• Journal of Korean Society of Transportation
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• v.32 no.2
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• pp.93-105
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• 2014

This study evaluated the relative efficiency of mobile emission reduction countermeasures through a Data Envelopment Analysis (DEA) approach and determined the priority of countermeasures based on the efficiency. Ten countermeasures currently applied for reducing greenhouse gases and air pollution materials were selected to make a scenario for evaluation. The reduction volumes of four air pollution materials(CO, HC, NOX, PM) and three greenhouse gases($CO_2$, $CH_4$, $N_2O$) for the year 2027, which is the last target year, were calculated by utilizing both a travel demand forecasting model and variable composite emission factors with respect to future travel patterns. To estimate the relative effectiveness of reduction countermeasures, this study performed a super-efficiency analysis among the Data Envelopment Analysis models. It was found that expanding the participation in self car-free day program was the most superior reduction measurement with 1.879 efficiency points, followed by expansion of exclusive bus lanes and promotion of CNG hybrid bus diffusion. The results of this study do not represent the absolute data for prioritizing reduction countermeasures for mobile greenhouse gases and air pollution materials. However, in terms of presenting the direction for establishing reduction countermeasures, this study may contribute to policy selection for mobile emission reduction measures and the establishment of systematic mid- and long-term reduction measures.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.358-383
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• 2015

The concept of 'carbon footprint' has been developed as a means of quantifying the specific emissions of the greenhouse gases (GHGs) that cause global warming. Although there are still neither clear definitions of the term nor rules for units or the scope of its estimation, it is broadly accepted that the carbon footprint is the total amount of GHGs, expressed as $CO_2$ equivalents, emitted into the atmosphere directly or indirectly at all processes of the production by an individual or organization. According to the ISO/TS 14067, the carbon footprint of a product is calculated by multiplying the units of activity of processes that emit GHGs by emission factor of the processes, and by summing them up. Based on this, 'carbon labelling' system has been implemented in various ways over the world to provide consumers the opportunities of comparison and choice, and to encourage voluntary activities of producers to reduce GHG emissions. In the agricultural sector, as a judgment basis to help purchaser with ethical consumption, 'low-carbon agricultural and livestock products certification' system is expected to have more utilization value. In this process, the 'cradle to gate' approach (which excludes stages for usage and disposal) is mainly used to set the boundaries of the life cycle assessment for agricultural products. The estimation of carbon footprint for the entire agricultural and forestry sector should take both removals and emissions into account in the "National Greenhouse Gas Inventory Report". The carbon accumulation in the biomass of perennial trees in cropland should be considered also to reduce the total GHG emissions. In order to accomplish this, tower-based flux measurements can be used, which provide a direct quantification of $CO_2$ exchange during the entire life cycle. Carbon footprint information can be combined with other indicators to develop more holistic assessment indicators for sustainable agricultural and forestry ecosystems.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.583-592
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• 2016

IMO (International Maritime Organization) in the UN (United Nations) set up that aim at reducing $CO_2$ emission from ship by up to 30 percent until 2030. The final purpose of this study is the development of marine thermoelectric generation system using waste heat from vessel of internal combustion engines. Before the development of marine thermoelectric generation system, this paper carried out the fundamental heat analysis of marine thermoelectric generation system. It was able to obtain the valuable results about the efficiency improvement of the thermoelectric generation system. The results is as follows : 1) It was confirmed that the efficiency of thermoelectric generation system improves to 8.917 % with increasing the temperature difference of peltier module by reducing the temperature difference between peltier module and heat source at the hot side. 2) System efficiency according to change in the external load resistance was confirmed that the change width of about 6 % which does not significantly occur. 3) System efficiency in the case stainless steel at the same condition is 8.707 %. System efficiency could be confirmed that the stainless steel is higher than duralumin (8.605 %), copper (8.607 %).

• Korean Journal of Remote Sensing
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• v.36 no.6_3
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• pp.1681-1690
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• 2020

A scanning lidar system has been developed. The system has two wavelength observation channels of 532 and 1064 nm and is capable of 360-degree horizontal scanning observation. In addition, an analysis method that can classify the measured particle as an indicator of coarse-mode particle (PM2.5-10) and an indicator of fine-mode particles (PM2.5) and calculate the mass concentration of each has been developed by using the backscatter coefficient at two wavelengths. It was applied to the data calculated by observation. The mass concentrations of PM10 and PM2.5, which showed a distribution of 22-110 ㎍/㎥ and 7-78 ㎍/㎥, respectively, were successfully calculated in the Ulsan Onsan Industrial Complex using the developed scanning lidar system. The analyzed results showed similar values to the mass concentrations measured on the ground around the lidar observation area, and it was confirmed that high concentrations of 80-110 ㎍/㎥ and 60-78 ㎍/㎥ were measured at points discharged from factories, respectively.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.444-449
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• 2023

The current study involved the calculation of air pollutant emission factors (EFs) generated from the incineration of agricultural residues. The process included sample collection, weight measurement, moisture measurement, incineration system configuration, and concentration measurement. The average CO emission factor of gaseous air pollutants from the incineration of barley and wheat agricultural residues was calculated as 0.08289 kg/kg and 0.06665 kg/kg, respectively, whereas the average NO_X emission factor for barley and wheat agricultural residues was determined to be 0.00518 kg/kg and 0.00185 kg/kg, respectively. In the existing air pollutant emission calculation manual, the EF is presented only for barley. Therefore, in this study, we have introduced the EF for wheat, previously absent in the calculation manual. Additionally, the air pollutant calculation manual presents the EF of air pollutants as one value, but in this study, EF values corresponding to 2.5% and 97.5% were presented in consideration of the distribution of experimental values as shown in EMEP/EEA data.

• Korean Chemical Engineering Research
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• v.62 no.2
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• pp.163-172
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• 2024

In this study, two different scenarios for ammonia liquefaction in the green ammonia manufacturing process were proposed, and the economic-feasibility and environmental impact of each scenario were analyzed. The two liquefaction processes involved gas-liquid separation before cooling at high pressure (high pressure cooling process) or after decompression without the gas-liquid separation (low pressure cooling process). The high-pressure cooling process requires higher capital costs due to the required installation of separation units and heat exchangers, but it offers relatively lower total utility costs of 91.03 $/hr and a reduced duty of 2.81 Gcal/hr. In contrast, although the low-pressure cooling process is simpler and cost-effective, it may encounter operational instability due to rapid pressure drops in the system. Environmental impact assessment revealed that the high-pressure cooling process is more environmentally friendly than the low-pressure cooling process, with an emission factor of 0.83 tCO₂eq less than the low-pressure cooling process, calculated based on power usage. Consequently, the outcomes of this study provide relevant scenario and a database for green ammonia synthesis process adaptable to various process conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.6
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• pp.555-568
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• 2014

The construction equipment is one of the major sources for hazardous air pollutants in Korea, and the its management has been of great concern recently. The objective of this study was to estimate each contribution of emission of construction equipments according to their production year, electric power consumption and type. To achieve this goal, we developed pollutant emission factors for the machineries manufactured after 2009, which are excluded from the present framework of Korean air pollutants inventory, CAPSS. More than 800 data obtained from emission investigations were utilized for the estimation. Compared with the previous estimation, the scheme used this study was modified to incorporate new emission factors as well as to include the corresponding activity data. Such improvement allow us to gain more detailed emission informations which are better characterized by specifications of construction equipments. The total amount of pollutants emitted from construction equipments in 2011 were estimated as 126.8, 7.0, 58.3, and 17.0 kton for $NO_x$, PM, CO, and VOC, respectively. The estimation results indicate that the increase in the emission of equipments is significantly related to their age and power consumption. The emissions of the older ones manufactured from 1992~1996 were estimated to be the contribution ranged from 23.7% to 26.8%, whereas the newer ones (2009~2011) showed the attributions of 11.3~21.5%. In addition, the results show that the emission of each equipment was increased with the increase in the electric power consumption of engine, probably due to their average output power. Among the nine types of machinery compared, excavators and forklifts were investigated to contribute relatively higher emissions in the level of 39.8~44.0% and 32.0~34.2%, respectively.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.393-399
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• 2017

According to the United Nations Framework Convention on Climate Change (UNFCCC), all parties have to submit the national GHG inventory report. Estimating carbon stocks and changes in Land Use, Land-Use Changes and Forestry (LULUCF) needs an activity data and emission factors. So this study was conducted to develop carbon emission factor for Robinia pseudoacacia L., Betula platyphylla var. japonica, and Liriodendron tulipifera. As a result, the basic wood density ($g/cm_3$) was 0.64 for R. pseudoacacia, 0.55 for B. platyphylla, and 0.46 for L. tulipifera. Biomass expansion factor was 1.47 for R. pseudoacacia, 1.30 for B. platyphylla, and 1.24 for L. tulipifera. Root to shoot ratio was 0.48 for R. pseudoacacia, 0.29 for B. platyphylla, and 0.23 for L. tulipifera. Uncertainty of estimated emission factors on three species ranged from 3.39% to 27.43% within recommended value (30%) by IPCC. We calculated carbon stock and change using these emission factors. Three species stored carbon in forest and net $CO_2$ removal was $1,255,398\;t\;CO_2/yr$ during 5 years. So we concluded that our result could be used as emission factors for national GHG inventory report on forest sector.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.449-455
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• 2009

The increase of industrial carbonic dioxide emissions has accelerated the carbonation of reinforced concrete structures, which drops off their durability. Although advanced countries have already taken safety control measures against the carbonation of RC structures, it is still difficult now to accurately predict the actual carbonation depth. Additionally, it requires much time and efforts. Recently, it is possible to get the data more rapidly through accelerated carbonation test with the $CO_2$ concentration of 100%. In this paper, the carbonation test results obtained by two test methods such as the normal carbonation test method and the accelerated carbonation test method, were compared to investigate the carbonation characteristics of fly ash concrete. The accelerated carbonation test on concrete specimens with the pre-curing age of 180 days was also carried out to examine the carbonation characteristics of fly ash concrete at long-term age. Consequently, fly ash concrete at early age was vulnerable to carbonation and however, its carbonation resistance at long-term ages was improved compared with OPC concrete.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.3
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• pp.85-92
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• 2015

For concerning the climate change issues, the carbon sequestration and importance of soil organic matter are receiving high attention. To evaluate carbon sequestration in soil is important to determine the soil organic carbon (SOC) fractions such as WESOC (Water extractable soil organic carbon), and $CO_2$ emission by soil microbial respiration. However, the analyses for those contents are time-consuming procedure. There were studied the feasibility of MIRS (Mid-Infrared Spectroscopy), which has short analysis time for determining the WESOC and an incubated carbon in this study. Oven-dried soils at $100^{\circ}C$ and $350^{\circ}C$ were scanned with MIRS and compared with the chemically analyzed WESOC and cumulative carbon dioxide generated during 30, 60, 90, and 120 days of incubation periods, respectively. It was observed that an optimized determination coefficient was 0.6937 between WESOC and untreated soil processed by spectrum vector normalization (SNV) and 0.8933 between cumulative $CO_2$ from 30 days incubation and soil dried at $350^{\circ}C$ after subtracting air-dried soil processed by 1st derivatives. Therefore, it was shown that Quantification of soil organic carbon fractions was possibility to be analyzed by using MIRS.