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Highlights • Cumulative mileage affects motorcycle exhaust emissions. • Aerosol related TEFs and MEQ assessment are conducted in this study. • The lowest pollutants emission factors could be found during the lowest mileage. • PM 2.5 and total p-PAHs expressed the moderate to high correlation with NOx. • Higher impact of health risk was found at higher cumulative mileages motorcycles. Abstract This research investigates the mileage and the health risk assessment of aerosol carcinogenicity and mutagenicity emitted by ten in-use motorcycles. The total p-PAHs emission factor of ten in-use motorcycles are 676.3 μg km−1 with average of 67.6 ± 13.6 μg km−1. Naphthalene (Nap) shows the largest emission factors, followed by phenanthrene (PA) and fluoranthen (FL). The mileage present high correlation coefficient (Rsp = 0.681) with CO. CO is associated with cumulative mileage leading to bad combustion efficiency, which caused low to high relationship for total p-PAHs (Rsp = 0.388), PM 2.5 (Rsp = 0.680) and NOx (Rsp = 0.799). Both PM 2.5 and total p-PAHs are generally generated via incomplete combustion and the results expressed the moderate to high correlation (Rsp = 0.578, 0.898) with NOx. Taking into consideration of high-mileage motorcycles (30,001–50,000 km), the toxic equivalent of carcinogenicity and mutagenicity exhaust are about 4.67, 1.99 and 3.89, 2.0 times higher than low (10,001–20,000 km) and middle (20,001–30,000 km) cumulative mileages, respectively. Therefore, in the conclusion of our study in compared with that of other research directed the fact that lower carcinogenicity and mutagenicity emission factor were found at lower cumulative mileages motorcycles however, the impact increases with the high cumulative mileage motorcycles. [ABSTRACT FROM AUTHOR]

Abstract: An optically accessible single-cylinder high-speed direct-injection (HSDI) diesel engine was used to investigate the spray and combustion processes for biodiesel blends under different injection strategies. The experimental results indicated that the heat release rate was dominated by a premixed combustion pattern and the heat release rate peak became smaller with injection timing retardation. The ignition and heat release rate peak occurred later with increasing biodiesel content. Fuel impingement on the wall was observed for all test conditions. The liquid penetration became longer and the fuel impingement was stronger with the increase of biodiesel content. Early and late injection timings result in lower flame luminosity due to improved mixing with longer ignition delay. For all the injection timings, lower soot luminosity was seen for biodiesel blends than pure diesel fuel. Furthermore, NO x emissions were dramatically reduced for premixed combustion mode with retarded post-TDC injection strategies. [Copyright &y& Elsevier]

This study investigated the emissions of carbonyl compounds (CBCs) and regulated harmful matters (traditional pollutants) from an HDDE (heavy-duty diesel engine) at one low load steady-state condition, 24.5% of the max load (40 km h−1), using five test fuels: premium diesel fuel (D100), P100 (100% palm-biodiesel), P20 (20% palm-biodiesel + 80% premium diesel fuel), PF80P20 (80% paraffinic fuel + 20% palm-biodiesel), and PF95P05 (95% paraffinic fuel + 5% palm-biodiesel). Experimental results indicate that formaldehyde was the major carbonyl in the exhaust, accounting for 70.3–75.4% of total CBC concentrations for all test fuels. Using P100 and P20 instead of D100 in the HDDE increased CBC concentrations by 9.74% and 2.89%, respectively. However, using PF80P20 and PF95P05 as alternative fuels significantly reduced CBC concentrations by 30.3% and 24.2%, respectively. Using PF95P05 instead of D100 decreased CBCs by 30.3%, PM by 11.1%, THC by 39.0%, CO by 34.0%, NOx by 24.3%, and CO2 by 7.60%. The wide usage of paraffinic–palmbiodiesel blends as alternative fuels could protect the environment. However, it should be noted that only one engine operated at one low load steady-state condition was investigated. [Copyright &y& Elsevier]

Abstract: Biodiesels are promoted as alternative fuels and their applications in diesel engines have been investigated by many researchers. However, the particle size distribution emitted from heavy-duty diesel engines fueled with palm-biodiesel blended with premium diesel fuel and paraffinic fuel blended with palm-biodiesel has seldom been addressed. Thus, five test fuels were used in this work to study the particle size distribution: D100 (premium diesel fuel), B100 (100% palm-biodiesel), B20 (20vol% palm-biodiesel+80vol% D100), BP9505 (95vol% paraffinic fuel+5vol% palm-biodiesel) and BP8020 (80vol% paraffinic fuel+20vol% palm-biodiesel). A Micro-Orifice Uniform Deposit Impactor (MOUDI) equipped with aluminum filters was used to collect size-resolved samples. Experimental results indicated that palm-biodiesel blends and paraffinic fuel blends could improve combustion efficiency in diesel engines, but pure palm-biodiesel could cause incomplete combustion. Adding palm-biodiesel to diesel fuel would slightly increase particles with diameter <0.31μm but paraffinic fuel blends could decrease particles with diameter <1μm. The mass median diameter of overall particles (MMDo) and σ g,o are 0.439μm and 3.88 for D100; 0.380μm and 3.24 for B20; 0.465μm and 4.22 for B100; 1.40μm and 4.92 for BP9505; 1.46μm and 2.25 for BP8020. There are more particles with low aerodynamic diameters (diameter <0.31μm) in the exhaust of D100, B20 and B100 fuels. On the other hand, a greater fraction of particulate matter of BP9505 and BP8020 existed in coarse particles (diameter: 2.5–10μm). Energy efficiency also increases significantly by 12.3–15.1% with the introduction of paraffinic fuel blends into the engine. Nevertheless, paraffinic fuel blends also reduce the emission of particulate matters by 36.0–38.4%. Carbon monoxide was decreased by 36.8–48.5%. Total hydrocarbon is 39.6–41.7% less than diesel fuel combustion. Nitrogen oxides emission is about 5% lower for paraffinic fuel. These results show that paraffinic fuel can be very competitive and replaced diesel fuels in the future. [Copyright &y& Elsevier]

Abstract: This study investigated polycyclic aromatic hydrocarbon (PAH) and regulated harmful matter (traditional pollutant) emissions, fuel consumption, and the assessment of the inferior condition of engine oil from heavy-duty diesel engines (HDDEs) fueled with palmbiodiesel–PDF (premium diesel fuel) blends and paraffinic–palmbiodiesel blends under brand-new (the mileage was zero) engines accumulated mileage test. Experimental results indicated that the emissions of THC and CO increased with operation time but the emissions of NO x and PAHs decreased with operation time between 0 and 300h (18,000km). Using palmbiodiesel–PDF blends or paraffinic–palmbiodiesel blends instead of PDF in HDDEs reduced the emissions of THC (10.7–44.2%), CO (0.664–15.6%), CO2 (0.763–2.55%), NO x (1.25–4.97%), PM (6.11–26.8%), total PAHs (43.0–90.2%) and total BaPeq (63.1–89.6%) significantly. [Copyright &y& Elsevier]

Abstract Efficient energy usage and energy saving is one of the nowadays necessity for all scientists of IC engine. This is because of the current environmental challenges that have tremendously increased concerning air pollution, particularly pollutant emissions from vehicles. Yet, industries and governments alike have disregarded this phenomenon which has been considerably contributing to climate change. It is against this background that, the research works carried out in this present study is predominantly focusing on improving energy efficiency and reducing emission levels from diesel engines. This can be achieved with the help of atmospheric-plasma system which can offer a noble solution to the above-mentioned challenges due to its potential to improve combustion efficiency which leads to energy efficiency, while reducing emission levels from diesel engines. In this study, the performance and emissions of a diesel generator supplemented with an atmospheric-plasma system was examined. The diesel engine was used to examine the effects of fuel composition, or brake specific fuel consumption, thermal efficiency and pollutant emissions at different plasma system voltages. To this end, we equally examined the effects of atmospheric-plasma system on energy efficiency improvement and emissions reduction from diesel engine as the main purpose of this study. We do so by testing the diesel-fueled engine generator under the atmospheric-plasma system. The tests were carried out at a constant state condition with the engine running at 2200 rpm with torque and power outputs of 10.4 Nm (75% of the max load) and 2.1 kW, separately, for the tested fuels and this was used to increase the output voltage of the plasma system during this study. The plasma system ionized the intake air and improved the formation of free radicals upon combustion. During this study, the output voltage of the plasma was set within the range of 0–7 kV. The experimental results have indicated that formaldehyde, acetaldehyde and acrolein account for more than 75% of total carbonyl compounds emissions. Simultaneously, it was also observed from the results that higher plasma system voltage reduces pollutants emissions levels. Hence, such reduction is predominantly evident for nitrogen oxides, particulate matters and carbon monoxide. However, the marginal improvements of engine performance and emissions reduction become insignificant when the plasma system voltage reaches 6 kV. On the other hand, increasing the amount of plasma system voltages in diesel engine continues to significantly reduce pollutant emissions. Graphical abstract Image 1 Highlights • Atmospheric plasma system saves energy and reducing emission levels. • Formaldehyde, acetaldehyde and acrolein accounts for 75% of carbonyl compounds. • Higher plasma system voltage lowers pollutants emissions levels. • Improve engine performance as plasma system voltage reaches 6 kV. • PM concentration has been reduced considerably by higher plasma voltage. [ABSTRACT FROM AUTHOR]

Background: The immunotoxicity of engine exhausts is of high concern to human health due to the increasing prevalence of immune-related diseases. However, the evaluation of immunotoxicity of engine exhausts is currently based on expensive and time-consuming experiments. It is desirable to develop efficient methods for immunotoxicity assessment.Methods: To accelerate the development of safe alternative fuels, this study proposed a computational method for identifying informative features for predicting proinflammatory potentials of engine exhausts. A principal component regression (PCR) algorithm was applied to develop prediction models. The informative features were identified by a sequential backward feature elimination (SBFE) algorithm.Results: A total of 19 informative chemical and biological features were successfully identified by SBFE algorithm. The informative features were utilized to develop a computational method named FS-CBM for predicting proinflammatory potentials of engine exhausts. FS-CBM model achieved a high performance with correlation coefficient values of 0.997 and 0.943 obtained from training and independent test sets, respectively.Conclusions: The FS-CBM model was developed for predicting proinflammatory potentials of engine exhausts with a large improvement on prediction performance compared with our previous CBM model. The proposed method could be further applied to construct models for bioactivities of mixtures. [ABSTRACT FROM AUTHOR]

Abstract: Although many researches focused on the polychlorinated dibenzo-p-dioxins/dibenzofuran (PCDD/F) emissions from stack, in the bottom ash and in the surrounding environment, researches focused on PCDD/F mass distributions in the whole incineration plant have seldom been addressed. This study determined PCDD/F emissions in the whole plant. A high-resolution gas chromatograph/high-resolution mass spectrometer was utilized for analyzing 17 PCDD/F species. Experimental results displayed that PCDD/Fs were formed during fly ash from super heater (SH), economizer (EC), semi-dryer absorber (SDA) and fabric filter (FF) was transferred to fly ash pit. Mass distribution ratios of PCDD/Fs in g I-TEQ (Toxicity Equivalency Quantity) per week from stack, SH, EC, SDA, FF, generation and bottom residue (BR) in start-up operations were 14.6%, 0.1%, 8.3%, 1.0%, 41.7%, 33.4% and 0.9%, respectively. Above results indicated that main PCDD/F source in the MSWI was from fly ash. However, the fly ash is easily controlled and PCDD/F emitted from stack flue gases will be difficult to be handled. Therefore, we should pay more attention on PCDD/F emission from flue gases especially from start-up procedure. Besides, fly ash should be controlled by sodium hypophosphite before being landfilled. MSWI did require further detoxification treatments for the solid residues and flue gases. [Copyright &y& Elsevier]

This paper intend to investigate the effects of biodiesel fuel blends comprising of waste-cooking oil and butanol-diesel (B10W10–B10W40) under steady-state conditions. Both particulate organic carbon (OC) and PM including PM 2.5 and PM 10 significantly decreased with the increasing percentage of biodiesel fuel blends. The fuel blend of B10W40 also demonstrated the most effective function in reducing the emissions of PM 10 and PM 2.5 in the volume by 59.4% and 57.7%, respectively. Moreover, the emissions of nitrogen oxides decreased with the blending of B10W10-B10W40 (13.9–28.5%), while the brake specific fuel consumption was substantially increased (5.69–13.4%). The overall biological toxicity of PM 10 generated from the fuel tested in this study was determined according to Single Cell Gel Electrophoresis assay in human alveolar basal epithelial A549 cells and micronucleus assay in CHO-K1 cells. In addition, the volume of more than 20% waste-cooking oil (B10W20 and B10W40) significantly reduced diesel-induced genotoxicity in lung cells and micronucleus formation in CHO-K1 cells. Collectively, these results indicated that biodiesel fuel blends with the butanol could be a potential alternative fuels for diesel engines because of its substantial property with a significant reduction of the PM-related genotoxicity and the emissions of PM, particulate OC, and NO X . [ABSTRACT FROM AUTHOR]

Abstract: This work investigated the effects of induction of hydrogen and oxygen mixture (H2/O2) to a heavy-duty diesel engine (HDDE) on the thermal performance, fuel consumption and emission characteristics. The HDDE was tested at one low load steady-state condition, 24.5% of the max load (40km/h), using neat diesel and seven H2/O2 mixtures: 10–70L/min, interval 10L/min. The results show that brake thermal efficiency is increased from 31.1% for neat diesel to 39.9% for 70L/min of H2/O2 mixture. For 10–40L/min of H2/O2 mixture addition, the brake specific fuel consumption (BSFC) was higher than that of neat diesel. However, for 50, 60 and 70L/min of H2/O2 mixture addition, the BSFC was lower than that of neat diesel by about 3.2%, 9.9% and 10.5%, respectively. Due to improved combustion efficiency, the emission concentrations of hydrocarbon, carbon dioxide and carbon monoxide were all lowered, while those of the nitrogen oxides were increased. [Copyright &y& Elsevier]

Abstract: Biodiesels have received increasing attention as alternative fuels for diesel engines and generators. This study investigates the emissions of particulate matter (PM), total carbon (TC), e.g., organic/elemental carbons, and polycyclic aromatic hydrocarbons (PAHs) from a diesel generator fuelled with soy-biodiesel blends. Among the tested diesel blends (B0, B10 (10vol% soy-biodiesel), B20, and B50), B20 exhibited the lowest PM emission concentration despite the loads (except the 5kW case), whereas B10 displayed lower PM emission factors when operating at 0 and 10kW than the other fuel blends. The emission concentrations or factors of EC, OC, and TC were the lowest when B10 or B20 was used regardless of the loading. Under all tested loads, the average concentrations of total-PAHs emitted from the generator using the B10 and B20 were lower (by 38% and 28%, respectively) than those using pure petroleum diesel fuel (B0), while the emission factors of total-PAHs decreased with an increasing ratio of biodiesel to premium diesel. With an increasing loading, although the brake specific fuel consumption decreased, the energy efficiency increased despite the bio/petroleum diesel ratio. Therefore, soy-biodiesel is promising for use as an alternative fuel for diesel generators to increase energy efficiency and reduce the PM, carbon, and PAH emissions. [Copyright &y& Elsevier]