On the selection of optimum thermodynamic conditions for the GAS process

In this work, the new definition of the relative molar volume change as recently proposed by de la Fuente Badilla et al. [J. Supercrit. Fluids 17 (2000) 13] has been further investigated. Simulation results show that, according to this new definition, each solvent shows a distinguished molar volume change behavior for a given anti-solvent. In addition, it is shown that the pressure, at which the curve of the relative molar volume change has a minimum, exactly coincides with the pressure at which almost all the solute precipitates in a very narrow pressure window. The results also indicate that the thermodynamically suitable operating temperature should be close, but below the critical temperature of the anti-solvent. Based on these findings, a thermodynamic strategy is proposed to select the proper combination sol vent-anti-solvent for a given solute and the optimum operating conditions as well. (C) 2004 Elsevier B.V. All rights reserved.