(636a) Modeling and Design of Reactive Chromatography for the Synthesis of Propylene Glycol Methyl Ether Acetate with Anion Exchange Resin

Simulated moving bed reactor (SMBR), is an extension of single reactive chromatography to a continuous and countercurrent operation. SMBR have many advantages over conventional reactors, especially for equilibrium limited and thus reversible reactions. In such reactions, in-situ separation of the products drives the reversible reactions to completion beyond thermodynamic equilibrium and also achieves continuous recovery of the products of high purity ^[1].

In the present work, we study an application of SMBR to transesterification synthesis using anion exchange resin as a catalyst and adsorbent, which will be a new platform for ester production. Among numerous esters, this study focuses on the production of propylene glycol methyl ether acetate (DOWANOL™ PMA glycol ether acetate), one of the most commonly used esters with a high industrial demand. DOWANOL™ PMA glycol ether acetate is the second-most used propylene glycol ether with nearly 90% of its use in surface coatings ^[2]. It is very efficient at dissolving resins used in paints, inks, lacquers, and other types of surface coatings such as in automotive, architectural, metal-coil, and industrial maintenance coatings ^[3]. Also, it is used in household products such as cleaners, paints (including spray paint), lacquers, varnishes, and pesticides. However, no study has been conducted on a SMBR for the formation of DOWANOL™ PMA glycol ether acetate using an anion exchange resin.

In this presentation, a case study of process development for the ester product is discussed. Equilibria and kinetics of the reaction and adsorption are investigated by carrying out batch reaction experiments and chromatographic pulse tests. Model parameters are obtained from batch experiments by the inverse method, where a transport dispersive model with a linear driving force for the adsorption rate is used for modeling. Using parameters obtained from the experiments, the SMBR is designed and optimized considering multiple objectives—to maximize the production rate of DOWANOL™ PMA glycol ether acetate, maximize the conversion of the transesterification reaction, and minimize the consumption of the excess reactant, DOWANOL™ PM glycol ether, which also acts as the desorbent in the chromatographic separation.

 [1] G. Agrawal, J. Oh, B. Sreedhar, S. Tie, M.E. Donaldson, T.C. Frank, A.K. Schultz, A.S. Bommarius, Y. Kawajiri. Optimization of reactive simulated moving bed systems with modulation of feed concentration for production of glycol ether ester, Journal of Chromatography A, 2014 (196-208)

[2] Dow Chemical Company. Product Safety Assessment 2008

[3] S.T. Cragg, R.J Boatman Patty’s Toxicology 2001 (7)