• Journal of the Korean GEO-environmental Society
• /
• v.24 no.6
• /
• pp.5-11
• /
• 2023

The engineering industry heavily relies on fossil fuels such as coal and petroleum to generate energy through combustion. However, this process emits carbon dioxide into the atmosphere, leading to global warming. To mitigate this issue, researchers have explored various methods to reduce carbon dioxide emissions, one of which is carbon dioxide underground storage technology. This innovative technology involves capturing carbon dioxide from industrial plants and injecting it into the saturated ground layer beneath the earth's surface, storing it securely underground. Despite its potential benefits, carbon dioxide underground storage efficiency needs improvement to optimize storage in a limited space. To address this challenge, our research team has focused on improving storage efficiency by utilizing surfactants. Furthermore, we evaluated how different carbon dioxide states, including gaseous, liquid, and supercritical, impact storage efficiency based on their respective pressures and temperatures within the underground reservoir. Our findings indicate that using surfactants and optimizing the injection rate can effectively enhance storage efficiency across all carbon dioxide states. This research will pave the way for more efficient carbon dioxide underground storage, contributing to mitigating the environmental impact of fossil fuels on the planet.

• Plant Journal
• /
• v.9 no.2
• /
• pp.42-45
• /
• 2013

The worldwide issue of greenhouse gas reduction has recently drawn great attention to carbon capture and storage(CCS). In this study, we developed a 10,000 ton/year pilot injection plant for geological storage of carbon dioxide. Major components of the pilot plant include a pressure pump, a booster pump, and an inline heater to bring liquid carbon dioxide into its supercritical state. The test results show that the pilot plant readily achieves the injection pressure and temperature, showing satisfactory control performance. The overall power consumption is 2,000 ~ 2,500 W, more than 75% of which consumed by the pressure pump. This study will facilitate varied research on greenhouse gas reduction as the only domestically developed system for geological injection.

• The Journal of Engineering Geology
• /
• v.28 no.2
• /
• pp.161-174
• /
• 2018

$CO_2$ storage site for small-scale demonstration has been investigated in Yeongil Bay, Pohang, SE Korea, using seismic survey and exploration well data. We found a potential storage formation consisting mainly of conglomerate and sandstone. The storage formation unconformably overlies volcanic basement rocks that are located in a depth from 650 to 950 m (below sea level). The depth of the storage formation is suitable for injecting supercritical $CO_2$ in the Pohang Basin. The average thickness of the storage formation is about 123 m, which possibly provides sufficient capacity at the level of small-scale storage demonstration. The overlying fine-grained deposits consist mainly of marine hemipelagic muds and interlayered turbidite sands. The overlying formation is considered as a good seal rock that is over 600 m thick and widely distributed in the onshore and offshore portions of the basin. NNE-trending faults found in the study area likely formed at basement level, probably not continue to seafloor. Such faults are interpreted as syndepositional faults involved to the basin initiation. This study reveals that the offshore area of the Pohang Basin contains deep geological formations suitable for small-scale $CO_2$ storage demonstration.

• Geophysics and Geophysical Exploration
• /
• v.14 no.1
• /
• pp.58-68
• /
• 2011

As part of basic studies of monitoring carbon dioxide ($CO_2$) storage using electrical and seismic surveys, laboratory experiments have been conducted to measure resistivity and P-wave velocity changes due to the injection of $CO_2$ into water-saturated sandstone. The rock sample used is a cylinder of Berea sandstone. $CO_2$ was injected under supercritical conditions (10 MPa, $40^{\circ}C$). The experimental results show that resistivity increases monotonously throughout the injection period, while P-wave velocity and amplitude decrease drastically due to the supercritical $CO_2$ injection. A reconstructed P-wave velocity tomogram clearly images $CO_2$ migration in the sandstone sample. Both resistivity and seismic velocity are useful for monitoring $CO_2$ behaviour. P-wave velocity, however, is less sensitive than resistivity when the $CO_2$ saturation is greater than ~20%. The result indicates that the saturation estimation from resistivity can effectively complement the difficulty of $CO_2$ saturation estimations from seismic velocity variations. By combining resistivity and seismic velocity we were able to estimate $CO_2$ saturation distribution and the injected $CO_2$ behaviour in our sample.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.16 no.1
• /
• pp.42-52
• /
• 2013

Carbon Capture and Storage (CCS) is a mitigation technology essential in tackling global climate change. In Korea, many research projects are aimed to commercialize CCS business around 2020. Public acceptance can be a key factor to affect the successful proceeds of CCS near future. Therefore this paper provides a concise insight into the application of environmental impact assessment and risk assessment procedures to support the sustainable CCS projects. Futhermore, bottlenecks regarding the environmental impacts assessment and related domestic and foreign legislation are revised. Finally, suggestions to overcome these bottlenecks and recommendations for future research are made in conclusion.

• Economic and Environmental Geology
• /
• v.51 no.3
• /
• pp.223-232
• /
• 2018

The viscous force of fluids and the capillary force acting on the pore network of the porous media are important factors determining the immiscible displacement during geological $CO_2$ sequestration, these were directly affected by geological formation conditions and injection conditions. This study aimed to observe the migration and distribution of injected fluid and pore water, and quantitatively investigate displacement efficiency on various injection temperatures. This study aimed to perform micromodel experiments by applying n-hexane used as a proxy fluid for supercritical $CO_2$. In this study, immiscible displacement process from beginning of n-hexane injection to equilibrium of the distribution of the n-hexane and pore water was observed. The images from experiment were used to observe the displacement pattern and estimate the areal displacment efficiency of the n-hexane. For investigate the affects of the injection temperatures on the migration in macroscopic, migration of n-hexane in single pore was analyzed. The measurement revealed that the displacement efficiency at equilibrium state decreases as the temperature increases. The result from experiments indicate that the temperatures can affect the displacement pattern by changing the viscous forces and the capillary forces. The experimental results could provide important fundamental information on reservoir conditions and fluid injection conditions during geological $CO_2$ sequestration.

• Coastal and Ocean
• /
• v.3 no.2
• /
• pp.13-27
• /
• 2010

• Economic and Environmental Geology
• /
• v.49 no.5
• /
• pp.371-380
• /
• 2016

This study aims to identify the mineraloical and petrographical characteristics of caprock from drilling cores of Pohang basin as a potential $CO_2$ storage site. Experiments and modeling were conducted in order to investigate the geochemical and mineralogical caprock effects of carbon dioxide. A series of autoclave experiments were conducted to simulate the interaction in the $scCO_2$-caprock-brine using a high pressure and temperature cell at $50^{\circ}C$ and 100 bar. Geochemical and mineralogical alterations after 15 days of $scCO_2$-caprock-brine sample reactions were quantitatively examined by XRD, XRF, ICP-OES investigation. Results of mineralogical studies, together with petrographic data of caprock and data on the physicochemical parameters of brine were used for geochemical modeling. Modelling was carried out using the The Geochemist's Workbench 11.0.4 geochemical simulator. Results from XRD analysis for caprock sample showed that major compositional minerals are quartz, plagioclase, and K-feldspar, and muscovite, pyrite, siderite, calcite, kaolinite and montnorillonite were included on a small scale. Results from ICP-OES analysis for brine showed that concentration of $Ca^{2+}$, $Na^+$, $K^+$ and $Mg^{2+}$ increased due to dissolution of plagioclase, K-feldspar and muscovite. Results of modeling for the period of 100 years showed that the recrystallization of kaolinite, dawsonite and beidellite, at the expense of plagioclase and K-feldspar is characteristic. Volumes of newly precipitation minerals and minerals passing into brine were balanced, so the porosity remained nearly unchanged. Experimental and modeling results indicate the interaction between caprock and $scCO_2$ during geologic carbon sequestration can exert significant impacts in brine pH and solubility/stability of minerals.

• Tunnel and Underground Space
• /
• v.20 no.5
• /
• pp.309-317
• /
• 2010

CCS (Carbon dioxide Capture and Storage) is a means of mitigating the contribution of $CO_2$ to the Greenhouse gas, from large point sources such as power plants and steel companies. CCS is a process whereby $CO_2$ is captured from gases produced by fossil fuel combustion, compressed, transported and injected into deep geologic formations for permanent storage. CCS applied to a conventional power plant can reduce $CO_2$ emissions to the atmosphere by approximately 80~90% compared to a plant without CCS. The IPCC estimates that the economic potential of CCS will be between 10% and 55% of the total carbon mitigation effort by year 2100. In this paper, overseas sites where CCS technology is being applied and technical development trends for CCS are briefly reviewed.

• The Journal of Engineering Geology
• /
• v.28 no.1
• /
• pp.69-79
• /
• 2018

The Korean government attempts to reduce $CO_2$ emissions by 37% to 314.7 Mt $CO_2$, down from the estimated 850.6 Mt $CO_2$ until 2030 in order to confront green house effect. In this context, in 2014, Korean government launched $CO_2$ Storage Environmental Management Research (K-COSEM) Center for carrying out pilot-scale research on $CO_2$ leakage from underground $CO_2$ storage facilities. For the detection of $CO_2$ leakage, it is necessary to identify hydrologeological and geophysical characteristics of the subject area. In the study site of Naesan-ri, Daeso-myeon, Eumseong-gun, Chungbuk Province, two times injection tests (June 28-July 24, 2017 and August 07-September 11, 2017) of $CO_2$ and $SF_6$ dissolved waters, respectively, was conducted to understand the leakage behavior of $CO_2$ from underground. The injection well was drilled to a depth of 24 m with a 21-m casing and screen interval of 21~24 m depth. Two times resistivity surveys on August 18, 2017 and September 1, 2017, were conducted for revealing the flow of the injected water as well as the electrical properties of the study site. The study results have shown that the high-resistivity zone and the low-resistivity zone are clearly contrasted with each other and the flow direction of the injected water is similar to natural groundwater flow. Besides, the low resistivity zone is widely formed from the depth of injection to the shallow topsoil, indicating that the weathered zone of high permeability has high $CO_2$ leakage potential.