Investigation of the intrinsic reaction kinetics and the mass transfer phenomena of nonanoic acid esterification with 2-ethylhexanol promoted by sulfuric acid or Amberlite IR120

Nonanoic acid is obtained as main coproduct in the synthesis of azelaic acid from oleic acid. The increase of azelaic acid production, being a monomer useful to synthesize biodegradable polyesters, lead to a high availability of nonanoic acid, that can be used as feedstock in esterification reactions to obtain lubricants and solvents. In this work, the esterification of nonanoic acid with 2-ethylhexanol to produce a solvent were conducted in a batch reactor in the presence of either a homogeneous (H₂SO₄) or an heterogenous catalyst (Amberlite IR120). The intrinsic reaction kinetics was investigated by considering all the physical and chemical phenomena occurring in the reaction network, leading to the determination of thermodynamic and kinetic parameters. The activation energy values of both catalysts are similar (≈60 kJ/mol) and the enthalpy value of Δ_rH = 10.3 kJ/mol showed that the reaction is slightly endothermic. The reaction is shifted to the products as demonstrated by the reference equilibrium constant equal to 1.69 at 333 K. The obtained results will be useful to design industrial reactors.