Pollutant emissions from passenger cars in traffic congestion situation in the State of Kuwait: options and challenges

Rapid population growth in Kuwait, accompanied with rising standard of living, has resulted in a sweeping increase in the use of passenger vehicles for transportation. Consequently, deterioration of ambient air quality near major roadways has become an issue of public concern. The knowledge of real world road vehicle emission factors is an essential element to the development of any strategy aimed at the reduction of air pollution in urban areas. This work focuses on investigating exhaust emission pollutants from passenger cars for idle and slow acceleration (stop-and-go) traffic conditions. We found that vehicle emissions are minimal during idle mode for all vehicle categories. However, it was interesting to observe that during the slow acceleration mode HC and CO emissions increased for light vehicles with relatively high mileage (higher than 40,000?km). We can conclude from this study that with the growing vehicle ownership, and congestion it causes, the vehicular exhaust emissions is a major sources of air pollution in densely populated centers in the state of Kuwait, where idle and stop-and-go driving cycle is a common occurrence.     

Characterisation of CO/NO/SO2 emission and ash-forming elements from the combustion and pyrolysis process

Bioenergy is considered as a sustainable energy which can play a significant role in the future’s energy scenarios to replace fossil fuels, not only in the heat production, but also in the electricity and transportation sectors. Emission formation and release of main ash-forming elements during thermal conversion of biomass fuels at different conditions have been the scope of this study. The experiments were conducted in a quartz glass reactor where the temperature and atmosphere could be controlled. The selected fuels represent a wide range of biomass compositions. They are torrefied softwood, spruce bark, waste wood, miscanthus, and wheat straw. The fuels were first grinded and then pressed with a pellet maker into pellets of the same size and weight. For each fuel, the experiments were carried out under both oxidation and pyrolysis condition, with atmosphere of 3 % O₂ + 97 % N₂ and 100 % N₂, respectively, at four residence times. The selected temperatures under which experiments were performed are 800, 900, and 1,050 °C. The concentration of SO₂, NO, CO, and CO₂ emissions and O₂ were monitored online by three analysers, simultaneously. The residue weight was measured after each process, and the comparison with the ash content of the fresh pellet is made. Additionally, the release of several ash-forming elements (K, Zn, Na, and Mn) from the fuels has been quantified as function of temperature and residence time by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Time-dependent formation of NO and SO₂ and other emissions is presented and discussed with respect to different temperature and combustion conditions.     

Evaluation of current status and future directions of wind energy in India

Wind energy is the fastest growing electricity generation technology. During the last decade of the 20th century, grid-connected wind capacity worldwide has doubled approximately every 3 years. Climate change is a major challenge to sustainable development worldwide and is increasingly recognized by forward-looking political and business leaders. One of the tasks we are facing is a profound transformation of our energy system over the next few decades of replacing fossil fuels with renewable energies and dramatically increasing energy efficiency. At present, wind energy is receiving considerable attention in the world. In this study, development of wind energy system and the potential of wind energy in India have been investigated. This paper presents the progress made by wind energy in the recent years, and discusses the potential of this technology. The aim of the work is to investigate the wind energy plants and projects in India. It can be concluded from this analysis that wind energy utilization in India and throughout world has sharply increased.     

Estimates of the air quality benefits of using natural gas in industrial and transportation applications in Lima, Peru

Reductions in air pollutant emission and ambient concentrations of air pollutants, which would occur in Lima when natural gas (NG) is substituted for existing fuels, were estimated. The analysis suggests that current emission inventories under-predict ambient concentrations. Despite the uncertainty in emissions, the analysis also suggests that significant changes in air pollutant concentrations could be achieved with widespread replacement of diesel and gasoline fuels with NG.     

Study on possible economic and environmental impacts of electric vehicle infrastructure in public road transport in Kolkata

Transport sector in India accounts for 20 % of total commercial energy demand of the country, of which a considerable amount is consumed in the form of liquid and gaseous fuel. A major part of these fuels are imported by the Government. Apart from the import expenditure, Government of India has subsidized these fuels to make it available at affordable prices. To check the financial burden and achieve environmental benefits, technical advancement in present system or alternative infrastructure is required. The present study examines the possible impacts on economy and environment by the implementation of battery electric vehicles (BEVs) along with the conventional road transport system in metropolitans with a case study of Kolkata. The major impact has been observed in controlling the vehicular emission with a decrease in CO₂ level by 26.27 t per day, on replacement of only 2 % of the present public transport by suitable BEVs. Maintaining similar service for the passengers the electrical energy required by the alternative vehicles has been estimated to be 41,766 kWh per day. This energy has been proposed to be supplied by remodeled fuel stations equipped with solar photovoltaic systems, if charging strategy is based on renewable sources. In case of fuel economy, the infrastructure has shown the potential in reducing the consumption of diesel and autogas (LPG) by 11,654 and 3,256 liter per day, respectively.     

Estimation of the Impact of Traveler Information Apps on Urban Air Quality Improvement

With the rapid growth of vehicle population and vehicle miles traveled, automobile emission has become a severe issue in the metropolitan cities of China. There are policies that concentrate on the management of emission sources. However, improving the operation of the transportation system through apps on mobile devices, especially navigation apps, may have a unique role in promoting urban air quality. Real-time traveler information can not only help travelers avoid traffic congestion, but also advise them to adjust their departure time, mode, or route, or even to cancel trips. Will such changes in personal travel patterns have a significant impact in decreasing emissions? If so, to what extent will they impact urban air quality? The aim of this study is to determine how urban traffic emission is affected by the use of navigation apps. With this work, we attempt to answer the question of whether the real-time traffic information provided by navigation apps can help to improve urban air quality. Some of these findings may provide references for the formulation of urban traffic and environmental policies.     

Evolving technological systems for diesel engine emission control: balancing GHG and local emissions

The Triad—North America, Japan and Europe—now addresses diesel vehicle emissions by requiring 40–80% reductions from new heavy-duty trucks and passenger car diesels. The requirements imply introduction of new technology and fuels stepwise during 2005–2012 that will leave emissions from new diesel vehicles on par with the levels of gasoline passenger cars. This paper studies the recent development of diesel engine emission control in response to new regulation. The role for Swedish actors, including two of the world’s major truck manufacturers, is especially studied. The increasingly global Technological System for diesel engine emission control is compelled to manage further reductions of nitrogen oxides emissions and fuel consumption and CO₂, the balance of which has been the subject of several large legal disputes. Swedish OEMs are at present split into two technological sub-trajectories, while the future may be multi-pronged and include new engine types and fuels. Interestingly, similar commercial advantages that were sought by the pioneers introducing advanced feedback loop catalysis in gasoline cars in the 1970s are now sought by some heavy-duty diesel engine manufacturers by conversely avoiding the mainstream—Selective catalytic reduction—solution. Incremental innovation is the new radical.     

Air pollution control in ferroalloy manufacturing industries: an Indian regulatory assessment

Ferroalloy manufacturing involves many unit operations and unit processes. Commencing from the material handling to manufacturing and product collection, a ferroalloy plant emits a wide range of air pollutants. The selection of appropriate air emission control technology is, therefore, very important in such a situation. In this article, few case studies from Indian operating plants are analyzed from the standpoint of installed air pollution control devices. Analyses revealed design flaws in many of these air pollution control devices leading to their collapse with the deterioration of the ambient air quality. As regulatory measures, recommendations are made specifying the air pollution control devices to curb air emission from various stages of the ferroalloy making operations for meeting the air emission standards. Prior to putting forward recommendations in this article, described are the different aspects of the ferroalloy manufacturing with the emphasis of source of emission for both particulate matter as well as gaseous pollutants.     

武汉市空调公交车内空气质量的测试调查与改善建议

通过对武汉市具有典型代表性的空调公交车内空气环境质量进行跟踪测试,以及对武汉市百名不同领域的人员进行问卷调查,由测量计算结果、调查结论与相关公共交通工具卫生标准的对比发现:空调公交车内新风量不足、CO2浓度超标等问题是导致车内空气品质不佳的主要原因,这直接导致了大部分乘客在乘坐空调公交车时出现头晕、困倦、胸闷等不适问题。提出了几个投资成本低、便于操作的改进措施与建议,以期达到车内环境与节能最优化的效果。     

Influence of air intake pipe on engine exhaust emission

The exhaust emissions of a four-cylinder four-stroke petrol engine have been measured. Tests have been conducted at engine speeds ranges from 1000 to 4000 rpm and at air intake pipe diameters of 20, 25, 30, 35, 40 and 63 mm. The results demonstrate that the concentrations of the hydrocarbon (HC) and that of the carbon monoxide (CO) are relatively high at small air intake pipe diameter of 20 mm and at low engine speed of about 1000 rpm. Both pollutants have a minimum at large air intake pipe diameter of about 63 mm and at high engine speed of about 4000 rpm. The exhaust emissions HC and CO increase also as the ambient pressure decreases and as the altitude of the engine increases. The values of carbon dioxide (CO₂) and the oxygen (O₂) remain relatively constant at a wide range of different operating conditions. Therefore the knowledge about the effect of the above parameters could lead to improve the emission control technology as well as the engine performance on engine development and design.     

Experimental investigation of impact of diesel particulate filter on smoke and NO<Subscript>x</Subscript> emissions of a Euro-I compression ignition engine with active and off-board regeneration

Old engines (Euro III or earlier) produce more emissions, and it will be difficult to entirely stop their usage especially in developing and under-developed nations; hence, it is desired that appropriate emission reduction technologies are tested on such engines to analyze their feasibility and economical acceptability. While most such studies have been conducted on constant speed stationary engines and modern engines, this study tried to analyze the effectiveness of an uncoated wall-flow type ceramic diesel particulate filter on a Euro-I, water-cooled, direct injection, variable speed, compression ignition engine in a laboratory set-up in India. Also, this study focused on diesel particulate filter regeneration by two methods: active regeneration by diesel injection in the particulate filter using an electronic control unit and off-board regeneration by taking out and heating the diesel particulate filter in an electrical resistance furnace at 650 °C for 10 h. The results, in the form of smoke emission, NO_x emission and engine performance, obtained using both the regeneration methods were analyzed, and conclusions were drawn. It was found that using diesel particulate filter, particulate matter emissions (smoke) were almost entirely eliminated. It was also found that off-board regeneration had numerous advantages compared to active regeneration. Since a furnace would be needed for off-board regeneration, an exchange process for diesel particulate filter is suggested.     

Combustion performance of rubber seed methyl ester using aromatic and phenolic antioxidants in a multi-cylinder diesel engine

This paper analyzes the effect of antioxidants on engine combustion performance of a multi-cylinder diesel engine fueled with rubber seed biodiesel blends. Four antioxidants, namely 2-tert-butylbenzene-1,4-diol, N,N′-diphenyl-1,4-phenylenediamine, 2(3)-tert-Butyl-4-methoxyphenol and N-phenyl-1,4-phenylenediamine, were added at concentrations of 1000 and 2000 ppm to rubber seed biodiesel blends. Antioxidants blends increased the brake power by 4.21% and decreased the brake-specific fuel consumption by 6.82% compared to base biodiesel blends. The NO emissions reduction percentage for antioxidants fuels was 9.78% compared to base line biodiesel. However, the treated biodiesel blends increased carbon monoxide, hydrocarbon and smoke opacity up to 32.20, 42.15 and 43.92%, respectively, compared to non-treated blends. Compared to diesel fuel, antioxidants fuels decreased the brake power and increased the brake-specific fuel consumption, cylinder pressure and heat release rate. But compared to biodiesel blends, the cylinder pressure and heat release rate with antioxidants were reduced by 4.17 and 6.87%, respectively. It can be concluded that antioxidants addition is effective in increasing the oxidation stability and controlling the NO emissions of rubber seed biodiesel fueled diesel engines.     

A comparison of major petroleum life cycle models

Many organizations have attempted to develop an accurate well-to-pump life cycle model of petroleum products in order to inform decision makers of the consequences of its use. Our paper studies five of these models, demonstrating the differences in their predictions and attempting to evaluate their data quality. Carbon dioxide well-to-pump emissions for gasoline showed a variation of 35 %, and other pollutants such as ammonia and particulate matter varied up to 100 %. Differences in allocation do not appear to explain differences in predictions. Effects of these deviations on well-to-wheels passenger vehicle and truck transportation life cycle models may be minimal for effects such as global warming potential (6 % spread), but for respiratory effects of criteria pollutants (41 % spread) and other impact categories, they can be significant. A data quality assessment of the models’ documentation revealed real differences between models in temporal and geographic representativeness, completeness, as well as transparency. Stakeholders may need to consider carefully the tradeoffs inherent when selecting a model to conduct life cycle assessments for systems that make heavy use of petroleum products.     

Investigation of Thermophysical Properties of Thermal Degraded Biodiesels

Biofuels are an alternative to fossil fuels and can be made from many different raw materials. The use of distinct catalyst and production processes, feedstocks, and types of alcohol results in biofuels with different physical and chemical properties. Even though these diverse options for biodiesel production are considered advantageous, they may pose a setback when quality specifications are considered, since different properties are subject to different reactions during usage, storage and handling. In this work, we present a systematic characterization of biodiesels to investigate how accelerated thermal degradation affects fuel properties. Two different types of biodiesel, commercially obtained from distinct feedstocks, were tested. The thermal degradation process was performed by maintaining the temperature of the sample at \(140 \,^{\circ }\hbox {C}\) under constant air flux for different times: 0 h, 3 h, 6 h, 9 h, 12 h, 24 h and 36 h. Properties such as density, viscosity, activation energy, volumetric thermal expansion coefficient, gross caloric value, acid value, infrared absorption, and temperature coefficient of the refractive index were used to study the thermal degradation of the biodiesel samples. The results show a significant difference in fuel properties before and after the thermal degradation process suggesting the formation of undesirable compounds. All the properties mentioned above were found to be useful to determine whether a biodiesel sample underwent thermal degradation. Moreover, viscosity and acid value were found to be the most sensitive characteristics to detect the thermal degradation process.     

Experience with the use of the acoustic emission technique for monitoring scale failure in wet and dry environments

Abstract

A brief survey of the acoustic emission technique for monitoring scale cracking and failure on 2.25–24% Cr steels in wet and dry environments is given. A number of acoustic emission test rigs are described. Some of the more simple test rigs are used for testing small oxidation coupons during isothermal oxidation. More sophisticated rigs have been used for testing full size heat exchanger tubes during thermal cycling.

Most acoustic emission measurements in a wet environment come from testing at temperatures below 650°C. There are examples from Alloy 800 and thermal barrier coatings that were tested at higher temperatures, 900°C and 1100°C, respectively. Through the years acoustic emission tests have been performed in dry air, dry air+10%H₂O, dry air+0.5%SO₂, and Ar+5%H₂+50%H₂O. Consequently, a wide variety of exposure temperatures and atmospheres can be investigated using acoustic emission techniques.

Qualitative acoustic emission results can detect when scale cracking occurs at exposure temperature, where such cracks are produced by growth stress. Acoustic emission signals have been measured during sample cooling, where the signal arises from scale cracking that is caused by the thermal expansion mismatch stress. Measured results have clearly shown that scale cracking caused by both growth stress and thermal expansion mismatch stress are affected by water vapor in the exposure environment. Post-test metallographic investigations show that crack orientation and the oxide scale phases are also affected by the gas composition in the test rig. Additionally the sample mass gain and scale thickness is affected by water vapor content.

Finally, acoustic emission techniques are helpful for understanding the phenomena of breakaway oxidation and spallation/exfoliation.     

Fracture process and reliability of concrete made from high grade recycled aggregate using acoustic emission technique under compression

The increasing amount of waste concrete makes desirable collection of high quality of recycled aggregate from waste concrete to be reused for construction. This research used high grade recycled coarse aggregate (RCA) created using pulsed power technology to make concrete specimens. Concrete created from natural aggregate was also prepared to compare the properties of concrete made using pulsed power recycled aggregate. Established acoustic emission (AE) parameter analyses which are AE hit, relationship between RA value and average frequency, and b-value of AE amplitude distribution were applied to analyze the concrete fracture behavior. In addition, AE Weibull analysis was also proposed to evaluate the reliability of the concrete. A set of AE measurement testing was applied to the concrete specimens during compression loading. At the age of 28 days, compressive strength reaches 35.4 MPa and Young’s modulus is 23.6 GPa. The results indicate that the fracture process and reliability of concrete made using pulsed power RCA is similar to that of natural coarse aggregate concrete suggesting that both concrete have equivalent characteristic under compression. Furthermore, the good agreement results shared by AE Weibull analysis with those of other analyses suggesting this method can also be employed as one parameter to determine the condition of concrete.     

我国煤电大气污染物控制现状及展望

"十二五"以来,我国煤电大气污染物的控制取得了很大的成就,烟尘、二氧化硫、氮氧化物排放总量和强度快速下降,控制水平达到世界先进水平。"十三五"乃至更长时期,煤电仍将承担国家大气污染物减排的重任。重点研发高性能、高可靠性、高适用性、高经济性污染物的控制技术、资源化技术、多污染物协同控制技术是未来我国煤电大气污染物控制的主要技术方向。预计到2020年,烟尘、二氧化硫、氮氧化物年排放量分别降至2×10~5~3×10~5 t、1×10~6~1.5×10~6 t、1×10~6~1.5×10~6 t。     

Impact of including land-use change emissions from biofuels on meeting GHG emissions reduction targets: the example of Ireland

The greenhouse gases (GHG) emissions from land-use change are of particular concern for land-based biofuels. Emissions avoided by substituting fossil fuels with biofuels may be offset by emissions from direct and indirect land-use changes (LUC). There is an urgent need to investigate what impact land-use change emissions may have on the expansion of bioenergy and biofuels, in the context of EU mitigation policies. This paper focuses on Ireland, which faces a number of challenges in delivering its renewable energy and GHG reduction targets. The Irish TIMES energy systems model was used to assess the impact of a range of land-use change emissions’ levels on the evolution of Ireland’s low-carbon energy system. A reference scenario was developed where LUC is ignored and Ireland achieves a least-cost low-carbon energy system by 2050. If high indirect land-use change (ILUC) emissions are included, this results in a decrease by 30 % in bioenergy and a 68 % increase in marginal abatement costs by 2050. Hydrogen is used instead of bioenergy in the freight sector in this scenario, while private cars are fuelled by renewable electricity. If GHG emissions from ILUC were considered less severe, indigenous grass biomethane becomes the key biofuel representing 31 % of total bioenergy consumption. This is in line with recent research in Ireland of the key role that grass biomethane can play.     

燃煤电厂超低排放湿法脱硫治霾影响分析

根据燃煤电厂湿法脱硫出口污染物排放浓度及其排放绩效,分析了超低排放湿法脱硫的治霾效果,阐明了湿法脱硫有利于减少SO₂、颗粒物、SO₃的排放量,这些污染物都是形成雾霾的前体物,表明超低排放湿法脱硫对雾霾治理有积极的贡献。同时,烟气超低排放具有协同治理有色烟羽的能力,对于有色烟羽治理应采取因地制宜的策略。煤电行业广泛开展烟气超低排放改造后,大气污染物排放量持续减少,空气环境质量逐年改善,湿法脱硫、烟气超低排放功不可没。     

Influence of pyrolytic temperature on the properties of ZnO films optimized for H2 sensing application

In this work, we report the influence of pyrolytic temperature on the properties of ZnO films deposited by a novel spray pyrolysis deposition route. XRD results revealed an improvement in crystal quality of the films with increase in growth temperature. The optical measurements of the films show a maximum transmittance of ~85 % and the band gap of ~3.5 eV. Photoluminescence spectra revealed that the UV emission peaks at 385 nm is improved with increase in growth temperature upto 300 °C, which corresponds to the increase of optical quality and decrease of Zn interstitial defect in the films. Gold ohmic contacts were evaporated on the optimized ZnO film prepared at the substrate temperature of 300 °C, and response of the film to different concentrations of hydrogen (150–500 ppm) at room temperature was investigated. The ZnO sensor showed significant sensitivity to hydrogen for concentration as low as 150 ppm at room temperature, and the sensor response was observed to increase with increase in hydrogen concentration. The increased sensitivity of the film was attributed to the large roughness of the film revealed from AFM analysis. The results ensure the application of our novel sensor, to detect H₂ at low concentration and at room temperature.