Vapor-Liquid Equilibria Measurement of Carbon Dioxide+1-Hexene and Carbon Dioxide+2-Ethyl-1-Butene Systems at High Pressure

변헌수,최태현 한국화학공학회 2004 Korean Journal of Chemical Engineering Vol.21 No.5

Pressure-composition isotherms were obtained for the carbon dioxide+1-hexene system at 40, 60, 80, 100 and 120 oC and pressure up to 120 bar and for carbon dioxide+2-ethyl-1-butene system at 40, 75 and 100 oC and pressure up to 115 bar. The accuracy of the experimental apparatus was tested by comparing the measured phase equilibrium data of the carbon dioxide+1-hexene system at 40 oC and 60 oC with those of Wagner and Wichterle [1987], and Jennings and Teja [1989]. The solubility of 1-hexene and 2-ethyl-1-butene for the carbon dioxide+1-hexene and carbon dioxide+2-ethyl-1-butene systems increases as the temperatures increases at constant pressure. These two carbon dioxide-polar solute systems exhibit type-I phase behavior, which is characterized by an uninterrupted critical mixture curve that has a maximum in pressure. The experimental data are modeled by using the Peng-Robinson equation of state. A good fit of the data is obtained with Peng-Robinson equation of state using two adjustable parameters for carbon dioxide+1-hexene and carbon dioxide+2-ethyl-1-butene systems.

Cloud-point measurement of the biodegradable poly(d,l-lactide-co-glycolide) solution in supercritical fluid solvents

변헌수,이하연 한국화학공학회 2006 Korean Journal of Chemical Engineering Vol.23 No.6

data of high pressure phase behavior betwen 35oC and 105oC and pressures up to 2,20bar is presented for poly(d,l-lactic acid)(d,l-PLA) and poly(lactide-co-glycolide)15 (PLGA15), PLGA25, and PLGA50 insupercritical carbon dioxide, trifluoromethane (CHF3), chlorodifluoromethane (CHClF2), dichloromethane (CH2Cl2),and chloroform (CHCl3). d,l-PLA dissolves in carbon dioxide at pressures of 1,250 bar, in CHF3 at pressures of 500to 750 bar, and in CHClF2 at pressures of 30-145 bar. As glycolic acid (glycolide) is added to the backbone of PLGA,the cloud point pressure increases by 36 bar/(mol GA) in carbon dioxide, 27 bar/(mol GA) in CHF3, and by only 3.9bar/(mol GA) in CHClF2. PLGA50 does not dissolve in carbon dioxide at pressures of 2,800 bar, whereas it is readilysoluble in CHClF2 at pressures as low as 95 bar at 40oC. Cloud point behavior of d,l-PLA, PLGA15, and PLGA25 insupercritical carbon dioxide shows the effect of glycolide content between 35oC and 108oC. Also, the phase behaviorfor poly(lactic acid) - carbon dioxide-CHClF2 mixture shows the changes of presure-temperature slope, and with CHClF2concentration of 6 wt% , 19 wt% , 36 wt% and 65 wt% . The cloud-point behavior shows the impact of glycolide contenton the phase behavior of PLA, PLGA15, PLGA25 and PLGA50 in supercritical CHClF2. A comparison was made betweenthe phase behaviors of d,l-PLA and poly(l-lactide)(l-PLA) in supercritical CHF3. The phase behavior of CHF3 as acosolvent for 5 wt% d,l-PLA-supercritical carbon dioxide system is presented for the effect being added 10 wt% and29 wt% to CHF3 content.

초임계 용매내에서 Poly(ethylene-co-butene) 에 대한 이성분 및 삼성분계의 상거동 및 혼합물 밀도

변헌수,김근빈 한국공업화학회 2000 응용화학 Vol.4 No.2

Phase equilibria and density of polymer in supercritical fluid are fundamental information for chemical process design and molecular structure analysis in polymer science. In this study, we measured high pressure phase equilibria and densities of poly(ethylene-co-butene)_10 and poly(ethylene-co-butene)_47 in two supercritical solvents; dimethyl ether (DME) and dimethyl ether-d (DME-d). A high-pressure moving-volume cell was used to measure the equilibrium properties. High pressure phase equlibria of poly(ethylene-co-butene)_(10)-dimethyl ether were measured at 106∼185 ℃ and pressure range of 486∼1,100 bar. The similar system, polyethylene-dimethyl ether showed higher equilibrium line by 100∼350 bar. The liquid-liquid equilibrium line of poly(ethylene-co-butene)_(10)-dimethyl ether and poly(ethylene-co-butene)_(10)-dimethyl ether-d existed within 110∼150 ℃ below 1,000 bar. Phase behavior of poly(ethylene-co-butene)_(10) and poly(ethylene-co-butene)_(47) in dimethyl ether were also measured.

고압에서 CO₂-아세토니트릴과 CO₂-아크릴로니트릴계에 대한 상거동에 관한 연구

변헌수,김윤섭,임종균,Byun, Hun-Soo,Kim, Youn-Sop,Im, Jong-Kyun 한국공업화학회 1998 공업화학 Vol.9 No.6

본 연구에서는 고압하에서 이산화탄소와 니트릴계인 아세토니트릴 (acetonitrile)과 아크릴로니트릴 (acrylonitrile)과의 이성분계에 대한 상평형데이터를 얻기 위해 실험을 수행하였다. 실험장치는 정지형으로서 본 실험을 위해 자체 제작하여 사용하였으며, 새로이 설계된 실험장치의 재현성과 정확도를 실험하기 위해 $75^{\circ}C$에서 이산화탄소-아세토니트릴계의 실험을 수행하여 McHugh 등[1]의 실험결과와 비교하였다. 이산화탄소와 아세토니트릴과의 이성분계 상거동 실험은 온도 $55.0^{\circ}C$, $75.0^{\circ}C$, 그리고 $100.0^{\circ}C$에서 실험하였으며, 이때 압력은 2.4~14.5 MPa 범위였으며, 이산화탄소-아크릴로니트릴계의 상평형 실험은 온도 $45.0^{\circ}C$, $65.0^{\circ}C$, $85.0^{\circ}C$, 그리고 $105.5^{\circ}C$와 압력 1.6~13.9 MPa 근처까지 실험하였다. 두 계에 대해 동일한 압력에서 아세토니트릴과 아크릴로니트릴의 용해도는 온도가 증가함에 따라 증가함을 알 수 있다. 또한 두 계에 대한 혼합물 임계곡선에나타내었다. 본 연구에서 실험한 결과를 Peng-Robinson상태방정식에 의해 계산하였으며, 그 결과 실험치와 계산치와의 좋은 일치를 보였다. In this work, high pressure binary phase equilibria data of carbon dioxide with acetonitrile and acrylonitrile were obtained experimentally. A new static type experimental apparatus was built to measure temperature, pressure and phase equilibria composition. The accuracy of the experimental apparatus was tested by comparing the measured phase equilibria data of the carbon dioxide-acetonitrile system at $75^{\circ}C$ with those of McHugh and coworkers. The binary phase behavior data of carbon dioxide-acetonitirle system were measured from 2.4 to 14.5 MPa at $55^{\circ}C$, $75^{\circ}C$ and $100^{\circ}C$. Also, the phase equilibria of the system carbon dioxide-acrylonitrile were measured from 1.6 MPa up to 13.9 MPa at $45^{\circ}C$, $65^{\circ}C$, $85^{\circ}C$ and $105^{\circ}C$. The solubility of acetonitrile and acrylonitrile increases as the temperatures increases at constant pressure. Also, these two carbon dioxide-polar solute system have continuous critical-mixture curves that exhibit maximums in pressure at temperatures between the critical temperatures of carbon dioxide and acetonitrile or acrylonitrile. The experimental data obtained in this study were modeled using the Peng-Robinson equation of state. Good agreement between calculated and experimental results was observed.

Correlation of vapor-liquid equilibria for binary mixtures with free energy-based equation of state mixing rules: Carbon dioxide with alcohols, hydrocarbons, and several other compounds

변헌수,곽철,Stanley I. Sandler 한국화학공학회 2006 Korean Journal of Chemical Engineering Vol.23 No.6

Phase equilibria measurement of binary mixtures for triethylene glycol dimethacrylate and triethylene glycol diacrylate in supercritical CO2

변헌수,이승엽 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.4

The phase equilibrium curves for the (CO2+triethylene glycol dimethacrylate) and (CO2+triethylene glycol diacrylate) systems at five temperatures (313.2, 333.2, 353.2, 373.2 and 393.2) K and pressures up to 30.34MPa were measured by synthetic apparatus. The solubility of triethylene glycol di(meth)acrylate in the (CO2+triethylene glycol dimethacrylate) and (CO2+triethylene glycol diacrylate) systems increased as the temperature increased at a fixed pressure. The (CO2+triethylene glycol dimethacrylate) and (CO2+triethylene glycol diacrylate) systems exhibited type-I phase equilibria. The experimental results for the (CO2+triethylene glycol dimethacrylate) and (CO2+triethylene glycol diacrylate) mixtures were correlated with the Peng-Robinson equation of state using a mixing rule including two adjustable parameters. The properties for the critical pressure, critical temperature and acentric factor of triethylene glycol dimethacrylate and triethylene glycol diacrylate were predicted with the Joback and Lyderson group contribution method.

고압에서 CO2 - 아세토니트릴과 CO2 - 아크릴로니트릴계에 대한 상거동에 관한 연구

변헌수,김윤섭,임종균 ( Hun Soo Byun,Youn Sop Kim,Jong Kyun Im ) 한국공업화학회 1998 공업화학 Vol.9 No.6

Poly(octadecyl acrylate) 초임계 용매-octadecyl acrylate계의 고압상거동

변헌수,김선영,최태현 한국공업화학회 2000 한국공업화학회 연구논문 초록집 Vol.2000 No.1

N/A N/A

Delphi/AHP 기반 발사장 주변 및 비행경로의 해상안전 강화를 위한 위협요인 분석

변헌수,신안태,박병문 한국화학공학회 2023 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.61 No.2

In this study, using the Delphi method, 20 responses to 4 questions (need for launch safety control, top- priority considerations for ensuring public safety during launch, necessary improvements for securing maritime safety, and maritime safety threat factors) regarding launch vehicles and public safety were obtained from experts, and their importance was evaluated to analyze the factors that threaten the reinforcement of maritime safety around launch sites and flight paths when launching. According to the results of an analytic hierarchy process (AHP) analysis, the consistency ratio of the four questions was 4.8%, which is lower than CR ≤ 0.1(10%), and the consistency percentage of the lower measurement indicators was 3.9~5.7%. The derived importance and priority of maritime safety threat factors during launching were in the following order: Substantial human and physical damage in case of launch accidents(0.36), Prepare legal bases (e.g., penalty details) regarding maritime control(0.32), Secure the safety of personnel, equipment, and facilities in danger zone(0.31), Unauthorized entry of vessels in maritime control zones and non-compliance to restrictions(0.30). This article can serve as a reference for strengthening maritime safety in areas around launch sites and flight paths. 본 연구는 Delphi/AHP 기법을 사용하여 발사장 주변 및 비행경로의 해상안전 강화를 위한 위협요인 및 중요도를분석하였다 . 우선 Delphi 기법으로 , 발사체 /공공안전 전문가 집단을 대상으로 4개 질문 (발사안전통제 필요성 , 발사 공공안전 확보 최우선 고려사항 , 해상안전 확보를 위하여 개선할 사항 , 해상안전 위협요인 )에 대하여 20개 항목으로 답변을 도출하였다 . 이를 기반으로 AHP 기법으로 각 항목의 중요도를 평가하였다 . AHP 분석결과 4개 질문에 대한 평균 일관성 비율은 4.8%이고 , 각 측정지표의 일관성 비율은 3.9~5.7%로써 CR ≤ 0.1(10%) 보다 낮으므로 모두 일관성이 있음을 확인하였다 . 중요도와 우선순위를 고려한 결과 , 발사안전통제가 필요한 이유로 발사 사고 시 인적 , 물적으로 큰 피해가 발생 가능성 때문 (0.36)으로 , 발사안전통제에서 최우선으로 고려할 사항은 위험구역 내 인원 , 장비 , 시설의 안전 확보 (0.31)로 나타났다 . 또한 , 발사 해상안전 위협요인으로 가장 우려되는 항목은 통제해역 내 선박의 무단 진입, 통제 불가 상황 (0.30)이며 , 현재 개선하여야 할 대책으로는 이러한 상황을 법적으로 통제할 수 있는 근거마련 (0.32) 이 가장 시급하다고 나타났다 . 본 논문은 위협요인을 전문가 의견 수렴을 통하여 도출하고 , 중요도 및 우선순위를 객관적으로 평가한 부분에 의미가 있다 . 향후 위험성 평가 및 안전통제 계획수립 단계에서 중요한 기초자료로 활용될 수있을 것으로 기대한다 .

해양사고 안전관리를 위한 정보시스템에 관한 연구

변헌수,신현식 한국정보통신학회 2001 한국정보통신학회논문지 Vol.5 No.1

본 연구는 경제성장의 급속한 발전으로 말미암아 해상으로의 수송 물량이 급격히 증가함으로 인하여, 해상에서 크고 작은 안전사고가 많이 일어나고 있는 바, 이에 따른 안전관리 체계의 중요성이 한층 고조되고 있다. 특히 안전관리 체계를 수립함으로서 인명과 재해를 방지 할 수 있으며, 국가적인 차원에서 철저한 안전사고 예방 및 해양정보 시스템 체계를 구축함으로서 보다 나은 제도적인 정보체계를 연구 고찰하고자 한다. There have been a lot of marine accidents due to the increasing transportation by sea in accordance with economic growth. Accordingly, we are fully aware of the importance of the development of safety control system so that may prevent the sacrifice of life and disasters on the sea. The objective of this research in to investigate the more effective system by establishing the prevention of safety accident and marine information system as a national project.