Feasibility of Solvent-Assisted Reactive Chromatography for the Synthesis of 2,2 Di-Methoxy Propane

Abstract

Reactive chromatography is beneficial for a reaction where reaction equilibrium limits productivity, the product forms azeotropes with the reactants, and product separation is difficult due to nonideality in the phase equilibrium. 2,2 Di-methoxy propane (DMP) production from methanol and acetone is one such example where DMP equilibrium conversion is less than 15% at 15 °C reaction temperature in a conventional batch process. Furthermore, DMP forms azeotropes with acetone and methanol, and product separation is difficult due to nonideality in the phase equilibrium. In this work, synthesis of DMP from methanol and acetone using an acidic resin (Amberlyst-15) as an adsorbent/catalyst is investigated in a fixed-bed chromatographic reactor (FBCR). Addition of solvents such as hexane or cyclohexane into the reaction system in the FBCR favorably influences the affinity of acetone and DMP to the catalyst bed. The addition of equal molar amounts of hexane and acetone results in an increase in the affinity of acetone toward the resin and a decrease in the affinity of DMP toward the resin. Thus, with the aid of solvents, one can completely exhaust the acetone in the reaction regime and thus decrease the downstream processing cost drastically. Moreover, DMP yield increases threefold compared to the case when a solvent is not used. The parameters in the reaction kinetics, dispersion coefficient, and adsorption parameter were estimated by conducting independent experiments in the FBCR. The reaction kinetics and adsorption isotherm results are obtained from the FBCR implemented in the model, which predicts the results that are in good agreement with the experimental data.

Transforming Ethyl Chloroacetate Production─Leveraging Reactive Chromatography with Amberlyst-15

“…The adsorbent Amberlyst-15 was selected as it has maximum affinity to water and the slightest affinity for ester, facilitating good separation during the reaction. , It is also a promising catalyst to offer a reasonably high reaction rate. The application of Amberlyst-15 as a catalyst has been reported to be useful for esterification by various researchers, , and it has been used successfully in several RC processes. − It is also known to be reusable for multiple synthesis cycles without its activity getting altered …”