Purification of tetrahydrofuran from aqueous azeotropic solution: continuous adsorption operation using molecular sieves

Abstract

Purification of chemicals is industrially important. Tetrahydrofuran (THF) is a useful chemical and the industrial requirement is minimum 99.5 mass %. THF forms a homogenous minimum boiling aqueous azeotrope due to which purification by distillation is difficult. The present work has used liquid-phase adsorption of the THF–water azeotropic mixture over different adsorbents in order to purify THF. Molecular sieves (3A and 4A) were observed to offer better separation. A methodology to make the process continuous is presented in this work so as to obtain high-purity THF by using adsorption over molecular sieves.