Process simulation and economic evaluation of the industrial production of triacetin from glycerol: Comparing acetic acid and acetic anhydride as possible reagents

Abstract

The objective of this work was to simulate, in Aspen HYSYS® v12.1, the process of obtaining triacetin from glycerol through three chemical routes: via acetic acid (Route 1), acetic anhydride (Route 2), and a combination of acetic acid and acetic anhydride in two separate reactors (Route 3). Additionally and as a novelty, it was investigated the technical and economic viability of a multipurpose plant to this end. It was verified that Route 1 resulted in the best triacetin breakeven prices, even though it would still not be competitive in the considered economic context. On the other hand, Route 2 presented the worst performance due to low conversion (11 %) and higher price of acetic anhydride. The combined route resulted in intermediate breakeven prices for triacetin, despite achieving the highest conversion (79 %) and highest final product purity (96 %). Yield/selectivity and the separation steps were identified as the main bottlenecks in these processes, with reactors and distillation columns accounting for more than 95 % of the equipment costs. The multipurpose plant proved technically possible, and it can be economically interesting depending on the market prices for acetic acid and acetic anhydride.