Kinetics of non-catalyzed hydrolysis of tannin in high temperature liquid water.

Author: Li-li LU ¹ ; Xiu-yang LU ; Nan MA
Author Information

1. Institute of Pharmaceutical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, China.
Publication Type:Journal Article
MeSH: Catalysis; Hydrolysis; Kinetics; Tannins; chemistry; Temperature
From: Journal of Zhejiang University. Science. B 2008;9(5):401-406
CountryChina
Language:English
Abstract: High temperature liquid water (HTLW) has drawn increasing attention as an environmentally benign medium for organic chemical reactions, especially acid-/base-catalyzed reactions. Non-catalyzed hydrolyses of gallotannin and tara tannin in HTLW for the simultaneous preparation of gallic acid (GA) and pyrogallol (PY) are under investigation in our laboratory. In this study, the hydrolysis kinetics of gallotannin and tara tannin were determined. The reaction is indicated to be a typical consecutive first-order one in which GA has formed as a main intermediate and PY as the final product. Selective decomposition of tannin in HTLW was proved to be possible by adjusting reaction temperature and time. The present results provide an important basic data and reference for the green preparation of GA and PY.