Catalytic flash pyrolysis for recovery of gasoline-range hydrocarbons from electric cable residue using a low-cost natural catalyst: An analytical Py-GC/MS study.

This investigation's novelty and objective reside in exploring catalytic flash pyrolysis of cross-linked polyethylene (XLPE) plastic residue in the presence of kaolin, with the perspective of achieving sustainable production of gasoline-range hydrocarbons. Through proximate analysis, thermogravimetric analysis, and heating value determination, this study also assessed the energy-related characteristics of cross-linked polyethylene plastic residue, revealing its potential as an energy source (44.58 MJ kg-1) and suitable raw material for pyrolysis due to its low ash content and high volatile matter content. To understand the performance as a low-cost catalyst in the flash pyrolysis of cross-linked polyethylene plastic residue, natural kaolin was subjected to characterization through thermogravimetric analysis, X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray fluorescence (XRF). Cross-linked polyethylene plastic residue was subjected to thermal and catalytic pyrolysis in an analytical microreactor coupled to gas chromatography-mass spectrometry (Py-GC/MS system), operating at 500 °C, to characterize the distribution and composition of volatile reaction products. The application of kaolin as a catalyst resulted in a decline of the relative concentration of hydrocarbons in the diesel range (C8-C24) from approximately 87 % to 28 %, and a reduction in lubricating oils (C14-C50) from about 70 % to 13 %, while concomitantly increasing the relative concentration of lighter hydrocarbons in the gasoline range (C8-C12) from around 28 % to 87 %. Therefore, catalytic flash pyrolysis offers the potential for converting this plastic waste into a new and abundant chemical source of gasoline-range hydrocarbons. This process can be deemed viable and sustainable for managing and valorizing cross-linked polyethylene plastic residue.

Will changes in charging and gasoline prices affect electric vehicle sales? Evidence from China.

Electric vehicles and gasoline vehicles are substitutes for each other, and the cost of fuel is an important factor when consumers are faced with choices. Understanding the influence of changes in gasoline prices and charging prices on electric vehicle sales is of reference significance for promoting electric vehicles in the private sector. This paper uses data covering 212 prefecture-level cities from January, 2020, to August, 2022, for analysis, and the results show that different income groups have different sensitivities to the difference in oil and electricity prices. Additionally, changes in gasoline prices and charging prices will significantly affect electric vehicle sales in low-income and middle-income cities, electric vehicle sales in high-income cities will not be affected. Compared with nonpilot cities, residents of pilot cities are more sensitive to fuel price changes, indicating that the policy basis has a certain positive effect on the promotion of electric vehicles. It is recommended to consider the income status of regional residents when formulating policies for the use of electric vehicles. At the same time, publicity efforts should be increased to highlight the gap between the cost of fuel vehicles and electric vehicles.

Developing a carbon footprint model and environmental impact analysis of municipal solid waste transportation: A case study of Tehran, Iran.

The greenhouse gas emitted due to transportation is the third greatest emitter globally, and its impact has become a threat to the environment, public health, and economic development. Waste transportation is excluded in studies of waste management despite its significant environmental impacts such as global warming and human toxicity. The objective of this study is to develop a quantification model to estimate the carbon footprint of waste transportation and environmental impact assessments in three categories applied in Tehran using IPCC guidelines. In Tehran, light and heavy vehicles ran on diesel fuel. Data on fuel and waste characteristics were provided by Tehran's department of transportation and municipality, respectively. In this study, transport-related emissions are 8.47 k tonCO2eq/y, and the carbon footprint of waste transportation is 93.57 g of CO2 eq per ton of waste transported (t.km), which is relevant to three main parameters: the amount of waste transported annually, the freight shipped from the temporary station to the disposal landfill site, and fossil fuels consumed. Also, an environmental impact assessment in three categories - human health (global warming, abiotic depletion, and ozone layer depletion), resources (fossil fuels), and ecosystem quality (acidification and eutrophication) - using SimaPro, a Life Cycle Assessment (LCA) tool is presented. Global warming (3.49 kg CO2 eq/t MSW), human toxicity (0.95 kg 1,4-DB eq/t MSW), and freshwater aquatic eco-toxicity (0.04 kg 1,4-DB eq/t MSW) have the greatest impact among categories. Sensitivity analysis of the effective parameters allows us to conclude one of the potential implications of this study would be the introduction of natural gas or biogas-based trucks replacing diesel fuel vehicles to improve air quality and mitigate the greenhouse gas emission.Implications: This paper addresses the significant issue of global warming, particularly in Iran, a developing country that ranks among the top contributors to greenhouse gas emissions. The study emphasizes the importance of evaluating emissions across various sectors such as electricity, waste, etc., Specifically, in this paper we focus on developing a model to quantify the environmental impact resulting from the combustion of fossil fuels in vehicles, focus on the metropolitan city of Tehran as a case study. By examining the waste transportation process, we aim to provide decision-makers with effective strategies to mitigate the environmental consequences. In this paper, we develop a simple quantification term of Carbon Footprint to calculate total greenhouse gas emission of waste transportation process. Carbon Footprint is a fraction which, its numerator is total greenhouse gas emission and its denominator is total waste transported in traveled distance. Effective parameters have been investigated and based on parameters and emission factors taken out of IPPC, the carbon footprint model have been developed. The total greenhouse gas emission of this study and the carbon footprint has estimated at 8.47 k tonCO2eq/y and 93.57 g CO2eq/t.km respectively. Furthermore, the paper explores additional environmental impacts beyond global warming, including abiotic depletion, ozone layer depletion, acidification, eutrophication, human toxicity, photochemical oxidation, and freshwater aquatic eco-toxicity. Using SimaPro software these eight impact categories have been estimated. in this study we identify fossil fuel consumption, traveled distance, and mass transported are the primary parameters influencing greenhouse gas emissions and the carbon footprint. To reduce emissions in the waste transportation system, we suggest promoting renewable biofuels, highlighting Iran as a suitable candidate due to its high percentage of biodegradable material in municipal solid waste. Additionally, the study assesses nonrenewable energy and mineral extraction using the IMPACT 2002+ V2.15/IMPACT 2002+ method, revealing that global warming (100 years), human toxicity (100 years), freshwater aquatic eco-toxicity, nonrenewable energy, and mineral extraction have the most significant impacts on the municipal solid waste transportation system. Overall, this research underscores the need for quantifying environmental impacts and recommends strategies to mitigate them in waste transportation processes, particularly in developing countries like Iran.

Assessment and usability of Jatropha biodiesel blend with phenolic antioxidant to control NOx emissions of an unmodified diesel engine.

The excessive utilization of fossil fuels has worsened global warming and exacerbated the levels of air pollution in the environment, forcing us to consider alternative fuels for compression ignition engines. The current research aims to explore the possibilities of renewable fuels outperforming diesel fuel in terms of combustion, performance, and emission characteristics. Biodiesel is an environmentally friendly and renewable alternative fuel. The major drawback of biodiesel is the significant rise in nitrogen oxide (NOx) emissions. The main novelty and objective of this research is to investigate the performance and emission characteristics of variable compression ratio diesel engine using DPA antioxidant additive. For this investigation, diesel, Jatropha biodiesel (B30) and 100 ppm of phenolic antioxidant diphenylamine (DPA) blended with B30 have been used as fuel named B30+DPA100. From experimental outcomes, the inclusion of diphenylamine to B30 blend resulted in brake-specific fuel consumption (BSFC) and exhaust gas temperature (EGT) being reduced by 8.86% and 4.12%, respectively, compared to B30. Simultaneously, there was a 1.11% increase in brake thermal efficiency (BTHE). The B30+DPA100 fuel blend demonstrates effective control over NOx and other emissions. The emissions of NOx, carbon monoxide (CO), hydrocarbon (HC), and smoke from the B30+DPA100 blend have shown a reduction of 6.8%, 5.34%, 7.86%, and 15.67%, respectively, when compared to diesel. However, there has been an increase in carbon dioxide (CO2) by 7.8%. One notable advantage of the B30+DPA100 blend is the significant decrease in NOx emissions. Additionally, the cylinder pressure for B30+DPA100 has been lowered by 4.93% compared to B30. On the other hand, the net heat release rate (NHR) has experienced a 1.72% increase. The particle size of different elements present in the crankcase oil has been calculated by Zetasizer Nano. The analysis revealed varying particle sizes for different elements in the crankcase oil: aluminum (2.724 µm), chromium (2.78 µm), iron (2.423 µm), and lead (2.587 µm).

Optimization of Bauhinia parviflora biodiesel production for higher yield and its compatibility assessment with water and Di-tert-butyl peroxide emulsion.

The current study aims to attain a higher yield of biodiesel from Bauhinia tree seed wastes through process optimization using response surface methodology (RSM) and assess its compatibility in the diesel engine blended with water and Di-tert-butyl peroxide (DTBP). The Bauhinia parviflora biodiesel (BPB) transesterification originated using a fixed quantity of catalyst, and the transesterification process parameters such as oil-molar ratio (OMR), process temperature (PT), and reaction time (RT) were optimized. Fourier transform infrared spectroscopy (FTIR) and Gas chromatography-mass spectrometry (GC-MS)analysis were applied to characterize and quantify the BPB, and ASTM standards were followed to measure the properties. The prepared BPB (30%) was blended with 10% water and 2% BTBP to enhance the performance and emission characteristics of the BPB in the diesel engine. The optimization result implies that the higher yield of BPB (91.4%) was attained for OMR of 9.2:1, PT of 76 °C, and RT of 67 min. The FTIR report indicates that the carbon-based components are pretty good in the prepared BPB. The GC-MS report indicates that the fatty acids are converted into corresponding methyl esters, and the measured fuel properties are within the prescribed limits. The diesel engine's performance is effectively improved for the BPB blended with water and DTBP. The proposed fuel's overall improvement in hydrocarbon, carbon monoxide, smoke, and oxides of nitrogen emissions is 27.2%, 34.9%, 16.7%, and 11.2%, respectively.

Environment impact assessment of agricultural diesel engines utilizing biodiesel derived from phoenix sylvestris oil.

Uncontrolled emissions, massive price increases, and other factors encourage searching for a suitable diesel engine fuel alternative. In its processed form, vegetable oil biodiesel is an appealing green alternative fuel for compression ignition engines. Vegetable oil esters have qualities comparable to those of standard diesel fuel. As a result, biodiesel may be utilized to run a diesel engine without any further alterations. This article analyses the potential of Phoenix sylvestris oil, which may be found in forest belts across the globe, as a viable feedstock for biodiesel extraction. Phoenix sylvestris oil is found to be abundant in different forest belts worldwide. The free fatty acid must first be transformed into esters using catalytic acid esterification before proceeding to alkaline catalytic esterification. The molar ratio (6:1), catalyst concentration (1 wt%), reaction temperature (60 °C), and reaction time (2 h) have all been optimized for biodiesel extraction. Biodiesel produced had characteristics that were similar to standard biodiesel specifications. The biodiesel yield from Phoenix sylvestris oil was 92.3% under optimum conditions. The experimental results revealed that the Phoenix sylvestris oil biodiesel performed better than neat Phoenix sylvestris oil and its blends. Phoenix sylvestris oil blend produced better brake thermal efficiency with lower smoke, hydrocarbon, and CO emissions. The biodiesel produced from non-edible Phoenix sylvestris oil has the potential to be employed as a viable alternative to diesel fuel.

Techno-economic assessment of hydrotreated vegetable oil as a renewable fuel from waste sludge palm oil.

To date, the development of renewable fuels has become a normal phenomenon to solve the problem of diesel fuel emissions and the scarcity of fossil fuels. Biodiesel production has some limitations, such as two-step processes requiring high free fatty acids (FFAs), oil feedstocks and gum formation. Hydrotreated vegetable oil (HVO) is a newly developed international renewable diesel that uses renewable feedstocks via the hydrotreatment process. Unlike FAME, FFAs percentage doesn't affect the HVO production and sustains a higher yield. The improved characteristics of HVO, such as a higher cetane value, better cold flow properties, lower emissions and excellent oxidation stability for storage, stand out from FAME biodiesel. Moreover, HVO is a hydrocarbon without oxygen content, but FAME is an ester with 11% oxygen content which makes it differ in oxidation stability. Waste sludge palm oil (SPO), an abundant non-edible industrial waste, was reused and selected as the feedstock for HVO production. Techno-economical and energy analyses were conducted for HVO production using Aspen HYSYS with a plant capacity of 25,000 kg/h. Alternatively, hydrogen has been recycled to reduce the hydrogen feed. With a capital investment of RM 65.86 million and an annual production cost of RM 332.56 million, the base case of the SPO-HVO production process was more desirable after consideration of all economic indicators and HVO purity. The base case of SPO-HVO production could achieve a return on investment (ROI) of 89.03% with a payback period (PBP) of 1.68 years. The SPO-HVO production in this study has observed a reduction in the primary greenhouse gas, carbon dioxide (CO2) emission by up to 90% and the total annual production cost by nearly RM 450 million. Therefore, SPO-HVO production is a potential and alternative process to produce biobased diesel fuels with waste oil.

Performance and environmental impact assessment of diesel engine operating on high viscous punnai oil-diesel blends.

The increasing demand for energy consumption because of the growing population and environmental concerns has motivated the researchers to ponder about alternative fuel that could replace diesel fuel. A new fuel should be cheaply available, clean, efficient, and environmentally friendly. In this paper, the engine operated with neat punnai oil blends with diesel was investigated at various engine load conditions, keeping neat punnai oil and diesel as base fuels. The performance indicators such as brake specific energy consumption (BSEC), brake thermal efficiency (BTE), and exhaust gas temperature (EGT); emission indicators such as carbon monoxide (CO), oxides of nitrogen (NOx), and smoke opacity; and combustion parameters like cylinder pressure and heat release rate were examined. The brake thermal efficiency of diesel is 29.2%, whereas it was lower for neat punnai oil and its blends at peak load conditions. Concerning the environmental aspect, oxides of nitrogen emission showed a decreasing trend with higher smoke emissions for Punnai oil blends. Detailed combustion analysis showed that on smaller concentrations of punnai oil in the fuel blend, the duration of combustion has improved significantly. However, for efficiency and emissions, the P20 (20% punnai oil and 80% diesel) blend performs similar to that of diesel compared to all other blending combinations. When compared with diesel, the P20 blend shows an improvement in BSEC by 26.37%. It also performs closer in HC emission, a marginal increase in smoke opacity of 4% with reduced NOx and CO2 emission of 7.9% and 4.65% respectively. Power loss was noticed when neat punnai oil and higher blends were used due to the high density and low calorific value of punnai oil blends which leads to injecting more fuel for the same pump stroke.

Novel short-term national strategies to promote the use of renewable hydrogen in road transport: A life cycle assessment of passenger car fleets partially fuelled with hydrogen.

This work presents an energy analysis combined with a comparative environmental life cycle assessment (LCA) of eight different passenger car fleets that use renewable hydrogen and a conventional fuel (natural gas or gasoline) under the same total energy input and the same hydrogen-to-mixture energy ratio. The fleets under comparison involve vehicles that use the two fuels separately or in a mixture. Using Italy as an illustrative country, this research work aims to help policy-makers implement well-supported strategies to promote the use of hydrogen in road transport in the short term. The proposed strategies achieve a carbon footprint reduction between 7 % and 35 % with respect to their conventional fleet benchmark. Within the current context, the results suggest the energy and environmental suitability of using hydrogen blends as short-term solutions, involving vehicles that require minor modifications with respect to current compressed natural gas vehicles and gasoline vehicles, while paving the way for pure hydrogen mobility.

Cancer risk assessment and source apportionment of the gas- and particulate-phase of the polycyclic aromatic hydrocarbons in a metropolitan region in Brazil.

A risk assessment and a source apportionment of the particulate- and gas-phase PAHs were conducted in a high vehicular traffic and industrialized region in southeastern Brazil. Higher concentrations of PAHs were found during summer, being likely driven by the contributions of PAHs in the vapor phase caused by fire outbreaks during this period. Isomer ratio diagnostic and Principal Component Analysis (PCA) identified four potential sources in the region, in which the Positive Matrix Factorization (PMF) model confirmed and apportioned as gasoline-related (31.8%), diesel-related (25.1%), biomass burning (23.4%), and mixed sources (19.6%). The overall cancer risk had a tolerable value, with ∑CR = 4.6 × 10-5, being ingestion the major via of exposure (64% of the ∑CR), followed by dermal contact (33% of the ∑CR) and inhalation (3%). Mixed sources contributed up to 45% of the overall cancer risk (∑CR), followed by gasoline-related (up to 35%), diesel-related (up to 15%), and biomass burning (up to 10%). The risk assessment for individual PAH species allowed identifying higher CR associated with BaP, DBA, BbF, BaA, and BkF, species associated with gasoline-related and industrial sources. Higher risks were associated with PM2.5-bound PAHs exposure, mainly via ingestion and dermal contact, highlighting the need for measures of mitigation and control of PM2.5 in the region.

Assessment of the Actual Toxicity of Engine Exhaust Gas Emissions from Euro 3 and Euro 6 Compliant Vehicles with the BAT-CELL Method Using In Vitro Tests.

Legal restrictions on vehicle engine exhaust gas emission control do not always go hand in hand with an actual reduction in the emissions of toxins into the atmosphere. Moreover, the methods currently used to measure exhaust gas emissions do not give unambiguous results on the impact of the tested gases on living organisms. The method used to assess the actual toxicity of gases, BAT-CELL Bio-Ambient-Tests using in vitro tests, takes into account synergistic interactions of individual components of a mixture of gases without the need to know its qualitative and quantitative composition and allows for determination of the actual toxicity of the gas composition. Using the BAT-CELL method, exhaust gases from passenger vehicles equipped with spark-ignition engines complying with the Euro 3 and Euro 6 emission standards were tested. The results of toxicological tests were correlated with the results of chromatographic analysis. It was shown that diverse qualitative composition of the mixture of hydrocarbons determining the exhaust gases toxicity may decrease the percentage value of cell survival. Additionally, it was proven that the average survival of cells after exposure to exhaust gases from tested vehicles meeting the more restrictive Euro 6 standard was lower than for vehicles meeting the Euro 3 standard thus indicating the higher toxicity of exhaust gases from newer vehicles.

Assessment of carbon emission and primary energy input of a gasoline combustion-powered 2.0 T SUV in China.

With the use of vehicles, large amounts of carbon dioxide are emitted by combustion of gasoline and energy consumes in their lifecycle. Therefore, the objective of this study is to evaluate the lifecycle carbon emission and primary energy input of a widely used sport utility vehicle (SUV) in China with the lifecycle assessment method. The results show that total petrol consumption of an SUV in lifetime is 21,300 kg; the CO2 emissions and primary energy input in the manufacturing, assembly, operation, and decommissioning phase are respectively 8857, 443, 54,925, and 443 kg and 123,413, 6171, 12,341, and 6171 MJ. The average CO2 emission intensity and energy input intensity of materials are respectively 2.74 kg/kg and 64.9 MJ/kg. The primary energy input of materials in manufacturing phase occupies 83.3%, and CO2 emission in use phase is 64,267.3 kg (occupied 92.62%), mainly attributed to the combustion of petrol.

Health Status Assessment of Diesel Engine Valve Clearance Based on BFA-BOA-VMD Adaptive Noise Reduction and Multi-Channel Information Fusion.

Regarding the problem of the valve gap health status being difficult to assess due to the complex composition of the condition monitoring signal during the operation of the diesel engine, this paper proposes an adaptive noise reduction and multi-channel information fusion method for the health status assessment of diesel engine valve clearance. For the problem of missing fault information of single-channel sensors in condition monitoring, we built a diesel engine valve clearance preset simulation test bench and constructed a multi-sensor acquisition system to realize the acquisition of diesel engine multi-dimensional cylinder head signals. At the same time, for the problem of poor adaptability of most signal analysis methods, the improved butterfly optimization algorithm by the bacterial foraging algorithm was adopted to adaptively optimize the key parameter for variational mode decomposition, with discrete entropy as the fitness value. Then, to reduce the uncertainty of artificially selecting fault characteristics, the characteristic parameters with a higher recognition degree of diesel engine signal were selected through characteristic sensitivity analysis. To achieve an effective dimensionality reduction integration of multi-channel features, a stacked sparse autoencoder was used to achieve deep fusion of the multi-dimensional feature values. Finally, the feature samples were entered into the constructed one-dimensional convolutional neural network with a four-layer parameter space for training to realize the health status assessment of the diesel engine. In addition, we verified the effectiveness of the method by carrying out valve degradation simulation experiments on the diesel engine test bench. Experimental results show that, compared with other common evaluation methods, the method used in this paper has a better health state evaluation effect.

Assessment of particle and gaseous emissions and reductions from gasoline direct injection passenger car and light-duty truck during passive regeneration.

This study evaluated the effectiveness of two passive regenerating gasoline particulate filters (GPFs) on reducing both gaseous and particle phase pollutants from a gasoline direct inject (GDI) passenger car (PC) and light-duty truck (LDT). In the absence of filter regeneration, observations from this study are consistent with other studies demonstrating how particle number (PN), particulate matter (PM), and black carbon (BC) emissions were reduced from the two vehicles with the use of GPFs. The significance of this study was to demonstrate the ability of the GPF to mitigate gaseous and particulate pollutants during severe passive filter regeneration, which was often observed on the LDT during aggressive US06 drive cycle testing. Partial filter regeneration happened on the LDT during some FTP-75 tests, as well as on the PC during some US06 drive cycles, however, this did not impact the GPF filtration efficiency (FE) to reduce particulate and gaseous pollutants. Using a cleaner fuel with lower overall tailpipe PM emissions could potentially lead to more frequent partial regenerations. This could produce the benefit of lower exhaust back pressure during and immediately after regeneration but still provide sufficient reduction in both particle and gaseous emissions.

Biological toxicity risk assessment of two potential neutral carbon diesel fuel substitutes.

We investigated the biological response of soluble organic fraction (SOF) and water-soluble fraction (WSF) extracted from particulate matter (PM) emitted by an automotive diesel engine operating in a representative urban driving condition. The engine was fueled with ultra-low sulfur diesel (ULSD), and its binary blends by volume with 13% of butanol (Bu13), and with hydrotreated vegetable oil (HVO) at 13% (HVO13) and 20% (HVO20). Cytotoxicity, genotoxicity, oxidative DNA damage and ecotoxicity tests were carried out, and 16 polycyclic aromatic hydrocarbons (PAH) expressed as tbenzo(a)pyrene total toxicity equivalent (BaP-TEQ) were also analyzed. The Hepatocarcinoma epithelial cell line (HepG2) was exposed to SOF for 24 h and analyzed using comet assay, with the inclusion of formamidopyrimidine DNA glycosylase (FPG) and endonuclease III (Endo III) to recognize oxidized DNA bases. The WSF was evaluated through acute ecotoxicity tests with the aquatic microcrustacean Daphnia pulex (D. Pulex). Results showed that there was no cytotoxic activity for all tested SOF concentrations. Genotoxic responses by all the SOF samples were at same level, except for the HVO13 which was weaker in the absence of the enzymes. The addition of the FPG and Endo III enzymes resulted in a significant increase in the comet tail, indicating that the DNA damage from SOF for all tested fuel blends involves oxidative damage including a higher level of oxidized purines for ULSD and Bu13 in comparison with HVO blends, but the oxidized pyrimidines for HVO blends were slightly higher compared to Bu13. The WSF did not show acute ecotoxicity for any of the fuels. Unlike other samples, Bu13-derived particles significantly increase the BaP-TEQ. The contribution to the genotoxic activity and oxidative DNA from SOF was not correlated to BaP-TEQ, which means that the biological activity of PM might be affected also by other toxic compounds present in particulate phase.

Are electric vehicles cost competitive? A case study for China based on a lifecycle assessment.

Promoting the development of electric vehicles (EVs) is regarded as an important measure to ensure energy security, mitigate climate change, and solve the transport sector's air pollution problems. Nowadays, compared to gasoline vehicles, whether the EVs are more competitive in terms of cost is still a question. There is no consensus achieved since the total cost depends on the development stage of the automobile industry and power generation structure as well as the cost accounting boundary. Many of existing studies did not include the costs occurred in all the stages. In response to this concern, this study estimates the lifecycle cost covering the whole process of production, use, disposal, and infrastructure construction as well as externalities for passenger battery electric vehicle (BEV), fuel cell vehicle (FCV), and gasoline vehicle (GV) by applying the comprehensive lifecycle cost model to China. The results indicate that in 2018, BEV and FCV were more expensive than GV (1.2-5.3 times), but that BEV will become cheaper after 2025, and its cost advantage will be enlarged to $419 (5%) compared to GV by 2030. The lifecycle cost of FCV will be $527 (or 5%) lower than that of GV by 2030. These results clarify that the costs of vehicle production account for the largest proportion in the total lifecycle cost.

Seasonality, atmospheric transport and inhalation risk assessment of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from industrial belts of Odisha, India.

This study is the first attempt to assess the presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) enlisted by the US Environmental Protection Agency in PM2.5 and PM10 from industrial areas of Odisha State, India. During 2017-2018, bimonthly sampling of PM10 and PM2.5 was carried out for 24 h in the industrial and mining areas of Jharsuguda and Angul in Odisha during the pre-monsoon, monsoon, and post monsoon seasons. Highest mean concentration of ∑16PAHs in PM2.5 was observed during the post monsoon (170 ng/m3) period followed by pre-monsoon (48 ng/m3) and monsoon (16 ng/m 3) periods, respectively. A similar trend of ∑16PAHs was also observed in PM10 with higher levels observed during post monsoon (286 ng/m3) followed by pre-monsoon (81 ng/m3) and monsoon (27 ng/m3) seasons. Diagnostic ratios and principal component analysis suggested diesel, gasoline and coal combustion as the major contributors of atmospheric PAH pollution in Odisha. Back trajectory analysis revealed that PAH concentration was affected majorly by air masses originating from the northwest direction traversing through central India. Toxic equivalents ranged between 0.24 and 94.13 ng TEQ/m3. In our study, the incremental lifetime cancer risk ranged between 10-5 and 10-3, representing potential cancer risk.

Assessment of In-Use NOx Emissions from Heavy-Duty Diesel Vehicles Equipped with Selective Catalytic Reduction Systems.

This work evaluated the nitrogen oxide (NOx) emissions of 277 heavy-duty diesel vehicles (HDDVs) from three portable emission measurement system testing programs. HDDVs in these programs were properly maintained before emission testing, so the malfunction indicator lamp (MIL) was not illuminated. NOx emissions of some HDDVs were significantly higher than the certification standard even during hot operations where exhaust temperature was ideal for selective catalytic reduction to reduce NOx. For engines certified to the 0.20 g/bhp-hr NOx standard, hot operation NOx emissions increased with engine age at 0.081 ± 0.016 g/bhp-hr per year. The correlation between emissions and mileage was weak because six trucks showed extraordinarily high apparent emission increase rates reaching several multiples of the standard within the first 15,000 miles of operation. The overall annual increase in NOx emissions for the HDDVs in this study was two-thirds of what was observed in real-world emissions for HDDVs at the Caldecott Tunnel over the past decade. The vehicles at the Caldecott Tunnel would include those without proper maintenance, and the inclusion of these vehicles possibly explains the difference in the rate of emission increase. The results suggest that HDDVs need robust strategies to better control in-use NOx emissions.

An Assessment on Ethanol-Blended Gasoline/Diesel Fuels on Cancer Risk and Mortality.

Although cancer is traditionally considered a genetic disease, the epigenetic abnormalities, including DNA hypermethylation, histone deacetylation, and/or microRNA dysregulation, have been demonstrated as a hallmark of cancer. Compared with gene mutations, aberrant epigenetic changes occur more frequently, and cellular epigenome is more susceptible to change by environmental factors. Excess cancer risks are positively associated with exposure to occupational and environmental chemical carcinogens, including those from gasoline combustion exhausted in vehicles. Of note, previous studies proposed particulate matter index (PMI) as a measure for gasoline sooting tendency, and showed that, compared with the other molecules in gasoline, 1,2,4-Trimethylbenzene, 2-methylnaphthalene and toluene significantly contribute to PMI of the gasoline blends. Mechanistically, both epigenome and genome are important in carcinogenicity, and the genotoxicity of chemical agents has been thoroughly studied. However, less effort has been put into studying the epigenotoxicity. Moreover, as the blending of ethanol into gasoline substitutes for carcinogens, like benzene, toluene, xylene, butadiene, and polycyclic aromatic hydrocarbons, etc., a reduction of secondary aromatics has been achieved in the atmosphere. This may lead to diminished cancer initiation and progression through altered cellular epigenetic landscape. The present review summarizes the most important findings in the literature on the association between exposures to carcinogens from gasoline combustion, cancer epigenetics and the potential epigenetic impacts of biofuels.

Fuel-cell technologies for private vehicles in Brazil: Environmental mirage or prospective romance? A comparative life cycle assessment of PEMFC and SOFC light-duty vehicles.

Fuel cell vehicles (FCV) have been proclaimed as a zero-tailpipe emissions alternative for passenger transportation; however, their overall environmental performance must be evaluated on a per-case basis. Although the environmental impacts (EI) of FCV have been already described in the literature, there is no evidence of comprehensive life cycle assessment studies analyzing the Brazilian case and its unique features, such as, the availability of biogenic feedstocks for hydrogen production via steam reform, high share of renewables in the electricity mix and the a novel powertrain technology based on solid-oxide fuel cells (SOFC) which could run on bioethanol. The purpose of this study was to quantify the EIs of polymer-electrolyte fuel cell (PEMFC) vehicles when hydrogen is produced in Brazilian conditions for a current and a 2030 scenario. Additionally, we intended to quantify the EIs of a prospective SOFC vehicle. Considering the significant burden of hydrogen production, we further aimed to explore several pathways and feedstocks for production. We found that SOFC vehicles could become a competitive alternative for impact mitigation in 2030. Most significant impact reductions are not likely to arise from fuel cell weight reduction as its burden is low compared to other car components or fuel production. As for today, PEMFC vehicles would not be competitive for any evaluated impact category. In fact, for global warming potential (GWP), they perform as bad as gasoline-fueled conventional vehicles. Assuming a centralized hydrogen production scheme, the distribution infrastructure was not a large contributor on a per-km basis. Nevertheless, building an entire hydrogen production and distribution infrastructure could be avoided under the SOFC powertrain technology. The environmental modelling of the SOFC was bound to uncertainties due to the lack of data. For GWP, the current ICEV ethanol car is competitive even for 2030 technologies, assuming the land does not come from deforestation.