Catalytic Conversion of Glucose to Levulinate Ester Derivative in Ethylene Glycol

• Main Authors: Weiwei Hao, Xing Tang, Xianhai Zeng, Yong Sun, Shijie Liu, Lu Lin
• Format: Article
• Language: English
• Published: North Carolina State University 2015-05-01
• Series: BioResources
• Subjects: Kinetic study; Glucose; Levulinate ester derivative; Ethylene glycol
• Online Access: http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_10_3_4191_Hao_Catalytic_Conversion_Glucose_Levulinate

A comprehensive, kinetic experiment on the conversion of glucose to 2-hydroxyethyl levulinate ethylene ketal (HLEK), in a cascade of reactions in ethylene glycol, catalyzed by low-concentration sulfuric acid, was conducted. The ethylene glycol/sulfuric acid system was found to be tolerant of a high glucose concentration, and no solid humins were created. At a high initial glucose concentration (30 wt %), an HLEK yield of 27.6% was achieved at a moderate temperature (433 K) after a 330-min reaction with dilute sulfuric acid (0.15 mol/L). In ethylene glycol, more than half of the initial glucose was converted into glucosides within 5 min, and a dynamic equilibrium between these species was achieved; thus, it is reasonable to assume that the ratio of glucosides to glucose was constant (1.35:1) during the entire reaction process. The production of HLEK from glucose via glucosides as a function of the process variables was well-represented by a simplified first-order kinetic model, and the rate expressions were applied to determine the optimum conditions for batch processing.