• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.294-298
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• 2005

Absorption and regeneration characteristics of sorbent used in a fluidized-bed process to capture $CO_2$ from flue gas have been measured in a thermo gravimetric analyzer. A sorbent Sorb NH prepared for fluidized-bed process was faster than pure $Na_2CO_3$ in absorption and regeneration reaction rate. Activation energy of apparent absorption reaction of sorbent Sorb NH was estimated as -10,100 cal/g mol and that of pure $Na_2CO_3$ as -12,200 cal/g mol. Activation energy of apparent regeneration reaction of sorbent Sorb NH was estimated as about 12,050 cal/g mol and that of pure $Na_2CO_3$ as about 11,320 cal/g mol.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2000.05a
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• pp.134-139
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• 2000

Crab shell의 중금속 제거 가능성과 그 효율을 검토하기 위하여 chemical sorbent인 cation exchange resin(CER), zeolite, granular activated carbon(GAC), powdered activated carbon(PAC)의 중금속 제거능을 비교한 결과 다음과 같은 결론을 도출할 수 있었다. 1) 0.1 mM～l.0 mM의 초기 중금속 농도에서 중금속 제거량에 미치는 영향을 비교해 보았을 때 중금속 제거의 평형에 도달하는 시간은 농도가 높을수록 오래 걸렸으며 단위 흡착제 질량당 중금속 제거량은 초기 중금속 농도가 높을수록 증가하였다. 특히 구리 이온 제거 실험에서는 낮은 농도에서 crab shell의 구리 이온 제거량이 CER의 경우보다 조금 떨어지는 경향을 보였으나, 대부분의 중금속 제거에 있어서는 crab shell이 다른 chemical sorbent에 비해 뛰어난 중금속 제거능력을 보였다. 2) 흡착 등온 모델에 적용해 보았을 때, 단위 흡착제 질량당 중금속 최대 흡착량이 crab shell > CER > zeolite > PAC =GAC의 순으로, 모든 중금속 제거 실험에서 crab shell이 가장 뛰어난 것으로 나타났다. 실제 폐수처리 공정에서는 GAC나 PAC가 많이 이용되고 있는데, 수중의 중금속을 보다 효율적이고 경제적으로 처리할 수 있는 crab shell을 폐수처리 공정에 응용할 수 있는 방안을 검토할 필요성이 있을 것으로 판단된다.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.1
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• pp.47-53
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• 2003

An experimental study on the chromatographic separation of maltopentaose from a mixture, including glucose, maltose, maltotriose, and maltopentaose, was carried out in a nonionic polymeric sorbent column while varying the operating conditions, such as the solution pH, buffer contents, and isopropyl alcohol (1PA) concentration. Unlike the pH and buffer contents, the IPA concentration had a Significant impact on the single component chromatograms for maltopentaose. The retention times of the maltooligosaccharides with the nonionic polymeric sorbent Sp207 were in the following order: glucose < maltose < maltotriose < maltopentaose. From the experimental binary, ternary, and quaternary chromatograms, gradient chromatographic separation with a changing IPA concentration as a function of time was required to obtain high-purity maltopentaose and reduce the elution time.

• Journal of Environmental Health Sciences
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• v.22 no.4
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• pp.1-9
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• 1996

Experiments have been made to test the practical feasibility of using calcined manganese ore to desulfurize hot reducing gas. In this study, the effects of particle size of sorbents, temperature of sulfidation, flow rate and sorbent characteristics on the $H_2S$ removal efficiency of calcined manganese ore were investigated. Experimental results showed that the removal efficiency of $H_2S$ was optimum when the temperature was about 800$\circ$C and that the smaller particle size the higher the $H_2S$ removal efficiency. When the temperature was above 800$\circ$C, the reactivity of sorbent has lowered because agglomeration of sorbent increased intraparticle transport resistance, and this phenomenon was confirmed by SEM photographs. As the temperature increases, capacity for the $H_2S$ removal was increased but the equilibrium concentration of $H_2S$ was not affective.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.2
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• pp.291-302
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• 2000

This experiments have been made to develop of manganese-based sorbent for the removal of hydrogen sulfide from hot coal gases. Manganese-based sorbent were tested in an ambient-pressure fixed-bed reactor to determine steady state $H_2S$ concentrations, breakthrough times and feasibility of the sorbent when subjected to cycle sulfidation and regeneration testing. Effects of particle size of sorbent, temperature of sulfidation, regeneration temperature and regeneration characteristics on the $H_2S$ removal efficiency were investigated. Experimental results showed that the $H_2S$ removal efficiency was optimal when the temperature was about $800^{\circ}C$ and the smaller particle size, the better $H_2S$ removal efficiency but in the range of 0.214~0.631mm didn't influence it much. The equilibrium constant(K) is represented as a log(K)=3.396/T-1.1105 and the utilization efficiency of sorbents was about 92% at $800^{\circ}C$. Regeneration in air produced $SO_2$ concentration as high as 8.5% at $800^{\circ}C$, 8.4% at $850^{\circ}C$, and 8.8% at $900^{\circ}C$ and may be used in sulfuric acid production.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.671-678
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• 2000

Reaction characteristics of simultaneous removal of SOx and NOx have been investigated in a thermogravimetric analyzer and tubular fixed bed reactor using the $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst. Sulfur removal capacity of $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst is largely enhanced above both the temperature of $450^{\circ}C$ and the loading of 6wt% due to the participation of alumina support in a sulfation reaction. The NO reduction efficiency of 8wt% $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst shows the maximum value at $370^{\circ}C$ and then decreases with the increase of reaction temperature due to the oxidation of $NH_3$ gas. The presence of sulfate on the surface of sorbent/catalyst enhances the optimum reaction temperature showing the maximum deNOx efficiency. In the simultaneous removal of SOx and NOx at $250^{\circ}C$. deNOx activity of $CuO/{\gamma}-Al_2O_3$ sorbent/catalyst is rapidly decreased due to the formation of ammonium salts such as $NH_4HSO_4$. In the simultaneous removal reaction of SOx and NOx, the optimum temperature showing the maximum deNOx efficiency increases to $400^{\circ}C$ due to the presence of $SO_2$ gas.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.262-268
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• 2015

This study established an analytical method to simultaneously determine six organophosphorous pesticides [methyldemetone-S, diazinon, fenitrothion, parathion, phentoate, and O-ethyl O-(4-nitrophenyl) phenylphosphonothioate (EPN)] and carbaryl in water using a gas chromatography/mass spectrometry (GC/MS) system coupled with on-line micro extraction by packed sorbent (MEPS) and programmed temperature vaporizer (PTV) injector. Polystyrene divinylbenzene (PDVB) was used as a sorbent of MEPS. The effects of elution solvents, pH, elution volume and draw-eject cycles of samples on sample pretreatment process were investigated. Also, quality assurance and quality control (QA/QC) and the recovery of the pesticides in environmental samples were evaluated. The elution was performed using $30{\mu}L$ of a mixed solvent (acetone : dichloromethane = 80 : 20 (v/v)). Sample pretreatment processes were optimized with seven cycles of draw-eject of sample (1 mL) spiking an internal standard and sulfuric acid. At lower pH, the analytical sensitivity of diazinon decreased, but that of carbaryl increased. The method detection limit and the limit of quantification for this method were 0.02~0.18 and $0.08{\sim}0.59{\mu}g/L$, respectively. The method precision and accuracy were 1.5~11.5% and 83.3~129.8%, respectively, at concentrations of $0.5{\sim}5.0{\mu}g/L$. The recovery rates for all the pesticides except carbaryl in various environmental samples ranged 75.7~129.3%. The recovery rate of carbaryl in effluent sample was over 200% whereas carbaryl in drinking water, groundwater, and river water were in the acceptable range.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.17-24
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• 2021

The development of a new sorbent for carbon dioxide depends on several factors, such as fast adsorption/absorption velocity, hydrophobicity, and lower regeneration temperature than commercial sorbent. In this study, aminosilane grafted activated carbon was synthesized to capture CO2. Methyltrimethoxysilane (MTMS) and 3-aminopropyl-triethoxysilane (APTES) were used as the grafting precursor of the amine functional group. The APTES grafting activated carbon showed higher sorption property than MTMS used one. The characteristics of the separation mechanism of carbon dioxide were examined by measuring the adsorption capacity according to temperature and carbon dioxide partial pressure. The absorption capacity of carbon dioxide was similar to amine grafting activated carbon and activated carbon at 25℃, but amine-grafted activated carbon was higher at 75℃. The amine functional group-grafted activated carbon showed higher absorption capacity than activated carbon with a 1% carbon dioxide partial pressure. Aminosilane grafting of activated carbon was chemically absorbed but also showed the characteristics of physical adsorption. The reforming activated carbon with an amine functional group grafted solid absorption/adsorption sorbent would significantly impact the material engineering industry and carbon dioxide adsorption process. The functionalized sorbent is a high-performance composite material. The developed sorbent may have applications in other industrial processes of absorption/adsorption and separation.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.05a
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• pp.667-672
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• 2003

화석연료의 연소로 생성되는 $CO_2$는 지구온난화의 주범으로, 대부분 화력발전 등 에너지 산업에서 발생되는 배가스로 대기 중에 방출되고 있으며, 많은 나라들이 규제를 정하고 있다. 우리나라도 선진국과 같이 2008년부터 자발적 의무를 부담할 것을 요구하는 등 국제적인 요구가 증대되고 있다.(중략)

• Particle and aerosol research
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• v.10 no.2
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• pp.75-82
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• 2014

It is necessary to find out the reaction characteristics of $CaCO_3$ sorbent particles in air and $O_2/CO_2$ atmospheric conditions in order that an in-furnace desulfurization technique can be applied to oxy-fuel combustion system. In this study, rate of change of GMD(geometric mean diameter) and specific surface area of $CaCO_3$ sorbent particles reacted in DTF(drop tube furnace) experimental setup were analyzed to investigate the effect of particle size and humidity on the reaction characteristics of them. In air atmospheric condition, calcination process occurs actively within shorter residence times as the particle size increases. On the contrary, in $O_2/CO_2$ atmospheric condition, a calcination process is delayed as particle size increases. The increment of humidity accelerates calcination process in an air atmospheric condition and increase rate of calcination in an $O_2/CO_2$ atmospheric condition.