Solubilities of CO2 in, densities and kinematic viscosities of poly(propylene glycol) diglycidyl ether and poly(ethylene glycol) monooleate

Abstract

Densities and kinematic viscosities of polymer absorbents such as poly(propylene glycol) diglycidyl ether(PPDE) with molecular weights of 380 and 640, and poly(ethylene glycol) monooleate(PEGM) with molecular weight of 460 were respectively measured at atmosphere and temperatures ranging from 273.15 K to 333.15 K, and correlated with linear equation and Vogel-Fulcher-Tamman equation respectively. The density declines slightly while the kinematic viscosity decreases greatly with the increase of temperature. The result also showed that increasing the molecular weight is beneficial for the decrease of density and the increase of kinematic viscosity. In addition, CO2 solubilities in the selected polymer absorbents were determined by using an isothermal synthetic method, under pressures up to 1.2 MPa and at temperatures ranging from 273.15 K to 303.15 K. The four-parameter nonrandom two-liquid (NRTL) model was used to fit the experimental data, and model parameters were obtained. According to the absorbents as PPDE380, PEGM460, and PPDE640, the mean relative deviations of the pressure between the experimental and fitted data were 1.03%, 1.15%, and 1.31%, and the maximum deviations of that were 2.73%, 2.57%, and 2.55%. The result showed that decreasing the absorption temperature has a large effect on improving absorption capacity. Henry’s constants were calculated from NRTL model and compared with those of experimental data. Relatively good correspondence was obtained with the experimental and calculated data. To assess the selected absorbents for CO2 capture preliminarily, densities and kinematic viscosities of, CO2 solubilities in selected absorbents were compared with common solvents used in industrial plants, other polymer absorbents, and some ionic liquids. The result showed the selected absorbent as PPDE640 has moderate density and kinematic viscosity, the highest CO2 absorption capacities of all the compared absorbents, which showed that PPDE640 has potential research value for CO2 capture.