Vapor–Liquid Equilibrium of Formaldehyde and Isobutanol/ n -Butanol at 71.5 and 95 kPa by Catalytic Boosting

Abstract

Formaldehyde forms oligomers in water and/or alcohol, which significantly affect the vapor–liquid equilibrium (VLE) and complicate experimental investigation. An experimental study typically requires specialized devices with a comparatively long residence time due to the kinetic limitations of oligomer formation. Speeding up the reaction kinetics by adding a catalyst enables the experimental study of formaldehyde-containing aqueous or alcoholic mixtures using short residence time measurements. We validate the novel experimental method by reproducing available VLE data for the systems (formaldehyde + water), (formaldehyde + methanol), and (formaldehyde + isoprenol). Additionally, we present new experimental data for the isobaric VLE in the system of formaldehyde and isobutanol/n-butanol between 71.5 and 95.0 kPa. We also present an activity-based physicochemical model for formaldehyde-containing systems, which agrees well with the experimental data.