Feature ArticleDehydration of 1-octanol to di-n-octyl ether in liquid phase with simultaneous water removal over ion exchange resins: Effect of working-state morphologies

•1-Octanol dehydration can be successfully performed in presence of acidic sulfonic ion exchange resins.•The catalytic behaviour changes when the polar compounds disappear from the reacting medium.•The best selectivity to di-n-octyl ether was found in gel-type resin and macroreticular with low crosslinking degree.•Macroreticular resins with medium or high crosslinking give good results in olefins formation.

The influence of the concentration of polar reactants and products on the working-state morphology of ion exchange catalysts has been investigated over different acidic ion-exchange resins for di-n-octyl ether (DNOE) synthesis from 1-octanol dehydration at 423-448 K and atmospheric pressure in a batch reactor equipped with a Dean & Stark device. By removing water formed 1-octanol conversion was practically complete; the olefin formation being the main secondary reaction. When 1-octanol is completely consumed the working-state morphology of ion exchange resins changes, which influences the selectivities towards products. At this point, for microporous resins all reactions stop while with macroreticular ones DNOE decomposes and significant amounts of olefin dimers appears. The best selectivity to DNOE was found in gel-type and macroreticular resins with low crosslinking degree. Macroreticular resins with medium or high crosslinking give good results in olefin formation.

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