• Journal of Climate Change Research
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• v.2 no.2
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• pp.107-113
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• 2011

In this research, we described the experimental results for the improvement of Potassium based sorbents. These sorbents have been actually used in the 0.5 MW $CO_2$ capture plant located in Hadong #3 Power Plant. Firstly, we had shaped two kinds of sorbents using a spray dryer. These sorbents applied magnetite & copper oxide as an additive. And the magnetite sorbent was evaluated more excellent relatively in the attrition index. Secondly, We had obtained TGA multicycle experimental results of the improved Potassium based sorbent which applied magnetite as an additive. Consequently, $CO_2$ sorption capacity had been sustained 5.5 wt% after 2nd cycle and attrition index was very excellent as 0.5%. Finally, we had investigated the characteristics of the sorbent following in properties of supporters. As a result, the sorption capacity of the KMO sorbent used base material as a supporter was appeared as 7.2 wt%.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.1-12
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• 2023

Coal gasification is a process of incomplete coal combustion to produce a syngas composed of hydrogen and carbon monoxide. It is one of methods to utilize coal cleanly because the process does not emits nitrogen oxides or sulfur oxides and particulate matters. In addition, chemicals can be produced using syngas. Coal gasification is classified as IGCC (Integrated Gasification Combined Cycle), Plasma coal gasification and UCG (Underground Coal Gasification). Recently, WGS (Water Gas Shift) reactor and carbon capture system have been combined to gasifier to produce hydrogen from coal. In this study, the coal gasification and method of hydrogen production from syngas was summarized, and the hydrogen production from coal gasification project was investigated.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2019.10a
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• pp.83-83
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• 2019

Increasing the CO₂ concentration in the atmosphere induce high temperature and rising sea levels. So the technology that capture and reuse of the CO₂ have been recently become popular. Among other methods, CRR(CO2₂ reduction reaction) is typical method of CO₂ reusing. Electrocatalyst can show more higher efficiencies in CRR than photocatalyst because it doesn't use nature source. Nowadays, finding high efficient electrocatalyst by controlling electronic (affected by stoichiometry) and geometric (affected by atomic arrangement) factors are very important issues. Mono-atomic electro-catalyst has limitations on controlling binding energy because each intermediate has own binding energy range. So the Multi-metallic electro-catalyst is important to stabilize intermediate at the same time. Carbon monoxide(CO) which is our target product and important feedstock of useful products. Au is known for the most high CO production metal. With copper, Not only gold/copper has advantages which is they have FCC packing for easily forming solid solution regardless of stoichiometry but also presence of adsorbed CO on Cu promotes the desorption of CO on Au because of strong repulsion. And gold/copper bi-metal catalyst can show high catalytic activity(mass activity) although it has low selectivity relatively Gold. Actually, multi-metallic catalyst structure control method is limited in the solution method which is takes a lot of time. In here, we introduce CTS(carbo thermal shock) method which is using heat to make MMNP in a few seconds for making gold-copper system. This method is very simple and efficient in terms of time(very short reaction time and using carbon substrate as a direct working electrode) and increasing reaction sites(highly dispersed and mixing alloy structures). Last one is easy to control degree of mixing and it can induce 5 or more metals in one alloy system. Gold/copper by CTS can show higher catalytic activity depending on metal ratio which is altered easily by changing simple variables. The ultimate goals are making CO₂ test system by CTS which can check the selectivity depending on metal types in a very short time.

• Membrane Journal
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• v.33 no.5
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• pp.240-247
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• 2023

Even among gas separation methods, CO₂ capture and separation via membranes is an ever-growing field, with many different membrane compositions continually being developed. Ionic liquid (IL) based composite membranes show excellent performance values in separating CO₂. Similarly, various copolymer/IL composite membranes also display improved performance. The addition of fillers such as graphene oxide to these copolymer/IL composite membranes shows a further enhanced version of these fillers, most likely due to the strong interactions that occur between ILs and organic fillers, which consequently improves factors such as the affinity, selectivity, and adsorption of CO₂. Copolymer/IL composite membranes utilizing a metal-organic framework (MOF) showed improved CO₂ permeability. This review discusses the study of various combinations of ionic liquid and copolymer composite membranes for carbon dioxide separation.

• Journal of the Korean Institute of Gas
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• v.16 no.6
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• pp.55-66
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• 2012

The practical way to minimize the greenhouse gas is to reduce the emission of carbon dioxide. For this reason, CCS(Carbon Capture and Storage) technology, which could reduce carbon dioxide emission, has risen as a realistic alternative in recent years. In addition, the researcher is recently working into ways of applying CCS technologies with deep saline aquifer. In this study, the evaluation model on the feasibility of $CO_2$ sequestration in the deep saline aquifer using ANN(Artificial Neural Network) was developed. In order to develop the efficiency-evaluation model, basic model was created in the deep saline aquifer and sensitivity analysis was performed for the aquifer characteristics by utilizing the commercial simulator of GEM. Based on the sensitivity analysis, the factors and ranges affecting $CO_2$ sequestration in the deep saline aquifer were chosen. The result from ANN training scenario were confirmed $CO_2$ sequestration by solubility trapping and residual trapping mechanism. The result from ANN model evaluation indicated there is the increase of correlation coefficient up to 0.99. It has been confirmed that the developed model can be utilized in feasibility of $CO_2$ sequestration at deep saline aquifer.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.5
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• pp.342-351
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• 2014

The present paper investigates the performance of direct wet mineral carbonation technology to fix carbon dioxide ($CO_2$) from relatively high $CO_2$ concentration feeding gas using wollastonite ($CaSiO_3$)-water (and 0.46 M acetic acid) suspension solution. To minimize the energy consumed on the process, the carbonation in this work is carried out at atmospheric pressure and slightly higher room temperature. As a result, carbon fixation is confirmed on the surface of $CaSiO_3$ after carbonation with wollastonite-water suspension solution and its amount is increased according to the $CO_2$ composition in the feeding gas. The leaching and carbonation ratio of wollastonite-water suspension system obtained from the carbonation with 50% of $CO_2$ composition feeding gas is 13.2% and 10.4%, respectively. On the other hand, the performance of wollastonite-acetic acid in the same condition is 63% for leaching and 1.39% for carbonation.

• Clean Technology
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• v.28 no.1
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• pp.9-17
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• 2022

Electrochemical carbon dioxide (CO₂) reduction technology, one of the promising solutions for climate change, can convert CO₂, a representative greenhouse gas (GHG), into valuable base chemicals using electric energy. In particular, carbon monoxide (CO), among various candidate products, is attracting much attention from both academia and industry because of its high Faraday efficiency, promising economic feasibility, and relatively large market size. Although numerous previous studies have recently analyzed the GHG reduction potential of this technology, the assumptions made and inventory data used are neither consistent nor transparent. In this study, a comparative life cycle assessment was carried out to analyze the potential for reducing GHG emissions in the electrochemical CO production process in a more transparent way. By defining three different system boundaries, the global warming impact was compared with that of a fossil fuel-based CO production process. The results confirmed that the emission factor of electric energy supplied to CO₂-electrolyzers should be much lower than that of the current national power generation sector in order to mitigate GHG emissions by replacing conventional CO production with electrochemical CO production. Also, it is important to disclose transparently inventory data of the conventional CO production process for a more reliable analysis of GHG reduction potential.

• Smart Structures and Systems
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• v.22 no.5
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• pp.527-546
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• 2018

This article presents an analysis into the nonlinear forced vibration of a micro cylindrical shell reinforced by carbon nanotubes (CNTs) with considering agglomeration effects. The structure is subjected to magnetic field and transverse harmonic mechanical load. Mindlin theory is employed to model the structure and the strain gradient theory (SGT) is also used to capture the size effect. Mori-Tanaka approach is used to estimate the equivalent material properties of the nanocomposite cylindrical shell and consider the CNTs agglomeration effect. The motion equations are derived using Hamilton's principle and the differential quadrature method (DQM) is employed to solve them for obtaining nonlinear frequency response of the cylindrical shells. The effect of different parameters including magnetic field, CNTs volume percent and agglomeration effect, boundary conditions, size effect and length to thickness ratio on the nonlinear forced vibrational characteristic of the of the system is studied. Numerical results indicate that by enhancing the CNTs volume percent, the amplitude of system decreases while considering the CNTs agglomeration effect has an inverse effect.

• Journal of Ocean Engineering and Technology
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• v.25 no.4
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• pp.54-58
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• 2011

The need and importance of developing and utilizing the oceans, not only as sources of renewable energy and mineral resources, but also as countermeasures to global warming such as for CCS (carbon capture and storage), have continued to increase, especially in countries with limited land areas and resources. Therefore, it is necessary to assess the sustainability of an ocean utilization technology or system not only from an economic point of view but also from an ecological one. For this purpose, it might be effective to develop a comprehensive evaluation method and/or index, by which the assessment of and decisions about a technology and system can be made more objectively. It would also be useful to have an environmental simulation model, which was developed and reported in a previous research. The aim of this study was to modify a reasonable and quantitative index, with which a comprehensive evaluation system can be established, to assess environmental sustainability and risk.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.227-234
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• 2004

For gaseous fuel combustion with inherent $CO_2$ capture and low NOx emission, chemical-looping combustion(CLC) may yield great advantages of savings of energy to $CO_2$ separation and suppressing the effect on environment. In chemical-looping combustor, fuel is oxidized by metal oxide medium (oxygen carrier particle) in a reduction reactor. Reduced particles are transported to oxidation reactor and oxidized by air and recycled to reduction reactor. The fuel and the air are never mixed, and the gases from reduction reactor, $CO_2$ and $H_2O$, leave the system as separate stream. The $H_2O$ can be easily separated by condensation and pure $CO_2$ is obtained without any loss of energy for separation. The purpose of this study is to demonstrate inherent $CO_2$ separation and no NOx emission and to confirm high $CO_2$ selectivity, no side reaction (i.e., carbon deposition, hydrogen generation) by continuous reduction and oxidation experiment in a 50kWtb chemical-looping combustor. NiO/bentonite particle was used as a bed material and $CH_4$ and air were used as reacting gases for reduction and oxidation respectively.