SCR and DPF have reduced WTW emissions of NOx, PM, CO, and NMHC, but have slight increases in WTW GHG emissions. Third, we conclude that although the measures are independently successful at achieving their specific goals, their combination decreases some of these benefits. Only through improved testing, assessment methods, and transparency can we fully understand the interrelation of mitigation measures, and apply this understanding to policy aimed at reducing the overall environmental and social impacts of transport.

Metal-containing fuel additives catalyzing soot combustion in diesel particle filters are used in a widespread manner, and with the growing popularity of diesel vehicles, their application is expected to increase in the near future. Detailed investigation into how such additives affect exhaust toxicity is therefore necessary and has to be performed before epidemiological evidence points towards adverse effects of their application. The present study investigates how the addition of an iron-based fuel additive (Satacen®3, 40 ppm Fe) to low-sulfur diesel affects the in vitro cytotoxic, oxidative, (pro-)inflammatory, and mutagenic activity of the exhaust of a passenger car operated under constant, low-load conditions by exposing a three-dimensional model of the human airway epithelium to complete exhaust at the air-liquid interface. We could show that the use of the iron catalyst without and with filter technology has positive as well as negative effects on exhaust toxicity compared to exhaust with no additives: it decreases the oxidative and, compared to a non-catalyzed diesel particle filter, the mutagenic potential of diesel exhaust, but increases (pro-)inflammatory effects. The presence of a diesel particle filter also influences the impact of Satacen®3 on exhaust toxicity, and the proper choice of the filter type to be used is of importance with regards to exhaust toxicity. Figure ᅟ.

The complexity and large variability of transport-emitted aerosols leads to necessity of comprehensive characterization of their physico-chemical and toxicological properties, remaining great uncertainties in health effect assessments. Particles produced by combustion of fossil diesel (B0), 20% rapeseed methyl ester in fossil diesel (B20), and pure rapeseed methyl ester (B100) were sampled from exhaust of an Opel Astra diesel engine using sulfated ash, phosphorous and sulfur (SAPS) lube oil with low and high ash content. Microscopic and chemical characterization is performed to quantify the common and specific properties of diesel/biodiesel exhausts. Hydrophobic saturated aliphatic dominate diesel particle chemistry. Oxygen and nitrogen-containing functionalities are specific for more hydrophilic biodiesel particles. A full range of chemical species for individual particles is grouped by clustering technique combined with water-soluble ion measurements. Analysis of group abundance shows carbonaceous particles (soot externally mixed with inorganic salts) and inorganic fly ash (metal oxides) in a structure of exhaust, in correlation with inorganic contaminations in fuel and lube oil. Quantification of particle types in terms of physicochemical relevance supports the identification of groups which may act as biomicromarkers discriminating between diesel and biofuel exhaust and micromarkers of using high ash lube oil, thus providing a basis for correlative toxicological assessment of diesel/biofuel engine emissions.

This work presents results of particle mass, number and size measurements inside passenger cars (PCs), vans and urban buses. Effects of the in-cabin air purifier on particle concentrations and average size inside a vehicle are studied. Use of the air purifier leads to a dramatic reduction, by 95–99%, in the measured ultrafine particles number concentration inside a vehicle compared with outside readings. Extremely low particle concentrations may be reached without a danger of vehicle occupants' exposure to elevated CO2 levels. The lowest values of particle concentrations inside a PC without air purifier are registered under the recirculation ventilation mode, but the issue of CO2 accumulation limits the use of this mode to very short driving events. Lower PM concentrations are found inside newer cars, if this ventilation mode is used. Great differences by a factor of 2.5–3 in PM10 concentrations are found between the PCs and the buses. Smoking inside a car leads to a dramatic increase, by approximately 90 times, in PM2.5 concentrations.

Polycyclic aromatic hydrocarbons (PAHs) of exhaust emissions were studied in four direct-injection turbocharged four-cylinder diesel engines, with power ratings of 90–136 kW. The engines were operated on biodiesel (B-100), a blend of 30% biodiesel in diesel fuel (B-30), and heated rapeseed oil (RO) in two independent laboratories. Diesel particle filters (DPF) and selective catalytic reduction (SCR) systems were used with B-30 and B-100. Concentrations of individual PAHs sampled in different substrates (quartz, borosilicate fiber and fluorocarbon membrane filters, polyurethane foam) were analyzed using different methods. Benzo[a]pyrene toxic equivalents (BaP TEQ) were calculated using different sets of toxic equivalency factors (TEF). Operation on B-100 without aftertreatment devices, compared to diesel fuel, yielded a mean reduction in PAHs of 73%, consistent across engines and among TEF used. A lower PAH reduction was obtained using B-30. The BaP TEQ reductions on DPF were 91–99% using B-100, for one non-catalyzed DPF, and over 99% in all other cases. The BaP TEQ for heated RO were higher than those for B-100 and one half lower to over twice as high as that of diesel fuel. B-100 and RO samples featured, compared to diesel fuel, a relatively high share of higher molecular weight PAH and a relatively low share of lighter PAHs. Using different sets of TEF or different detection methods did not consistently affect the observed effect of fuels on BaP TEQ. The compilation of multiple tests was helpful for discerning emerging patterns. The collection of milligrams of particulate matter per sample was generally needed for quantification of all individual PAHs.

NO2 is much more toxic than NO. Due to the use of oxidation catalysts and catalytic coatings in the exhaust gas systems in the last decades and due to the use of low sulphur fuels the average NO2-portion in exhaust gases of vehicles increases. Diesel oxidation catalysts (DOC) and Pt-containing DPF-coatings are generally used to support the regeneration of particle filters, which can be a source of strongly increased NO2-production. The present work shows some examples and summarizes the experiences in this matter elaborated at the Laboratories for IC-Engines & Exhaust Emissions Control (AFHB) of the University of Applied Sciences Biel-Bienne, Switzerland, during some research activities on engine dynamometers in the years 2010-2012. In general it can be stated: 1) with a Pt-coated catalyst (DOC), or with catalytic surface filter (CSF) there is a maximum of NO2/ NOx – ratio typically in the exhaust gas temperature range around 350 °C, 2) with higher Pt-content in the coating there is a higher potential for NO2-formation, 3) lower NO2-production appears with: higher spatial velocity, higher S-content in fuel and with DOC/DPF used and/or soot loaded, 4) in some cases of semi active regeneration systems, or with the use of RME conditions with higher NO2-rates can appear.

During the first decade of Diesel particle filter development and deployment in cars, trucks, buses and underground sites, DPF regeneration methods were engineered to be compatible with the then prevalent high sulfur content in the fuel > 2000 ppm. The mainly used methods were burners, electrical heaters, replaceable filters and non-precious metal fuel additives. Low sulfur Diesel fuel became only available from 1996 in Sweden, 1998 in Switzerland, and after 2000 everywhere in Europe. Thus, the deployment of precious metal catalytic converters was feasible both as original equipment and retrofitting of in-use engines. The so-called CRT particle filters using PGM-catalysis for providing NO2 for low temperature regeneration became very successful wherever ULSD was available. However, in many applications, e.g. off-road and in the construction industry, Diesel engines continued to run on high sulfur fuel and in many emerging countries, even on-road Diesel fuel still contains between 1000 and 2000 ppm sulfur. These countries suffer very much from air pollution through increasing Diesel particle emissions and the high impact of black carbon particles on human health as well as on the global warming is worrying. Hence, the necessity for modern particle filters which are compatible with high sulfur content of the fuel. In the context of Chinese megalopolis, this paper reports investigation of a fuel which is typical for China (containing > 1000 ppm sulfur) and compares results with European standard Diesel fuel. The test objects were two modern SiC particle filters, which were regenerated using different iron-based FBC. The combustion attributes of the soot were investigated by TGA and their EC/OC composition was examined. The results indicate that at the given test conditions the fuel sulfur does not significantly change the filters’ physical and chemical properties. Neither the filter particle loading process nor the filter regeneration is noticeably different for the high sulfur test fuel compared to the ultra-low sulfur European fuel. Therefore VERT-verified iron-based FBC-type DPF can be used in countries where ULSD is not yet available.