Reverse flow adsorption: integrating the recovery and recycling of homogeneous catalysts

Abstract

Homogeneous catalysts are not applied often when compared to the use of heterogeneous catalysis due to various drawbacks of the usual recovery methods. In this paper, a novel concept is proposed for the integrated recovery and recycling of homogeneous catalysts. It combines an adsorptive separation with the reverse flow technology: reverse flow adsorption. Na + loaded Amberlyst 15 proved to be one of several suitable adsorbents for the reversible adsorption of homogeneous catalysts. A simplified plug flow model for packed beds showed that the implementation of the reverse flow adsorption concept into an oxo-synthesis process would only require two adsorption beds with a very small relative volume of only 1% compared to the volume of liquid reaction phase in the reactor. The adsorption temperature, which was chosen to be equal to the reaction temperature, was well within the stability constraints of the homogeneous catalyst and therefore, decomposition of the catalyst is not expected. Reverse flow adsorption is a promising concept that overcomes the drawbacks of the standard recovery methods and therefore, has a high potential to succeed.