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Hydrocarbon/N2 혼합물의 분리를 위한 PEI-PDMS 중공사 복합막의 기체 투과 특성
이충섭,조은혜,하성용,임지원 한국막학회 2012 멤브레인 Vol.22 No.4
n-Pentane의 분리 및 회수를 위해 분리막의 제조가 용이하고 유기용매에 대한 내용매성이 있는 polyetherimide (PEI)를 지지체로 poly (dimethyl siloxane) (PDMS)를 코팅하여 중공사 복합막을 제조하였다. 제조된 기체 분리막의 특성을 알아보기 위하여 n-Pentane과 질소를 이용하여 공급농도와 stage cut의 변화에 따른 n-pentane과 질소의 투과도, permeate, retentate의 농도, 농축도, 회수율을 측정하였다. n-pentane과 질소의 투과도는 각각 2485.3, 9.9 GPU를 나타내었고, stage cut이 감소하고 공급농도가 증가할수록 투과측의 n-pentane 농도는 증가하는 경향을 나타내었다. 반면 회수효율의 경우에는 stage cut이 증가할수록 공급농도가 감소할수록 증가하는 경향을 나타내었다. For the separation and recovery of n-pentane from nitrogen environment, the poly (dimethyl siloxane) (PDMS) composite membranes supported by polyetherimide (PEI) hollow fiber membranes were prepared. To characterize the gas separation properties of the resulting membranes, the permeance of n-pentane and nitrogen, concentrations of permeate and retentate, and recovery ratio were measured for n-pentane and nitrogen mixtures. The permeance of n-pentane and nitrogen, 2485.3 and 9.9 GPU, were observed respectively. As the stage cut decreases and the feed concentration increases, the n-pentane concentration in permeate tends to increase. In the meanwhile, the recovery efficiency tends to increase as the stage cut increases and the feed concentration decreases.
Subchronic Inhalation Toxicity Study of n-pentane in Rats
Kim, Jong-Kyu,Cho, Hae-Won,Han, Jeong-Hee,Lee, Sung-Bae,Chung, Yong-Hyun,Rim, Kyung-Taek,Yang, Jeong-Sun Occupational Safety and Health Research Institute 2012 Safety and health at work Vol.3 No.3
Objectives: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. Methods: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. Results: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. Conclusion: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).
n-Pentane & n-Hexane as Coguests of sH Hydrates in the Mixture with 2,2-Dimethylbutane and Methane
이종원(Lee, Jong-Won),Lu, Hailong,Moudrakovski, Igor L.,Ripmeester, Christopher I. Rat 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.11
n-Pentane and n-hexane, previously regarded as non-hydrate formers, are found to form structure H hydrate in mixtures with 2,2-dimethylbutane. Even though they are thought to be too large to fit into the largest cage of the structure H hydrate, powder XRD and NMR measurements show that they form gas hydrates in mixtures with other sH hydrate former. These findings are of fundamental interest and also will impact the composition and location of natural gas hydrates and their potential as global energy resource and climate change materials.
Ghim, G.,Lee, J. Pergamon ; Elsevier Science Ltd 2016 Applied thermal engineering Vol.106 No.-
The existence of temperature gliding in non-azeotropic mixture working fluids provides a promising opportunity for greatly improved resource utilization in organic Rankine cycle (ORC) systems for geothermal applications. The condensation heat transfer degradation associated with working fluid mixtures is an unavoidable penalty that may reduce the utilization and system benefits by necessitating larger heat exchangers. The objective of the current study is an experimental investigation of condensation heat transfer for R245fa, n-pentane, and a composition of their mixture. Quasi-local condensation heat transfer coefficients are measured in a straight horizontal smooth tube with flow conditions at mass flux G=100 and 150kg(m<SUP>2</SUP>s)<SUP>-1</SUP>, local equilibrium quality x=0.05-0.80, and reduced pressures P<SUB>r</SUB>=0.05-0.15. The reduced condensation heat transfer coefficients from the test are compared with the predictions from already established mixture correction methods in the literature. Pure components R245fa and n-pentane condensation heat transfer data are well predicted by Shah (1979) correlations for all test conditions. However, their non-azeotropic mixture condensation heat transfer data require additional correction parameter to account for the heat transfer degradation. This correction parameter is correlated by the temperature gliding gradient of mixture fluids. Test data with mixture working fluids from current study are reasonably well predicted by the corrected in-tube correlation.
이종원(Lee, Jong-Won) 한국신재생에너지학회 2007 한국신재생에너지학회 학술대회논문집 Vol.2007 No.11
분자 크기가 너무 커 가스 하이드레이트를 형성하지 않는다고 알려진 n-펜탄과 n-헥산이 다른 구조-H 형성 화합물과 혼합되어 사용될 경우 구조-H 동공 내에 함께 포접되는 것으로 확인되었다. 구조-H 하이드레이트의 형성 및 미세구조 분석은 고체 NMR 및 X-선 회절 분광법을 이용하여 확인하였다. 이러한 혼합 화합물에서 보이는 구조-H 하이드레이트 형성은 전체적인 구조-H 형성 화합물에서 나타나는 일반적 특징인 것으로 여겨진다.
루프 열사이폰 내부 증기유동에 대한 수치해석과 실험결과 비교
이윤용(Yun Yong Lee),강환국(Hwan Kook Kang),김대영(Dae Young Kim),김영득(Young Deug Kim) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.-
In this study, the experiments and numerical analysis were carried out for the purpose of designing the loop thermosyphon used in the ESS battery room, for the characteristics of vapor pressure drop and the friction coefficient according to various types of working fluid and vapor flow operating in the room temperature range. It is important to design the microchannel and the vapor line with the prediction of the flow resistance considering the physical properties of the working fluid in the loop thermosyphon.
Im, Soo Ik,Shin, Sangcheol,Park, Jun Woo,Yoon, Hyung Jin,Go, Kang Seok,Nho, Nam Sun,Lee, Ki Bong Elsevier 2018 Chemical Engineering Journal Vol.331 No.-
<P><B>Abstract</B></P> <P>The solvent deasphalting (SDA) process is a heavy oil upgrading process in which deasphalted oil (DAO) is extracted from heavy oil feedstock by precipitating asphaltene using an excess amount of alkane solvent (C3-C6). After the extraction, solvent recovery should be carried out for separating the solvent from the DAO in order to recycle the expensive solvent. In the conventional solvent recovery method, the mixture of solvent and DAO is heated to evaporate the solvent, which requires massive heat energy, resulting in reduced process efficiency. In this study, CO<SUB>2</SUB> is applied for the first time to selectively separate solvent from DAO at a relatively low temperature. The experimental results in a batch separator indicate that the temperature required for high solvent recovery of over 80% decreases from 200°C to 40°C when using CO<SUB>2</SUB> compared to the conventional method. The theoretical approach using Hansen distance calculation based on the Hansen solubility parameter (HSP) was used to verify the mechanism of solvent separation using CO<SUB>2</SUB>. The results suggest that the increase in the interaction between CO<SUB>2</SUB> and solvent causes the separation of solvent from DAO, leading to an increase in solvent recovery. Also, numerical simulation results show the possibility of continuous operation for solvent recovery using CO<SUB>2</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Solvent recovery using CO<SUB>2</SUB> was newly developed for solvent deasphalting process. </LI> <LI> High solvent recovery was achieved at relatively low temperature. </LI> <LI> CO<SUB>2</SUB> acts as an anti-solvent to separate the solvent from DAO. </LI> <LI> Numerical simulation confirmed the possibility of a new solvent recovery operation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
소형가스터빈용 인젝터의 분무 특성에 따른 반응 유동장 전산 해석
김세환(Seihwan Kim),정인석(In-Seuck Jeung),박희호(Hee-Ho Park),나상권(Sangkwon Na) 한국추진공학회 2010 한국추진공학회 학술대회논문집 Vol.2010 No.5
항공용 저출력 소형 가스터빈 엔진에 적용을 위한 연료 분사기의 분무 특성에 따른 반응 유동장에 대한 수치해석을 수행하였다. 인젝터의 개발에 있어 연료의 분무 상태가 엔진 성능에 큰 영향을 미치므로 다양한 변수에 대한 고려가 요구되고 있다. 본 연구에서는 정지 상태의 유동장에 분사기를 위치시키고 액적의 평균 직경, 분사 압력, 분사각을 변경하며 그에 따른 반응 특성을 살펴보았다. 해석 결과 분사압과 분사 각도가 클수록, 액적의 직경이 작을수록 활발한 반응이 일어나지만 분사압이 큰 경우 영역내에서 기화되는 연료량이 감소함을 확인할 수 있었다. This work shows the result of numerical simulation on a reacting flow by varying atomization properties which can be obtained from a injector for a small and low power aircraft gas turbine engine. Because the atomization properties mainly affect on the performance of the engine, a lot of efficiency tests are needed when a new injector is developed. Nowadays researches has been actively performed using computational analysis. Using commercial package CFD-ACE+, basic studies on the reacting flow field have been conducted. Those results show that the reaction rate is increased when higher pressure and wider angle spray condition are used. More smaller parcels can also enhance the fuel-air reaction.