• Journal of Korean Society for Atmospheric Environment
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• v.31 no.6
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• pp.562-572
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• 2015

$NO_x$ emissions from diesel vehicles have been regarded as a main cause of high $NO_2$ concentration in metropolitan area. Recent studies have shown that the on-road $NO_x$ emissions of diesel vehicles are quite higher than the emission limits specified with the pre-defined test method for emission certification. To reduce air pollutants effectively, the discrepancy of emissions in certification and real-driving conditions should be tackled. In this study, the real-driving emissions have been estimated with portable emission measurement system (PEMS). The results of this study have shown that the on-road $NO_x$ emissions from diesel vehicles have been decreased as the introduction of stricter emission regulation, EURO-6, but additional reduction should be still required and robust technologies should be applied to control $NO_x$ in real-driving conditions. RDE-LDV (Real Driving Emission - Light Duty Vehicles) test method being developed in the European Union can represent excessive on-road $NO_x$ emissions of diesel vehicles as applied emission technologies and can be a solution to remove discrepant $NO_x$ emissions between certification and Korean real-driving conditions. Among the $NO_x$ reduction technologies for EURO-6 diesel vehicles, selective catalytic reduction (SCR) system has shown the better performance than lean $NO_x$ trap (LNT) system to control on-road $NO_x$ emissions. Implementing RDE-LDV will require vehicle manufacturers to adopt the more effective $NO_x$ reduction technology in real driving conditions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.3
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• pp.114-128
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• 2013

Greenhouse gas emissions have been an important issue in different countries because of their effects on global warming. The government has to organize greenhouse gas reduction measures suitable to regional characteristics by establishing annual implementation plans and comprehensive policies based on the UNFCCC. The transportation sector is one of the major contributors of air pollution; hence increasing need to estimate current and future traffic emissions precisely. Under these circumstances, a number of emission models have been developed recently. However, current methods of estimation cannot carry out effective analyses because it does not reflect vehicle movement characteristics. This study aims to present a new method for calculating road traffic emissions in Goyang city. A travel demand model is utilized to carry out GHG emission estimates according the traffic data (fleet composition, vehicle kilometers travelled, traffic intensity, road type, emission factors and speed). This study evaluates two approaches to estimate the road traffic emissions in Goyang City: Pollution-Emis and the Handbook of Emission Factors for Road Transport (HBEFA v.3.1) which is representative of the "average speed" and the "traffic situation" model types. The evaluation of results shows that the proposed emission estimation method may be a good practice if vigilant implementation of model inputs is observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.5
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• pp.9-14
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• 2002

The durability prediction of emission control components, especially 02 sensor and catalytic converter, is getting more important as emission regulation is getting stricter and vehicle durability mileage requirement is also extended from 80,000 ㎞ to 160,000 km in Korean market. And the duration of vehicle mileage accumulation to get vehicle exhaust emission deterioration factor for certification is required to be shorter in order to reduce the vehicle development time. Since most of the vehicle emission development tests are done on chassis dynamometer and aging bench by using vehicle aging modes, real road condition and in-use driving patterns must be reflected into them to predict the vehicle emission level and to meet emission regulation especially at high mileage. In order to get the frequent driving pattern of vehicle and the aging characteristic of emission components, a vehicle was tested by changing drivers and driving roads around Seoul. Real road driving patterns were analyzed and compared with those of the certification modes which are well known in automotive industry.

• Journal of ILASS-Korea
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• v.22 no.4
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• pp.218-224
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• 2017

In order to improve the quality of air in urban areas, the emission regulations are being strengthened by the government. The on-road test of light-duty vehicles was started with PEMS because certification test mode does not sufficiently reflect on-road conditions. Therefore, The PEMS-based test was implemented from Sep. 2017 in Europe and Korea. However, this is lack of data on various on-road patterns in Korea. The purpose of the present study has analyzed the effect of speed per acceleration and acceleration on NOx emission on-road driving. The test route consisted of urban, rural, and motorway in Seoul. This study has been conducted by Euro-6 vehicles using on SCR system with PEMS. The on-road emission characteristics were evaluated by moving averaging windows (MAW) method. In results, RDE-NOx by severe driving pattern has been 1.4 times higher than soft driving pattern NIER Route 1.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.217-224
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• 2012

In general, transportation sources include both on-road vehicles and off-road equipment. Off-road vehicles have usually used diesel engines, which have the disadvantage of high NOx emission. Common rail direct injection (CRDI) and after-treatment systems have been applied to meet the exhaust gas emission regulations for diesel vehicles. In the present, agricultural machinery has satisfied the Tier 3 emission regulations by using waste gate turbocharger (WGT) and internal exhaust gas recirculation (EGR). In this paper, the combustion and emission characteristics of an EGR system applied to a 56kW off-road vehicle in non-road transient cycle (NRTC) mode have been investigated. The EGR map was made from foundation experiments determining the EGR duty for all engine operating conditions, and then this map was applied to the NRTC mode. Consequently, the NOx emission was reduced by the EGR system, and the Tier 4 interim emission regulations were satisfied by using both the EGR system and an after-treatment system.

• Asian Journal of Atmospheric Environment
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• v.9 no.2
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• pp.146-157
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• 2015

Emissions of ozone precursors ($NO_x$ and VOCs) and photochemical ozone creation potentials (POCPs) of VOC emission sources were investigated in the largest port city (i.e., Busan), Korea during the year 2011. This analysis was performed using the Clean Air Policy Support System (CAPSS) national emission inventory provided by the National Institute of Environmental Research (NIER), Korea. For $NO_x$, the emissions from off-road mobile sources in Busan were the most dominant (e.g., $31,202ton\;yr^{-1}$), accounting for about 60% of the total $NO_x$ emissions. The emission from shipping of off-road mobile sources (e.g., $24,922ton\;yr^{-1}$) was a major contributor to their total emissions, amounting to 47% of the total $NO_x$ emissions due to the port-related activities in Busan. For VOCs, the emission source category of solvent usage was predominant (e.g., $36,062ton\;yr^{-1}$), accounting for approximately 82% of the total VOC emissions. Out of solvent usages, the emission from painting was the most dominant ($22,733ton\;yr^{-1}$), comprising 52% of the total emissions from solvent usages. The most dominant VOC species emitted from their sources in Busan was toluene, followed by xylene, butane, ethylbenzene, n-butanol, isopropyl alcohol, and propane. The major emission sources of toluene and xylene were found to be painting of coil coating and ship building, respectively. The value of POCP for the off-road mobile source (61) was the highest in ten major activity sectors of VOC emissions. Since the POCP value of ship transport of off-road mobile source (72) was also high enough to affect ozone concentration, the ship emission can play a significant role in ozone production of the port city like Busan.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.3
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• pp.188-195
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• 2009

Generally. mobile sources of air pollution were classified in on-road and non-road. Due to increased registration number of construction equipment in Korea. updated emission factors for non-road mobile sources, such as construction machinery. should be developed. NONROAD model of U.S. EPA already has introduced transient adjustment factors and sulfur adjustment factors for emission factors of diesel powered engine. In addition to this. European Environment Agency (EEA) has proposed emission factors for off-road machinery including several types of construction equipment. In this study. six types of construction equipment, such as excavator. forklift, loader, crane, roller and bulldozer, were studied to estimate emission factors based on total registration status in Korea. Total 445 construction equipments between 2004 and 2007 model year were tested with KC1-8 mode and air pollutants (CO, THC, $NO_x$, and PM) were measured. After statistical estimation and calculation, emission factors for CO, THC, $NO_x$, and PM for excavator, forklift, loader, crane, roller and bulldozer were provided and compared with previous emission factors. Moreover, updated emission factors for six types of construction equipment in this study were verified after comparison with emission factors of U.S. EPA. Finally, estimated emission amounts of four air pollutants were suggested according to six types of construction equipment.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.25-34
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• 2022

Recently, as a study to air cooled slag, which is an industrial by-product, research is being proceed to use it as a material for concrete. In this study, the workability, air content, compressive strength, CO₂ emission and economic feasibility of concrete were analyzed when air cooled slag, an industrial by-product, was applied as aggregate for rural road pavement concrete. As a result of the analysis, both the slump and air contents test results of concrete using the air cooled slag aggregate satisfied the target values, and the compressive strength was increased when the air cooled slag aggregate was used compared to when the natural aggregate was applied. On the other hand, the largest amount of CO₂ emission by raw material was found in aggregate. The carbon emission of rural road pavement concrete using air cooled slag aggregate increased when the Korean LCI DB was applied compared to when natural and crushed aggregates were applied, and the emission decreased when the German LCI DB was applied. This results are due to differences in the viewpoints of industrial by-products. However, considering the recycling of waste from the environmental aspect, it is necessary to simultaneously review the CO₂ emission and recycling aspects in the future. Also, the application of air cooled slag aggregate had the effect of improving the economic efficiency of rural road pavement concrete about 18.75%.

• Journal of Environmental Impact Assessment
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• v.9 no.4
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• pp.257-269
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• 2000

This study is to investigate the methodology and applicability on emission control by both MECHANICAL Model and Fugitive Dust Model (FDM) through the comparison of field measurement data and calculated data. Comparing to the method of AP-42 emission fector on the production of flying dust the MECHANICAL Model was proved to be more applicable to the calculation emission rate on the various dust emission conditions on a unpaved road. The seperate calculation on annual mean emission amount and a 24working hours amount was undertaken for the easy management of fugitive dust. Dust concentration predicted by FDM is similar with a measurement value.

• International Journal of Highway Engineering
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• v.18 no.1
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• pp.23-31
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• 2016

PURPOSES : This study aimed to offer a greenhouse gases table to assist a road designer in calculating the greenhouse gases for a road environment when making a decision about an alternative road. METHODS : This study developed an operation mode table of greenhouse gases using the MOVES program. Similar factors for Korean vehicles and fuels are reflected in the MOVES program, which was made in the USA. Finally, a paired t-test was conducted to calculate the site data and MOVES data. Through these studies, a methodology was suggested for calculating carbon emissions based on various types of roads alignments. RESULTS : The site results for a passenger truck on the road were statistically significant when the vehicle speed was above 65 km/h. However, a future study will consider factors for various road alignments and vehicles. CONCLUSIONS : This study will contribute to the theoretical basis for reducing carbon emissions from roads by helping road designers make decisions about road alternatives in terms of the road environment.