Phase Behaviors, Density, and Isothermal Compressibility of Styrene + CO₂, Ethylbenzene + CO₂, and Ethylbezene + Styrene + CO₂ Systems

Abstract

The critical points, bubble points, and dew points of ethylbenzene + CO 2 , styrene + CO 2 , and ethylbezene + styrene + CO 2 mixtures were measured in CO 2 -rich region, and the density of the mixtures were also determined. For all the mixtures, the critical temperatures and critical pressures increase with the decrease of CO 2 concentration in the concentration range studied. The phase separation pressures of the mixtures increased with increasing temperature at a fixed composition, but at constant temperature the phase separation pressures decreased as the CO 2 mole fraction in the mixtures was reduced. The Peng-Robinson equations of state was used to calculate the critical points, bubble points, and dew points parameters. The results agreed reasonably with the experimental data. The isothermal compressibility (K T ) of the mixtures was also investigated. It is demonstrated that the trend of K T to pressure varies slowly as the pressure is far from the phase separation points. However, K T is sensitive to pressure and reaches the maximum as the pressure approaches to the phase separation points. At the critical temperatures, K T varies more significantly with pressure than that at bubble points and dew points.

An Additional Condition of Efficiency of the Supercritical Fluid Extraction Process

“…A similar behavior was also characteristic of CO 2methyl phenyl carbinol [21], CO 2 -ethylbenzene [22,23], and CO 2 -acetophenone [24,25] systems. The binodals of the CO 2 -methyl phenyl carbinol system were investigated at temperatures of 303.15, 313.15, and 323.15 K and were within the pressure range up to 16.0 MPa, whereas for the CO 2 -ethylbenzene system, to the temperature range 308-328 K and the pressure range up to 8.5 MPa.…”

Phase Equilibria of the Systems CO2 + Styrene, CO2 + Safrole, and CO2 + Styrene + Safrole

“…The binary interaction parameters for all systems investigated in this work are presented in Table . For the system CO 2 + styrene, the interaction parameters are estimated by using experimental data of this work and a series of experimental data obtained in literature at different temperatures than that investigated in this work. − For the ternary system modeling, only binary information was taken into account, considering binary interaction parameters for the safrole + styrene system equal to zero.…”

“…The binary interaction parameters for the systems CO 2 + styrene and CO 2 + safrole were estimated through the maximum likelihood method coupled to a bubble- or dew-point algorithm for VLE calculation according to the Asselineau formulation. , A global temperature fitting procedure was adopted in this work. The simulated annealing stochastic algorithm was employed to minimize the maximum likelihood objective function. , The parameters for the system CO 2 + styrene were obtained by fitting the experimental data obtained in this work together with those reported in the literature. − Critical properties and constants are presented in Table .…”

“…For the design and operation of high-pressure systems, the phase behavior of the reactional system is a key factor, due to its influence on chemical product formation and process development . Many works can be found in the literature about the phase equilibria of different monomers and carbon dioxide systems. − …”

“…For instance, Suppes and McHugh used the synthetic method to obtain bubble, dew, and critical points for the system CO 2 + styrene in the temperature range of 308 K to 373 K. Tan et al obtained experimental data of vapor–liquid equilibria for the binary and ternary systems involving ethylbenzene, styrene, and carbon dioxide at temperatures of 308 K, 318 K, and 328 K by using an analytical method with circulation. Zhang et al investigated the same systems of Tan and co-workers measuring bubble, dew, mixture critical points, and mixture density for several pressures and temperatures.…”