Etherification of Biodiesel-Based Glycerol with Bioethanol over Tungstophosphoric Acid To Synthesize Glyceryl Ethers

摘要

ABSTRACT: Etherification of biodiesel-based glycerol with bioethanol was investigated over a series of catalysts. The etherification of glycerol performed on add catalysts, such as H-ZSMS, H-/3, tungstophosphoric acid (HPW), FeCI_3, A1C1_3, and H_2SO_4, was found. Basic catalysts (such as alkaline earth oxides, MgO) are inactive for the reaction. Bulk HPW and Si02-supported HPW catalysts exhibited the highest activity among the tested catalysts, with a 97.1% conversion of glycerol. Over the HPW catalyst, the etherification reactions were carried out at different temperatures, varied ratios between ethanol and glycerol, different catalyst amounts, and different reaction times. The SiO_2-supported HPW catalyst has a high initial activity, but it deactivated gradually because of the leaching of HPW.