Isothermal Vapor-Liquid Equilibria at 333.15K and Thermodynamic Excess Properties for the Binary System of Methanol+Dimethyl Carbonate

Methanol+Dimethyl Carbonate 혼합계의 333.15 K 등온 기-액 평형과 열역학 과잉 물성

  • Han, Kyu-Jin (Division of New Materials Engineering, College of Engineering, Chungnam National University) ;
  • Park, So-Jin (Division of New Materials Engineering, College of Engineering, Chungnam National University)
  • 한규진 (충남대학교 공과대학 신소재공학부) ;
  • 박소진 (충남대학교 공과대학 신소재공학부)
  • Received : 2005.02.01
  • Accepted : 2005.03.23
  • Published : 2005.06.30

Abstract

Recently, dimethyl carbonate (DMC) is considered as an alternative of MTBE (methyl tert-butyl ether), additive for non-leaded gasoline with their fast biodegradation rate and low toxicity. DMC is usually synthesized so far by oxidative carbonylation of methanol, and recently developed synthetic process is also started with methanol. Since the phase equilibria of the system, consisted of DMC and methanol or other reaction products on different temperature and pressure is necessary for the optimum separation process design and operation. However the reported phase equilibria and physical properties for DMC mixtures in the Dortmund Data Bank (DDB; thermodynamic property data bank) are quite rare. Besides, infinitely dilute properties are not found. In this work, isothermal vapor-liquid equilibria at 333.15 K for methanol+DMC binary system and mixing properties, excess molar volume and viscosity deviation at 298.15 K are directly measured and correlated. Additionally, infinitely dilute activity coefficient of methanol in the DMC solvent at three different temperatures are measured and compared with predicted values using modified UNIFAC (Dortmund).

Dimethyl carbonate(DMC)는 낮은 독성과 빠른 생분해성으로 인해 MTBE(methyl tert-butyl ether)를 대체할 수 있는 무연가솔린의 첨가제로 주목받는 물질로, 주로 methanol의 carbonylation에 의해 합성되고, 원가절감을 위해 methanol을 출발물질로 한 새로운 DMC 제조공정의 개발이 진행 중에 있다. 이에 필요한 다양한 조건하의 DMC 관련 혼합계의 상평형 자료 및 물성은 Dortmund Data Bank(DDB)검색 결과, 매우 부족하며 무한희석 활동도계수에 대한 자료는 전무한 것으로 나타났다. 이 글에서는 methanol+DMC계의 333.15 K에서의 이성분계 등온 기-액 평형과, 혼합물성으로써 methanol+DMC계의 과잉부피 및 점도편차를 298.15 K에서 측정하였다. 또한, 무한희석상태에서 DMC 용매에서의 methanol의 무한희석 활동도계수를 303.15, 313.15, 323.15 K에서 각각 측정하였으며, 측정값은 modified UNIFAC(Dortmund)식에 의한 계산 값과도 비교하였다.

Keywords

Acknowledgement

Supported by : 한국에너지관리공단

References

  1. Won, W., Feng, X. and Lawless, D., 'Separation of Dimethyl Carbonate/Methanol/Water Mixtures by Pervaporation Using Crosslinked Chitosan Membranes,' Separation and Purification Technology, 31(2), 129-140(2003) https://doi.org/10.1016/S1383-5866(02)00176-4
  2. Bertilsson, F. and Karlsson, H. T., '$CO_{2}$ Utilization Options. Part II: Assessment of Dimethyl Carbonate Production,' Energy Conv. Manage, 37(12), 1733-1739(1996) https://doi.org/10.1016/0196-8904(96)00019-2
  3. Harris, H. G. and Prausnitz, J. M., 'Relative Lewis Acidities of Polar Organic Solvents from Chromatographic Measurements,' J. Chromat. Sci., 7, 685-689(1969) https://doi.org/10.1093/chromsci/7.11.685
  4. Romano, E., Trenzado, J. L., Gonzales, E., Matos, J. S., Segade, L. and Kiminez, E., 'Thermophysical Properties of Four Binary Dimethyl Carbonate+1-Alcohol Systems at 288.15-313.15 K,' Fluid Phase Equilibria, 211(2), 219-240(2003) https://doi.org/10.1016/S0378-3812(03)00203-6
  5. Francesconi, R. and Comelli, F., 'Excess Molar Enthalpies and Excess Molar Volumes of Binary Mixtures Containing Dimethyl Carbonate+Four Butanol Isomers at (288.15, 298.15, and 313.15) K,' J. Chem. Eng. Data, 44(1), 44-47(1999) https://doi.org/10.1021/je980124f
  6. Comelli, F. and Francesconi, R., 'Isothermal Vapor-Liquid Equilibria Measurements, Excess Molar Enthalpies, and Excess Molar Volumes of Dimethyl Carbonate+Methanol, +Ethanol, and+Propan- 1-ol at 313.15,' J. Chem. Eng. Data, 42(4), 705-709(1997) https://doi.org/10.1021/je960321j
  7. Canosa, J., Rodriguez, A. and Tojo, J., 'Densities, Refractive Indices and Speeds of Sound of the Ternary Mixtures (Dimethyl Carbonate+Methanol+Ethanol) and (Dimethyl Carbonate+Methanol+ 1-Propanol) at T=298.15 K,' J. Chem. Thermodyn., 35(12), 2021-2031(2003) https://doi.org/10.1016/j.jct.2003.08.011
  8. Kolb, B., 'Application of an Automated Head-Space Procedure for Trace Analysis by Gas Chromatography,' J. Chromatography, 122, 533-568(1976)
  9. Park, S. J. and Lee, T. J., 'Vapor-Liquid Equilibria and Excess Molar Properties of MTBE+Methanol and +Ethanol Mixtures,' Korean J. Chem. Eng., 12(1), 110-114(1995) https://doi.org/10.1007/BF02697715
  10. Park, S. J. and Oh, J. H., 'Isothermal Vapor-Liquid Equilibria of 2-Methoxy-2-methylbutane(TAME)+n-Alcohol(C1-C4) Mixtures at 323.15 and 333.15 K,' J. Chem. Eng. Data, 42(3), 517-522(1997) https://doi.org/10.1021/je960302+
  11. Redlich, O. and Kister, A. T., 'Algebraic Representation of Thermodynamic Properties and the Classification of Solutions,' Ind. Eng. Chem., 40(2), 345-348(1948) https://doi.org/10.1021/ie50458a036
  12. Krummen, M., Gruber, D. and Gmehling, J., 'Measurement of Activity Coefficients at Infinite Dilution in Solvent Mixtures Using the Diluter Technique,' Ind. Eng. Chem. Res., 39(6), 2114-2123(2000) https://doi.org/10.1021/ie990830p
  13. Perry, R. H., 'Perry's Chemical Engineer's Handbook,' McGraw- Hill(1984)
  14. Gmehling, J., Unpublished Parameter(Personal Communication), Oldenburg, Germany(2003)