Chemical equilibrium and liquid–liquid equilibrium in ternary mixtures of formaldehyde, water, and isobutanol/ n-butanol between 295 K and 348 K

Mixtures of formaldehyde, water, and isobutanol/ n-butanol exhibit a ternary liquid-liquid equilibrium, as water and butanol are only partially miscible. In the present work, we study the chemical and liquid-liquid equilibria of the systems (formaldehyde + water + isobutanol) and (formaldehyde + water + n-butanol). The species distributions in the chemical equilibrium of both systems are measured between 298 K and 348 K using nuclear magnetic resonance (NMR) spectroscopy. Ternary liquid-liquid equilibrium data are reported between 295 K and 324 K. The experimental data is used to develop a model of the reactive liquid-liquid equilibria for mixtures of formaldehyde, water, and isobutanol/n-butanol. • Research on the reactive LLE of mixtures of formaldehyde, water, and isobutanol/ n-butanol. • Chemical equilibrium of oligomer formation investigated between 298 K and 348 K using NMR spectroscopy. • Ternary LLE measurements between 295 K and 324 K. • Development of UNIFAC-based phase equilibrium model.