• 한국산업보건학회지
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• 제15권3호
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• pp.270-276
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• 2005

This study was conducted to examine whether a specific synthetic metalworking fluid (MWF), "A", in use for 10 months without replacement, displayed microbial resistance and to identify the additives associated with the control of microbial growth. Three synthetic MWF products ("A", "B", and "C") were studied every week for two months. Microbial deterioration of the fluids was assessed through evaluation by endotoxin, bacteria and fungi levels in the MWFs. In addition, formaldehyde, boron, ethanolamine, and copper levels were also studied to determine whether they influence microbial growth in water-based MWFs. Throughout the entire study in the sump where MWF "A" was used, bacteria counts were lower than 103 CFU/mL, and endotoxins never exceeded 103 EU/mL. These levels were significantly lower than levels observed in sumps badly deteriorated with microbes. Boron levels in MWF "A" ranged from 91.7 to 129.6 ppm, which was significantly higher than boron levels found in other MWF products. The total level of ethanolamine (EA) in MWF "A" ranged from 35,595 to 57,857 ppm (average 40,903 ppm), which was over ten times higher than that found in other MWFs. Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) concentrations in MWF "A" were also significantly higher than seen in other MWFs. However, although EA and boron might improve anti-microbial performance, their abuse can pose a serious risk to workers who handle MWFs. From an industrial hygiene perspective, our study results stress that the positive synergistic effect of boron and EA in reducing microbial activity in MWF must be balanced with the potentially negative health effects of such additives. Our study also addresses the disadvantage of failing to comprehensively report MWF additives on Material Safety Data Sheets (MSDS). Future research in MWF formulation is needed to find the best level of EA and boron for achieving optimal synergistic anti-microbial effects while minimizing employee health hazards.

• 멤브레인
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• 제22권1호
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• pp.46-53
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• 2012

본 연구에서는 석탄 화력발전소의 연소 후 $CO_2$ 회수 기술인 알칸올 아민 수용액을 이용한 아민흡수법에서 전체 운전비의 80% 가량을 차지하는 탈거에너지의 저감을 위해 새로운 탈거기술인 분리막을 이용한 감압탈거 기술을 제시하고자 한다. 막의 소재로는 소수성막인 PE (polyethylene)를 지지체로 하고 $5{\mu}m$ 두께의 PDMS (polydimethylsiloxane)를 코팅한 복합막을 제조하여 적용하였으며, 흡수액으로 MEA (monoethanolamine) 30 wt% 수용액을 사용하였다. 온도의 변화에 따른 영향을 알아보기 위하여 흡수액 온도를 $25{\sim}80^{\circ}C$로 변화시켜 이산화탄소의 탈거특성을 살펴보았으며, 흡수용액의 $CO_2$ 함량($CO_2$ loading)에 따른 영향을 고찰하기 위하여 $CO_2$ 함량을 변화시켰다. 또한 감압탈거 시 탈거측 압력을 60~360 mmHg(abs.)로 변화시켜 진공도에 따른 탈거특성을 연구하였다. 아민수용액의 온도가 증가할수록, 이산화탄소 부하량이 증가할수록 이산화탄소의 탈거량은 증가하는 경향을 보이고 있으며, 감압이 감소함에 따라 이산화탄소의 탈거량 역시 증가하고 있는 것을 확인하였다. 막의 안정성 실험 결과 PTFE 단일막에 비하여 PDMS-PE 복합막의 경우 감압탈거 막공정에 적용하기 안정한 막이라고 판단된다.

• 에너지공학
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• 제14권4호
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• pp.219-225
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• 2005

지구온난화의 주원인인 이산화탄소를 배가스에서 제거하는데 있어 화학적 흡수법은 다년간 광범위하게 응용되어오고 있으며, 주로 MEA(monoethanolamine), AMF(2-amino-2-methyl-1-propanol), MDEA(N-methyldiethanolamine)와 같은 알칸올아민계열의 물질들이 흡수제로 사용되고 있다. 본 연구에서는 환형아민계열의 Piperazine, Piperidine, Cyclohexylamine을 앞서 언급한 물질들을 대체할 새로운 흡수제 후보로 선정하여, 상용화된 MEA를 대상으로 용해도($CO_2$ loading)와 흡수능(loading capacity) 및 반응속도를 비교하였는데, Piperazine이 최적의 흡수제임을 알 수 있었다. 실험은 질량 기준으로 5, 10, $15\%$ 농도, 30, 40, $50^{\circ}C$ 온도에서 수행하였고, 재적정법으로 반응 종료 후 액체 시료 내 이산화탄소의 용해도를 분석하였으며 가스 크로마토그래프 분석을 통해 반응속도를 비교할 수 있었다.

• Asian Journal of Atmospheric Environment
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• 제10권2호
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• pp.99-113
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• 2016

In order to improve the portability of basic absorbents monoethanolamine (MEA) and glycine (Gly), both were supported on microporous activated carbon (AC). Chemical modification by alkali-metal ion exchange (of Li, Na, K) was carried out on Gly-based absorbents. All supported absorbents were subjected to $CO_2$ absorption capacity (pure $CO_2$) and selectivity (indoor level) tests. Textural and chemical characterizations were carried out on test sorbents. All impregnation brought about significant reduction of specific surface area and microporosity of the adsorbent Depreciation in the textural properties was found to result to reduction in pure $CO_2$ sorption. Contrarily, low-level $CO_2$ removal capacity was enhanced as the absorbent dosage increases, resulting in supported 5 molar MEA in methanol solution. Adsorption capacities were improved from 0.016 and 0.8 in raw ACs to 1.065 mmol/g for MEA's. Surface chemistry via X-ray photoelectron spectroscopy (XPS) of the supported sorbents showed the presence of amine, pyrrole and quaternary-N. In reducing sequence of potency, pyridine, amine and pyrrolic-N were noticed to contribute significantly to $CO_2$ selective adsorption. Furthermore, the adsorption isotherm study confirms the presence of various SNGs heterogeneously distributed on AC. The adsorption mechanism of the present AC adsorbents favored Freundlich and Langmuir isotherm at lower and higher $CO_2$ concentrations respectively.

• Korean Chemical Engineering Research
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• 제49권2호
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• pp.256-262
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• 2011

아민 흡수 공정에서 아민은 $O_{2}$ 및 고온에 의해 비가역반응을 일으키며, 이러한 현상을 열화반응이라 한다. 열화반응은 아민의 가치를 떨어뜨릴 뿐만 아니라 부식, fouling과 같은 문제를 일으킨다. 따라서, 본 연구에서는 여러가지 화학흡수제(MEA; monoethanolamine, AMP; 2-amino-2-methyl-propanol, DAM; 1,8-diamino-p-menthane)를 이용하여 i) 50, $120^{\circ}C$에서의 흡수평형, ii) $CO_{2}$ 및 $CO_{2}/O_{2}$ 계에서 흡수제의 열화에 따른 농도변화 및 초기열화속도상수, iii) 산소 $(O_{2})$에 의한 열화 영향을 살펴보았다. DAM은 흡수영역에서 MEA와 AMP에 비해 400~270% 높은 흡수평형부하를 보이며, MEA나 AMP에 비해 흡수/재생영역에서 흡수평형부하가 커 흡수능이 우수하였다. $CO_{2}$계에서 DAM의 초기열화속도상수는 $2.254{\times}10^{-4}$ $cycle^{-1}$로 MEA와 AMP의 $2.761{\times}10^{-4}$ $cycle^{-1}$, $2.416{\times}10^{-4}cycle^{-1}$에 비해 작아 열화가 늦게 진행되며, $O_{2}$ 주입시 초기열화속도상수는 1.3배 증가하여 2배 증가한 MEA보다 열화 영향이 적었다. 이러한, 일련의 열화반응은 GC chromatogram에서 새로운 peak의 생성과 FT-IR spectrum 분석을 통하여 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제34권3호
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• pp.783-787
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• 2013

The separation and capture process of carbon dioxide from power plants is garnering interest as a method to reduce greenhouse gas emissions. In this study, aqueous alkanolamine solutions were studied as absorbents for $CO_2$ capture. The solubility of $CO_2$ in aqueous alkanolamine solutions was investigated with a continuous stirred reactor at 313, 333 and 353 K. Also, the heat of absorption ($-{\Delta}H_{abs}$) between the absorbent and $CO_2$ molecules was measured with a differential reaction calorimeter (DRC) at 298 K. The solubility and heat of absorption were determined at slightly higher than atmospheric pressure. The enthalpies of $CO_2$ absorption in monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), and 2-amino-2-methyl-1-propanol (AMP) were 88.91, 70.44, 44.72, and 63.95, respectively. This investigation showed that the heat of absorption is directly related to the quantity of heat for absorbent regeneration, and is dependent on amine type and $CO_2$ loading.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 1부
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• pp.310-313
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• 2011

본 논문에서는 지구온난화의 주요원인 중의 하나인 이산화탄소를 포집하기 위한 새로운 흡수제를 연구하였다. 액상 흡수법에서 가장 중요한 핵심 기술요소는 성능과 경제성면에서 우수한 흡수제를 개발하는 것이다. 흡수평형장치인 VLE(Vapor-Liquid Equilibrium)장치를 사용하여 신규흡수제의 이산화탄소 흡수능을 평가하고 특성을 알아봄으로써 신 흡수제를 개발하고자 하였다. 기존 아민흡수제인 MEA(monoethanolamine), DEA(diethanolamine)와 비교한 결과 아미노산염 흡수제의 경우 MEA (1.108), DEA (1.105)의 이산화탄소 흡수능보다 0.15～0.2 (mol $CO_2$/mol absorbent) 더 높은 흡수능과 2.5～3배 더 빠른 겉보기 속도를 나타내는 것을 확인하였다. 본 연구를 통하여 개발된 아미노산염 흡수제가 경제적인 이산화탄소 포집공정을 구현할 수 있는 가능성을 확인하였다.

• 한국해양공학회지
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• 제36권3호
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• pp.168-180
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• 2022

The IMO has decided to proceed with the early introduction of EEDI Phase 3, a CO₂ emission regulation to prevent global warming. Measures to reduce CO₂ emissions for ships that can be applied immediately are required to achieve CO₂ reduction. We set six different CO₂ emission scenarios according to the type of ship and fuel, and designed a monoethanolamine-based CO₂ capture process for ships using a rate-based model of Aspen Plus v10. The simulation model using Aspen Plus was validated using pilot plant operation data. A ship inevitably tilts during operation, and the performance of a tilted column decreases as its height increases. When configuring the conventional CO₂ capture process, we considered that the required column heights were so high that performance degradation was unavoidable when the process was implemented on a ship. We applied a parallel column concept to lower the column height and to enable easy installation and operation on a ship. Simulations of the parallel column confirmed that the required column height was lowered to less than 3 TEU (7.8 m).

• 대한환경공학회지
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• 제31권7호
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• pp.505-514
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• 2009

지구온난화 원인물질인 이산화탄소의 신규 흡수제로 serine 칼륨염을 제안하였고, serine 칼륨염의 이산화탄소 흡수특성을 monoethanolamine(MEA)의 결과와 비교하고 평가하였다. 비분산적외선 방식의 $CO_2$ 분석기를 장착한 스크리닝 장치와 흡수평형 측정장치를 이용하여 각 흡수제의 $CO_2$ 흡수/탈거 성능을 속도론적 양적으로 분석하였다. Serine 칼륨염의 유효 $CO_2$ 부하능은 0.425로써 MEA의 0.230보다 거의 두 배나 높았으며, cyclic capacity는 각각 0.354와 0.298로써 serine 칼륨염이 더 우수하였다. 한편 serine 칼륨염의 반응속도는 $CO_2$ 부하능이 0.1 이상에서 급격히 감소하여 MEA의 절반을 유지하였다. 흡수속도 증대를 위해 반응 촉진제로 plperazme과 tetraethylenepentamine을 흔합한 결과 각 경우 포화 $CO_2$ 부하능이 13.7%, 18.7% 증대되었다. Serine의 카르복실기에 서로 다른 종류의 금속을 치환하였을 때 ($Li^+,\;Na^+\;K^+$), serine 칼륨염의 $CO_2$ 흡수량이 나트륨염과 리튬염에 비해 각각 29.2%, 35.0% 높았다. 비슷한 기본구조를 가진 아미노산인 valine과 isoleucine 칼륨염의 흡수실험 결과, 벌키한 side group의 영향으로 인해 흡수속도가 serine 칼륨염에 비해 다소 느렸다. 반응 중 발생하는 침전과 이의 긍정적 이용 방법을 문헌에 근거하여 제안하였다.

• 에너지공학
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• 제28권4호
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• pp.8-12
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• 2019

Thermal amine scrubbing is the most advanced CO₂ capture technique but its largescale application is hindered due to the large heat requirement during solvent regeneration step. The addition of a solid metal oxide catalysts can optimize the CO₂ desorption rate and thus minimize the energy consumption. Herein, we evaluate the solvent regeneration performance of Monoethanolamine (MEA) and Diethanolamine (DEA) solvents without and with two metal oxide catalysts (TiO₂ and V₂O₅) within a temperature range of 40-86℃. The solvent regeneration performance was evaluated in terms of CO₂ desorption rate and overall amount of CO₂ desorbed during the experiments. Both catalysts improved the solvent regeneration performance by desorbing greater amounts of CO₂ with higher CO₂ desorption rates at low temperature. Improvements of 86% and 50% in the CO₂ desorption rate were made by the catalysts for MEA and DEA solvents, respectively. The total amount of the desorbed CO₂ also improved by 17% and 13% from MEA and DEA solvents, respectively. The metal oxide catalyst-aided regeneration of amine solutions can be a new approach to minimize the heat requirement during solvent regeneration and thus can remove a primary shortfall of this technology.