Recovery of acetate by anion exchange with consecutive CO2-expanded methanol desorption: A model-based approach.

Production of bio-based acetate is commonly hindered by the high costs of the downstream processing. In this paper, a model is developed to describe a new method that recovers acetate salts using anion exchange resins, and subsequently desorbs and upgrades them using CO 2 -expanded alcohol. The model consists of equilibrium parameters for both the adsorption and desorption step. The calculated parameters are: for the adsorption K C l - Ac - = 0.125 , K C l - HC O 3 - = 0.206 and K OV , HAc = 0.674 mol / kg resin mol / kg solution , and for the desorption p K MeCO 3 - Ac - = 3.71 . The maximum experimental concentration of acetic acid obtained in CO 2 -expanded methanol is 0.427 mol/kg (20 g/L MeOH ) at an operating pressure of 31 bar. The model represents the expected trends for all species, and can be used to design a multicolumn system for the recovery and upgrading of carboxylates. [ABSTRACT FROM AUTHOR]