Process intensification for energy efficient reactive distillation of trioxane production from aqueous formaldehyde

Abstract

Trioxane is an essential platform chemical for producing polyoxymethylene dimethyl ethers and polyformaldehyde. However, the traditional manufacturing process requires high energy consumption because of the conversion limited by the chemical equilibrium (6%) and azeotrope of formaldehyde, water, and trioxane. Therefore, this study proposes the novel reactive distillation followed by the pressure-swing distillation process as an attractive energy-saving candidate. The kinetic was performed by D006-BD cationic-exchange resin catalyst and fitted by pseudo-homogeneous model. The rigorous model of reactive distillation process was established, and the experiments of reactive distillation were carried out to verify the accuracy of modeling. Based on the rigorous model, the effect of operating parameters on reactive distillation column was analyzed. The result showed that formaldehyde conversion could be improved to 79.55% in the reactive distillation column, and the whole process condenser duty reduced by 6.33%, reboiler duty reduced by 18.35% compared with the conventional process involving reactor.