• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.335-342
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• 2018

Various technologies to cope with the energy and environmental issues related to the chemical and electric power industry are in development and demonstration stage. Especially, the absorption process of carbon dioxide ($CO_2$) using amine solution is a key technology of the $CO_2$ capture and storage (CCS). In this study, we identify the major risk factors and suggest strategies for safety improvement by analyzing and assessing commercial the amine-based $CO_2$ separation process. HAZOP method was used to assess the risk for the process. We provide facilities and operational strategies to mitigate or eliminate major risk factors by assessing the relative ranks of identified risk factors using a risk matrix.

• Clean Technology
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• v.27 no.4
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• pp.367-371
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• 2021

The oxy-combustion system is one of the carbon recovery and storage technologies (CCS: Carbon capture & storage) that performs coal combustion using pure oxygen and recirculated flue gas. This is a technology that facilitates storage of carbon dioxide by generating an exhaust gas consisting of only carbon dioxide without a process of separating carbon dioxide and nitrogen when coal is burned using pure oxygen and recirculated flue gas mixture instead of a conventional air combustion system that produces carbon dioxide and nitrogen mixed exhaust gas. In this study, the characteristics of generated NO and SO₂ as atmospheric pollutants during oxy-combustion were examined using O₂/CO₂ mixed simulation gas. The reaction temperature was varied from 900 ℃ to 1200 ℃ and oxygen partial pressure was varied from 30% to 50%. The results showed that NO and SO₂ concentrations in flue gas increased as the oxygen concentration and the reaction temperature in the furnace increased. The partial pressure of CO₂ in flue gas also increased as the oxygen concentration and the reaction temperature in the furnace increased. As a results of comparing NO production of 30% O₂/CO₂ oxy-combustion with air combustion, NO in flue gas increased with reaction temperature in both experiments and NO of oxy-combustion was 40 ~ 80 ppm lower than that of air combustion.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.574-580
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• 2014

Storage tanks of Carbon dioxide ($CO_2$) carriers utilized for the purpose of carbon capture and storage (CCS) into subsea strata have to undergo a pre-cooling session before beginning to load cryogenic liquid cargos in order to prevent physical and thermal deterioration of tanks which may result from cryogenic $CO_2$ contacting tank walls directly. In this study we propose dynamic model to calculate the tank inflow of $CO_2$ gas injected for precooling process and its dynamic simulation results under proportional-integral control algorithm. We selected two cases in which each of them had one controlled variable (CV) as either the tank pressure or the tank temperature and discussed the results of that decision-making on the pre-cooling process. As a result we demonstrated that the controlling instability arising from nonlinearity and singularity of the mathematical model could be avoided by choosing tank pressure as CV instead of tank temperature.

• 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.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.4
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• pp.191-198
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• 2008

To design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. $CO_2$ capture process from the major point sources such as power plants, transport process from the capture sites to storage sites and storage process to inject $CO_2$ into the deep marine geological structure can be simulate with numerical modeling. The purpose of this paper is to compare and analyse the relevant equations of state including ideal, BWRS, PR, PRBM and SRK equation of state. We also studied the effect of thermodynamic equation of state in designing the compression and transport process. As a results of comparison of numerical calculations, all relevant equation of state excluding ideal equation of state showed similar compression behavior in pure $CO_2$. On the other hand, calculation results of BWRS, PR and PRBM showed totally different behavior in compression and transport process of captured $CO_2$ mixture from the oxy-fuel combustion coal-fired plants. It is recommended to use PR or PRBM in designing of compression and transport process of $CO_2$ mixture containing NO, Ar and $O_2$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.12
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• pp.6973-6979
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• 2014

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 $CO_2$ emissions. CCS technology is comprised of the capture, transport, and storage processes. During the capture process, impurities other than $CO_2$ are inevitably flowed into the $CO_2$ stream. In the present study, corrosion characteristics of a phosphate coated tube for $CO_2$ transportation was investigated with a $CO_2$ stream composed of $CO_2$, $H_2O$, $SO_2$, and $NO_2$. The test specimen was a phosphate coated steel tube, which was filled with $CO_2$ 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 $SO_2$ or $NO_2$. This suggests that the $SO_2$, $NO_2$ and $H_2O$ concentration should be strictly controlled. These results suggest that the $SO_2$ and $NO_2$ concentration should be controlled below 175ppm and 65ppm, respectively.

• 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.11 no.4
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• pp.181-190
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• 2008

To response climate change and Kyoto protocol and to reduce greenhouse gas emissions, marine geological storage of $CO_2$ is regarded as one of the most promising option. Marine geological storage of $CO_2$ is to capture $CO_2$ from major point sources(eg. power plant), to transport to the storage sites and to store $CO_2$ into the marine geological structure such as deep sea saline aquifer. To design a reliable $CO_2$ marine geological storage system, it is necessary to perform numerical process simulation using thermodynamic equation of state. The purpose of this paper is to compare and analyse the relevant equations of state including ideal, BWRS, PR, PRBM and SRK equation of state. To evaluate the predictive accuracy of the equation of the state, we compared numerical calculation results with reference experimental data. Ideal and SRK equation of state did not predict the density behavior above $29.85^{\circ}C$, 60 bar. Especially, they showed maximum 100% error in supercritical state. BWRS equation of state did not predict the density behavior between $60{\sim}80\;bar$ and near critical temperature. On the other hand, PR and PRBM equation of state showed good predictive capability in supercritical state. Since the thermodynamic conditions of $CO_2$ reservoir sites correspond to supercritical state(above $31.1^{\circ}C$ and 73.9 bar), we conclude that it is recommended to use PR and PRBM equation of state in designing of $CO_2$ marine geological storage process.

• 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.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.9-16
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• 2013

An experiment was conducted to evaluate the biochemical adverse effect of increased carbon dioxide in seawater on marine polychaete, Perinereis aibuhitensis. We measured the available energy reserves, Ea (total carbohydrate, protein, and lipid content) and the energy consumption, Ec (electron transport activity) of Perinereis aibuhitensis exposed for 7-d to a range of $CO_2$ concentration such as 0.39 (control =390 ppmv), 3.03 (=3,030 ppmv), 10.3 (=10,300 ppmv), and 30.1 (=30,100 ppmv) $CO_2$ mM, respectively. The cellular energy allocation (CEA) methodology was used to assess the adverse effects of toxic stress on the energy budget of the test organisms. The results of a decrease in CEA effect of increased carbon dioxide in seawater from all individual in Ea and Ec. Increase of carbon dioxide reduced pH in seawater, significantly. The chemical changes in sea- water caused by increasing $pCO_2$ might cause stresses to test organisms and changes in the cellular energy allocations. Results of this study can be used to understand the possible influence of $CO_2$ concentration increased by the leakage from sub-sea bed storage sites as well as fossil fuel combustion on marine organisms.