Problems of operation of positive pressure ventilators on the basis of surveys of Polish officers of the State Fire Service

Positive pressure ventilators (PPV) used by 97.7% of officers of the National Fire Service in Poland, are characterized by work that is not in line with the expectations of the firefighters. In order to improve the technical and operational features of these devices, a survey was conducted among 25,000 eligible firefighters, identifying the application of these devices, problems in use and expected development directions. A total of 682 officers voluntarily completed the survey. Based on their findings, it was determined that ventilators are most often used to smoke out buildings after or during a fire. Mentioned problems when using these devices were mainly noise (78.2%), exhaust emissions (68.5%), and impediments to mobility through the device's relatively heavy weight (40.2%). Other inconveniences were mentioned by less than 20% of firefighters. Polish firefighters expect the development of these devices mainly in terms of the above-mentioned features (noise reduction (81.7%) and reduction of the weight and size of the ventilators (about 50%)). Other expectations relate to the improvement of smoke removal in buildings: increasing the efficiency of smoke removal (46.4%) and efficiency regarding the rate of smoke removal in a building by increasing the size of the incoming airflow from the building's surroundings (33.2%). About 15% of firefighters expect changes in the operation of the ventilator itself, that is, an increase in the effective operating time (electric ventilators) and an increase in the device's uptime. The aim of the article is to identify the issues encountered during the operation and to indicate the expected direction of development for PPV by users. This information can be used by engineers to initiate new development work on these devices.

Towards zero pollution vehicles by advanced fuels and exhaust aftertreatment technologies

Vehicular emissions deteriorate air quality in urban areas notably. The aim of this study was to conduct an in-depth characterization of gaseous and particle emissions, and their potential to form secondary aerosol emissions, of the cars meeting the most recent emission Euro 6d standards, and to investigate the impact of fuel as well as engine and aftertreatment technologies on pollutants at warm and cold ambient temperatures. Studied vehicles were a diesel car with a diesel particulate filter (DPF), two gasoline cars (with and without a gasoline particulate filter (GPF)), and a car using compressed natural gas (CNG). The impact of fuel aromatic content was examined for the diesel car and the gasoline car without the GPF. The results showed that the utilization of exhaust particulate filter was important both in diesel and gasoline cars. The gasoline car without the GPF emitted relatively high concentrations of particles compared to the other technologies but the implementation of the GPF decreased particle emissions, and the potential to form secondary aerosols in atmospheric processes. The diesel car equipped with the DPF emitted low particle number concentrations except during the DPF regeneration events. Aromatic-free gasoline and diesel fuel efficiently reduced exhaust particles. Since the renewal of vehicle fleet is a relatively slow process, changing the fuel composition can be seen as a faster way to affect traffic emissions.

Comparison of machine learning algorithms for predicting diesel/biodiesel/iso-pentanol blend engine performance and emissions

In this study, machine learning techniques, namely artificial neural network (ANN), support vector machine (SVM), and extreme gradient boosting (XGBoost), were used to comprehensively evaluate engine performance and exhaust emissions for different fuel blends. To obtain valuable insights on optimizing engine performance and emissions for alternative fuel blends and thus contribute to the advancement of knowledge in this field, we focused on iso-pentanol ratios while maintaining the biodiesel ratios constant. The maximum brake thermal efficiency (BTE) values for the diesel (30.13 %), D85B10P5 (29.92 %), D80B10P10 (29.89 %), and D70B10P20 (29.79 %) blends were achieved at 1600 rpm. At 1600 rpm, the brake-specific fuel consumption (BSFC) values for the diesel, D85B10P5, D80B10P10, and D70B10P20 blends were 189.93, 200.93, 202.93, and 203.95 g kWh-1, respectively. In engine performance prediction, the ANN model exhibited superior performance, yielding regression coefficient (R2), root mean square error, and mean absolute error values of 0.984, 0.411 %, and 0.112 %, respectively, in BTE prediction, and 0.958 %, 6.9 %, and 2.95 %, respectively, in BSFC prediction. In exhaust gas temperature prediction, the SVM model exhibited the best performance, yielding an R2 value of 0.981. Although all models successfully predicted NOx emissions, the ANN model exhibited the best performance, achieving an R2 value of 0.959. In CO2 and hydrocarbon estimation, the XGBoost model exhibited the best performance, yielding R2 values of 0.956 and 0.973, respectively. Therefore, the ANN model can be used to accurately predict engine performance, and the XGBoost model can be used to accurately predict emission parameters.

Performance and emission characteristics of a diesel engine fuelled by biodiesel from black soldier fly larvae: Effects of synthesizing catalysts with citric acid

Biodiesel has several environmental benefits, such as biodegradability, renewability and lower soot emissions. However, biodiesel has undesirable properties such as higher viscosity and density and low calorific value compared to petroleum diesel, resulting in high Brake Specific Fuel Consumption (BSFC), reduced Brake Power (BP) and increased NOX emissions creating an environmental concerns in biodiesel development. This study investigated the effects of synthesizing transesterification catalysts (CaO and NaOH) with Citric Acid (CA) on the quality of biodiesel and biodiesel blends produced from Black Soldier Fly Larvae (BSFL) (Hermetia Illucens). The quality of biodiesel and blends was determined based on fuel properties, engine performance and emission composition characteristics. The tests were performed on a single-cylinder, four-stroke, Compression Ignition (CI) diesel engine at five loads at a constant speed of 1500 rpm. The results showed that synthesizing the catalysts with CA significantly affected the fatty acid profile of the biodiesel compared to physical fuel properties. B100 (pure BSFL biodiesel) exhibited higher BSFC by 10.57-13.97 % and lower BP by 4.21-7.83 % than diesel fuel. However, the Brake Thermal Efficiency (BTE) of biodiesel was higher than that of diesel fuel by 0.82-4.34 % at maximum load. Synthesizing catalysts with CA improved the viscosity of biodiesel by 0.93-2.81 % and effectively reduced NOX, HC and Smoke opacity by 2.23-3.16 %, 4.95-5.83 % and 20.51-41.15 %, respectively.

Biodiesel production from Mastic oil via electrolytic transesterification: optimization using response surface methodology and engine test

This study aimed to synthesize the biodiesel from Mastic oil by electrolysis method. Mastic gum is a potential and inexpensive feedstock for the biodiesel production. The oil content of Mastic gum was ~ 20% of the total gum weight. The gas chromatography-mass spectrometry (GC-MS) analysis was exploited to measure the oil's fatty acid profile. The response surface methodology (RSM) via Box-Behnken design (BBD) was utilized to specify the best processing condition of the electrolytic transesterification process. According to the RSM-BBD results, the highest predicted biodiesel yield was 95% at the reaction time of 1 h, methanol to oil ratio of 4:1, and catalyst weight of 1.2 wt%. Under these conditions, the produced Mastic oil biodiesel was blended with the neat diesel at different volume ratios of 5:95 (B5), 10:90 (B10), and 15:85 (B15). These fuel mixtures were tested in a single-cylinder engine to assess engine performance and exhaust emissions. The experiments exhibited that blending biodiesel with diesel can slightly improve the engine performance. Moreover, the application of blends with high volumes of biodiesel decreased the exhaust emissions, such as carbon monoxide (CO), carbon dioxide (CO2), and unburned hydrocarbons (UHC) by 54.54%, 41%, and 39.3%, respectively. However, the nitrogen oxide (NOx) emission increased because of the higher oxygen content of the biodiesel. It was also found that the physical and chemical characteristics of the Mastic oil biodiesel are the same as diesel, consistent with the ASTM standard. The Fourier transform infrared (FTIR) analysis also confirmed the biodiesel production.

Enhancement of combustion effect leading to improved performance and exhaust emissions of an SI engine with ferrous oxide and graphite nanoparticles

The present study was conducted to investigate the effectiveness of new, less toxic, less harmful, and nonmetallic graphite (G) and metallic iron oxide (Fe2O3) nanofuel additives by analyzing experimentally their consequences on exhaust emissions and performance of an air cooled, single cylinder, 4-stroke gasoline engine. Fe2O3 and graphite nanoparticles at 40, 80, and 120 mg/l of gasoline concentrations were mixed with gasoline by means of a magnetic stirrer. Brake power (BP), brake-specific fuel consumption (BSFC), torque (T), brake thermal efficiency (BTE), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO2) emissions were the investigated parameters. Experimental results indicated that G-blends showed a higher rise in brake power, brake thermal efficiency and torque and a greater reduction in the brake-specific fuel consumption as compared to that of Fe2O3 fuel blends. Moreover, the G-blends produced less NOx and CO2 than Fe2O3 blends but produced more emissions of CO and HC than that of Fe2O3 blends. On average, G-blends produced 0.46%, 0.71%, and 1.71% more torque, power, and BTE and 2.43%, 1.87%, and 13.39% less brake-specific fuel consumption (BSFC), NOx, and CO2 than Fe2O3 blends, respectively. So, in terms of the eight parameters, four performance parameters (i.e., T, BP, BSFC, BTE), and four engine emission exhaust indicators (i.e., CO, NOx, HC, CO2), graphite nanoparticles showed more positive results for 6 parameters (T, BP, BSFC, BTE, NOx, CO2), while two parameters HC and CO showed negative results with graphite as compared to that of Fe2O3 nanoparticles. So, overall, we conclude that nanoparticles of graphite are more engine and environment friendly than that of iron oxide fuel additives.

Exhaust emissions of gaseous and particle size-segregated water-soluble organic compounds from diesel-biodiesel blends

This study assessed the emissions of gaseous pollutants and particle size distributed water-soluble organics (WSO) from a diesel vehicle fuelled with ultralow sulphur diesel (B0) and 10 (B10), 20 (B20), and 30% (B30) biodiesel blends in a chassis dynamometer tested under transient mode. Particulate emission sampling was carried out in an ultraviolet (UV) test chamber using a 10-stage impactor. Samples were grouped into three size fractions and analysed by gas chromatography-mass spectrometry. Increasing the biofuel ratio up to 30% in the fuel reduced WSO emissions by 20.9% in comparison with conventional diesel. Organic acids accounted for 82-89% of WSO in all tested fuels. Dicarboxylic acids were the most abundant compound class, followed by hydroxy, aromatic, and linear alkanoic acids. Correlations between compounds demonstrated that adding biodiesel to diesel fuel reduces the emissions of nitrogen oxides (NOx), benzene, toluene, ethylbenzene and xylenes (BTEX), methane (CH4), total and nonmethane hydrocarbons (THC and NMHC), and dicarboxylic and hydroxy acids, but increases emissions of carbon dioxide (CO2) and alkanoic and aromatic acids. Emissions of dicarboxylic and hydroxy acids were strongly correlated with the biodiesel content. WSO emissions of coarse and fine (1.0-10 μm) particles decreased with the increasing biofuel content in fuel blend. The total share of ultrafine (0.18-1.0 μm) and nanoparticles (< 0.18 μm) increased in WSOs emissions from B20 and B30 blends, when compared with petrodiesel. The biodiesel content also affected the chemical profile of WSO size fractions.

Investigating impacts of COVID-19 on urban mobility and emissions

The COVID-19 pandemic has severely impacted human activities in a way never documented in modern history. The prevention policies and measures have abruptly changed well-established urban mobility patterns. In this context, we exploit different sources of urban mobility data to gain insights into the effects of restrictive policies on the daily mobility and exhaust emissions in pandemic and post-pandemic periods. Manhattan, the most densely populated borough in New York City, is chosen as the study area. We collect data generated by taxis, sharing bikes, and road detectors between 2019 and 2021, and estimate exhaust emissions using the COPERT (Computer Programme to calculate Emissions from Road Transport) model. A comparative analysis is conducted to identify important changes in urban mobility and emission patterns, with a particular focus on the lockdown period in 2020 and its counterparts in 2019 and 2021. The results of the paper fuel the discussion on urban resilience and policy-making in a post pandemic world.

An experimental investigation on the effects of magnesia and alumina nano additives on the exhaust emissions and performance of CI engine using spirulina microalgae biodiesel

The need for non-renewable fuels is steadily decreasing with their ever-increasing cost and air pollution. As a result, renewable fuel such as biofuel is used as a fuel substitute for diesel engines. The effects of magnesia and alumina nanoparticles on the exhaust pollutants and performance of a naturally aspirated, 17.5 compression ratio, 4-stroke CI engine operating on spirulina microalgae biodiesel, and its amalgams were explored. Oxides of nitrogen, thermal efficiency, carbon dioxide, fuel consumption, and hydrocarbons were among the attributes studied. Test outcomes revealed that the doping of magnesia and alumina nano additives in spirulina biodiesel resulted in increased thermal efficiency and oxides of nitrogen, succeeded by a decrease in fuel consumption and hydrocarbons, at all loads, compared to amalgams without nano additives. At maximum load, the increase in thermal efficiency and oxides of nitrogen was found to be 1.15 and 1.46% with nano magnesia-doped blends when compared to corresponding spirulina blends. On the other, hand when nano alumina is doped in spirulina amalgams, the increase in thermal efficiency and oxides of nitrogen was observed to be 0.82 and 0.97%, respectively. Similarly, fuel consumption and hydrocarbons were reduced by 1.02 and 9.52%, 1.014, and 7.66%%, respectively, for magnesia and alumina-enriched biodiesel, contrasted to that of biodiesel blends.

Impact assessment of new generation high-speed agricultural tractor aerodynamics on transportation fuel consumption and related phenomena

New generation agricultural tractors contribute to transportation by increased travel speeds. There is not any available aerodynamic data on the authentic agricultural tractor form. On-road transportation by tractors is between 8 and 30% of their operational time. In this work, two agricultural tractors are modelled via computational fluid dynamics for nine different speeds to determine aerodynamic resistances. Constant speed travel scenarios are analyzed. Corresponding speeds are 5 and 10 to 80 km/h with 10 km/h increments. Reynolds number changes between 1.6 × 10⁵ and 2.98 × 10⁶. The characteristic lengths are taken as the square root of the streamwise projected area of the tractor geometries. Aerodynamic forces exerted on the tractors change between 3 and 746 N. The calculated drag coefficients are found as independent from Reynolds number and are 0.6 and 0.78 for the two different types of driver compartments. The approximated aerodynamic related fuel consumptions for 1-h changes between 0.002 and 8.28 lt/s which correspond to 0.001 to 5.76 kg/s carbon emission. A potential improvement in decreasing aerodynamic resistance about 20% is discussed by spatial data. Since the conducted work is being regarded as the first instance in the literature, it is estimated that several consecutive reports will be triggered.

Dynamic changes in provincial exhaust emissions in China in the carbon peak and neutrality setting: based on the effects of energy consumption and economic growth

Reducing exhaust emissions, promoting economic development, and realizing clean energy utilization have always been concerns in China. To measure the relationship between them, this study selects the data related to energy consumption, economic growth, and exhaust emissions from 2000 to 2019 in 30 Chinese provinces. By constructing a panel vector autoregressive (PVAR) model, the dynamic relationship between them in China is quantitatively analyzed. The results show that there is a long-term interaction between energy consumption, economic growth, and exhaust emissions. Among them, economic growth is highly dependent on energy consumption, but it can promote the reduction of exhaust emissions. However, energy consumption will produce a large amount of industrial waste, such as sulfur dioxide and carbon dioxide emissions. Specifically, the industrial structure and energy structure have the most obvious impact on reducing industrial sulfur dioxide emissions and carbon emissions, with the proportion between 0.071-0.090 and 0.031-0.032, respectively. Therefore, the adjustment of industrial structure and energy structure is the key to exhaust emission reduction.

The effect of biodiesel production method on its combustion behavior in an agricultural tractor engine

In this study, biodiesel fuel was produced from waste cooking oil (WCO) using a heterogeneous catalyst under microwave (MB) and conventional (CB) heating, and fueled in an agricultural tractor engine to evaluate the engine performance as well as emissions. The biodiesels presented different fatty acid methyl ester (FAME) profiles where MB had lower unsaturated FAME chains. Beyond the transesterification reaction time, the energy consumed for MB biodiesel production diminished by around eight times compared to that required for CB production. The engine results confirmed the positive influence of blending net diesel fuel with biodiesel for enhancing the engine performance and reducing the emissions. More than 20% increment in the engine power and torque was detected at all engine loads (the engine speed was adjusted at 1500 rpm). The hydrocarbon (HC), carbon monoxide (CO), and smoke opacity (SO) indicated significant reductions compared to when net diesel fuel was used. According to statistical analysis, CB25 and MB25 fuels presented a suitable combination as fuel where MB25 provided better engine performance, lower HC and SO emissions, with CO emissions reaching the minimum amount by CB fuels.

Influence of non-commercial fuel supply systems on small engine SI exhaust emissions in relation to European approval regulations

The development and operation of road infrastructure require machines and equipment driven by low-powered internal combustion engines. In this study, we conducted emission tests on five small spark-ignition engines. We used the most popular commercial design on the market, the Lifan GX 390, with a carburettor power system, and another commercial power unit, the Honda iGX 390, with an innovative power system characterised by an electronically controlled carburettor flap. The remaining three tested constructions were proprietary solutions modernising the design of the Lifan GX 390 engine: one had an electronic injection and ignition system powered by gasoline, whereas the other two had systems powered by alternative fuels. Emission tests were conducted under identical operating conditions on an engine dynamometer complying with European Union guidelines (Regulation 2016/1628/EU). The results of the tests showed that the innovative solutions in most cases reduced CO, CO₂ and hydrocarbon emissions but increased NO_x compounds.

Source identification of exhaust and non-exhaust traffic emissions through the elemental carbon fractions and Positive Matrix Factorization method

Our study implies the importance of exhaust and non-exhaust emissions in a highway road tunnel, which is crucial to assess their impacts on air quality, human health, climate and developing functional methods for controlling. The total suspended particulates (TSP) and road dust (RD) samples were collected by PUF samplers and manually sweeping, respectively. Campaigns were performed in the summer and winter of 2014 in a highway road tunnel in Bolu, Turkey. Chemical analyses were presented to characterize the contents of organic carbon (OC) fractions (OC1,2,3,4), elemental carbon (EC) fractions (EC1,2,3,4,5,6), polycyclic aromatic hydrocarbons (PAHs) and metals (Al, Ba, Ca, Cu, Mg, Mn, Pb, Sr, Cr and Fe) in the collected TSP and RD samples. Positive matrix factorization (PMF) and orthogonal (Deming) regression analysis were applied to find out the exhaust and non-exhaust vehicle emissions of metal and carbonaceous species in the tunnel. The results showed that the identified source profiles included resuspended road dust (43%), non-exhaust emissions (37%), diesel exhaust emissions (13%), and gasoline exhaust emissions (7%). The relationship between emission markers of metal species and EC carbon fractions was supported by correlation studies. Among these EC fractions, EC4 and EC2 were the most abundant fractions in aerosol and RD samples, respectively and so they highly represented the diesel and non-exhaust emissions. Besides, the EC1 fraction was the indicator of gasoline-fueled emissions. Lower EC1 and higher soot-EC contribution obtained in tunnel aerosol (AS) samples showed the dominance of diesel-fueled vehicles in the tunnel. The data represented herein would help to identify the characteristic of vehicle emissions.

Effects of cordierite particulate filters on diesel engine exhaust emissions in terms of pollution prevention approaches for better environmental management

In this study, a specific diesel fuel is experimentally tested in a 4-cylindered diesel engine with and without a cordierite-based diesel particulate filter (CPF) to show the prevention of emissions by using an after treatment system (ATS). In this context, engine exhaust emissions, total particle concentration (TPC) and soot concentration are investigated. The diesel engine is firstly evaluated with the data directly measured from the engine output (DEO) (without after treatment option), and then the changes in the exhaust emission are examined by using an ATS which is a cordierite-based diesel particulate filter to prevent pollution. In this regard, total particle concentration of DEO option is found to be 6134041.20 1/cm³ and total particle concentration by using CPF is obtained to be 707.84 1/cm³. 99.99% reduction in TPC is achieved thanks to the use of CPF. The soot concentration of DEO option is calculated to be 2.158 mg/m³. However, the soot concentration is found to be 0.014 mg/m³ by using the CPF. The particulate matters are burned at high temperatures after being filtered at the exhaust output thanks to the regeneration process within the CPF after treatment. CO emissions decreased from 0.7489 g/kWh to 0.7273 g/kWh with the CPF utilization, while HC emissions decreased from 0.0965 g/kWh to 0.0900 g/kWh via CPF. However, an increase in CO₂ and NO_x emissions are observed due to oxidation in the CPF.

Numerical investigation on the effect of water in the reduction of diesel engine exhaust emissions using a novel ionic chemical kinetics mechanism

This paper aims to investigate the role of water in the reduction of diesel exhaust emissions. To do so, a multi-zone thermodynamic model coupled to a novel semi-detailed ionic chemical kinetics mechanism is used. This mechanism includes 467 reactions and 105 species containing 51 ionic reactions and 15 ions. The mechanism contains 6 basic ionic reactions, 23 NOx-related ionic reactions, and 22 soot-related ionic reactions. Four different amounts of water are added to the in-cylinder mixture and the effects of water in the formation of soot and NOx are investigated. The results showed that water does not have a regular effect on diesel exhaust soot, but causes a significant reduction in exhaust NOx. Water has decreased the temperature of the combustion chamber and consequently has reduced the ionic current inside the combustion chamber. Reduction of the in-cylinder ion current decreases the mass of NOx-related ions and results in reduced exhaust NOx. Adding 5% water reduces the in-cylinder ion current by 47%. Five percent water also reduces engine exhaust NOx to 33%. Among NOx-related ions, water has the greatest effect on N+ ions and reduces its amount to less than 20%. Water affects the progress rate of ionic reactions, and 5% of water reduces the progress rate of the fastest reaction to 14% of its initial value.

Novel environmentally friendly fuel: The effect of adding graphene quantum dot (GQD) nanoparticles with ethanol-biodiesel blends on the performance and emission characteristics of a diesel engine

Biodiesel fuel has some disadvantages including increase in NO_x, poor atomization and incomplete combustion. Additives and catalysts can be used to reduce the negative effects of biodiesel fuel. In addition, the use of metal oxide and metal nanoparticles causes environmental hazards. However, using biodegradable nanoparticles can significantly reduce such concerns. The present study investigated the effect of adding GQD + E to B10 fuel on the emission and performance characteristics of a diesel engine. B10 was blended with GQD (90 ppm) and bioethanol (E2, E4, E6 and E8% vol). Performance and emission characteristics, including power, torque, SFC, CO, CO₂, UHC and NO_x emissions were measured at the speeds of 1800, 2100 and 2400 rpm and full load mode. According to the results, the addition of GQD + E to B10 improved torque and power and decreased SFC, CO, UHC and NO_x. Finally, the B10 + E6 + GQD90 fuel was the best fuel regarding improved engine performance and reduced exhaust emission. The average of changes in power and torque, SFC, CO, UHC and NO_x compared to D100 for B10 + E6 + GQD90 were + 15.69%, +15.39%, -17.58%, -30.30%, -38.91% and -1.54%, respectively.

Effect of ultrasonic irradiation on the properties and performance of biodiesel produced from date seed oil used in the diesel engine

In the present study, the effect of ultrasound irradiation on the transesterification parameters, biodiesel properties, and its combustion profiles in the diesel engine was investigated. Moreover, date seed oil (DSO) was firstly utilized in the ultrasound-assisted transesterification reaction. DSO was extracted from Zahidi type date (Phoenix dactylifera) and was esterified to reduce its Free Fatty Acid (FFA) content. Biodiesel yield was optimized in both heating methods, so that the yield of 96.4% (containing 93.5% ester) at 60 °C, with 6 M ratio of methanol/oil, 1 wt% of catalyst (NaOH) and at 90 min of reaction time was reported. The ultrasound irradiation did not influence the reaction conditions except reaction time, reduced to 5 min (96.9% yield and 91.9% ester). The ultrasonic irradiation also influenced on the physicochemical properties of DSO biodiesel and improved its combustion in the diesel engine. The analysis results related to the engine and gas emission confirmed that the ultrasound-assisted produced biodiesel has lower density and viscosity, and higher oxygen content facilitating injection of fuel in the engine chamber and its combustion, respectively. Although, B40 (biodiesel blend consisting of 40% biodiesel and 60% net diesel fuel) as a blend of both fuels presented higher CO₂ and lower CO and HC in the emissions, the DSO biodiesel produced by ultrasound irradiation presented better specifications (caused about 2-fold improvement in emissions than that of conventional method). The findings of the study confirmed the positive effect of the ultrasound irradiation on the properties of the produced biodiesel along with its combustion properties in the diesel engine, consequently reducing air pollution problems.

Effect of induction hydroxy and hydrogen along with algal biodiesel blend in a CI engine: a comparison of performance and emission characteristics

Gaseous fuel as a combustion enhancer with a pilot fuel offers significant benefits in improving engine efficiency. Hydrogen and hydroxy are the two most common gaseous fuels that have been widely investigated in the CI engine but which one performs best is still inconvenient. In this study, hydrogen and hydroxy were injected with BD40 (v/v) separately in a common diesel engine to compare the performance and emission characteristics of these fuels. Engine performance parameters include brake thermal efficiency (BTE) and brake-specific energy consumption (BSEC), and exhaust emissions include hydrocarbon (HC), CO, CO₂, NOx, and smoke opacity. The induction of both hydroxy and hydrogen with BD40 has a positive effect on engine performance and emissions except NOx when compared to neat diesel fuel and BD40. The BTE of hydroxy-rich BD40 increased by 7.2% while BSEC reduced by 7.6% as compared to BD40 with hydrogen. The CO, HC, and smoke opacity of hydroxy-operated engine was found to be better than hydrogen-inducted engine. The NOx emission increased with the induction of both gaseous fuels and hydroxy-enriched BD40 produced 12.5% more emission than hydrogen-operated BD40 engine. Thus, more concisely, hydroxy-operated biodiesel engine performed better than hydrogen engine in terms of BTE, BSEC, CO, HC, and smoke opacity.

Assessment of Euro 5 diesel vehicle NOx emissions by laboratory and track testing

The Volkswagen scandal has promoted experimental campaigns worldwide aimed to assess the real exhaust emissions of in-use vehicles. Attention has been paid to diesel vehicle NOx emissions that are much higher than legislative type-approval limits. This paper analysed exhaust emissions of a fleet of ten Euro 5 diesel vehicles. NOx emissions were measured during laboratory and track testing. In both cases, the type-approval test was carried out with cold and warm starts. Moreover, in the laboratory, a modified type-approval test and a real urban driving cycle were executed in order to characterise emissions in multiple operating conditions, outside of the homologation boundaries. The testing environment did not influence the emissions behaviour of the tested vehicles. Track and laboratory results, in fact, were comparable when ambient conditions were comparable. The parameter which played the main role in terms of NOx emissions is the ambient temperature, fixed at 23 °C in laboratory and not controlled on the track. Above 28 °C, NOx emissions were much higher than the approval limit (almost 600 mg/km). Moreover, warm driving cycles always introduced higher NOx emissions than cold ones, because of the partial use and/or deactivation of the EGR circuit (one of effective measures to reduce NOx formation). The ratio between warm and cold emissions ranged from 2 to 5. The engine parameter which helped explain the relationship between NOx emissions and thermal engine status was the intake air temperature. For intake air temperatures below 40 °C, NOx emissions were lower than 0.2 g/km. Above 40 °C, they suddenly increased up to almost 0.6 g/km. Another issue highlighted by the experimental results was that dynamic real driving caused the highest NOx emissions (almost 1 g/km).

Effect of anhydrous ethanol/gasoline blends on performance and exhaust emissions of spark-ignited non-road engines

Ethanol is a renewable fuel and it is considered an alternative to gasoline in Otto-cycle engines. The present study evaluated the behavior of exhaustion gas carbon monoxide (CO) and total hydrocarbons (THC) according to the levels of anhydrous ethyl alcohol (AEA) added to gasoline in different proportions (E0, E10, E20, E27, that is, pure gasoline and its blends with AEA at 10, 20, and 27% v/v) in the use of non-road single cylinder engines of different powers (13 and 6.5 hp), to the loads applied to engine-generators and the air-fuel ratio (A/F) admitted to the engine cylinders. Also, the performance of engine-generators was verified in terms of mass, specific and energetic consumption and efficiency of the evaluated systems for the same blends and loads. The results showed that an increase in the AEA content in the blend resulted in significant drops in CO and THC concentrations for both engine-generators, while fuel consumption showed a slight upward trend; the increases in applied loads resulted in an increase in CO and THC concentrations and fuel consumption. In general, a higher AEA content (oxygenated) in the blends had a greater effect on gaseous emissions compared to the effect on consumption and system efficiency.

A review on the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends

Biodiesels have gained much popularity because they are cleaner alternative fuels and they can be used directly in diesel engines without modifications. In this paper, a brief review of the key studies pertaining to the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends, exhaust aftertreatment systems, and low-temperature combustion technology is presented. In general, most biodiesel blends result in a significant decrease in carbon monoxide and total unburned hydrocarbon emissions. There is also a decrease in carbon monoxide, nitrogen oxide, and total unburned hydrocarbon emissions while the engine performance increases for diesel engines fueled with biodiesels blended with nano-additives. The development of automotive technologies, such as exhaust gas recirculation systems and low-temperature combustion technology, also improves the thermal efficiency of diesel engines and reduces nitrogen oxide and particulate matter emissions.

Legal regulations of restrictions of air pollution made by non-road mobile machinery-the case study for Europe: a review

The high awareness of intensification and frequency of smog phenomenon all over the world in XXI age makes for detailed analyses of the reasons of its formation and prevention. The governments of the developed countries and conscious of real hazards, including many European countries, aim to restrict the emission of harmful gases. In literature, we can find the discussions on the influence of this phenomenon on the health and life of inhabitants of contaminated areas. Some elaborations of prognostic models, descriptions of pollution sources, the manner of their restriction, and the analysis of causal-consecutive correlation are also popular. The influence of pollutions resulting from the operation of vehicles, planes, and the industry are well described. However, every machine and device which is driven with a combustion engine has the effect on the general level of anthropogenic pollutions. These drives are subject of different regulations limiting their emission for service conditions and applications. One of the groups of such machines described in European and American regulations is non-road mobile machinery. The aim of this paper is the presentation of the problem of weak analysis and application of engineering and technological tools for machinery drive emission, despite of many publications on hazards and problems of emission. These machines have the influence on both the increase of global contamination and the machine users. The regulations of the European Union take into consideration the generated hazards and restrict the emission of machine exhaust gases by approval tests-these regulations are continually improved, and the effects of these works are new emission limits in 2019. However, these activities seem to be liberal as opposed to limits of the emission for passenger and goods vehicles where the technological development of the construction is greater and the regulations are the most rigorous. During the analysis of the development of non-road mobile machinery in the correlation with automotive vehicles, we can indicate engineering and technological solutions which are limiting the emission of non-road mobile machinery, but which are not applied. Due to liberal regulations for this group of machinery, the producers do not apply innovative solutions which can be found in road vehicles. The paper presents the synthetic review of existing EU regulations concerning limits of the emission of harmful exhaust gases which are generated by spark-ignition combustion engines of non-road mobile machinery. The authors show the divergences between the limits of the emission of harmful exhaust gases generated by road vehicles and non-road mobile machinery (boats and railway engines are not taken into account). The authors present the directions of the development of the combustion process control and systems limiting the emission of harmful exhaust gases. High innovative automotive industry was indicated as the direction of the development for limiting the influence of the emission on the environment by non-road mobile machinery.

Analysis of the performance, emission and combustion characteristics of a turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends using kernel-based extreme learning machine

The purpose of this study is to investigate the performance, emission and combustion characteristics of a four-cylinder common-rail turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends. A kernel-based extreme learning machine (KELM) model is developed in this study using MATLAB software in order to predict the performance, combustion and emission characteristics of the engine. To acquire the data for training and testing the KELM model, the engine speed was selected as the input parameter, whereas the performance, exhaust emissions and combustion characteristics were chosen as the output parameters of the KELM model. The performance, emissions and combustion characteristics predicted by the KELM model were validated by comparing the predicted data with the experimental data. The results show that the coefficient of determination of the parameters is within a range of 0.9805-0.9991 for both the KELM model and the experimental data. The mean absolute percentage error is within a range of 0.1259-2.3838. This study shows that KELM modelling is a useful technique in biodiesel production since it facilitates scientists and researchers to predict the performance, exhaust emissions and combustion characteristics of internal combustion engines with high accuracy.

Did policies to abate atmospheric emissions from traffic have a positive effect in London?

A large number of policy initiatives are being taken at the European level, across the United Kingdom and in London to improve air quality and reduce population exposure to harmful pollutants from traffic emissions. Trends in roadside increments of nitrogen oxides (NO_X), nitrogen dioxide (NO₂), particulate matter (PM), black carbon (CBLK) and carbon dioxide (CO₂) were examined at 65 London monitoring sites for two periods of time: 2005-2009 and 2010-2014. Between 2005 and 2009 there was an overall increase in NO₂ reflecting the growing evidence of real world emissions from diesel vehicles. Conversely, NO₂ decreased by 10%·year^-1 from 2010 onwards along with PM_2.5 (-28%·year^-1) and black carbon (-11%·year^-1). Downwards trends in air pollutants were not fully explained by changes in traffic counts therefore traffic exhaust emission abatement policies were proved to be successful in some locations. PM₁₀ concentrations showed no significant overall change suggesting an increase in coarse particles which offset the decrease in tailpipe emissions; this was especially the case on roads in outer London where an increase in the number of Heavy Good Vehicles (HGVs) was seen. The majority of roads with increasing NO_X experienced an increase in buses and coaches. Changes in CO₂ from 2010 onwards did not match the downward predictions from reduced traffic flows and improved fleet efficiency. CO₂ increased along with increasing HGVs and buses. Polices to manage air pollution provided differential benefits across London's road network. To investigate this, k-means clustering technique was applied to group roads which behaved similarly in terms of trends to evaluate the effectiveness of policies to mitigate traffic emissions. This is the first time that London's roadside monitoring sites have been considered as a population rather than summarized as a mean behaviour only, allowing greater insight into the differential changes in air pollution abatement policies.

Did policies to abate atmospheric emissions from traffic have a positive effect in London?

A large number of policy initiatives are being taken at the European level, across the United Kingdom and in London to improve air quality and reduce population exposure to harmful pollutants from traffic emissions. Trends in roadside increments of nitrogen oxides (NO_X), nitrogen dioxide (NO₂), particulate matter (PM), black carbon (CBLK) and carbon dioxide (CO₂) were examined at 65 London monitoring sites for two periods of time: 2005-2009 and 2010-2014. Between 2005 and 2009 there was an overall increase in NO₂ reflecting the growing evidence of real world emissions from diesel vehicles. Conversely, NO₂ decreased by 10%·year^-1 from 2010 onwards along with PM_2.5 (-28%·year^-1) and black carbon (-11%·year^-1). Downwards trends in air pollutants were not fully explained by changes in traffic counts therefore traffic exhaust emission abatement policies were proved to be successful in some locations. PM₁₀ concentrations showed no significant overall change suggesting an increase in coarse particles which offset the decrease in tailpipe emissions; this was especially the case on roads in outer London where an increase in the number of Heavy Good Vehicles (HGVs) was seen. The majority of roads with increasing NO_X experienced an increase in buses and coaches. Changes in CO₂ from 2010 onwards did not match the downward predictions from reduced traffic flows and improved fleet efficiency. CO₂ increased along with increasing HGVs and buses. Polices to manage air pollution provided differential benefits across London's road network. To investigate this, k-means clustering technique was applied to group roads which behaved similarly in terms of trends to evaluate the effectiveness of policies to mitigate traffic emissions. This is the first time that London's roadside monitoring sites have been considered as a population rather than summarized as a mean behaviour only, allowing greater insight into the differential changes in air pollution abatement policies.

Performance and exhaust emission characteristics of variable compression ratio diesel engine fuelled with esters of crude rice bran oil

As a substitute to petroleum-derived diesel, biodiesel has high potential as a renewable and environment friendly energy source. For petroleum importing countries the choice of feedstock for biodiesel production within the geographical region is a major influential factor. Crude rice bran oil is found to be good and viable feedstock for biodiesel production. A two step esterification is carried out for higher free fatty acid crude rice bran oil. Blends of 10, 20 and 40 % by vol. crude rice bran biodiesel are tested in a variable compression ratio diesel engine at compression ratio 15, 16, 17 and 18. Engine performance and exhaust emission parameters are examined. Cylinder pressure-crank angle variation is also plotted. The increase in compression ratio from 15 to 18 resulted in 18.6 % decrease in brake specific fuel consumption and 14.66 % increase in brake thermal efficiency on an average. Cylinder pressure increases by 15 % when compression ratio is increased. Carbon monoxide emission decreased by 22.27 %, hydrocarbon decreased by 38.4 %, carbon dioxide increased by 17.43 % and oxides of nitrogen as NO_x emission increased by 22.76 % on an average when compression ratio is increased from 15 to 18. The blends of crude rice bran biodiesel show better results than diesel with increase in compression ratio.

Determinants of aerosol lung-deposited surface area variation in an urban environment

Ultrafine particles are characterized by a high surface area per mass. Particle surface has been reported to play a significant role in determining the toxicological activity of ultrafine particles. In light of this potential role, the time variation of lung deposited surface area (LDSA) concentrations in the alveolar region was studied at the urban background environment of Barcelona (Spain), aiming to asses which processes and sources govern this parameter. Simultaneous data on Black Carbon (BC), total particle number (N) and particle number size distribution were correlated with LDSA. Average LDSA concentrations in Barcelona were 37 ± 26 μm(2)cm(-3), levels which seem to be characteristic for urban environments under traffic influence across Europe. Results confirm the comparability between LDSA data provided by the online monitor and those calculated based on particle size distributions (by SMPS), and reveal that LDSA concentrations are mainly influenced by particles in the size range 50-200 nm. A set of representative daily cycles for LDSA concentrations was obtained by means of a k-means cluster technique. The contribution of traffic emissions to daily patterns was evidenced in all the clusters, but was quantitatively different. Traffic events under stable atmospheric conditions increased mean hourly background LDSA concentrations up to 6 times, attaining levels higher than 200 μm(2)cm(-3). However, under warm and relatively clean atmospheric conditions, the traffic rush hour contribution to the daily LDSA mean appeared to be lower and the contribution of new urban particle formation events (by photochemically induced nucleation) was detected. These nucleation events were calculated to increase average background LDSA concentrations by 15-35% (maximum LDSA levels=45-50 μm(2)cm(-3)). Thereby, it may be concluded that in the urban background of Barcelona road traffic is the main source increasing the aerosol surface area which can deposit on critical regions of the human lung, followed by nucleation episodes.