Example Hydrolysis of Acetic Anhydride

Wajge and Reklaitis (1999) considered a simple single duty multiperiod operation using the hydrolysis reaction of acetic anhydride (Ullmann, 1985) to demonstrate the RBDOPT framework. Acetic anhydride is manufactured by dehydration of acetic acid. The by-product of the process is a mixture of acetic anhydride, water and acetic acid with boiling points 412 K, 373.2 K and 391.1 K respectively for each component in the mixture. The main concern is that the acetic anhydride and water in the mixture may hydrolyse quite quickly to produce back the acetic acid. 

Wajge and Reklaitis (1999) considered the following operation sequence using a CBD column  

CUT 1 - Recover most of the water (the lowest boiling component) 

CUT 2 - Maximise the amount of acetic acid recovery, thus leaving acetic anhydride as the final bottom product in the reboiler. 

Amount of Distillate in CUT 1, kmol Composition of CUT1, molefraction Amount of Distillate in CUT 2, kmol Composition of CUT2, molefraction Amount of Bottom Product in CUT2, kmol Composition of Bottom Product, molefraction Total Batch Time, hr  

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