scholarly journals SCR systems for NOx reduction in heavy and light duty vehicles

2016 ◽  
Vol 164 (1) ◽  
pp. 32-36
Author(s):  
Piotr JAWORSKI ◽  
Sebastian JAROSIŃSKI ◽  
Azael CORTES CAPETILLO ◽  
Łukasz KAPUSTA ◽  
Adam ZIÓŁKOWSKI ◽  
...  
Keyword(s):  
Air Pollution ◽  
Automotive Industry ◽  
Urban Areas ◽  
Nox Reduction ◽  
Road Transport ◽  
Light Duty ◽  
Scr System ◽  
Light Duty Vehicles ◽  
Transport Emissions ◽  
System Designs

Air pollution has become an important worldwide problem. The European Commission credits road and water transport as the major source of NOx pollution, and of being responsible for around 50% of the total air pollution in urban areas. During the last decade, the use of SCR technologies have gained popularity as a method for NOx reduction, the technology is widely considered as one of the solutions for road transport emissions. This paper presents a review of the different SCR system designs derived from the various factors and regulations in the automotive industry which have influenced the technology, along with a parametric study of a proprietary SCR system for heavy duty application.

The Role of Road Infrastructure and Air Pollution in the Recent Suburbanization of India’s Cities

2017 ◽  
Vol 8 (2) ◽  
pp. 151-169 ◽  
Author(s):  
Matthew J. Holian ◽  
Kala Seetharam Sridhar
Keyword(s):  
Air Pollution ◽  
Population Density ◽  
Urban Areas ◽  
Regression Models ◽  
Central City ◽  
Road Transport ◽  
Transport Infrastructure ◽  
Multiple Regression Models ◽  
Indian Cities

This article re-examines the suburbanization of Indian cities by calculating population density gradients, for a large number of urban agglomerations, using recent data and Mills’ two-point method. In the next step, we estimate multiple regression models to explore the determinants of suburbanization. This study presents several methodological advances over previous research, by incorporating new measures of transport infrastructure, air pollution and city–suburb income ratios as determinants of suburbanization of Indian cities. Our results clearly show that suburbanization is higher in urban areas with higher population and lower central city–suburban literacy ratios. We find some evidence that suburbanization is higher in urban areas with more road transport infrastructure, consistent with our expectations, though results concerning air pollution run counter to expectations. However, these could relate to caveats regarding the data and methods.

scholarly journals Economic Evaluation of the Urban Road Public Transport System Efficiency Based on Data Envelopment Analysis

2021 ◽  
Vol 12 (1) ◽  
pp. 57
Author(s):  
Alberto Romero-Ania ◽  
María Auxiliadora De Vicente Oliva ◽  
Lourdes Rivero Gutiérrez
Keyword(s):  
Land Use ◽  
Air Pollution ◽  
Data Envelopment Analysis ◽  
Public Transport ◽  
Urban Areas ◽  
Road Transport ◽  
City Council ◽  
Pollutant Emission ◽  
Data Envelopment ◽  
Public Road

Air pollution resulting from massive urban development and increased use of private vehicles is a major environmental concern, with particular relevance in urban areas. Urban public road transport has a significant impact on shaping land use patterns, air pollution and welfare. It must therefore be efficient in terms of air pollution in order to contribute to sustainable metropolitan mobility and economic growth. This study proposes a novel and consistent data envelopment analysis, aiming to identify which urban public transport vehicle is the most efficient in terms of air pollution and therefore environmentally suitable for use in public road transport systems. The case of Madrid has been analyzed, as it is representative of other large cities, which have similar bus alternatives and the common objective of reducing air pollution. Madrid City Council data has been compiled by authors and assessed by a panel of twenty experts to determine the model criteria weights. The results show that the plug-in electric vehicle has the lowest pollutant emission values while delivering the highest performance. Useful recommendations are provided to support public policy decisions related to the complex relationships between urban land use, urban transport and air pollution in urban areas.

scholarly journals THE PREDICTIVE EFFECTS OF PROTECTION MOTIVATION THEORY ON ADAPTIVE BEHAVIOUR TOWARDS URBAN AIR QUALITY

2019 ◽  
Vol 5 (1) ◽  
pp. 69-74
Author(s):  
Syazwani Sahrir
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Urban Air Pollution ◽  
Road Transport ◽  
Protection Motivation Theory ◽  
Adaptive Behaviour ◽  
Urban Air ◽  
Protection Motivation ◽  
Motivation Theory ◽  
Behavioural Responses

In urban areas, the rigid division of residential, commercial, employment and recreational areas forms a reliance on road transport, which leads to high levels of emission that gradually affects the quality of the urban environment. We establish the Protection Motivation Theory (PMT) as a framework for explaining adaptive behavioural responses among urban communities in Malaysia. Participants (N = 450) answered to face-to-face questionnaire survey, and the results specify establishment for the proposed model, with perceived vulnerability (H1) (ß = 0.246, t = 4.534, P=0.000) and and self-efficacy (H3) (ß = 0.510, t = 9.653, P=0.000) positively predicting adaptive behaviour on  urban air pollution. The results presented that these structures were able to predict 47% of the variance of adaptive behaviour. The study establishes a significant contribution to the literature by contributing an indication of PMT as an ideal framework for adaptive behavioural responses on urban air pollution.

scholarly journals Management of road transport-induced air pollution in urban areas: A case study of Owerri, Nigeria

2021 ◽  
Vol 1 (1) ◽  
pp. 030-044
Author(s):  
Onyeka JO ◽  
Obi LE ◽  
Igiri VC
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Air Pollutants ◽  
Environmental Concern ◽  
Field Work ◽  
Road Transport ◽  
Road Transportation ◽  
The Road ◽  
Push And Pull

Environmental concerns have continued to be on the increase as human activities soar. One such environmental concern is air pollution. A major contributor to air pollution is the road transportation activities. This paper sets out to provide a management strategy for air pollution owing to road transportation in urban areas, with Owerri Nigeria as a case study. A field study was conducted in Owerri to ascertain the total passenger requirement, number and mix of passenger vehicles as well as measure three main road transport-induced air pollutants at five locations in the city. The result of the field work showed existing commuter vehicles mix of 56.2:63.7: 19.6:1.6:1 of salons, wagons, mini-buses, coaster buses and big buses respectively, of a total of 85,950 vehicles and air ambient pollutants level higher than the recommended standards. A new model was developed to achieve a remix of 10:33:53: 14:1 of same vehicle types and reduction in traffic volume and target air pollutants. The analyses show that mini-buses and coaster buses have advantage over salon cars, wagon vehicles and big buses in terms of traffic congestions and pollutants release into the environment. The two bus types could be said to have least pollutants release per passenger carried. An optimal vehicle remix, which gives higher priority to these buses have been shown to reduce congestion by 40%, Carbon monoxide by 40%, Nitrogen Dioxide by 50% and Methane by 50%. It therefore recommends that vehicular remix of 10:33:53: 14:1, for salon: wagon: mini-buses: coaster buses: big buses be adopted for Owerri commuters’ transportation need. It concludes that governments should adopt economic instruments embedded in a “push and pull” strategy, leveraging on disincentive and incentive measures to skew road transportation to the use of mini and coaster buses as a deliberate means of reducing air pollution in cities.

scholarly journals An Overview of Lean Exhaust deNOx Aftertreatment Technologies and NOx Emission Regulations in the European Union

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 404
Author(s):  
Tommaso Selleri ◽  
Anastasios D. Melas ◽  
Ameya Joshi ◽  
Dario Manara ◽  
Adolfo Perujo ◽  
...  
Keyword(s):  
European Union ◽  
New Technologies ◽  
Road Transport ◽  
Pollutant Emission ◽  
Nox Emissions ◽  
The European Union ◽  
Heavy Duty ◽  
Light Duty ◽  
Light Duty Vehicles ◽  
Heavy Duty Vehicles

This paper reviews the recent advances in the management of nitrogen oxide (NOx) emissions from the internal combustion engine of light-duty and heavy-duty vehicles, addressing both technical and legal aspects. Particular focus is devoted to the often-virtuous interaction between new legislation imposing more restrictions on the permitted pollutant emission levels and new technologies developed in order to meet these restrictions. The review begins first with the American and then European directives promulgated in the 1970s, aimed at limiting emissions of pollutants from road transport vehicles. Particular attention is paid to the introduction of the Euro standards in the European Union for light- and heavy-duty vehicles, used as a legal and time frame reference for the evolution of emission aftertreatment systems (ATSs). The paper also describes governmental approaches implemented for the control of pollutant emissions in circulating vehicles, such as market surveillance and in-service conformity. In parallel, it is explained how the gradual introduction of small-scale devices aimed at the NOx control, such as lean NOx traps (LNTs) systems, and, most of all, the selective catalytic reduction (SCR) of NOx, permitted the application to road-transport vehicles of this ATS, originally designed in larger sizes for industrial usage. The paper reviews chemical processes occurring in SCR systems and their advantages and drawbacks with respect to the pollutant emission limits imposed by the legislation. Their potential side effects are also addressed, such as the emission of extra, not-yet regulated pollutants such as, for example, NH3 and N2O. The NOx, N2O, and NH3 emission level evolution with the various Euro standards for both light- and heavy-duty vehicles are reported in the light of experimental data obtained at the European Commission’s Joint Research Centre. It is observed that the new technologies, boosted by increasingly stricter legal limits, have led in the last two decades to a clear decrease of over one order of magnitude of NOx emissions in Diesel light-duty vehicles, bringing them to the same level as Euro 6 gasoline vehicles (10 mg/km to 20 mg/km in average). On the other hand, an obvious increase in the emissions of both NH3 and N2O is observed in both Diesel and gasoline light-duty vehicles, whereby NH3 emissions in spark-ignition vehicles are mainly linked to two-reaction mechanisms occurring in three-way catalysts after the catalyst light-off and during engine rich-operation. NH3 emissions measured in recent Euro 6 light-duty vehicles amount to a few mg/km for both gasoline and Diesel engines, whereby N2O emissions exceeding a dozen mg/km have been observed in Diesel vehicles only. The present paper can be regarded as part of a general assessment in view of the next EU emission standards, and a discussion on the role the SCR technology may serve as a NOx emission control strategy from lean-burn vehicles.

scholarly journals Numerical Optimization of a SCR System Based on the Injection of Pure Gaseous Ammonia for the NOx Reduction in Light-Duty Diesel Engines

2020 ◽  
Author(s):  
Augusto Della Torre ◽  
Gianluca Montenegro ◽  
Angelo Onorati ◽  
Tarcisio Cerri ◽  
Enrico Tronconi ◽  
...  
Keyword(s):  
Diesel Engines ◽  
Numerical Optimization ◽  
Nox Reduction ◽  
Gaseous Ammonia ◽  
Light Duty ◽  
Scr System

A compact solid SCR system for NOx reduction in passenger cars and light duty trucks

MTZ worldwide ◽  
2003 ◽  
Vol 64 (6) ◽  
pp. 14-17 ◽  
Author(s):  
Michael Krüger ◽  
Patrick Nisius ◽  
Volker Scholz ◽  
Andreas Wiartalla
Keyword(s):  
Nox Reduction ◽  
Passenger Cars ◽  
Light Duty ◽  
Scr System

scholarly journals Urban Air Quality Guidance Based on Measures Categorization in Road Transport

2021 ◽  
Vol 7 (2) ◽  
pp. 253-267
Author(s):  
Beti Angelevska ◽  
Vaska Atanasova ◽  
Igor Andreevski
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Urban Areas ◽  
Road Transport ◽  
Urban Air Quality ◽  
Mitigation Measures ◽  
Annual Reports ◽  
Urban Air ◽  
Air Pollution Control ◽  
Pollution Levels

Air pollution is a cause for serious concerns in urban areas in Republic of North Macedonia. Intensive development of road transport increases the main air pollutants’ concentrations - particulate matter and nitrogen dioxide, whose monitored values are continuously exceeding the limit. The main disadvantage of the national plans and annual reports is the absence of comprehensive and categorized list of reduction/mitigation measures for road transport impacts on air quality. Analyzing the current air pollution problem and road transport contribution this paper provides the needed and detailed categorization of short-to-long term reduction/mitigation measures consisting of five subcategories. Based on measure categorization, a guiding frame for urban air quality is designed, intended for further support and assistance for local authorities in the process of air pollution control. Designed with integrated activities, the air quality guidance enables them to select suitable measures to manage road transport pollution and to evaluate their effects estimating the changes in air pollution levels. Hence, the guidance can be used for thorough planning of air quality issues caused by road transport and for policy making. Contributing for urban air quality improvement the guidance is a first step towards the implementation of air pollution management in urban areas. Doi: 10.28991/cej-2021-03091651 Full Text: PDF

Convective Мodel of Еmission Distribution on the Road Overpass Under Neutral Weather Conditions.

2018 ◽  
pp. 23-31
Author(s):  
Rostyslav Sipakov ◽  
Olena Voloshkina ◽  
Volodimir Trofimovich ◽  
Irina Klimova
Keyword(s):  
Air Pollution ◽  
Urban Areas ◽  
Weather Conditions ◽  
Road Transport ◽  
Euler Method ◽  
Motor Vehicles ◽  
Hydrocarbon Emissions ◽  
Atmospheric Air ◽  
The Road ◽  
On The Road

An analysis of the degree of atmospheric air pollution in urban areas showed its dependence on a growing number of personal vehicles operating on traditional fuels. This work proves the possibility of applying the theory of a convective jet for estimating and forecasting atmospheric air pollution in megacities, depending on weather conditions and the number of cars that are simultaneously in traffic jams in a car overpass. We use the integral Euler method to calculate the parameters of a convective jet. The conditions for the appearance of neutral ways are determined and based on the considered main ways of distribution of emissions in the atmosphere. The method for calculating the amount of hydrocarbon emissions from road transport was used to determine the secondary pollution by formaldehyde of atmospheric air into the territories of megalopolises as a result of photochemical transformations. The presented studies allow to single out the share of greenhouse gas emissions from road transport in the context of total emissions in a megacity. A method for calculation of concentrations of pollution from motor vehicles based on this model has been developed. This method allows the use of specially synthesized external influences with the subsequent processing of the results of observations and subsequent analysis of the consequences. The effectiveness of the proposed mathematical model can be increased in combination with the use of "green structures". This method is suitable for finding optimal management decisions at the municipal level and the formation of the environmental policy of the city.

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