Recovery of acetate by anion exchange with consecutive CO&lt;sub&gt;2&lt;/sub&gt;-expanded methanol desorption: A model-based approach

Cabrera Rodriguez, C.I.; Cartin Caballero, C.M.; Platarou, E.; de Weerd, F.A.; van der Wielen, L.A.M.; Straathof, Adrie J.J.

doi:10.1016/j.seppur.2018.03.068

Recovery of acetate by anion exchange with consecutive CO₂-expanded methanol desorption

Title

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

Author

Cabrera Rodriguez, C.I. (TU Delft BT/Bioprocess Engineering)
Cartin Caballero, C.M. (TU Delft BT/Bioprocess Engineering; Universidad Nacional de Costa Rica)
Platarou, E. (TU Delft Applied Sciences)
de Weerd, F.A. (TU Delft Applied Sciences)
van der Wielen, L.A.M. (TU Delft BT/Bioprocess Engineering; University of Limerick)
Straathof, Adrie J.J. (TU Delft BT/Bioprocess Engineering)

Faculty

Applied Sciences

Date

2018-09-12

Abstract

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 CO₂-expanded alcohol. The model consists of equilibrium parameters for both the adsorption and desorption step. The calculated parameters are: for the adsorption K_Cl^- ^{Ac^-}=0.125, K_Cl^- ^{HCO₃ ^-}=0.206 and K_OV,HAc=0.674[Formula presented], and for the desorption pK_{MeCO₃ ^-} ^{Ac^-}=3.71. The maximum experimental concentration of acetic acid obtained in CO₂-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.