Comparison between Ethanol and Diethyl Carbonate as Ethylating Agents for Ethyl Octyl Ether Synthesis over Acidic Ion-Exchange Resins

Abstract

Direct addition of bioethanol to diesel reduces the quality of commercial blends. An alternative way to introduce bioethanol into diesel is as linear ether such as ethyl octyl ether (EOE). EOE synthesis by 1-octanol (OcOH) reaction with ethanol (EtOH) or diethyl carbonate (DEC) over acidic ion-exchange resins has been studied in a 100-mL batch reactor (130–150 °C, 25 bar). The main drawback for ethylating OcOH in both reaction systems is the loss of ethyl groups by diethyl ether formation. In OcOH excess, selectivity to EOE with respect to EtOH and to DEC was found to be similar (58–59%) when the ethylating agent was entirely consumed. However, the initial reaction rate of EOE formation from DEC is lower, due to the formation of ethyl octyl carbonate as reaction intermediate. Accordingly, EtOH showed to be more interesting ethylating agent to produce a synthetic biofuel such as EOE over acidic ion-exchange resins.