Predicting the Vapor–Liquid Equilibria Phase Envelope for Non-ideal Mixtures of Cyclopentanol and Cyclopentyl Methyl Ether

Cyclopentyl methyl ether (CPME) is an underexplored green alternative to commonly used, relatively toxic, and highly volatile organic content containing ethereal solvents. Traditional CPME synthesis requires energy-intensive azeotropic distillation. Optimizing a distillation column requires sets of rigorous experiments to generate a reliable vapor–liquid equilibria (VLE) data set. Albeit Grand Canonical Monte Carlo calculations remain a hallmark method to calculate VLE, its computational cost for nonideal binary mixtures is significant. We present a less-demanding approach using classical molecular dynamics simulations with the two-fluid theory and nonrandom two-liquid local composition model to derive the VLE profile of CPME and cyclopentanol. These VLE profiles are found to be in good qualitative agreement with the experiments. Shorter time scale (10 ns), small system size (121 molecules), affordable computational cost (∼500 CPU hours), and qualitative consistency with experiments highlight its applicability. Additionally, simulations reveal a strong hydrogen bond (H-bond) between cyclopentanol–cyclopentanol and CPME–cyclopentanol (vs the absence of an H-bond between CPME–CPME) as a possible reason for the lower volatility of cyclopentanol-rich mixtures. The applicability of the simulated VLE profile is finally demonstrated in generating a preliminary design for a distillation column using the McCabe-Thiele approach, along with necessary precautions near the azeotropic point.