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Vehicular ammonia emissions are currently unregulated, even though ammonia is harmful for a variety of reasons, and the gas is classed as toxic. Ammonia emissions represent a serious threat to air quality, particularly in urban settings; an ammonia emissions limit may be introduced in future legislation. Production of ammonia within the cylinder has long been known to be very limited. However, having reached its light-off temperature, a three-way catalyst can produce substantial quantities of ammonia through various reaction pathways. Production of ammonia is symptomatic of overly reducing conditions within the three-way catalyst (TWC), and depends somewhat upon the particular precious metals used. Emission is markedly higher during periods where demand for engine power is higher, when the engine will be operating under open-loop conditions.

Due to concern over emissions of greenhouse gases (GHG; particularly carbon dioxide - CO2), energy consumption and sustainability, many jurisdictions now regulate fuel consumption, fuel economy or exhaust emissions of CO2. Testing is carried out under laboratory conditions according to local or regional procedures. However, a harmonized global test procedure with its own test cycle has been created: the World Harmonized Light Vehicles Test Cycle - WLTC. In this paper, the WLTC is compared to the New European Driving Cycle (NEDC) and the FTP-75 cycle used in the USA. A series of emissions tests were conducted at BOSMAL on a chassis dynamometer in a Euro 6-complaint test facility to determine the impact of the test cycle on CO2 emissions and fuel consumption. While there are multiple differences in the test cycles in terms of dynamicity, duration, distance covered, mean/maximum speed, etc, differences in results obtained over the three test cycles were reasonably limited.

This paper evaluates the possibility of using bioethanol blends (mixtures of gasoline fuel and ethanol derived from biomass) of varying strengths in an unmodified, small-displacement European Euro 5 light-duty gasoline vehicle. The influence of different proportions of bioethanol in the fuel blend (E5, E10, E25, E50 and E85) on the emission of gaseous pollutants, such as: carbon monoxide, hydrocarbons, oxides of nitrogen and carbon dioxide was tested at normal (22°C) and low (-7°C) ambient temperatures for a light-duty vehicle during the NEDC cycle on a chassis dynamometer. Engine performance metrics were also tested. All test results are presented in comparison to standard European gasoline (E5). Tailpipe emission data presented here suggest that modest improvements in air quality could result from usage of low-to-mid ethanol blends in the vehicle tested.

The paper evaluates the possibility of using different biodiesel blends (mixture of diesel fuel and Fatty Acid Methyl Esters) in modern Euro 4/ Euro 5 direct-injection, common-rail, turbocharged, light-duty diesel engines. The influence of different quantity of RME in biodiesel blends (B5, B20, B30) on the emission measurement of gaseous pollutants, such as: carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx), carbon dioxide (CO2) and particulate matter (PM) for light-duty-vehicle (LDV) during NEDC cycle on the chassis dynamometer as well as engine performance and reliability in engine dyno tests were analysed. All test results presented have been to standard diesel fuel. The measurement and analysis illustrate the capability of modern light-duty European diesel engines fueled with low and medium percentages of RME in biodiesel fuel with few problems.

The aim of this paper is to analyse the results of regulated and unregulated emissions and carbon dioxide (CO2) emissions of passenger cars equipped with compression-ignition engines that meet the emission Euro 6d standards. Both test vehicles featured selective catalytic reduction (SCR) systems for control of oxides of nitrogen (NOx) and one vehicle also featured a passive NOx absorber (PNA). Research was performed using the current European Union exhaust emission test methods for passenger cars (Worldwide harmonized Light vehicles Test Procedures (WLTP)). Emission testing was performed on a chassis dynamometer, within a climatic chamber, at two different ambient temperatures: 23°C (i.e. Type I test) and -7°C (known as a Type VI test - currently not required for this engine type according to EU legislative requirements).

Ammonia is a reactive nitrogen compound (RNC - nitrogen-based gaseous molecules with multiple adverse impacts on human health and the biosphere). A three-way catalyst can produce substantial quantities of ammonia through various reaction pathways. This study presents a brief literature review, and presents experimental data on ammonia emissions from seven Euro 5 passenger cars, using different gasoline fuels and a CNG fuel. All vehicles were tested on a chassis dynamometer over the New European Driving Cycle. For six of the vehicles, ammonia was quantified directly at tailpipe (using two different analyzers); emissions from one vehicle were subjected to Fourier Transform Infra-Red (FTIR) analysis. Emissions of ammonia from these vehicles were generally low in comparison to other chassis dynamometer studies, perhaps attributable to the favorable laboratory test conditions and the age of the vehicles.

An increased of carbon monoxide and hydrocarbons emissions from gasoline engines in ambient temperatures at or below 0°C is a key issue, not only in Scandinavia or northern parts of the USA and Canada, but also in countries of Central and Eastern Europe. It is typical of Poland and neighbouring countries that for six to seven months (from October to April) air temperature fails to about 0°C at night, while in winter months this temperature often fails below -10 to even -20°C. Due to this, in these countries the cars are started in the morning when the engine and all other parts of the car are considerably cool. This paper presents a special climatic conditions in view of their effect on the actual exhaust emission from a car with SI engine and results of emission tests for such gaseous pollutants as CO, HC and NOx, achieved during tests performed on a chassis dynamometer according to ECE and FTP 75 cycles.

This paper discusses the legislative situation regarding type approval of plug-in hybrid vehicles (also known as off-vehicle charging hybrid-electric vehicles, OVC-HEV) in the range of exhaust emissions and fuel consumption. A range of tests were conducted on two Euro 6d-complaint OVC-HEVs to quantify emissions. Procedures were based on EU legislative requirements. For laboratory (chassis dyno) testing, two different test cycles and three different ambient temperatures were used for testing. Furthermore, in some cases additional measurements were performed, including measurement of emissions of particulate matter and continuous analysis of regulated and unregulated pollutants in undiluted exhaust. Consumption of electrical energy was also monitored. On-road testing was conducted on the test vehicle tested on the chassis dyno in the tests mentioned above, as well as on a second OVC-HEV test vehicle.

This paper reviews the emissions from direct injection (DI) diesel engine in the initial period of controlled engine operation following start-up. The tests were undertaken in „cold start” mode (temperature of cooling water and lube oil equal to ambient temperature) and „warm start” mode* (after attaining a state of equilibrium). Both results were compared.

Particle number (PN) emission limits were introduced in the European Union’s regulations for light-duty and heavy duty vehicles in the years 2011-2014. Since then, PN measurements have become a common practice in the automotive sector. Many studies showed that the current methodology, which counts particles >23 nm, misses a large fraction of particles for some engine technologies, such as port fuel injection vehicles or vehicles fueled with compressed natural gas (CNG). However, data for the latest technology vehicles are lacking. For this reason, we measured PN emissions >23 nm and >10 nm of >30 CNG, gasoline and diesel-fueled vehicles. Two systems were measuring in parallel from the full dilution tunnel; one with an evaporation tube and the other with a catalytic stripper. The PN emission levels spanned over three orders of magnitude depending on whether there was a particulate filter installed or not.

European Union RDE (real driving emissions) legislation requires that new vehicles be subjected to emissions tests on public roads. Performing emissions testing outside a laboratory setting immediately raises the question of the impact of ambient conditions - especially temperature - on the results. In the spirit of RDE legislation, a wide range of ambient temperatures are permissible, with mathematical moderation (correction) of the results only permissible for ambient temperatures <0°C and >+30°C. Within the standard range of temperatures (0°C to +30°C), no correction for temperature is applied to emissions results and the applicable emissions limits have to be met. Given the well-known link between the thermal state of an engine and its emissions following cold start, ambient temperature can be of great importance in determining whether a vehicle meets emissions requirements during an RDE test.

Ethanol has a long history as an automotive fuel and is currently used in various blends and formats as a fuel for spark ignition engines in many areas of the world. The addition of ethanol to petrol has been shown to reduce certain types of emissions, but increase others. This paper presents the results of a detailed experimental program carried out under standard laboratory conditions to determine the influence of different quantities of petrol-ethanol blends (E5, E10, E25, E50 and E85) on the emission of regulated and unregulated gaseous pollutants and particulate matter. The ethanol-petrol blends were laboratory tested in two European passenger cars on a chassis dynamometer over the New European Driving Cycle, using a constant volume sampler and analyzers for quantification of both regulated and unregulated emissions.

The use of biofuels (biodiesel and gasoline-alcohol blends) in vehicle powertrains has grown in recent years in European Union, the United States, Japan, India, Brazil and many other countries due to limited fossil fuel sources and necessary reduction of anthropogenic CO2 emissions. European car manufacturers have approved up to 5 percent of biodiesel blend in diesel fuel (B5 biodiesel blend) which meets European fuel standards EN 14214 and EN 590. The goal for research is to achieve higher biodiesel content in diesel fuel B10 and B20, without resorting to larger diesel engines and fuel feed system modernization. This paper evaluates the possibility of using higher FAME content in biodiesel blends (mixture of diesel fuel and Fatty Acid Methyl Esters) in modern Euro 4 vehicle with direct-injection, common-rail and turbocharged light-duty diesel engine with standard engine ECU calibration and standard injection equipment (not tuned for biodiesel).

Due to limited fossil fuel resources and a need to reduce anthropogenic CO₂ emissions, biofuel usage is increasing in multiple markets. Ethanol produced from the fermentation of biomass has been of interest as a potential partial replacement for petroleum for some time; for spark-ignition engines, bioethanol is the alternative fuel which is currently of greatest interest. At present, the international market for ethanol fuel consists of E85 fuel (with 85 percent ethanol content), as well as lower concentrations of ethanol in petrol for use in standard vehicles (E5, E10). The impact of different petrol-ethanol blends on exhaust emissions from unmodified vehicles remains under investigation. The potential for reduced exhaust emissions, improved security of fuel supply and more sustainable fuel production makes work on the production and usage of ethanol and its blends an increasingly important research topic.

Exhaust gas aftertreatment systems can, under certain conditions, create undesired chemical species as a result of their elimination reactions. A prime example of this is ammonia (NH3), which is not formed in the combustion reaction, but which can be formed within a three-way catalyst (TWC) when physicochemical conditions permit. The elimination of NOx in the TWC thus sometimes comes at the cost of significant emissions of NH3. Ammonia is a pollutant and a reactive nitrogen compound (RNC) and NH3 emissions should be analyzed in this context, alongside other RNC species. Examination of the literature on the subject published over the past two decades shows that ammonia, a species which is currently not subject to systematic emissions requirements for road vehicles in any market, is often identified as forming the majority of the RNC emissions under a range of operating conditions.

Ethanol has long been a fuel of considerable interest for use as an automotive fuel in spark ignition (SI) internal combustion engines. In recent years, concerns over oil supplies, sustainability and geopolitical factors have lead multiple jurisdictions to mandate the blending of ethanol into standard gasoline. The impact of blend ethanol content on gaseous emissions has been widely studied; particulate matter emissions have received somewhat less attention, despite these emissions being regulated in the USA. Currently, in the EU particulate matter emissions from SI engines are partially regulated - only vehicles featuring direct injection SI engines are subject to emissions limits. A range of experiments was conducted to determine the impact of fuel ethanol content on the emissions of solid pollutants from Euro 5 passenger cars.

The selective catalytic reduction (SCR) of nitrogen oxides by ammonia is commonly applied as a method of exhaust aftertreatment for lean burn compression ignition (CI) engines. The catalytic reactor of an SCR system, like all catalytic emission control devices, is susceptible to partial deactivation as its operating time progresses. Long-term exposure of an SCR reactor to exhaust gas of fluctuating temperature and composition results in variations of the characteristics of its catalytically active layer. The aim of this study was to observe and investigate the variation of parameters characterizing the SCR reactor as a result of its ageing. Attention was paid to changes in ammonia storage capacity, selectivity of chemical reactions and maximum achievable NOx conversion efficiency. The experimental setup was a heavy duty (HD) Euro VI-compliant engine and its aftertreatment system (ATS). The setup was installed on a transient engine dyno instrumented with emission measurement devices.