화학공학소재연구정보센터
HWAHAK KONGHAK, Vol.31, No.4, 448-456, August, 1993
초임계이산화탄소를 이용한 에탄올농축에 관한 연구
A Study on Concentration of Ethanol Solution by Supercritical CO2
초록
초임계유체상과 액상 모두를 계속해서 순환시키는 circulation type의 고압상평형장치를 이용하여 CO2-C2H5-OH-H2O계 및 CO2-C2H5OH계에 대한 고압상평형실험을 수행하였으며, 에탄올을 고농도로 농축하기 위한 조건을 조사하였다. 그 결과 액상에탄올 고농도영역에서도 기-액 2상이 공존하기 위한 조건, 즉 각 온도에서 계의 압력이 CO2-C2H5OH계의 임계압력(Pc,m=0.1203T-29.44)이하일 때, 에탄올-물의 상압공비조성(89.4 mol%)이상으로 에탄올농축이 가능함을 알 수 있었다. 또 에탄올의 물에 대한 분리계수 및 초임계유체상으로의 에탄올용해도 관계를 조사한 결과, Patel-Teja 상태방정식을 이용하여 구한 계산치는 실험치와 정량적으로 많은 오차를 보였지만 정성적으로는 유사한 경향을 나타냄을 알 수 있었다.
High pressure vapor-liquid equilibria for CO2-C2H5OH-H2O and CO2-C2H5OH systems were measured using a circulation type of apparatus in which both vapor and liquid phase were continuously recirculated. The conditions to obtain the high ethanol concentration were also investigated. It was possible to concentrate ethanol above the atmospheric ethanol-water azeotropic composition(89.4 mol%) when the system pressure was below the critical pressure(Pc,m=0.1203T-29.44) of CO2-C2H5OH system at which vapor-liquid two phases were coexisted at the ethanol high concentration regime. In the relationships between separation factor(ethanol to water) and ethanol solubility in the supercritical fluid phase, it was found that the calculated values by Patel-Teja equation of state had some errors quantitively with the experimental data, but qualitively represented the similar tendencies.
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