The solubilities of isobutylene in aqueous solutions of p-toluene sulfonic acid were estimated in a wide range of concentrations in terms of effective solubilities in pseudo-components at a static equilibrium cell, and the complexation of isobutylene in acid solutions.
The solubilities of isobutylene observed at 33℃ and below 1 atm were increased with increasing of the acid concentrations and abnormal increases were observed at higher acid concentrations, above 40 wt.%, which may due to the large amount of the complexation in the acid solutions. And at fixed acid concentrations, the solubilities of isobutylene were increased as the temperature and pressure increase.
In calculating the solubilities of isobutylene with solution model the chemical complexation in the acid environment was incorporated into activity coefficients with the use of the physical and chemical interactions and the chemical effects were found to be dominant in the solubilization of isobutylene at highly concentrated acid solutions, but less at dilute solutions.
Using the pseudo-component concept, best fitted set of parameters of Redilich-Kister equation were determined and P-X diagrams were calculated for each pseudo-components.