Comparison of adsorption equilibrium of fructose, glucose and sucrose on potass...

• Author(s): Nobre, C. ; Santos, Maria João ; Dominguez, Ana ; Torres, D. ; Rocha, Orlando ; Peres, A. M. ; Rocha, I. ; Ferreira, E. C. ; Teixeira, J. A. ; Rodrigues, L. R.
• Date: 2009
• Persistent ID: http://hdl.handle.net/1822/9718
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Adsorption isotherm; Macroporous resin; Gel-type resin; Cations; Sugars
• Document Type: Article
• Language: English

Description

Adsorption equilibrium of fructose, glucose and sucrose was evaluated on sulfonated poly(styrene-co-divinylbenzene) cation-exchange resins. Two types of resins were used: potassium (K+) gel-type and sodium (Na+) macroporous resins. Influence of the cation and effect of the resin structure on adsorption were studied. The adsorption isotherms were determined by the static method in batch mode for mono-component and multi-component sugar mixtures, at 25 and 40 °C, in a range of concentrations between 5 and 250 g L−1. All adsorption isotherms were fitted by a linear model in this range of concentrations. Sugars were adsorbed in both resins by the following order: fructose > glucose > sucrose. Sucrose was more adsorbed in the Na+ macroporous resin, glucose was identically adsorbed, and fructose was more adsorbed in the K+ gel-type resin. Data obtained from the adsorption of multi-component mixtures as compared to the mono-component ones showed a competitive effect on the adsorption at 25 °C, and a synergetic effect at 40 °C. The temperature increase conducted to a decrease on the adsorption capacity for mono-component sugar mixtures, and to an increase for the multi-component mixtures. Based on the selectivity results, K+ gel-type resin seems to be the best choice for the separation of fructose, glucose and sucrose, at 25 °C.