Measurement and correlation of dye solubility in supercritical carbon dioxide

Dry dyeing which does not use water is a new approach in textile industry in order to reduce or eliminate effluent wastewater. Supercritical carbon dioxide is an alternative solvent which is considered for dry dyeing processes. This study focused on the determination of the dye solubility in supercritical carbon dioxide. The solubility in supercritical carbon dioxide of two disperse dyes, C.I. disperse blue 3 and C.I. disperse blue 79 at temperatures from 323.7 to 413.7 K and pressures from 100 to 300 bar have been measured, using a flow-type equilibrium cell. The effect of temperature, pressure and density of carbon dioxide on solubility of dyes has been investigated. The solubility data were correlated with fairly good accuracy with an expanded liquid model that needs no critical properties and vapor pressure of dyes.