Investigation of the Energy-Saving Design of an Industrial 1,4-Dioxane Dehydration Process with Light Feed Impurity

Abstract

In this work, several energy-saving designs of an industrial 1,4-dioxane dehydration process with small amounts of triethylamine (TEA) impurity were compared. The original process contains a preconcentrator column to remove TEA and two other columns operated at different pressures by pressure-swing distillation to separate the remaining azeotrope-containing mixture. To save on the operating costs of this process, two alternative designs were investigated. The first combines the condenser of a high-pressure column with the reboiler of a low-pressure column. The second design uses a completely different method for this separation by heterogeneous azeotropic distillation. This second design can further be thermally coupled into a dividing-wall column with only one column shell. It was found that significant savings in the operating costs (49.09%) and in the total annual cost (43.31%) can be realized by using this second design as compared to the original process. The proposed method uses the light impurity a...