Coadsorption Equilibria on Molecular Sieves 3A and Densities of Liquid Mixtures Containing Formaldehyde, Methanol, and Water at 295.15 and 313.15 K

Liquid solutions of formaldehyde, methanol, and water are reactive mixtures in which many oligomeric species are formed. The coadsorption equilibrium from such mixtures on molecular sieves 3A is studied in form of isotherms at 295.15 and 313.15 K. The densities of the liquid phase are measured and reported. Single-component adsorption isotherms of water from 2-propanol on molecular sieves 3A at both temperatures are also presented. A model, which simultaneously considers the physical adsorption equilibrium and the chemical equilibrium in the bulk phase, is regressed to the experimental adsorption data of the three binary subsystems. This model predicts the adsorption from ternary mixtures with good accuracy and is used to estimate separation factors and adsorption enthalpies. Thus, it provides a solid basis for the design of adsorptive processes for drying mixtures containing formaldehyde.