Kinetics of carbonylation of n-propanol and n-butanol using homogeneous Rh complex catalyst

Abstract

The kinetics of carbonylation of n-propanol and n-butanol using homogeneous Rh complex catalyst is reported here. The effects of RhCl₃ . 3H₂O, hydroiodic acid and alcohol concentrations, CO pressure and temperature on the overall carbonylation rate have been investigated. In n-propanol carbonylation, n-butyric acid and isobutyric acid were formed with n/iso ratio of 3.5:1. In n-butanol carbonylation, n- and iso-valeric acids were formed. The n/iso ratio in both cases was found to be independent of conversion levels and temperature. The carbonylation reactions were found to be first order with respect to RhCl₃.3H₂O and hydroiodic acid concentrations, zero order with CO and negative order with respect to alcohol concentrations in both cases. Rate equations have been proposed and activation energies of 23.3 and 24.49 kcal mol^-1 were observed for n-propanol and n-butanol carbonylations respectively. Finally, the specific rates and kinetic features of carbonylation of n-alcohols have been compared.