Abstract: The performance of supercritical fluid (SCF) as a solvent can be greatly affected by
addition of anentrainer to the system. In this study, a constant volume visual method is
used to measure the critical point ofCO2+n-butyraldehyde, CO2+ i-butyraldehyde and
CO2+alcohol binary systems and CO2+entrainer+trisodiumsalt of tri-(m-sulfonphenyl)phosphine
(TPPTS) ternary systems, which provides us good theoretical basis for super-critical
extraction and chemical reaction. The relationship between critical point and concentration
of the entrainerare discussed. The phase behavior of binary system and that of ternary
system are compared. The relationshipbetween the concentration of TPPTS and critical point
of binary systems are also discussed.

Key words: critical point, supercritical fluid, ternary system, phase equilibrium, tri-(m- sulfonphenyl)phosphine

摘要： The performance of supercritical fluid (SCF) as a solvent can be greatly affected by
addition of anentrainer to the system. In this study, a constant volume visual method is
used to measure the critical point ofCO2+n-butyraldehyde, CO2+ i-butyraldehyde and
CO2+alcohol binary systems and CO2+entrainer+trisodiumsalt of tri-(m-sulfonphenyl)phosphine
(TPPTS) ternary systems, which provides us good theoretical basis for super-critical
extraction and chemical reaction. The relationship between critical point and concentration
of the entrainerare discussed. The phase behavior of binary system and that of ternary
system are compared. The relationshipbetween the concentration of TPPTS and critical point
of binary systems are also discussed.

关键词: critical point;supercritical fluid;ternary system;phase equilibrium;tri-(m- sulfonphenyl)phosphine