Meang-Ik Cho

Experimental Study on N 2 Impurity Effect in the Pressure Drop During CO 2 Mixture Transportation

Carbon-dioxide capture and storage (CCS) process is consisted by capturing carbon-dioxide from large point source such as power plant and steel works, transporting and sequestrating captured in a stable geological structure. During CCS process, it is inevitable of introducing impurities from combustion, capture and purification process into stream. Impurities such as , , CO, , Ar, , , can influence on process efficiency, capital expenditure, operation expense of CCS process. In this study, experimental apparatus is built to simulate the behavior of transport under various impurity composition and process pressure condition. With this apparatus, impurity effect on mixture transportation was experimentally evaluated. The result showed that as ratio increased pressure drop per mass flow and specific volume of mixture also increased. In 120 and 100 bar condition the mixture was in single phase supercritical condition, and as ratio increased gradient of specific volume change and pressure drop per mass flow did not change largely compared to low pressure condition. In 70 bar condition the mixture phase changed from single phase liquid to single phase vapor through liquid-vapor two phase region, and it showed that the gradient of specific volume change and pressure drop per mass flow varied in each phase.

Study on the Immersion Corrosion Characteristics of Thermal Spray Coating for Sea Water Heat Exchanger

Abstract In the present study, immersion corrosion characteristics of Zn and Al thermal spray coating with sealer for the seawater heat exchanger are experimentally investigated. Total 8 coating types of Zn and Al thermal spray coating with silicone and epoxy sealer were tested with immersion corrosion testing in 80℃3.5%w NaCl solution and compared the corrosion characteristics between each coatings. To investigate the corrosion characteristics of the specimens, AC impedance, SEM, and thermal diffusivity were acquired and analyzed. As a result, on the surface of the specimens with silicone and epoxy sealer, blister did not occurred, so the sealers might be effective at increasing the corrosion resistance of the specimens immersed in the NaCl solution. Key Words : Thermal spray coating, Impedance, Resistance, Sea water, SEM 본 연구는 2013년 해양수산부의 재원으로 한국해양과학기술진흥원의 지원을 받아 수행된 “CO2 해양지중저장 기술개발” 및 “해양심층수의 에너지 이용기술개발”의 연구결과로 연구비 지원에 감사드립니다. * Corresponding Author : Young-Chul Kwon(Sunmoon Univ.)Tel: +82-10-8523-0923 email: yckweon1@sunmoon.ac.krReceived November 25, 2013 Revised (1st December 19, 2013, 2nd January 3, 2014) Accepted January 9, 2014

A Fundamentals study on Heat Exchanger using Deep Ocean Water: Effects of Corrosion on Heat Transfer Performance

This paper presents the effects of the tube materials and corrosion on the heat transfer performance of double-tube heat exchangers for the development of heat exchangers using deep sea water. Heat exchangers made of titanium, aluminum. stainless steel, iron, copper, and aluminum with electro-deposition coatings(Carbon black_, Carbon black_) were tested. Also, the heat transfer rate of each heat exchanger was calculated by using EES program. For the acceleration of corrosion by sea water, the temperature of sea water and the concentration of salt 3.5% were considered. And the specimens were immersed in sea water during 6 weeks. From the above experiment and analysis, aluminum with electro-deposition coating(Carbon black_) can be considered the most promising candidate for the replacement of titanium heat exchanger.

Experimental Study on the Argon Impurity Effect in the Pressure Drop of CO 2 mixture flow

During the carbon-dioxide capture and storage(CCS) process, is captured from large point source, and then injected and stored in stable geological structure for thousands and more years. Inside the captured flow, various impurities, such as , , argon, etc, are included inevitably. These impurities affect on the CCS process on various aspects. In this study, we designed and built experimental facility to evaluate the various impurity effect on the pipeline flow, and analyzed the effect of argon ratio and pressure variation on the pressure drop of flow. By comparing experimental data with 4 kinds of pressure drop model, we figured out and recommended the Cicchittis model since it showed most accurate result among compared models in this study.

Study of the corrosion effect of CO 2 stream with SO 2 and NO 2 on a phosphate coated steel tube

To mitigate global warming and climate change, many countries are investing massively on the development of CCS technology, which is assumed to be the key technology to reduce CO2 emissions. CCS technology is comprised of the capture, transport, and storage processes. During the capture process, impurities other than CO2 are inevitably flowed into the CO2 stream. In the present study, corrosion characteristics of a phosphate coated tube for CO2 transportation was investigated with a CO2 stream composed of CO2, H2O, SO2, and NO2. The test specimen was a phosphate coated steel tube, which was filled with CO2 stream with the impurities mentioned above. SEM-EDS analysis is conducted to investigate the corrosion behavior. The results showed that although the H2O concentration did not exceed the solubility limit, corrosion occurred in the specimen, which has an inflow of SO2 or NO2. This suggests that the SO2, NO2 and H2O concentration should be strictly controlled. These results suggest that the SO2 and NO2 concentration should be controlled below 175ppm and 65ppm, respectively.

Experimental Study on Coating Corrosion Characteristics of Heat Exchanger for Sea Water

Abstract In the present study, coating corrosion characteristics of the heat exchanger for sea water are experimentally investigated. Coating types by a teflon, an electrodeposition and a ceramic+silicon were tested and compared with the corrosion characteristics of an aluminum. For the acceleration of corrosion by sea water, the temperature of sea water 70℃ and the concentration of salt 3.5% were considered. And the specimens were immersed in sea water during 9 weeks. Coating corrosion characteristics were measured by using the impedance method and SEM. Experimental results showed that polarization resistances obtained from Bode plot were related to the corrosion resistance of coating types, and the corrosion resistance of double coating were maintained during 4 weeks. From SEM photograph, we saw that blisters was generated on the interface between metal and coating. Key Words : Coating, Impedance, Immersion, Resistance, Sea water, SEM 본 연구는 해양수산부에서 지원하는 “해양심층수의 에너지 이용기술개발” 결과로 연구비 지원에 감사드린다.

The Characteristics of CO2 Flow and Thermal Field in a Porous Media

International attention has been considerably paid for the technology of CO2 capture and storage (CCS) these days because of global warming. Among the technologies of CCS, the prediction of CO2 behavior in underground is very crucial for CO2 storage design. In the present study, a pore-scale level model is developed to mimic real porous structure and by using CFD (computational fluid dynamics) the characteristics of the CO2 flow and thermal fields are investigated in the pore-level micro porous structure. Varying the CO2 injection conditions such as flow rate, pressure and temperature, the behavior of CO2 is calculated. Especially, the physical conditions such as temperature and pressure are set up equivalent to the underground condition at which CO2 is injected. From the results, the injection condition of CO2 is very critical to the characteristics of the flow and thermal fields in the micro-scale porous structure.Copyright