• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.123-128
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• 2013

Carbon dioxide Capture and Storage (CCS) is one of the key players in greenhouse gas (GHG) reduction portfolio for mitigating climate change. CCS makes it possible not only to reduce a huge amount of carbon dioxide directly from coal power plant but also to maintain the carbon concentrated-energy infrastructure. The objective of the present paper is to review and introduce R&D progress and large scale demonstration plan focused on marine geological storage in Republic of Korea.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.101-115
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• 2016

We carried out laboratory material tests on two cements (KS-1 ordinary Portland and Class G) with changing W/S (Water/Solid) and the content of fly ash in order to evaluate their physical and mechanical properties. The specimens of KS-1 ordinary Portland cement were prepared with varying W/S (Solid=cement) in weight, while those of Class G cement were prepared with changing the content of fly ash in volume but maintaining W/S (Solid=cement+fly ash). The results of the material tests show that as the W/S in KS-1 ordinary Portland cement and the content of fly ash in Class G cement increase, the properties (density, sonic wave velocity, elastic constants, compressive and tensile strengths, thermal conductivity) decrease, but porosity and specific heat increase. In addition, an increase in confining pressure and in the content of fly ash leads to plastic failure behavior of the cements. The laboratory data were then used in a stability analysis of cement sheath for which an analytical solution for computing the stress distribution induced around a cased, cemented well was employed. The analysis was carried out with varying the injection well parameters such as thickness of casing and cement, injection pressure, dip and dip direction of injection well, and depth of injection well. The analysis results show that cement sheath is stable in the cases of relatively lower injection pressures and inclined and horizontal wells. However, in the other cases, it is damaged by mainly tensile failure.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.193-206
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• 2018

In this study, as part of the "Small-scale $CO_2$ Injection-Demonstration Project in Offshore Pohang Basin", we performed drilling and completion of a $CO_2$ injection well from the offshore platform installed in the Yeongil Bay, Pohang city, Gyeongsang buk-do. The drilling of injection well was carried out from an offshore platform installing on the sediment formations of the Pohang Basin. Drilling diameters were reduced by stages, depending on the formation pressure and groundwater pressure along a depth and the casing installation and cement grouting in drilled hole were performed at each stage. The injection well was drilled to a final depth of 816.5 m with a hole diameter of 4 7/8 inches (${\Phi}124mm$) and the perforated casing for an injection section was installed in a depth of 746.5~816.5 m. Injection tubing, packer, and christmas tree were installed for the completion of an injection well for $CO_2$. The validation project of the $CO_2$ injection was accomplished successfully by drilling the injection well and installing the injection facilities, and through the suitable $CO_2$ injection process. The current injection facility is a facility for small-scale injection demonstration of 100 tons. In the case of large-scale demonstration facility test of a capacity of 10,000 tons, research is underway through the upgrading of the injection facilities.

• Journal of Climate Change Research
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• v.8 no.3
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• pp.257-264
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• 2017

Carbon capture and storage (CCS) technology has been suggested as an ultimate strategy for mitigating climate change. However, potential leakage of $CO_2$ from the CCS facilities could lead to serious damage to environment. Plants can be a bio-indicator for $CO_2$ leakage as a cost-effective way, although plants' responses vary with plant species. In this study, a greenhouse experiment was conducted to investigate the relation between the $CO_2$ tolerance of corn species and the initial physiological responses to the elevated soil $CO_2$ concentration. Treatment groups included CI (99.99% $CO_2$ gas injection) and BI (no gas injection). Mean soil $CO_2$ concentration for the CI treatment was 19.5~39.4%, and mean $O_2$ concentration was 6.6~18.4%. The soil gas concentrations in the BI treatment were at the ambient levels. In the CI treatment, chlorophyll content was not decreased until the $13^{th}$ day of the $CO_2$ injection. On the $15^{th}$ day, leaf starch content and stomatal conductance were increased by 89% and 25% in the CI treatment compared to the BI treatment, respectively. This might be due to the compensatory reaction of corn to avoid high soil $CO_2$ stress. However, the prolonged $CO_2$ injection decreased chlorophyll content after 13 days. After $CO_2$ injection, plant biomass was reduced by 25% in the CI treatment compared to the BI treatment. Due to the inhibited root growth, leaf phosphorous and potassium contents were decreased by 54% on average in the CI treatment. This study indicates that corn has a high tolerance to soil $CO_2$ concentration of 30% for 2 weeks by its compensatory reactions such as an maintenance of chlorophyll content and an increase in stomatal conductance.

• The Journal of Engineering Geology
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• v.28 no.2
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• pp.183-192
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• 2018

It is imperative to inject carbon dioxide($CO_2$) into an aquifer for alleviating the emission of $CO_2$. However, faults in the aquifer can be reactivated due to pressure increasement. Analyses of pressure change of the aquifer is necessary to prevent the fault reactivation. In this research, we assess the stability of an aquifer in Pohang Yeongil bay by investigating the pressure variation of faults EF1 and EF2. Two scenarios, which repeat $CO_2$ injection and suspension during two years, are simulated. Each scenario includes cases of injection rates of 20, 40, and 100 tons/day. In addition, we analyze planned and predicted injection rates for each case. In case of 20 tons/day, the maximum pressure of faults is 65% of the reactivation pressure. Even if daily injection rates are increased to 40 and 100 tons/day, the maximum pressures are 71% and 80% of the reactivation pressures, respectively. For 20 and 40 tons/day cases, planned injection rates almost accord with predicted injection rates during whole simulation period. On the other hand, predicted injection rates are smaller than planned injection rates for the 100 tons/day case due to bottom-hole pressure limit of the injection well.

• Economic and Environmental Geology
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• v.50 no.6
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• pp.537-544
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• 2017

Stable carbon isotope ratio of carbon dioxide (${\delta}^{13}C_{CO2}$) is used as an important indicator in the researches for global climate change and carbon capture and sequestration technology. The ${\delta}^{13}C$ value has been usually analyzed with Isotope Ratio Mass Spectrometer (IRMS). Recently, the use of Laser Absorption Spectrometry (LAS) is increasing because of the cost efficiency and field applicability. The purpose of this study was to suggest practical procedures to prepare laboratory reference gases for ${\delta}^{13}C_{CO2}$ analysis using LAS. $CO_2$ gas was adjusted to have the concentrations within the analytical range. Then, the concentration of $CO_2$ was assessed in a lab approved by the Korea Laboratory Accreditation Scheme and the ${\delta}^{13}C_{CO2}$ value was measured by IRMS. When the instrument ran over 12 hours, the ${\delta}^{13}C$ values were drifted up to ${\pm}10$‰ if the concentration of $CO_2$ was shifted up to 1.0% of relative standard deviation. Therefore, periodical investigation of analytical suitability and correction should be conducted. Because ${\delta}^{13}C_{CO2}$ showed the dependency on $CO_2$ concentration, we suggested the equation for calibrating the concentration effect. After calibration, ${\delta}^{13}C_{CO2}$ was well matched with the result of IRMS within ${\pm}0.52$‰.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8870-8878
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• 2015

During the carbon-dioxide capture and storage(CCS) process, $CO_2$ is captured from large point source, and then injected and stored in stable geological structure for thousands and more years. Inside the captured $CO_2$ flow, various impurities, such as $N_2$, $O_2$, 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 $CO_2$ pipeline flow, and analyzed the effect of argon ratio and pressure variation on the pressure drop of $CO_2$ flow. By comparing experimental data with 4 kinds of pressure drop model, we figured out and recommended the Cicchitti's model since it showed most accurate result among compared models in this study.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.409-425
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• 2021

Carbon dioxide has been known to be a typical greenhouse gas causing global warming, and a number of efforts have been proposed to reduce its concentration in the atmosphere. Among them, carbon dioxide capture and storage (CCS) has been taken into great account to accomplish the target reduction of carbon dioxide. In order to commercialize the CCS, its safety should be secured. In particular, if the stored carbon dioxide is leaked in the arable land, serious problems could come up in terms of crop growth. This study was conducted to investigate the effect of carbon dioxide leaked from storage sites on soil fertility. The leakage of carbon dioxide was simulated using the facility of its artificial injection into soils in the laboratory. Several soil chemical properties, such as pH, cation exchange capacity, electrical conductivity, the concentrations of exchangeable cations, nitrogen (N) (total-N, nitrate-N, and ammonia-N), phosphorus (P) (total-P and available-P), sulfur (S) (total-S and available-S), available-boron (B), and the contents of soil organic matter, were monitored as indicators of soil fertility during the period of artificial injection of carbon dioxide. Two kinds of soils, such as non-cultivated and cultivated soils, were compared in the artificial injection tests, and the latter included maize- and soybean-cultivated soils. The non-cultivated soil (NCS) was sandy soil of 42.6% porosity, the maize-cultivated soil (MCS) and soybean-cultivated soil (SCS) were loamy sand having 46.8% and 48.0% of porosities, respectively. The artificial injection facility had six columns: one was for the control without carbon dioxide injection, and the other five columns were used for the injections tests. Total injection periods for NCS and MCS/SCS were 60 and 70 days, respectively, and artificial rainfall events were simulated using one pore volume after the 12-day injection for the NCS and the 14-day injection for the MCS/SCS. After each rainfall event, the soil fertility indicators were measured for soil and leachate solution, and they were compared before and after the injection of carbon dioxide. The results indicate that the residual concentrations of exchangeable cations, total-N, total-P, the content of soil organic matter, and electrical conductivity were not likely to be affected by the injection of carbon dioxide. However, the residual concentrations of nitrate-N, ammonia-N, available-P, available-S, and available-B tended to decrease after the carbon dioxide injection, indicating that soil fertility might be reduced. Meanwhile, soil pH did not seem to be influenced due to the buffering capacity of soils, but it is speculated that a long-term leakage of carbon dioxide might bring about soil acidification.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.253-254
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• 2014

지구온난화 문제는 한국가의 문제가 아니라 인류의 문제로 대두되어 많은 이에대한 많은 연구가 이루어 지고 있다. 지구온난화의 주 대상물질인 화석연료로부터 연소시 발생하는 이산화탄소를 감축하기위한 많은 규제와 노력이 요구된다. CCS(Carbon Capture & Storage)란 화석연료로 부터 연소시 대기 중으로 배출되는 온실가스($CO_2$)를 포집하여 재생 또는 지중, 해양에 저장하는 기술로서 국가녹색성장 핵심기술중의 하나로 분류되며, $CO_2$ 회수방안, 저장, 처리관련 연구를 비롯하여 국내외 적으로 활발한 연구가 이루어 지고 있다. 또한 순산소 연소기술을 통한 $CO_2$ 회수, 처리기술은 연료의 산화제를 공기대신 순도 95% 이상의 고농도 산소를 이용하여 순산소연소를 하며, 이때 발생하는 배가스의 대부분은 $CO_2$와 수증기로 구성되어 있다. 발생된 배가스의 약 70~80%를 다시 연소실로 재순환시켜 연소기의 열적 특성에 적절한 연소가 가능하도록 최적화함과 동시에 배가스의 $CO_2$ 농도를 80% 이상으로 농축시켜 회수를 용이하게 하며, 동시에 공해물질은 NOx 발생량을 10ppM 이하로 줄일 수 있는 기술이다. 천연가스를 생산하는 LNG기지에서 연소에 의한 이산화탄소를 발생시키는 기기로는 수중연소식기화기(SMV ; Submerged Combustion Vaporizer)를 들 수 있다. SMV는 버너를 이용하여 $-162^{\circ}C$ LNG를 $10^{\circ}C$의 LN로 기화시키는 설비로서 특히 동절기에 작동시키며 $CO_2$를 배출시키는 연소기다. 본 연구에서는 수중연소식 SMV에 순산소 연소방식을 적용하여 천연가스와 산소를 연소시키므로서 발생되는 $CO_2$를 LNG냉열을 이용 액체화 시켜 회수하는 연구를 수행하고 있다. 내용중에 수중연 소식 SMV에 대한 순산소 연소기를 개발하는 연구를 수행하였으며, 실제 SMV의 1/10크기, 열량기준 1/900로 모형을 제작하여 실험하였다. 연소기 노즐 은 직경 0.6mm, 배가스가 수조내에서 48개의 노즐을 제작하였다. 실험결과 일정량 이상의 $CO_2$ EGR율이 일정 값 이상이 되면 화염의 길이가 공기/NG 화염 길이와 큰 차이가 없었으며 $CO_2$ EGR율이 100%이상에서는 $CO_2$ EGR율 증가에 따른 화염길이 변화는 크게 나타나지 않았다. CO 배출 농도는 공기/NG 연소의 경우보다 높게 나타났으며, ${\lambda}$가 1.4보다 높은 조건에서는 측정되지 않았다. NOx의 배출 농도는 약 1~8ppm으로 나타났다.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.351-360
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• 2018

This study was conducted to analyze the responses of chlorophyll contents and growth of Pinus densiflora and Quercus variabilis seedlings on distance from the well and $CO_2$ flux after the artificial $CO_2$ release. From June 1 to 30, 2016, $CO_2$ gas was injected at the rate of $6L\;min^{-1}$ at the study site in Eumseong. Chlorophyll content was analyzed in the middle of July, 2016, and root collar diameter (RCD), height (H), and biomass were measured in May and December, 2016 after planting 2-year-old P. densiflora and 1-year-old Q. variabilis seedlings in May, 2015. The chlorophyll content of P. densiflora seedlings did not show a significant correlation with $CO_2$ flux, whereas the chlorophyll content of Q. variabilis seedlings showed a significant negative correlation with increasing $CO_2$ flux (P<0.05). The RCD and H growth rates of both species showed the significant difference in the distance from the well of the $CO_2$ anthropogenic release treatment. In particular, the RCD and H growth rate of P. densiflora seedlings and the RCD growth rate of Q. variabilis seedlings increased significantly as the seedlings were closer to the well, but the H growth rate of Q. variabilis seedlings decreased significantly. In addition, as the $CO_2$ concentration in the ground increases, ${\Delta}R/S$ ratio increases in both species, suggesting that the high $CO_2$ concentration in the soil promotes carbon distribution relative to the root part. The results of this study can be used as data necessary to monitor the $CO_2$ leakage and physiological and growth responses of both species to leakage of stored $CO_2$ in the future.