Recovery of benzothiazolium ionic liquids from the coexisting glucose by ion-exchange resins

The recycling of ionic liquids (ILs) is an essential process to recover them from complex systems for repeated use, which is very crucial for its "green" feature. Saccharides are a kind of common coexisting constituents with ILs in many applications. The study used ion-exchange resins to recover three kinds of benzothiazolium ionic liquids from coexisting glucose. Five ion-exchange resins with different function groups and ionic form were investigated by mixing with the solution of ILs and glucose in batch. Influencing factors were also investigated in detail for adsorption of ionic liquid from glucose aqueous solution. Among them, only D001 resin showed the weak adsorption capacity for glucose. Under the optimal conditions, the maximum adsorption ratio of [HBth][CF3SO3] was 98.58%. Moreover, desorption of target ILs and reuse of resins were also investigated, and the maximum desorption ratio of [HBth][CF3SO3] was 98.6%. After the ILs were applied in the extraction of saccharides in Lycium barbarum L. and hydrolysis of pretreated bagasse cellulose, the adsorption ratio of [HBth][CF3SO3] was 91.1% and [HBth][CH3SO3] was 90.8% by the recovery method respectively. (C) 2016 Elsevier B.V. All rights reserved.