• Journal of the Korean Society of Combustion
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• v.15 no.2
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• pp.1-11
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• 2010

Power generation systems based on the oxy-coal combustion with carbon dioxide capture and storage (CCS) capability are being proposed and discussed lately. Although a large number of lab scale studies for oxy-coal power plant have been made, studies of pilot scale or commercial scale power plant are not enough. Only a few demonstration projects for oxy-coal power plant are publicized recently. The proposed systems are evolving and various alternatives are to be comparatively evaluated. This paper presents a proposed approach for performance evaluation of a commercial 100 MWe class power plant, which is currently being considered for 'retrofitting' for the demonstration of the concept. The system is configurated based on design and operating conditions with proper assumptions. System components to be included in the discussion are listed. Evaluation criteria in terms of performance are summarized based on the system heat and mass balance and simple performance parameters, such as the fuel to power efficiency and brief introduction of the second law analysis. Also, gas composition is identified for additional analysis to impurities in the system including the purity of oxygen and unwanted gaseous components of nitrogen, argon and oxygen in air separation unit and $CO_2$ processing unit.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2940-2945
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• 2008

The scale of 2.4 MW MCFC was taken to construct a high-efficiency and economical power generation system without CO2 emission into the atmosphere for utilizing its exhaust gas. The conventional steam turbine power generation system (STGS) was evaluated and the net generated power (NGP) was estimated to be only 133 kW and the STGS is not economically feasible. A CO2-caputuring repowering system was proposed, where low temperature steam (LTS) produced at HRSG by using exhaust gas from MCFC is utilized as a main working fluid of a gas turbine, and the temperature of LTS was raised by combusting fuel in a combustor by using pure oxygen, not the air. It has been shown that NGP of the proposed system is 264 kW, and CO2 reduction amount is 608 t-CO2/y, compared to 306 t-CO2/y of STGS. The CO2 reduction cost was estimated to be negligible small, even when the costs of oxygen production and CO2 liquefaction facilities etc. were taken into account.

• Journal of the Korean Ceramic Society
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• v.49 no.2
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• pp.185-190
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• 2012

The purpose of this study was to examine a possibility that fly ash could be used as raw material for carbonation by conducting the experiment on magnetic separation and hydration of fly ash that contained a large amount of CaO composite. Wet magnetic separation experiment was performed to remove the component of magnetic substance that contained fly ash, which aimed at increasing the content of CaO in the non-magnetic domain. The selected fly ash was used for hydration experiment before the TG-DTA, XRF and XRD analyses were made to confirm the Ca component that could be carbonated. Then, the fly ash was turned to a hydrate that was favorable to dissociation of $Ca^{2+}$ ion. As a result, the magnetic separation enabled detecting the content of CaO component by up to 61 wt% in the non-magnetic domain. Since the hydrate was confirmed, it is believed that the fly ash can be used as raw material for carbonation.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.286-296
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• 2016

Offshore CCS technology is to transport and inject $CO_2$ which is captured from the power plant into the saline aquifer or depleted oil-gas fields. The more accumulated injected $CO_2$, the higher reservoir pressure increases. The increment of reservoir pressure make a dramatic change of the operating conditions of transport and injection systems. Therefore, it is necessary to carefully analyze the effect of operating condition variations over the injection period in early design phase. The objective of this study is to simulate and analyze the $CO_2$ behavior in the transport and injection systems over the injection period. The storage reservoir is assumed to be gas field in the East Sea continental shelf. The whole systems were consisted of subsea pipeline, riser, topside and wellbore. Modeling and numerical analysis were carried out using OLGA 2014.1. During the 10 years injection period, the change of temperature, pressure and phase of $CO_2$ in subsea pipelines, riser, topside and wellbore were carefully analyzed. Finally, some design guidelines about compressor at inlet of subsea pipeline, heat exchanger on topside and wellhead control were proposed.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.157-157
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• 2010

우리나라는 기후변화협약에 대응하기 위한 교토의정서를 비준한 국가로서, 아직 온실가스의 의무감축 대상 국가는 아니다. 그러나 2012년부터 시작될 교토의정서 2차 공약기간 중에 브라질, 중국 및 인도와 같이 2차 의무감축대상이 가장 유력시 되는 국가로 지목되고 있으므로, 이러한 변화에 능동적으로 대처할 수 있는 기술적, 사회적, 정책적 방안이 신속히 마련될 필요가 있다. 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, 대료적인 $CO_2$ 발생대상인 석탄화력발전소로 부터 $CO_2$ 회수방안, 회수, 처리관련 연구를 포함하여 국내외 적으로 활발한 연구가 이루어 지고 있다. 순산소 연소기술을 통한 $CO_2$ 회수, 처리기술은 연료(천연가스, 석탄, 석유)의 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, 특히 공해물질은 NOx 발생량을 10ppM 이하로 줄일 수 있다. 천연가스가 생산되는 LNG기지에서 LNG를 기화시키기 위하여 해수식 기화기(ORV : Open Rack Vaporizer와 수중연소식 기화기(SMV ; Submerged Combustion Vaporizer)를 사용하고 있으며, 특히 SMV는 버너를 이용하여 $-162^{\circ}C$ LNG를 $10^{\circ}C$의 LN로 기화시키는 설비로서 이때 연소시 $CO_2$를 상당량 발생시킨다. 본 논문에서는 SMV에서 순산소 연소방식을 적용하여 연료인 천연가스를 연소시키고, 이때 발생되는 $CO_2$와 수분이 주 성분인 배가스를 연소기에 재순환시켜, 연소실내 고온문제를 해결하며, 최종적으로 배가스중 $CO_2$는 $-162^{\circ}C$의 LNG 냉열을 이용하여 고순도의 액체 $CO_2$로 액화시키므로서 $CO_2$의 회수, 처리문제를 해결하는 방식을 소개하고자 한다. 이러한 방식은 천연가스에서 발생되는 $CO_2$ 회수를 LNG 냉열을 활용하므로서 폐열을 활용하는 에너지 효율적인 문제와 사용가능한 고순도 $CO_2$로 회수하므로서 환경적인 문제를 처리하는 기술이라 할 수 있다.

• Journal of Environmental Impact Assessment
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• v.26 no.2
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• pp.93-104
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• 2017

CCS (Carbon Capture and Storage) is a technical process to capture $CO_2$ from industrial and energy-based sources, to transfer and sequestrate impressed $CO_2$ in geological formations, oceans, or mineral carbonates. However, potential $CO_2$ leakage exists and causes environmental problems. Thus, this study was conducted to analyze the spatial and temporal variations of $CO_2$ fluxes and concentrations after artificial $CO_2$ release. The Environmental Impact Evaluation Test Facility (EIT) was built in Eumseong, Korea in 2015. Approximately 34kg $CO_2$ /day/zone were injected at Zones 2, 3, and 4 among the total of 5 zones from October 26 to 30, 2015. $CO_2$ fluxes were measured every 30 minutes at the surface at 0m, 1.5m, 2.5m, and 10m from the $CO_2$ releasing well using LI-8100A until November 13, 2015, and $CO_2$ concentrations were measured once a day at 15cm, 30cm, and 60cm depths at every 0m, 1.5m, 2.5m, 5m, and 10m from the well using GA5000 until November 28, 2015. $CO_2$ flux at 0m from the well started increasing on the fifth day after $CO_2$ release started, and continued to increase until November 13 even though the artificial $CO_2$ release stopped. $CO_2$ fluxes measured at 2.5m, 5.0m, and 10m from the well were not significantly different with each other. On the other hand, soil $CO_2$ concentration was shown as 38.4% at 60cm depth at 0m from the well in Zone 3 on the next day after $CO_2$ release started. Soil $CO_2$ was horizontally spreaded overtime, and detected up to 5m away from the well in all zones until $CO_2$ release stopped. Also, soil $CO_2$ concentrations at 30cm and 60cm depths at 0m from the well were measured similarly as $50.6{\pm}25.4%$ and $55.3{\pm}25.6%$, respectively, followed by 30cm depth ($31.3{\pm}17.2%$) which was significantly lower than those measured at the other depths on the final day of $CO_2$ release period. Soil $CO_2$ concentrations at all depths in all zones were gradually decreased for about 1 month after $CO_2$ release stopped, but still higher than those of the first day after $CO_2$ release stared. In conclusion, the closer the distance from the well and the deeper the depth, the higher $CO_2$ fluxes and concentrations occurred. Also, long-term monitoring should be required because the leaked $CO_2$ gas can remains in the soil for a long time even if the leakage stopped.

• Economic and Environmental Geology
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• v.48 no.1
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• pp.25-39
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• 2015

$CO_2$ geological storage plays an important role in reduction of greenhouse gas emissions, but there is a lack of research for CCS demonstration. To achieve the goal of CCS, storing $CO_2$ safely and permanently in underground geological formations, it is essential to understand the characteristics of them, such as total storage capacity, stability, etc. and establish an injection strategy. We perform the impedance inversion for the seismic data acquired from the Ulleung Basin in 2012. To review the possibility of $CO_2$ storage, we also construct porosity models and extract attributes of the prospects from the seismic data. To improve the quality of seismic data, amplitude preserved processing methods, SWD(Shallow Water Demultiple), SRME(Surface Related Multiple Elimination) and Radon Demultiple, are applied. Three well log data are also analysed, and the log correlations of each well are 0.648, 0.574 and 0.342, respectively. All wells are used in building the low-frequency model to generate more robust initial model. Simultaneous pre-stack inversion is performed on all of the 2D profiles and inverted P-impedance, S-impedance and Vp/Vs ratio are generated from the inversion process. With the porosity profiles generated from the seismic inversion process, the porous and non-porous zones can be identified for the purpose of the $CO_2$ sequestration initiative. More detailed characterization of the geological storage and the simulation of $CO_2$ migration might be an essential for the CCS demonstration.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.251-257
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• 2011

In the present study, a 3-dimensional (3D) numerical model was developed to mimic the micro porous structure of a geological $CO_2$ storage reservoir. Especially, 3D modeling technique assigning random pore size to a 3D micro porous structure was devised. Numerical method using CFD (computational fluid dynamics) was applied for the 3D micro porous structure to calculate supercritical $CO_2$ flow field. The three different configurations of 3D micro porous model were designed and their flow fields were calculated. For the physical conditions of $CO_2$ flow, temperature and pressure were set up equivalent to geological underground condition where $CO_2$ fluid was stored. From the results, the characteristics of the supercritical $CO_2$ flow fields were scrutinized and the influence of the micro pore configuration on the flow field was investigated. In particular, the pressure difference and consequent $CO_2$ permeability were calculated and compared with increasing $CO_2$ flow rate.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.1
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• pp.18-29
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• 2010

Offshore subsurface storage of $CO_2$ is regarded as one of the most promising options to response severe climate change. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources, to transport to the storage sites and to store $CO_2$ into the offshore subsurface geological structure such as the depleted gas reservoir and deep sea saline aquifer. Since 2005, we have developed relevant technologies for marine geological storage of $CO_2$. Those technologies include possible storage site surveys and basic designs for $CO_2$ transport and storage processes. To design a reliable $CO_2$ marine geological storage system, we devised a hypothetical scenario and used a numerical simulation tool to study its detailed processes. The process of transport $CO_2$ from the onshore capture sites to the offshore storage sites can be simulated with a thermodynamic equation of state. Before going to main calculation of process design, we compared and analyzed the relevant equation of states. To evaluate the predictive accuracies of the examined equation of states, we compare the results of numerical calculations with experimental reference data. Up to now, process design for this $CO_2$ marine geological storage has been carried out mainly on pure $CO_2$. Unfortunately the captured $CO_2$ mixture contains many impurities such as $N_2$, $O_2$, Ar, $H_{2}O$, $SO_{\chi}$, $H_{2}S$. A small amount of impurities can change the thermodynamic properties and then significantly affect the compression, purification and transport processes. This paper analyzes the major design parameters that are useful for constructing onshore and offshore $CO_2$ transport systems. On the basis of a parametric study of the hypothetical scenario, we suggest relevant variation ranges for the design parameters, particularly the flow rate, diameter, temperature, and pressure.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.485-494
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• 2013

$CO_2$ Monitoring, Mitigation and Verification (MMV) is the essential part in the Carbon Capture and Storage (CCS) project in order to assure the storage permanence economically and environmentally. In large-scale CCS projects in the world, the seismic time-lapse survey is a key technology for monitoring the behavior of injected $CO_2$. In this study, we developed a basic process procedure for 3-D seismic baseline data from the Aquistore project, Estevan, Canada. Major target formations of Aquistore CCS project are the Winnipeg and the Deadwood sandstone formations located between 1,800 and 1,900 ms in traveltime. The analysis of trace energy and similarity attributes of seismic data followed by spectral decomposition are carried out for the characterization of $CO_2$ injection zone. High trace energies are concentrated in the northern part of the survey area at 1,800 ms and in the southern part at 1,850 ms in traveltime. The sandstone dominant regions are well recognized with high reflectivity by the trace energy analysis. Similarity attributes show two structural discontinuities trending the NW-SE direction at the target depth. Spectral decomposition of 5, 20 and 40 Hz frequency contents discriminated the successive E-W depositional events at the center of the research area. Additional noise rejection and stratigraphic interpretation on the baseline data followed by applying appropriate imaging technique will be helpful to investigate the differences between baseline data and multi-vintage monitor data.