PHASE-EQUILIBRIA FOR CARBON-DIOXIDE ETHANOL-WATER SYSTEM AT ELEVATED PRESSURES

LIM JS LEE YY CHUN HS

Js. Lim et al., PHASE-EQUILIBRIA FOR CARBON-DIOXIDE ETHANOL-WATER SYSTEM AT ELEVATED PRESSURES, The Journal of supercritical fluids, 7(4), 1994, pp. 219-230

16

INGLESE

Article

Chemistry Physical","Engineering, Chemical

The Journal of supercritical fluids → ACNP

0896-8446

7

4

1994

219 - 230

ISI

0896-8446(1994)7:4<219:PFCESA>2.0.ZU;2-U

For applications related to the use of supercritical CO2 to concentrat e ethanol solutions from a fermentation broth, vapor-liquid equilibria for the CO2-C2H5OH and the CO2-C2H5OH-H2O system were measured at 313 .2, 323.2, 333.2, and 343.2 K at pressures up to 18.5 MPa over a wide range of ethanol concentration. A circulation type of equilibrium appa ratus in which both vapor and liquid phases were continuously recircul ated was adopted for measurements. Using CO2, aqueous ethanol can be c oncentrated above atmospheric azeotropic composition (89.4 mol %) when the pressure in the ternary system CO2-C2H5OH-H2O is below the critic al pressure of the binary system CO2-C2H5OH. The experimental measurem ents for the phase equilibria were compared with the results predicted by Patel-Teja equation of state using each one of the four types of m ixing rules: conventional, Wilson, Yu et al., and Adachi and Sugie. Go od estimation was obtained for the phase equilibria of the binary syst ems except for the conventional mixing rule. It was also found that th e phase behavior of the ternary system can be better predicted by the Patel-Teja equation of state with the Adachi and Sugie mixing rule tha n with the three other mixing rules, though the concentration is not e stimated satisfactorily.