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Electric vehicles (EVs) have emerged as a promising solution to mitigate environmental degradation caused by transportation. The increased concerns over climate change and air pollution have accelerated the adoption of EVs globally. The use of renewable energy sources such as solar and wind power to charge EVs significantly reduces the emission of harmful gases, contributing to cleaner air and a healthier environment. The transition to EVs has the potential to create a significant positive impact on the environment, reducing the carbon footprint of the transportation sector. This study will explore the potential benefits of EVs for reducing greenhouse gas emissions, air pollution, and noise pollution. Furthermore, this research will consider the impact of EVs on the energy grid and investigate the feasibility of integrating renewable energy sources to power EVs. The study will also examine the economic and social implications of EV adoption and the potential for job creation in the EV industry. The findings of this research will contribute to a better understanding of the role that EVs play in mitigating the environmental impact of transportation. This research is especially relevant as the world moves towards a more sustainable and decarbonized future. Policymakers, industry leaders, and consumers can use the insights gained from this study to make informed decisions about the future of transportation and its impact on the environment. In conclusion, this study aims to provide a comprehensive assessment of the environmental impact of EVs and their potential to create a sustainable future for transportation.

Radiation and flame scale characteristics of ceiling jet are important key elements, which are related to the safety of hydrogen energy transport. In this study, the flame radiation characteristics caused by hydrogen-blended natural gas (mixed gas) pipeline leakage fire were investigated experimentally. The effects of heat release rate, hydrogen addition ratio, nozzle diameter and source-ceiling height are considered. The flame shape of the ceiling jet fire is modeled by a cylinder cone and a cylindrical model. The WSGGM model is applied to calculate the flame emissivity. The flame emissivity is quantized by the equivalent diameter and gas type. The flame emissivity, downward received radiative heat flux and radiative heat flux under ceiling increase with the increase of hydrogen addition ratio. The view factor is calculated by the solid flame model. Moreover, the calculated flame radiative heat flux is in a favorable agreement with experimental results. The research results may provide reference for risk assessment of hydrogen mixing. • Effect of H 2 on flame radiation of CH 4 jet fire is studied experimentally. • Fame shape of ceiling jet was modeled by the cylinder cone and a cylindrical model. • A mathematical model for the flame emissivity estimation is proposed. • A prediction model of the flame radiation the gas mixture is reported. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of equivalence ratio on pollutant formation characteristics of CH4O/H2/NH3 ternary fuel combustion and analyzes the pollutant formation mechanisms of CO, CO2, and NOX at the molecular level. It was found that lowering the equivalence ratio accelerates the decomposition of CH4O, H2, and NH3 in general. The fastest rate of consumption of each fuel was found at φ = 0.33, while the rates of CH4O and NH3 decomposition were similar for the φ = 0.66 and φ = 0.4. CO shows an inverted U-shaped trend with time, and peaks at φ = 0.5. The rate and amount of CO2 formation are inversely proportional to the equivalence ratio. The effect of equivalence ratio on CO2 is obvious when φ > 0.5. NO2 is the main component of NOX. When φ < 0.66, NOX shows a continuous increasing trend, while when φ ≥ 0.66, NOX shows an increasing and then stabilizing trend. Reaction path analysis showed that intermediates such as CH3 and CH4 were added to the CH4O to CH2O conversion stage as the equivalence ratio decreased with φ ≥ 0.5. New pathways, CH4O→CH3→CH2O and CH4O→CH3→CH4→CH2O, were added. At φ ≤ 0.5, new intermediates CHO2 and CH2O2 were added to the CH2O to CO2 conversion stage, and new pathways are added: CH2O→CO→CHO2→CO2, CH2O→CO→CO2, CH2O→CHO→CO→CHO2→CO2, and CH2O→CH2O2→CO2. The reduction in the number of radical reactions required for the conversion of NH3 to NO from five to two directly contributes to the large amount of NOX formation. Equivalent ratios from 1 to 0.33 corresponded to 12%, 21.4%, 34%, 46.95%, and 48.86% of NO2 remaining, respectively. This is due to the fact that as the equivalence ratio decreases, more O2 collides to form OH and some of the O2 is directly involved in the reaction forming NO2. [ABSTRACT FROM AUTHOR]

Hydrogen, ammonia, and methanol are typical carbon-neutral fuels. Combustion characteristics and pollutant formation problems can be significantly improved by their blending. In this paper, reactive molecular dynamics were used to investigate the pollutant formation characteristics of hydrogen/ammonia/methanol blended fuel combustion and to analyze the mechanisms of CO, CO2, and NOX formation at different temperatures and blending ratios. It was found that heating can significantly increase blending and combustion efficiency, leading to more active oxidizing groups and thus inhibiting N2 production. Blended combustion pollutant formation was affected by coupling effects. NH3 depressed the rate of CO production when CH4O was greater than 30%, but the amount of CO and CO2 was mainly determined by CH4O. This is because CH4O provides more OH, H, and carbon atoms for CO and CO2 to collide efficiently. CH4O facilitates the combustion of NH3 by simplifying the reaction pathway, making it easier to form NOX. [ABSTRACT FROM AUTHOR]

Air-staged and flue gas recycle (FGC) combustion are important technologies to reduce NOx emissions. This study explores FGC ratios on the NOx formation in the primary combustion zone under air-staged combustion for a HT-NR3 swirl burner at different air excess coefficients. The coal combustion characteristics including gas velocity, temperature, gas components and NOx emission under different FGC ratios were analyzed. The results show that higher the FGC ratio will larger the gas temperature decrease and lower the NOx emission. Combined FGC technology with lower air excess coefficients technology, the NOx emission at outlet of furnace will be further reduced. When the air consumption excess coefficient is 0.8 with FGC ratio 20%, the NOx concentration at the furnace outlet will decrease from 208ppm to 138ppm, lower 33.6%.

This article employs the CoFlame Code to investigate the effects of hydrogen addition to fuel on soot formation characteristics in laminar coflow methane/air diffusion flames at atmospheric pressure. Numerical calculations were carried out using a detailed C1-C2 gas phase reaction mechanism and a soot model consisting of two pyrene molecules colliding into a dimer as soot nucleation, hydrogen abstraction acetylene addition (HACA) and pyrene condensation as surface growth, and soot oxidation by O2, O and OH radicals. Calculations were conducted for five levels of hydrogen addition on volume basis. To quantify the chemical effect of hydrogen, additional calculations are performed for addition of inert pseudo-hydrogen (FH2). The addition of H2 or FH2 does not have a strong influence on flame temperature. The results confirm that hydrogen addition can inhibit soot formation in the methane/air diffusion flame by reducing both the nucleation and surface growth steps of soot formation process. The effect of FH2 addition on soot formation suppression is more remarkable than H2, indicating that the chemical effect of hydrogen added to methane prompts soot formation. The dilution effect of hydrogen addition on soot formation suppression is stronger than its chemical effect on soot formation enhancement the present findings are consistent with those of previous numerical studies.

V-modified phosphomolybdic acid catalysts (V-HPMo/TiO2) supported on TiO2 were developed for selective catalytic reduction of NOx with NH3 (NH3-SCR). The V-doping could promote the catalytic activity of HPMo catalysts. When the V/Mo molar ratio is 1, the NOx conversion of V-HPMo/TiO2 can reach over 99% and N2 selectivity is close to 100% in the temperature range of 200–350 °C. After introducing 200 ppm SO2 and 4 vol.% H2O in the feed gas, the catalytic activity decreased by 15% and recovered within 2 h after cutting off SO2 and H2O. V-HPMo/TiO2 catalysts exhibit outstanding redox property and resistance to SO2&H2O. V-doping can also increase the Lewis acid sites and N2 selectivity of HPMo/TiO2 catalysts. The in-situ DRIFTS results show that NH3-SCR reaction over V-HPMo/TiO2 catalysts follows L–H mechanism at low temperature (< 150 °C) and both E-R and L–H mechanisms at high temperature (> 150 °C). [ABSTRACT FROM AUTHOR]