Influence of acid ion-exchange resins morphology in a swollen state on the synthesis of ethyl octyl ether from ethanol and 1-octanol

Ethyl octyl ether (EOE) liquid-phase synthesis from ethanol and 1-octanol over ion-exchange resins is feasible at 423 K, though diethyl ether and di-n-octyl ether are also formed. The influence of the catalyst morphology on the reaction was checked by testing 22 acidic resins. Gel-type resins of low cross-linking degree yielded larger amounts of EOE, whereas macroreticular ones of high cross-linking degree gave mainly diethyl ether. Ethanol conversion depends strongly on the resin acid capacity, [H+], whereas 1-octanol conversion and selectivity to EOE depend on the specific volume of swollen polymer, Vsp, and the porosity. The variation of ethanol and 1-octanol conversion and selectivity to EOE with respect to both alcohols, as well as ether TOF, as a function of [H+]/Vsp suggest that a fraction of the active sites does not take part in the EOE synthesis reaction on highly cross-linked resins. Amberlyst 70 could be interesting in industry due to its selectivity to EOE and higher thermal stability.