Exhaust Particulate Emissions Research Articles

Vehicle related non exhaust particle emissions – Euro 7 requirements

Vehicle related non exhaust particle emissions – Euro 7 requirements

Reducing Tyre Wear Emissions of Automated Articulated Vehicles through Trajectory Planning.

Effective emission control technologies and eco-friendly propulsion systems have been developed to decrease exhaust particle emissions. However, more work must be conducted on non-exhaust traffic-related sources such as tyre wear. The advent of automated vehicles (AVs) enables researchers and automotive manufacturers to consider ways to further decrease tyre wear, as vehicles will be controlled by the system rather than by the driver. In this direction, this work presents the formulation of an optimal control problem for the trajectory optimisation of automated articulated vehicles for tyre wear minimisation. The optimum velocity profile is sought for a predefined road path from a specific starting point to a final one to minimise tyre wear in fixed time cases. Specific boundaries and constraints are applied to the problem to ensure the vehicle's stability and the feasibility of the solution. According to the results, a small increase in the journey time leads to a significant decrease in the mass loss due to tyre wear. The employment of articulated vehicles with low powertrain capabilities leads to greater tyre wear, while excessive increases in powertrain capabilities are not required. The conclusions pave the way for AV researchers and manufacturers to consider tyre wear in their control modules and come closer to the zero-emission goal.

Active and Semiactive Suspension Systems for Minimizing Tire Wear in Articulated Vehicles

ABSTRACT Electric and hybrid propulsion systems for articulated vehicles have been gaining increased attention, with the aim to decrease exhaust particle emissions. However, the more environmentally-friendly electric or hybrid articulated vehicles are expected to have increased nonexhaust pollution-related sources because of their significantly increased mass compared with conventional vehicles. One of the main sources of nonexhaust pollution is tire wear, which could potentially cancel the benefits of removing the exhaust through electrification. Tire wear is mainly affected by internal (tire structure and shape) and external (suspension configuration, speed, road surface, etc.) factors. This work focuses on suspension systems and, more specifically, on the ability of active and semiactive suspensions to decrease tire wear in an articulated vehicle. In this direction, an articulated vehicle model that incorporates the tread in its modeling is built to study tire wear during cornering over a class C road. A novel active suspension design based on the H approach is suggested in this work and is compared with passive, semiactive, and other active suspension systems. The suspension systems are also compared mainly with regard to tire wear levels but also with other vehicle performance aspects (i.e., comfort and road holding). The H∞ active suspension design is the most effective in decreasing tire wear, with decreases of about 8% to 11%, but without neglecting the rest of the objectives.

An experimental study of the performance of a CI engine using ethanol as a fuel stabilizer

Ethanol is a promising alternative fuel owing to its renewable bio-based origin and lower carbon content, as well as its ability to significantly reduce particle emissions in diesel engines. To evaluate the particulate matter emissions and performance of ethanol-diesel blends, researchers conducted experiments using mineral blends of 5% and 10% ethanol with 95% and 90% diesel fuel, respectively, as well as biodiesel blends with 25% biodiesel and 75% diesel fuel, and 100% diesel as a baseline. These blends were tested in a CI engine with a constant RPM of 1350 and variable loads from 0.0 to 1.6 at intervals of 0.2 kg-m. The study found that biodiesel blends reduced exhaust particulate emissions compared to diesel fuel, while the brake specific fuel consumption decreased with increasing brake power, and the brake thermal efficiency increased as brake power increased. The sound pressure level was measured from different locations of the engine, and the results indicated that increasing the percentage of biodiesel led to a decrease in the sound pressure level. Overall, the study concluded that ethanol-blend fuel improved both brake and engine thermal efficiency while reducing particulate matter emissions. The engine experiments evaluated engine brake torque, braking power, brake specific fuel consumption, brake thermal efficiency, and particulate matter emissions under a variable load and a constant engine speed.

Experimental investigation of the effect of fuel oil, graphene and HHO gas addition to diesel fuel on engine performance and exhaust emissions in a diesel engine

Today, research for alternative fuels continues due to the increasing energy demand, exhaust emission restrictions, and depletion of fossil fuels. It is important to use diesel engines for the opening of new oil fields in Turkey and for the utilization of fuel oil to be produced in these oil fields. In this study, pure diesel (D) diesel 60% and fuel oil 40% (DF40) were supplied by volume with an ultrasonic mixer. 50 (DF4050 N) and 100 ppm (DF40100 N) graphene have been added to eliminate fuel oil's adverse combustion effects by keeping the fuel oil constant. In addition, HHO gas was added to improve the combustion even more with a flow rate of 5 (DF4050N5H and DF40100N5H) and 10 (DF4050N10H and DF40100N10H) lt/min into the intake manifold by using the HHO generator. Experiments were carried out at 3000 RPM constant speed at 3.2, 6.4, 7.9, and 12.8 Nm engine torque without any modification on the diesel engine. The effects of these mixtures on combustion performance and exhaust emissions were investigated. Exhaust gas temperature and emissions were measured in the experiments. According to the measurements, thermal efficiency, brake specific energy consumption (BSEC), HC, CO, CO2, particle emission, and NOx emission values are given. Brake specific energy consumption (BSEC), CO, HC, and particle emissions decreased, and thermal efficiency, NOx, CO2, and exhaust gas temperature increased with the engine torque value increased as a result of the experiments. Thermal efficiency and CO2 emission decreased, and BSEC, exhaust gas temperature, HC, CO, NOx, and particulate emissions increased by adding fuel oil to diesel fuel. The thermal efficiency was increased by adding graphene and HHO gas from the intake manifold to DF40 fuel. The thermal efficiency improved, and emissions decreased with the more addition of graphene and HHO gas. Adding HHO gas improved thermal efficiency significantly at the 12.8 Nm engine load. With the addition of graphene and HHO gas to DF40 fuel, the BSEC value was improved at high torque values. The effect of improving thermal efficiency is also understood from the decrease in CO emissions and the increase in CO2 emissions. HC and PM emissions decreased with the addition of graphene and HHO gas. It was observed that NOx and exhaust gas temperature increased with increasing thermal efficiency.

Study on CO emission during DOC assisted DPF regeneration

Diesel particulate filters is the most effective post-treatment device used to reduce diesel exhaust particulate emissions. As the amount of particulate matter captured in the diesel particulate filter continues to increase, the exhaust pressure of the diesel engine gradually increases, thereby affecting the power performance of the diesel engine. Therefore, when the particulate matter capture amount reaches a certain value, the diesel particulate matter filter needs to be regenerated. Regeneration of diesel particulate filters will produce secondary pollution, of which CO is one of the most important secondary pollution. In this paper, the CO generation mechanism and influencing factors in the regeneration process of diesel particulate filters are analyzed. The effects of exhaust pressure and exhaust flow on CO emission during regeneration are measured through experiments. The results show that when the exhaust back pressure is greater than 80kPa, the CO solubility in the exhaust gas increases rapidly, and decreases linearly with the increase of exhaust flow during regeneration. Therefore, in order to reduce the solubility of CO in tail gas during regeneration of diesel particulate filters, the exhaust back pressure shall be less than 80kPa and the exhaust flow shall be as high as possible.

Particle number, mass, and black carbon emissions from fuel-operated auxiliary heaters in real vehicle use

Fuel-operated auxiliary heaters (AHs) are frequent solutions to heat the vehicle engines and cabins in cold areas. Particulate exhaust emissions of AHs are unregulated; therefore, their contribution to local air quality and thus human health and even the global emissions budget is unknown. Experiments for studying the AH-originated emissions were performed under Finnish winter conditions mimicking real-world use for six selected vehicles with original AHs installed, including both gasoline- and diesel-powered heaters. We present quantitative results of particle number emissions down to 1.3 nm, particle size distributions, particulate mass, and black carbon, and compare to gaseous emissions. The start-up and shutdown phases showed the highest particle peaks, while the particle concentrations were stable between these. The mean particle number, mass and BC emission factors were found to be as high as 590×10 12 kg fuel −1 , 33 mg kg fuel −1 and mg 18 kg fuel −1 for gasoline-operated heaters and 560×10 12 kg fuel −1 , 20 mg kg fuel −1 and 12 mg kg fuel −1 for diesel-operated heaters. Comparing total number of particles larger than 23 nm emitted during vehicle preheating with AH to vehicle tailpipe emissions during drive shows that a typical heating cycle emits an equal number of particles to drive dozens or even thousands of kilometers. • Emissions from auxiliary vehicle heaters were measured under sub-zero conditions. • Auxiliary heaters can be noteworthy sources of particle emissions from vehicles. • Gasoline heaters produced mostly higher emissions than diesel heaters. • Pre-heating particle emissions were comparable to driving of notably long routes.

Rational design of hierarchically micrometer scaled macro-mesoporous ceria-zirconia composites for enhancing diesel soot catalytic combustion performance

Diesel soot particulate is the primary source of urban atmospheric fine particulate matters (PM2.5), catalytic soot elimination on diesel participate filter is invariably an important yet challenging subject, because of the inherently poor solid-solid contact of soot-catalyst. In this study, we report a hierarchically porous ceria-zirconia composite with micrometer scaled macroporous structure, CZ-8, for enhancing catalyst-soot contact efficiency and soot catalytic combustion performance. Scanning electron microscope (SEM), N2 adsorption-desorption and mercury porosimetry results demonstrate that the CZ-8 catalyst has definite micrometer scaled macroporous (0.5–5.0 μm) and interconnected mesoporous (∼20 nm) structure. Raman and X-ray diffraction (XRD) results show that the dominant crystal structure of the CZ-8 is cubic fluorite and the relatively larger crystalline grain contribute to the macroporous structure construction. The filamentous diesel soot particulate (hundreds nanometers or even several micrometers) is difficult to enter the pores of the conventional mesoporous ceria-zirconia catalysts. Nonetheless, it can enter the micrometer scaled pores of the CZ-8 and hence improve the soot-catalyst contact efficiency, and oxygen can efficiently contact with soot-catalyst through the mesopores. Accordingly, the CZ-8 catalyst displays a significantly lower light-off temperature and better soot catalytic combustion performance under loose and tight contact conditions. Thus, this work suggests that enhancing solid(soot)-solid(catalyst)-gas(oxygen) contact efficiency by hierarchically porous structure with micrometer scaled macropores of catalyst is a promising new pathway for improving soot catalytic combustion performance and controlling diesel exhaust particulate emissions.

Production of biodiesel and analysis of exhaust particulate emissions and metal concentration of lubricant oil of the compression ignition engine

In this research, biodiesel fuel is produced using potassium hydroxide (KOH) as a catalyst and methanol as a co-solvent through the transesterification process. The analysis of particulate matter emissions from a compression ignition (CI) engine with pure diesel fuel (D100), biodiesel-mixed (B30), and clove oil (CL3000 ppm) was carried out. The findings obtained revealed 5.27% reduction of particulate matter in biodiesel-blended fuel, and furthermore, when clove was added to the biodiesel-blended fuel, 11.61% reduction of particulate matter was observed as compared to pure diesel. It may be due to the higher oxygen ratio present in clove oil. The engine was run for 100 h on each fuel sample, and the data were taken and tested per 25 h for elemental analysis. The results manifest that the metal concentration found different elements in lubricant oil, i.e., lead (51.84), (24.89%), and (23.255%); copper (47.41%), (28.71%), and (23.86%); nickel (37.88%), (32.32), and (29.78%); and cadmium (46.12), (29.87%), and (24.01%) in diesel, biodiesel-blended fuel, and biodiesel blended with clove oil, respectively. This study found better results for engine life, which shows the lower metal concentration in biodiesel-blended fuel and clove oil than diesel. Furthermore, the fuels investigated in this research can reduce the wear of engine parts because biodiesel and clove oil contain a high oxygen ratio. Moreover, it has been found that biodiesel and clove oil as an antioxidant have a positive impact on noise emission levels for the CI engine.

Analysis of Particulate Matter Emissions and Performance of the Compression Ignition Engine Using Biodiesel Blended Fuel

As the world becomes more urbanized, the market for petroleum products increases. The supply of crude oil-based products such as diesel, gasoline, and natural gas is limited. Furthermore, natural resources are finite and their reservoirs are located in certain parts of the globe. Countries with low to no fossil fuel resources are experiencing a scarcity of petroleum products, necessitating the exploration of alternative energy resources. In this research, tests regarding the exhaust particulate emission, sound pressure level, and performance have been carried out using samples from diesel and biodiesel (waste cooking oil) blended fuel. Two fuel samples have been used, B25 (biodiesel 25% and 75% diesel) and 100% diesel as a baseline in a CI engine at constant RPM of 1350 and variable loads of 0.0 to 1.6 at an interval of 0.2Kg-m. The results show that particulate emissions are reduced by about 7.29% when using biodiesel blended fuel, whereas brake-specific fuel consumption of biodiesel blended fuel has decreased as brake power increased, and brake thermal efficiency increased as brake power increased. The sound pressure level was measured from different locations of the engine (back, front, left) and for varying load. The results show that B25 produces less noise than D100 in each case.

Comprehensive analysis of particle emissions from both exhaust and non-exhaust sources: a methodological approach

Particle emissions from engines have long been topic of research studies because of their detrimental impact on human health and environment. Light duty vehicles represent the main contributor of particles in the congested urban areas and in the next future thought there will be a drastic reduction of fossil fuels, an increasing of the electric vehicles and an improvement of battery technology, a good control of exhaust particle emissions must be yet guaranteed using accurate and effective measurements for their characterization.

Diesel exhaust particulate emissions and in vitro toxicity from Euro 3 and Euro 6 vehicles

Incomplete combustion processes in diesel engines produce particulate matter (PM) that significantly contributes to air pollution. Currently, there remains a knowledge gap in relation to the physical and chemical characteristics and also the biological reactivity of the PM emitted from old- and new-generation diesel vehicles. In this study, the emissions from a Euro 3 diesel vehicle were compared to those from a Euro 6 car during the regeneration of a diesel particulate filter (DPF). Different driving cycles were used to collect two types of diesel exhaust particles (DEPs). The particle size distribution was monitored using an engine exhaust particle sizer spectrometer and an electrical low-pressure impactor. Although the Euro 6 vehicle emitted particulates only during DPF regeneration that primarily occurs for a few minutes at high speeds, such emissions are characterized by a higher number of ultrafine particles (<0.1 μm) compared to those from the Euro 3 diesel vehicle. The emitted particles possess different characteristics. For example, Euro 6 DEPs exhibit a lower PAH content than do Euro 3 samples; however, they are enriched in metals that were poorly detected or undetected in Euro 3 emissions. The biological effects of the two DEPs were investigated in human bronchial BEAS-2B cells exposed to 50 μg/mL of PM (corresponding to 5.2 μg/cm2), and the results revealed that Euro 3 DEPs activated the typical inflammatory and pro-carcinogenic pathways induced by combustion-derived particles, while Euro 6 DEPs were less effective in regard to activating such biological responses. Although further investigations are required, it is evident that the different in vitro effects elicited by Euro 3 and Euro 6 DEPs can be correlated with the variable chemical compositions (metals and PAHs) of the emitted particles that play a pivotal role in the inflammatory and carcinogenic potential of airborne PM.

Influence of ethanol blending ratios on in-cylinder soot processes and particulate matter emissions in an optical direct injection spark ignition engine

Soot volume fraction distribution of ethanol blended fuels (ethanol volume fraction 0%, 20%, 40% and 60%, named as E0, E20, E40 and E60) were measured in an optical direct injection spark ignition (DISI) engine by combined laser induced incandescence (LII) and two-color (2C) method. Exhaust particulate matter (PM) emissions were measured by a Combustion DMS500 Fast Particulate Analyzer. For DISI engines, pool fire and the resulting diffusion flame are the main sources of soot in the cylinder. Choosing a suitable measurement plane and detection time, laser induced incandescent can be used to quantitatively measure the soot concentration produced by the pool fire. This research explores the effect of ethanol blending on engine particulate matter by comprehensively analyzing the soot process in the cylinder and exhaust particulate emissions. According to the two-dimensional quantitative soot volume fraction results, the maximum average soot volume fraction of the same fuel on the 10 mm plane is greater than the 5 mm plane; on the same plane, E20 shows the highest soot concentration compared to the other fuel blends which could be the physical properties of the ethanol become apparent. For exhaust particle emissions, ethanol can significantly reduce the total particle number and accumulation mode particle number. E0, E40 and E60 show fairly similar behavior between the exhaust particle emissions and the soot-LII imaging measurements. For E20, however, this is in poor agreement when comparing the soot-LII imaging results to the results of exhaust particle emission measurements.

Comparative analysis of non-exhaust airborne particles from electric and internal combustion engine vehicles

This paper evaluates the effect of the electrification of the small, medium, and large internal combustion engine (ICE) passenger cars on the levels of total particulate matter (PM). The total mean PM10 and PM2.5 emission factors (EFs) on urban, rural, and motorway roads are in the range of 26.13 − 39.57 mg km−1 veh−1 and 13.39 − 18.44 mg km−1 veh−1, respectively, from small to large ICE passenger cars. Correspondingly, the total mean PM10 and PM2.5 non-exhaust EFs on urban, rural, and motorway roads range from 27.76 to 43.43 mg km−1 veh−1 and 13.17 –19.24 mg km−1 veh−1 from equivalent small to large electric vehicles (EVs) without regenerative braking. These results show that the total non-exhaust PM from the equivalent EVs may exceed all PM from ICE passenger cars, including exhaust particle emissions, which are dependent mainly on the extent of regenerative braking, followed by passenger car type and road type. PM10 EFs for equivalent EVs without regenerative braking on urban, rural, and motorway roads are all higher than those from ICE cars. As for PM2.5, most of the equivalent EVs require different extents of regenerative braking to reduce brake emissions to be in line with all particle emissions from relative ICE cars.

Multi-Objective Optimisation of Tyre and Suspension Parameters during Cornering for Different Road Roughness Profiles

Effective emission control technologies and novel propulsion systems have been developed for road vehicles, decreasing exhaust particle emissions. However, work has to be done on non-exhaust traffic related sources such as tyre–road interaction and tyre wear. Given that both are inevitable in road vehicles, efforts for assessing and minimising tyre wear should be considered. The amount of tyre wear is because of internal (tyre structure, manufacturing, etc.) and external (suspension configuration, speed, road surface, etc.) factors. In this work, the emphasis is on the optimisation of such parameters for minimising tyre wear, but also enhancing occupant’s comfort and improving vehicle handling. In addition to the search for the optimum parameters, the optimisation is also used as a tool to identify and highlight potential trade-offs between the objectives and the various design parameters. Hence, initially, the tyre design (based on some chosen tyre parameters) is optimised with regards to the above-mentioned objectives, for a vehicle while cornering over both Class A and B road roughness profiles. Afterwards, an optimal solution is sought between the Pareto alternatives provided by the two road cases, in order for the tyre wear levels to be less affected under different road profiles. Therefore, it is required that the tyre parameters are as close possible and that they provide similar tyre wear in both road cases. Then, the identified tyre design is adopted and the optimum suspension design is sought for the two road cases for both passive and semi-active suspension types. From the results, significant conclusions regarding how tyre wear behaves with regards to passenger comfort and vehicle handling are extracted, while the results illustrate where the optimum suspension and tyre parameters have converged trying to compromise among the above objectives under different road types and how suspension types, passive and semi-active, could compromise among all of them more optimally.

Influences of alternative diesel fuels on tailpipe emissions and particulate matter under the highway fuel economy test cycle

Diesel engine vehicles are widely used worldwide in community and goods transport sectors due to their engine’s high efficiency and durability. Despite continuous improvements in various aspects, the combustion of compression ignition in conventional diesel engine is yet an important source of pollution and particulate matter that causes issues to human health and the environment. The objective of this research work is to study the use of conventional diesel (B7), biodiesel (B10) and premium diesel (DHi) fuels that affects to the release of exhaust gas and particulate matter emissions from tailpipes during a Highway Fuel Economy Test (HWFET) cycle. The experimental results have shown that the combustion of B7 and B10 reduced particulate matter by 0.38% and 51.0%, reduced total unburned hydrocarbon by 25.3% and 28.3%, reduced carbon monoxide by 43.3% and 64.0%, and reduced nitric oxide by 6.0% and 16.5%, respectively compared to DHi baseline on mass basis. The vehicle running on B10 releases a higher particle concentration with a smaller size compared to DHi.

A Comparative Study of Biofuels and Fischer–Tropsch Diesel Blends on the Engine Combustion Performance for Reducing Exhaust Gaseous and Particulate Emissions

The worldwide consumption of fossil hydrocarbons in the road transport sector in 2020 corresponded to roughly half of the overall consumption. However, biofuels have been discreetly contributing to mitigate gaseous emissions and participating in sustainable development, and thus leading to the extending of the commercial utilization of internal combustion engines. In this scenario, the present work aims at exploring the effects of alternative fuels containing a blend of 15% ethanol and 35% biodiesel with a 50% fossil diesel (E15D50B35) or 50% Fischer–Tropsch (F-T) diesel (E15FTD50B35) on the engine combustion, exhaust emissions (CO, HC, and NOx), particulate emissions characteristics as well as the performance of an aftertreatment system of a common rail diesel engine. It was found that one of the blends (E15FTD50B35) showed more than 30% reduction in PM concentration number, more than 25% reduction in mean particle size, and more than 85% reduction in total PM mass with respect to conventional diesel fuel. Additionally, it was found that the E15FTD50B35 blend reduces gaseous emissions of total hydrocarbons (THC) by more than 25% and NO by 3.8%. The oxidation catalyst was effective in carbonaceous emissions reduction, despite the catalyst light-off being slightly delayed in comparison to diesel fuel blends.

Fuel Economy and Emissions of E85 in Passenger Cars - A Move towards Flex Fuel Vehicle

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Many countries are developing strategies to curb the consumption of fossil fuels, and to increase the share of alternative fuels such as alcohols, natural gas, fuel cell and electricity in the energy pool in order to improve energy security and reduce atmospheric pollution. Alcohol fuels are promising one and it has been widely used in many countries as blending component for gasoline. Ethanol has a high-octane number but it has a lower calorific value than gasoline. The performance of engine may be affected with higher percentage of ethanol in gasoline due to demand for larger quantity of fuel that could not be supplied by vehicles which are tuned to run on gasoline only. In this study, a second electronic control unit (ECU) was installed in series with the existing commercial or primary ECU and an ethanol sensor was installed in the fuel line. This secondary ECU modulates the fuel injection pulse width of the primary ECU depending on ethanol concentration in the fuel. The vehicle studies were carried out using Indian automotive gasoline meeting IS:2796 specification and 85% ethanol blended gasoline (E85) in a climatically controlled chassis dynamometer lab in which test cell temperature maintained at 25±1 °C throughout the test. Modified Indian Driving Cycle tests (MIDC) and constant speed tests were carried out using E85 and commercial gasoline to investigate the fuel economy, gaseous mass emissions, particulate emission in terms number and size characteristics. Gaseous emission was reduced up to 30% with the penalty of reduction in fuel economy by approximately 30% over the MIDC. The vehicle power was maintained while using both fuels at respective constant speeds during the road load simulation cycles however an increase in fuel consumption was observed with E85. The tailpipe exhaust particle emission measurement had shown up to 50% reduction in exhaust particulate emissions with E85. This study demonstrates the potential of using higher blends of ethanol up to E85 and meeting power or speed demand at constant speeds and driving cycle tests.&lt;/div&gt;&lt;/div&gt;

Sooting propensity dependence on pressure of ethylbenzene, p-xylene, o-xylene and n-octane in laminar diffusion flames

Alkylbenzenes constitute a significant portion of middle-distillate transportation fuels, and they are judged as the key contributors to the extent of soot production and consequent exhaust particulate emissions in combustion engines. Because of the uncertainties involved in engine experiments due to boundary condition variation among test platforms and the difficulties involved in controlling engine variables independently, benchmark information on pressure dependence of sooting propensities of alkylbenzenes is essential to understand their influence on particulate emissions and provide a more consistent interpretation of engine data. One of the approaches to acquire such benchmark data is to investigate laminar diffusion flames doped with alkylbenzenes under tractable conditions at elevated pressures. Here, we study the influence of doping a methane laminar diffusion flame with alkylbenzenes having eight carbon atoms, namely ethylbenzene, p-xylene, and o-xylene and compare their sooting characteristics to that of n-octane at pressures up to 10 bar. Liquid hydrocarbons added to methane replaced 3% of the carbon in the base fuel keeping the carbon mass flow in the fuel stream fixed, at all pressures considered, to have tractable measurements. The flames of base fuel methane and those doped with liquid C8 hydrocarbons were stabilized on a laminar co-flow diffusion burner positioned inside a combustion chamber capable of elevated pressures and has suitable optical access. Radially resolved temperatures and soot volume fractions were evaluated from spectral emission of soot radiation from the flames. Soot yields, inferred from the radial distributions of soot volume fractions, of ethylbenzene, p-xylene, and o-xylene doped flames were found to be a factor of about 2.6–3.2 higher than that of n-octane at 2 bar; however, this difference gradually disappeared with increasing pressure and soot yields were almost the same above 6 bar. It appears that pressure dependence of sooting propensities of ethylbenzene, p-xylene, and o-xylene is weaker than that of n-octane within the pressure range of 2 to 10 bar.

Alcohol Fuels for Spark-Ignition Engines: Performance, Efficiency, and Emission Effects at Mid to High Blend Rates for Ternary Mixtures

This paper follows on from an earlier publication on high-blend-rate binary gasoline-alcohol mixtures and reports results for some equivalent ternary fuels from several investigation streams. In the present work, new findings are presented for high-load operation in a dedicated boosted multi-cylinder engine test facility, for operation in modified production engines, for knock performance in a single-cylinder test engine, and for exhaust particulate emissions at part load using both the prototype multi-cylinder engine and a separate single-cylinder engine. The wide variety of test engines employed have several differences, including their fuel delivery strategies. This range of engine specifications is considered beneficial with regard to the “drop-in fuel” conjecture, since the results presented here bear out the contention, already established in the literature, that when specified according to the known ternary blending rules, such fuels fundamentally perform identically to their binary equivalents in terms of engine performance, and outperform standard gasolines in terms of efficiency. However, in the present work, some differences in particulate emissions performance in direct-injection engines have been found at light load for the tested fuels, with a slight increase in particulate number observed with higher methanol contents than lower. A hypothesis is developed to explain this result but in general it was found that these fuels do not significantly affect PN emissions from such engines. As a result, this investigation supplies further evidence that renewable fuels can be introduced simply into the existing vehicle fleet, with the inherent backwards compatibility that this brings too.