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

• Acid resins are effective catalysts for ethyl octyl ether synthesis in liquid phase.
• Alcohols conversion increases with the acid capacity of the resins.
• Selectivity to ethyl octyl ether is greatly influenced by Vsp and [H+]/Vsp.
• The swollen morphology is a very significant factor in ethyl octyl ether synthesis.
• A fraction of acid sites does not take part in EOE synthesis in high cross-linked resins.

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.

The effect of ion-exchange resin morphology on the formation of ethyl octyl ether (EOE) from ethanol (EtOH) and 1-octanol (OcOH) at 423 K was studied on 22 catalysts. Diethyl ether (DEE) and di-n-octyl ether (DNOE) were also formed. The selectivity to the products (k) from each reactant (j  , in parentheses), Sjk, is a function of the number of acid sites per specific volume of the swollen polymer phase ([H+]/Vsp). This parameter could be used as a quick guide for selecting a resin catalyst for EOE synthesis.Figure optionsDownload high-quality image (105 K)Download as PowerPoint slide