Automobile Exhaust Pollution Research Articles

Hydrogen doping control method for gasoline engine acceleration transient air-fuel ratio

One of the primary contributors to automobile exhaust pollution is the significant deviation between the actual and theoretical air-fuel ratios during transient conditions, leading to a decrease in the conversion efficiency of three-way catalytic converters. Therefore, it becomes imperative to enhance fuel economy, reduce pollutant emissions, and improve the accuracy of transient control over air-fuel ratio (AFR) in order to mitigate automobile exhaust pollution. In this study, we propose a Linear Active Disturbance Rejection Control (LADRC) Hydrogen Doping Compensation Controller (HDC) to achieve precise control over the acceleration transient AFR of gasoline engines. By analyzing the dynamic effects of oil film and its impact on AFR, we establish a dynamic effect model for oil film and utilize hydrogen's exceptional auxiliary combustion characteristics as compensation for fuel loss. Comparative experimental results demonstrate that our proposed algorithm can rapidly regulate the AFR close to its ideal value under three different transient conditions while exhibiting superior anti-interference capability and effectively enhancing fuel economy.

Formation of atmospheric molecular clusters containing nitric acid with ammonia, methylamine, and dimethylamine.

This study investigates the formation of atmospheric molecular clusters containing ammonia (NH3, A), methylamine (CH3NH2, MA), or dimethylamine (CH3NHCH3, DMA) with nitric acid (HNO3, NA) using quantum mechanics. The Atmospheric Cluster Dynamic Code (ACDC) was employed to simulate the total evaporation rate, formation rate, and growth pathways of three types of clusters under dry and hydrated conditions. This study evaluates the enhancing potential of A/MA/DMA for NA-based new particle formation (NPF) at parts per trillion (ppt) levels. The results indicate that A/MA/DMA can enhance NA-based NPF at high nitric acid concentrations and low temperatures in the atmosphere. The enhancing potential of MA is weaker than that of DMA but stronger than that of A. Cluster growth predominantly follows the lowest free energy pathways on the acid-base grid, with the formation of initial acid-base dimers (NA)(A), (NA)(MA), and (NA)(DMA) being crucial. Hydration influences the evaporation rate and formation rate of clusters, especially for initial clusters. When the humidity is at 100%, the formation rate for NA-A, NA-MA, and NA-DMA clusters can increase by approximately 109, 107, and 104-fold compared to the corresponding unhydrated clusters, respectively. These results highlight the significance of nitric acid nucleation in NPF events in low-temperature, high-humidity atmospheres, particularly in regions like China with significant automobile exhaust pollution.

Air pollution reduction during COVID-19 lockdown in China: a sustainable impact assessment for future cities development

COVID-19 has significantly impacted people's daily lives worldwide in the past three years. During the COVID-19 lockdown in China, people's activities were restricted, private cars were banned, and some factories were shut down. It is expected that air pollution would be mitigated due to the reduction of automobile exhaust and factory pollution gas emissions during the COVID-19 lockdown. In this study, a city-level comparative study was investigated to quantify the impact of lockdown on air pollution in China. The concentration changes of air pollutants (NO2, SO2, CO, PM2.5, PM10) caused by the lockdown are studied covering 345 cities in China. The sensitivity analysis method was adopted to explore the variation scale of pollutant concentration in typical cities. Furthermore, the spatial distribution of pollutant changes between 2019 and 2020 and typical months are discussed using a composite index. The results showed that NO2, SO2 and PM10 concentrations had a significant reduction due to the lockdown, ranging from 15 to 30%. Pollutant emissions of 321 cities in February and March 2020 fell noticeably, and 272 cities showed a rebound of pollutant emissions after April 2020 when work and production resumed. The lessons learned from COVID-19 lockdowns offer valuable insights into how cities can better prepare for future crises and improve their resilience and adaptability.

Design and Simulation of the Power Transmission System of extended range electric Vehicle based on MATLAB/Simulink

With the rapid growth of automobile ownership, energy shortage and exhaust pollution have become the two major problems restricting the development of automobiles. Electric vehicles with zero fuel consumption and pollution-free advantages are the future direction of development. But battery technology is not mature at this stage, and the driving distance of electric vehicles is short. Extended range electric vehicle is a hybrid electric vehicle equipped with a range extender based on a pure electric vehicle. When the power is sufficient, the whole vehicle runs with pure electric power. When the power is insufficient, the range extender works to drive the vehicle. As a kind of electric vehicle that can extend driving range, the extended-range electric vehicle has great research significance at present. In this paper, based on MATLAB/Simulink platform, the simulation model of the vehicle power transmission system is built by using the experimental modeling method. According to the model, the dynamic performance simulation of the extended-range electric vehicle is carried out, and the rationality of parameter matching of the vehicle components is verified.

ETMS: Efficient Traffic Management System for Congestion Detection and Alert using HAAR Cascade

Rapid social development has resulted in the emergence of a new major societal issue: urban traffic congestion, which many cities must address. In addition to making it more difficult for people to get around town, traffic jams are a major source of the city's pollution crisis. In order to address the problems of automobile exhaust pollution and congestion, this paper uses the system dynamics approach to develop a model to study the urban traffic congestion system from the perspectives of trucks,private cars, bikes and public transportation. This project proposes a system for detecting vehicles and sending alerts when traffic levels rise to dangerous levels using Haar Cascade and Fuzzy Cognitive Maps (FCP). The proposed system uses Haar Cascade to detect moving vehicles, which are then classified using FCP. The system can make decisions based on partial or ambiguous information by utilising FCP, a soft computing technique, which allows it to learn from past actions. An algorithm for estimating traffic density is also used by the system to pinpoint active areas. In congested areas, the system will alert the driver if it anticipates a collision with another vehicle and also Experiments show that the proposed system is able to accurately detect vehicles and provide timely alerts to the driver, drastically lowering the probability of accidents occurring in heavily travelled areas.
 The importance of introducing such a system cannot be overstated in today's transportation system. It's a big deal for the future of intelligent urban planning and traffic control. Congestion relief, cleaner air, and increased security are just some of the long-term benefits that justify the high initial investment. To add, this system is adaptable to suburban and rural areas, which can also experience traffic congestion issues.

Characterization of Chemical Components and Optical Properties of Toluene Secondary Organic Aerosol in Presence of Ferric Chloride Fine Particles

Iron ion is the common transition metal ion in atmospheric aerosol, which can affect the components and optics of secondary organic aerosol (SOA). In the current study, the atmospheric photooxidation of toluene to produce SOA in the presence of ferric chloride fine particles is simulated in a smog chamber; on-line and off-line mass spectrometry and spectroscopic instruments are used to characterize constituents and optics of SOA. Compare with SOA formed in the absence of fine particles, the laser desorption/ionization mass spectra of toluene SOA generated in the presence of ferric chloride fine particles show ion peaks of m/z = 163 and 178, the UV-Vis spectra of the extracting solution for toluene SOA have peaks near 400 and 700 nm, and the electrospray ionization mass spectra contain peaks at m/z = 248 and 300. Based on this spectral information, it is shown that gaseous methylcatechol formed from photooxidation of toluene may react with iron ion on the surface of fine particles by complexing and oxidation–reduction, resulting in methylbenzoquinone products and metallo-organic complex ions such as [Fe(III)(CH3C6H3OO)]+, [Fe(III)(CH3C6H3 OO)2]− and [Fe(III)(CH3C6H3OO)Cl2]−. These products have strong light absorption ability, resulting in an increase in the averaged mass absorption coefficient (<MAC>) in the 200~1000 nm range and the MAC at 365 nm (MAC365) for toluene SOA, while <MAC> and MAC365 progressively increase with an increasing concentration of ferric chloride fine particles. These results serve as experimental references for the study of the formation mechanism and optical properties of metallo-organic complexes in atmospheric aerosol particles in regions experiencing high levels of fine particles of metal and automobile exhaust pollution.

Theoretical Study on the Electrochemical Catalytic Activity of Au-Doped Pt Electrode for Nitrogen Monoxide

In order to gradually reduce automobile exhaust pollution and improve fuel quality, the NOx sensor, which can be monitored in real time in an automobile engine’s electronic control system, has become an indispensable part of the automobile lean burn system. In these types of NOx sensors, Au-doped platinum electrodes have received great attention due to their selectivity towards NO. However, the reaction process of NO gas on the Au-doped platinum electrode in the sensor and the possible regulation mechanism is still unclear. In this paper, the density functional theory (DFT) was used to analyze the effect of Au-doped Pt electrodes on the performance of nitrogen oxide sensors in automobiles. Firstly, the adsorption energies of NO molecules on pure Pt and Au/Pt surfaces were compared. The adsorption and dissociation of NO on Pt substrates doped with Au monomers, dimers, and trimers were investigated. These results showed that Au can effectively weaken the adsorption energy of NO molecules on a Pt surface. It was noted that with the increase in the number of Au atoms on the surface of Pt(111), the adsorption capacity of NO molecules on the alloy surface becomes weaker. When observing the transition state of NO decomposition on three different alloy surfaces, the study showed that the activation energy and reaction heat of NO dissociation increased. It further showed that doping with Au increased the activation energy of NO decomposition, thereby effectively inhibiting the decomposition of NO.

Optimization of urban rail transit station spacing for minimizing passenger travel time

Urban rail transit, regarded as the backbone of urban public transportation, can effectively solve the problems of urban traffic congestion and automobile exhaust pollution. However, due to improper planning, unreasonable station location often appears, which seriously affects the service access and mobility of rail transit. In order to improve the station spacing and passenger transport efficiency, a calculation model of station spacing for minimizing passenger travel time was established. In order to enhance the adaptability of the model in different cities, the grid road network and radial road network are considered when establishing the model. The results show that the station spacing is related to the passenger access/egress speed, the passenger travel distance, the maximum train running speed, the train stop time and the train acceleration. The influence of these parameters on the station spacing is obtained through the control variate method, and there are indeed obvious differences under different road network conditions. The research results can provide theoretical reference for station planning of new lines. Since the station spacing of the operated lines cannot be changed, this study can provide reference for skip-stop operation.

Control Measures for Automobile Exhaust Emissions in PM2.5 Governance

This paper analyses the correlation between automobile exhaust, PM2.5, and air pollution to explore the rate of contribution of automobile exhaust to PM2.5 pollution and the effect of government regulation on automobile exhaust gas. The results show that the atmosphere is hazy and that car exhaust is the main cause of PM2.5 pollution. This paper divides the governance strategy into two methods: reducing the number of motor vehicles and reducing the emissions capacity of motor vehicles. It also analyses the effects of congestion control on public car travel and establishes a dynamic game model. To strengthen the influence of supervision on enterprises with regard to purifying devices and restrictions, this study also creates a “prisoner’s dilemma” model. The final results of the study show that restriction measures can effectively relieve road pressure. Additionally, congestion costs can alleviate environmental pressure, but it is difficult to determine the costs, and the difficulty of implementation increases. Increasing enterprises’ installation of purifying devices is not advisable or desirable in the short term. Finally, the paper offers some suggestions for the maintenance of the atmospheric environment and the management of automobile exhaust: (1) improve the national green transport system and environmental protection awareness; (2) advocate public transport as a mode of travel; and (3) reduce the use of buses and popularize new energy vehicles.

The Harm and Countermeasures of Automobile Exhaust Pollution Based on Deep Reinforcement Learning

The Harm and Countermeasures of Automobile Exhaust Pollution Based on Deep Reinforcement Learning

Research progress on air pollutant distribution in urban street canyons

Urban street canyon is one of the most important characteristics and spatial forms of cities. It is one of the most frequently used public spaces in cities, with the most serious automobile exhaust pollution and the largest population density. The unreasonable space configuration and internal composition might decrease self-purification of urban ventilation but increase local air pollutant concentration. Here, we reviewed the impacts of street canyon morphology, street trees, vehicle flow and meteorological factors on the distribution of air pollutants in street canyons. We scrutinized the relevant methods of numerical simulation, wind tunnel experiments, and field monitoring on the distribution and diffusion of air pollutants in street canyons. We recommended that future research should concentrate on the impacts of various parameters on the distribution and diffusion of air pollutants based on the field monitoring data. Meanwhile, further research should develop optimization strategies for street canyon design which is conducive to the dispersion of air pollutants, and put forward scientific support and optimization scheme for the controlling of air pollutants from the perspective of urban planning and pattern optimization.

Multi-Objective Nonlinear Programming Model for Reducing Octane Number Loss in Gasoline Refining Process Based on Data Mining Technology

To simultaneously reduce automobile exhaust pollution to the environment and satisfy the demand for high-quality gasoline, the treatment of fluid catalytic cracking (FCC) gasoline is urgently needed to minimize octane number (RON) loss. We presented a new systematic method for determining an optimal operation scheme for minimising RON loss and operational risks. Firstly, many data were collected and preprocessed. Then, grey correlative degree analysis and Pearson correlation analysis were used to reduce the dimensionality, and the major variables with representativeness and independence were selected from the 367 variables. Then, the RON and sulfur (S) content were predicted by multiple nonlinear regression. A multi-objective nonlinear optimization model was established with the maximum reduction in RON loss and minimum operational risk as the objective function. Finally, the optimal operation scheme of the operating variable corresponding to the sample with a RON loss reduction greater than 30% in 325 samples was solved in Python.

Study on mitigation of automobile exhaust pollution in an urban street canyon: Emission reduction and air cleaning street lamps

Affected by the rapid growth of the number of fuel motor vehicles, the automobile exhaust pollution in the street canyon is becoming more and more serious. Different from the pollution source control technology usually used for outdoor air pollution control, an air cleaning street lamp is designed in this work. A 3D steady numerical model with line source pollution is established to simulate the air flow and pollutant diffusion in street canyons and validated. Then, the distributions of pollutants in 90 scenarios of street canyons are numerically simulated. The results show that wind direction and wind speed have great influence on pollutants diffusion in street canyons. Air quality in street breathing zones is improved with the reduction of emission; however, the air quality inside the street canyon is still worse than that outside the street canyon. Scenario with air cleaning street lamps with four 45° downward air outlets is shown to work better in improving air quality. In most of the studied cases, air cleaning street lamps are found to be more effective than reducing emissions from automobiles. A better method to improve the air quality in street canyons is to combine emission reduction measures and air cleaning street lamps. For the high-pollution breathing zone under perpendicular, oblique and parallel approaching wind directions, by this better method the mean PM concentration decreases by 14.38%, 7.68% and 17.78%, respectively; the mean NOx concentration decreases by 24.92%, 21.33% and 29.03%, respectively; the mean CO concentration decreases by 12.77%, 7.45% and 15.05%, respectively.

Laboratory Study on Performance Evaluation and Automobile Exhaust Degradation of Nano‐TiO2 Particles‐Modified Asphalt Materials

Automobile exhaust pollution is a serious problem that restricts urban development, and it poses a serious threat to people’s lives and health and even the climate. At present, the treatment of automobile exhaust has attracted people’s attention, and numerous works have been focused on it thereafter. The purpose of the present study is to drive TiO2 nanoparticles application into pavement, and the study present an experimental investigation of performances and automobile exhaust purification of asphalt and its mixture modified by nano‐TiO2. In this work, a series of rheometer properties and pavement performances were studied, including penetration, softening point, ductility, DSR and BBR for asphalt binder, conventional pavement performances, and creep test for asphalt mixture. Moreover, the photocatalytic degradation test of automobile exhaust was conducted to assess degradation of TiO2 nanoparticles in the asphalt mixture on automobile exhaust. Results indicate that the TiO2 nanoparticle was beneficial to increase the viscosity and reduce the temperature sensitivity, which would enhance its high‐temperature stabilization capability of asphalt. Meanwhile, nano‐TiO2 can significantly enhance the rheometer properties of asphalt and its capacity of high‐temperature antirutting, and its low‐temperature performance could also comply with the specification. Besides, the incorporation of nano‐TiO2 in mixtures could effectively enhance the antirutting and anticracking as well as water stabilization. Moreover, the nano‐TiO2‐modified asphalt mixture possesses a positive impact on photocatalytic degradation of CH and NOx, which could provide a reference for the treatment of automobile exhaust. The photocatalytic degradation effect of asphalt mixtures modified by nano‐TiO2 on NOx is significantly better than that of CH.

A cross-sectional study of pulmonary function tests among the municipal street sweepers of Chitradurga District, Karnataka

Municipal street sweepers are exposed to large amount of dusts, microorganisms, toxins and automobile exhaust pollution. Chronic inhalation of such particulate matter has the potential to impair their pulmonary functions. The strict adherence to the standards and norms for the management of municipal solid wastes to reduce occupational health hazards in developing countries India is still a matter of concern. This study conducted among the municipal sweepers of Chitradurga district, compared the effects of chronic exposure to dust on the pulmonary function using spirometry test. This study also assessed the effects of smoking and irregular usage of protection masks, and compared the results with the healthy controls. Respiratory symptoms of cough (30%), chest pain (17.5%), catarrah and sneezing (21.5%) were found to be in higher percentage among the municipal street sweepers than the controls. Only 20% of participants municipal street sweepers used personal protective measures, wearing protective masks, regularly in the past 1 year, during sweeping streets. It was found that FEV1, FEV1/FVC, PEFR and FEF 25%-75% were significantly lesser among non-smoker street sweepers, when compared with that of non-smoking controls. Similarly these PFT values were significantly reduced among the smoker street sweepers and among the sweepers who didn’t use protective masks while sweeping. This study highlights the occupational hazard faced by municipal sweepers and attempts to emphasize on importance of usage of protective masks. Keywords: Street sweepers; Personal Protective Measures; Dust; Spirometry.

Automobile pollution control using catalysis

The emissions of pollutants from vehicles are generally low but the numbers of vehicles increasing on the road therefore the environmental pollutions are also increases. About 35% of CO, 30% of HC and 25% percent of NOx produced into the atmosphere is from the transportation sector. These pollutants have adverse effects on the environment and human health. The emissions from vehicles are generally depends upon the air–fuel ratio. The control techniques for exhaust gas emissions are engine modifications, fuel pretreatment, fuel additives, exhaust gas recirculation (EGR), positive crankcase ventilation (PCV) and an application of catalytic converters. A catalytic converter is a device that converts more toxic exhaust gas pollutants into less toxic pollutants. There are different types of catalysts used in the automobile exhaust gas treatment like noble metal and base metals catalysts etc. The catalytic converter was effective and consistent for reducing the noxious tailpipe emissions so that it was developed for use in the trucks, buses, cars, motorcycles and other construction equipped. This paper will discuss about the different types of recent developments in catalysis for automobile exhaust pollution control.

Automobile Exhaust Removal Performance of Pervious Concrete with Nano TiO2 under Photocatalysis.

The urban environment is facing serious problems caused by automobile exhaust pollution, which has led to a great impact on human health and climate, and aroused widespread concern of the government and the public. Nano titanium dioxide (TiO2), as a photocatalyst, can be activated by ultraviolet irradiation and then form a strong REDOX potential on the surface of the nano TiO2 particles. The REDOX potential can degrade the automobile exhaust, such as nitrogen oxides (NOx) and hydrocarbons (HC). In this paper, a photocatalytic environmentally friendly pervious concrete (PEFPC) was manufactured by spraying nano TiO2 on the surface of it and the photocatalytic performance of PEFPC was researched. The nano TiO2 particle size, TiO2 dosage, TiO2 spraying amount, and dispersant dosage were selected as factors to investigate the efficiency of photocatalytic degradation of automobile exhaust by PEFPC. Moreover, the environmental scanning electron microscope (ESEM) was used to evaluate the distribution of nano TiO2 on the surface of the pervious concrete, the distribution area of nano TiO2 was obtained through Image-Pro Plus, and the area ratio of nano TiO2 to the surface of the pervious concrete was calculated. The results showed that the recommended nano TiO2 particle size is 25 nm. The optimum TiO2 dosage was 10% and the optimum dispersant dosage was 5.0%. The photocatalytic performance of PEFPC was best when the TiO2 spraying amount was 333.3 g/m2. The change in the photocatalytic ratio of HC and NOx is consistent with the distribution area of nano TiO2 on the surface of the pervious concrete. In addition, the photocatalytic performance of PEFPC under two light sources (ultraviolet light and sunlight) was compared. The results indicated that both light sources were able to stimulate the photocatalytic performance of PEFPC. The research provided a reference for the evaluation of automobile exhaust removal performance of PEFPC.

Impact of gasoline upgrade policy on particulate matter pollution in China

Automobile exhaust pollution is one of the major contributors to the severe air pollution in China, and policies have been issued by the Chinese government to mitigate this problem. In this paper, we evaluate the impact of a recently implemented policy to upgrade the quality of gasoline on reducing the fine particulate matter (PM) concentration. Based on regression discontinuity (RD) design, we systematically analyze the policy effect on the PM10 and PM2.5 concentrations at three scales, namely, the macro-, meso-, and microscales. Macroscale analysis measures the impact on all cities, and mesoscale analysis measures it on all monitoring stations, while microscale analysis focuses on the rush hours at each station. Our results show that the policy has little effect on reducing particulate matter pollution at the macro- or mesoscale, while positive evidence does exist at the microscale when focusing on pollution reduction during rush hours, especially for areas near main roads or junctions with heavy traffic. Our research suggests that the policy impact is affected by the heterogeneous pollution sources, and the potential of mitigating air pollution by continually upgrading the quality of gasoline will be limited after five stages of upgrades. In addition, one single policy can hardly completely solve particulate matter pollution in China, and a systematic design consisting of a series of policies is needed to mitigate this problem.

Research on Traffic Congestion Based on System Dynamics: The Case of Chongqing, China

With the rapid development of society, urban traffic congestion has gradually become an important social problem that many cities need to solve. For Chongqing, traffic congestion not only affects residents’ normal travel but also brings more serious environmental pollution. Aiming at the problem of urban traffic congestion and automobile exhaust pollution, this paper adopts the system dynamics method to establish a model for studying urban traffic congestion system from the perspectives of private cars, trucks, and public transportation. First, we determine city motor vehicle trips as an indicator of the degree of traffic congestion in this paper. Second, we analyze the causal relationship between the growth of private cars, the travel of trucks, public transportation, population, and other factors and then build a model and test the stability of the model. Then, we add some practical policies to the model for policy analysis. Finally, it is concluded that the private car restriction policy is effective in controlling the amount of private car travel, and the purchase restriction policy controls the growth of the number of private cars from the root cause, but the development of public transportation is the most effective treatment measure in the long run.

Automobile exhaust gas purification material based on physical adsorption of tourmaline powder and visible light catalytic decomposition of g-C3N4/BiVO4

Pure g-C3N4, g-C3N4/BiVO4, and g-C3N4/BiVO4/tourmaline powder composite photocatalytic materials were prepared via the methods of one-step calcination and bi-dispersion direct mixing, and their automobile exhaust gas purification efficiencies were tested. Four types of samples (g-C3N4, BiVO4, g-C3N4/BiVO4, and g-C3N4/BiVO4/tourmaline powder) were characterized using various methods, such as X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller analysis, Fourier transform infrared spectroscopy, ultraviolet–visible light-near infrared spectroscopy, and X-ray photoelectron spectroscopy (XPS). The test results showed that the photocatalysis composite exhibited the highest purification efficiency when the mass ratio of g-C3N4/BiVO4 was 2 and the load of tourmaline powder was 25 wt%. The hydrocarbon, CO, and NO purification rates of the g-C3N4/BiVO4/tourmaline powder were 1.73, 1.74, and 2.52 times higher than those of pure g-C3N4, respectively. It was concluded from the XPS patterns that the heterojunction formed by g-C3N4 and BiVO4 promoted the separation of electron-hole pairs and charge migration, which enhanced the photocatalytic degradation of exhaust gas under visible light. Moreover, tourmaline powder increased the physical adsorption capacities of the composite materials for automobile exhaust by releasing several negative ions, thus considerably increasing their decomposition efficiencies. This study is of immense significance to the management of urban automobile exhaust pollution.