Selective synthesis of 2-ethoxy alkanes through ethoxylation of 1-alkenes with bioethanol over zeolite beta catalyst in a liquid phase continuous process

Abstract

1-Hexene was ethoxylated with ethanol and ethanol–water mixtures mimicking bioethanol in a liquid phase, continuous flow process over a fixed bed of zeolite beta catalyst at a reaction temperature of 423 K and a pressure of 6 MPa. The selectivity for ethoxy alkanes on a hexene basis exceeded 90%. GC-MS, ¹H & ¹³C-NMR and ¹³C DEPT NMR confirmed the main reaction products to be 2-ethoxy hexane and 3-ethoxy hexane in molar ratio 20 : 1. Side products were diethyl ether from ethanol and dodecenes and hexanol from 1-hexene. Under optimized reaction conditions, the catalyst was stable for at least 14 hours on-stream. The 2-ethoxylation activity of 1-alkenes by zeolite beta was confirmed in reactions with 1-octene and 1-decene. 1-Alkenes can be synthesized out of biomass via conversion into synthesis gas and the Fischer–Tropsch process. The here presented ethoxylation process could contribute green chemicals to the diesel pool and presents a pathway for synthesis of high boiling solvents.