Jong-Hyeon Jung

Removal characteristics of CO2 using aqueous MEA/AMP solutions in the absorption and regeneration process

The carbon dioxide (CO2) removal efficiency, reaction rate, and CO2 loading into aqueous blended monoethanolamine (MEA) + 2-amino-2-methyl-1-propanol (AMP) solutions to enhance absorption characteristics of MEA and AMP were carried out by the absorption/regeneration process. As a result, compared to aqueous MEA and AMP solutions, aqueous blended MEA + AMP solutions have a higher CO2 loading than MEA and a higher reaction rate than AMP. The CO2 loading of rich amine of aqueous 18 wt.% MEA + 12 wt.% AMP solution was 0.62 mol CO2/mol amine, which is 51.2% more than 30 wt.% MEA (0.41 mol CO2/mol amine). Consequently, blending MEA and AMP could be an effective way to design considering economical efficiency and used to operate absorber for a long time.

Reactivity of bio-sorbent prepared by waste shells of shellfish in acid gas cleaning reaction

Acid gas cleaning activity of bio-adsorbent prepared by waste shell of different shellfish species was investigated in a fixed bed reactor to evaluate its feasibility as an acid gas cleaning agent. The physicochemical properties of prepared adsorbents were measured using ICP, BET, SEM-EDX and XRD. The results showed that active chemical species of bio-sorbent are comparable to that of commercial limestone and lime. SO2/NOx removal capacity of waste shell of shellfish was higher than that of commercial limestone due to the enhanced physical properties. In particular, the desulfurization activity of clam based adsorbent was the best among the tested waste shells because of both higher calcium content and more specific surface area. These lead to the conclusion that commercial limestone can be substituted for bio-sorbent prepared by waste shell of clam.

The characteristics of the appearance and health risks of volatile organic compounds in industrial (pohang, ulsan) and non-industrial (gyeongju) areas.

Objectives The aim of this study was to identify the health and environmental risk factors of air contaminants that influence environmental and respiratory diseases in Gyeongju, Pohang and Ulsan in South Korea, with a focus on volatile organic compounds (VOCs). Methods Samples were collected by instantaneous negative pressure by opening the injection valve in the canister at a fixed height of 1 to 1.5 m. The sample that was condensed in -150℃ was heated to 180℃ in sample pre-concentration trap using a 6-port switching valve and it was injected to a gas chromatography column. The injection quantity of samples was precisely controlled using an electronic flow controller equipped in the gas chromatography-mass spectrometer. Results The quantity of the VOC emissions in the industrial area was 1.5 to 2 times higher than that in the non-industrial area. With regards to the aromatic hydrocarbons, toluene was detected at the highest level of 22.01 ppb in Ulsan, and chloroform was the halogenated hydrocarbons with the highest level of 10.19 ppb in Pohang. The emission of toluene was shown to be very important, as it accounted for more than 30% of the total aromatic hydrocarbon concentration. Conclusions It was considered that benzene in terms of the cancer-causing grade standard, toluene in terms of the emission quantity, and chloroform and styrene in terms of their grades and emission quantities should be selected for priority measurement substances.

Assessment of location of the air quality monitoring stations according to the analysis of wind sector division in Pohang

Abstract This study evaluated whether the installed location of air quality monitoring stations is at an optimal level in an effort to improve the health and environmental quality of the surrounding areas of the Pohang Steel Complex. As a result of analyzing the atmospheric flow field, it was found that the location of air quality monitoring stations was acceptable in case of Daesong-myeon(The 1st Division of Local Wind Sector) and Jukdo-dong(The 3rd Division of Local Wind Sector). However, the air quality monitoring stations installed at Daedo-dong and Jukdo-dong is judged to have made an overlapped measurement because the stations existed at the Division of the same Wind Sector. Accordingly, this study suggests that the further air quality monitoring stations should be additionally installed at Buk-gu areas of Pohang where more than 50% of the population of Pohang is living presently. As a result of the analysis of air contaminant concentration distribution, the Jangheung-dong area showed higher concentration distribution than other areas in case of PM

Chemical Characteristics and Particle Size Distribution of PM 10 in Iron and Steel Industrial Complex

The fine particulate matter() concentrations and contents were measured to check the health and environment influential factors in Pohang Iron and Steel Industrial Complex and its vicinities. In addition, the distribution for each year and season was surveyed using the regional air quality monitoring stations. The measuring on the inside the industrial complex showed for average concentration of which was measured by Dongil Industry and measured by steel manufacturing industry complex management office. Both of them satisfied the environmental air quality standard. The percentage of , , which are the secondary ions created out of the in Dongil Industry and steel manufacturing industry complex management office was checked and it was revealed that the percentage of was high and it is considered that the pollution source related with the sulfides exist at the industrial complex. They were in order of > > > > in Dongil Industry and > > > > in steel manufacturing industry complex management office.

Analysis of Wind Sector Division for Pohang Area - Part I : Coarse Division of Wind Sector for Pohang Area Using Meteorological Observation Data -

The air quality data is important for understanding and analyzing a surrounding influence. In that light, it is positively necessary for a propriety assessment to determine a location of the air quality monitoring sites. In this study, the climate analysis about temperature and wind, using the meteorological data in the Pohang, is conducted to do that. In the next stage, we distinguished the wind by east-west or north-south component, which has less correlation than temperature, analyzed and divided the wind sector. As the result, the wind circumstance of the Pohang is divided into major 5 wind sector; that is the urban area, the northeast coastal area, the east ocean and the west mountainous area. We think that an analysis on detailed wind sector by utilizing the numerical simulation is needed.

A Numerical Study on Performance Improvement of Canopy Hood in Melting Process

This study reviewed the capturing performance of a canopy hood used in some melting processes of a casting manufacturing factory through a site survey. In addition, this study compared and evaluated the flow field and pressure field for the plans to enhance the hazardous air pollutants collection capacity by using CFD model. The case-2(flange attached + double hood) can be improved in terms of collection performance, but is expected to increase in hood static pressure by about 70% more than the existing structure, so it was shown that its site applicability is not good. It is judged that the shape of case-3(flange attached + double cone attached) is most suitable to improve the suction efficiency. This is because a double cone is installed at the center of the opening to concentrate the flow rate on the edge of the hood and control the hume rising to the center of the hood without a static pressure rise via the slope of the cone.

Exposure Assessments of Chemical Risk Factors to Airborne Contaminants in Foundry Process

This study was performed to identify the state of the exposure and characteristics of pollutants by each process at 4 casting sites located in Gyeongsang-do from April to November 2013. The concentrations of methanol, crystallized silica glass, formaldehyde and phenol were analyzed by different process casting process, molding process, core process, and shakeout & finishing process. The highest concentration of methanol was found in casting and molding process, whereas the highest concentration of crystalline quartz(Silica) was observed in core process. The most oxidized steel dusts and the highest concentration of fume were found in shakeout & finishing process. As a result of this study, those labors working at the casting site were found to be constantly exposed to various forms of hazardous chemicals; therefore, it is considered that this is the time to manage and plan how to reduce them. In addition, it is required to thoroughly manage the local exhauster, and improve the process and working environment to reduce various forms of hazardous chemicals.

Improvement of Capturing Velocity in the Fume Hood using Computational Fluid Dynamics(I) - Uniform flow

This study used Computational Fluid Dynamics(CFD) to assess the properties of the air current inflow and the flow velocity distribution in the fume hood. In order to verify the effect of improvement, it was also predicted the characteristics of the flow pattern in case the hood face is structurally improved. The assessment of the capture velocity with the existing fume hood confirmed maximum 23 to 30% difference as compared to the root mean square (RMS). And the hood face showed great difference in flow velocity, with the flow velocity in the upper part is 58 to 68% faster than that in the lower part of the hood. So, as a result of the improvement of the hood designed to maintain a steady exhaust at the hood face (that is, installing a baffle on the inner wall and designing the slot type face), a difference of maximum 7% as compared to RMS appeared while maximum 12% differentiation in flow velocity through sections was predicted, showing mitigation of much of the difference in control velocity as compared to the previous structure.

Risk Factors for Health and Environmental Disease in Gyeongju, Pohang, and Ulsan

This study was undertaken in an attempt to provide scientific grounds in explaining the causes of environmental and respiratory diseases resulting from air pollutants in Gyeongju and its neighboring areas. In relation to heavy metals, lead (Pb) was 0.0135~0.1744 µg/m and high in order of Pohang, Ulsan, and Gyeongju while nickel (Ni) was 0.0023~0.0115 µg/m . The concentrations of heavy metals in the investigated areas did not exceed the environmental standards or Guideline Value of Korea or other countries. However, it is considered necessary to apply intensive control to some heavy metals including cadmium (Cd) that show a relatively high level of hazard. Based on the responses to the survey, measured personal interest in environmental pollution and the basic knowledge of the causes of the respiratory diseases was higher in those with a family history of allergic reactions to metals and bronchial asthma. The incidence of allergic disease was higher in those who are currently in poor health state. In addition, the general knowledge of environmental pollutants was higher in those with higher educational level and those with a higher interest in environmental pollution. Personal interest in environmental pollution was higher in those with higher basic knowledge of environmental pollutants. Therefore, it is necessary to increase the awareness through better education and campaigns on environmental pollution.