Solubility for Propane and Isobutane in [P₆₆₆₁₄]Cl from 278.15 to 348.15 K

Abstract

Absorption-cycle technology driven by low-grade thermal energy has attracted significant attention. Environment-friendly refrigerant/ionic-liquid absorbents have been currently proposed as promising candidates to traditional H2O/LiBr and NH3/H2O working pairs. The properties of refrigerant/absorbent pairs have a large impact on the performance of an absorption–refrigeration cycle, especially the solubility of the gaseous refrigerant in an absorbent. In this work, solubilities (vapor–liquid phase equilibrium) were measured for two new working pairs (isobutane/[P66614]Cl and propane/[P66614]­Cl) from 278.15 to 348.15 K by an isochoric saturation method. Solubilities increase with a decrease in temperature and an increase in pressure. The new data were correlated by the nonrandom two-liquid (NRTL) equation. Results show that the NRTL model provides small deviations distributed as a function of pressure. Furthermore, the enthalpy, entropy, and Gibbs energy of dissolution were estimated. Calculated enthalpies are negative indicating that the process of dissolution is exothermic. The Gibbs energy accords with the classical thermodynamics theory: the lower is the value, the more favorable is the dissolution capacity.

Oil Presence Effect on Thermodynamic Performance of the Evaporator Working with R290

“…Since the vapor pressures of oils are extremely low in the measured conditions, the tiny gaseous component of oil can be neglected. The mass fraction (w 1 ) of R290 dissolved in oil was calculated by 15,16…”

“…Solubilities of R290 in RL 32H and in RL 68H were measured using an isochoric saturation method, which has been described previously. , Its main characteristics is only presented. As shown in Figure , two stainless-steel cells were placed in a self-designed transparent bath.…”

“…Since the vapor pressures of oils are extremely low in the measured conditions, the tiny gaseous component of oil can be neglected. The mass fraction ( w 1 ) of R290 dissolved in oil was calculated by , where M 1 refers to the molar mass of R290; m 2 refers to the oil mass; n 1 refers to the mole number of dissolved R290 in oil, that is obtained by where the subscripts ‘equilib’ and ’ini’ are the equilibrium and initial states; ’sys’ and ’cell’ stand for the gas and equilibrium cells; V 2,cell is the volume of oil injected in the equilibrium cell. The vapor molar volume of R290 (υ gas ) is obtained from Refprop 9.1.…”

“…The thermodynamic equilibrium model is used to represent phase behavior of R290/oil blends, that is expressed by 16,17…”

“…The thermodynamic equilibrium model is used to represent phase behavior of R290/oil blends, that is expressed by , where the subscript i refers to the components in the blends: R290 (1) and oil (2); the superscript s refers to the saturation state; x and y are respectively the liquid-phase and vapor-phase mole fractions; p refers to the vapor pressure; γ refers to the activity coefficient. The correction factor, ζ, is calculated by where the superscripts V and L refer to the vapor phase and liquid phase, respectively.…”