Dehydration of 1-pentanol to di-n-pentyl ether over ion-exchange resin catalysts

The dehydration reaction of 1-pentanol to di-n-pentyl ether (DNPE) and water in the liquid phase was studied at 110-180degreesC and 1 MPa on sulfonic styrene-divinylbenzene (S/DVB) copolymers and the perfluoroalkanesulfonic resin NR50. S/DVB-based catalysts were macroreticular and gel-type resins both sulfonated conventionally and oversulfonated. Macroreticular resins tested include resins whose working phase in catalysis is gel phase (i.e. Amberlyst-15 and Amberlyst-35) and XN 1010 whose working phase in catalysis is macropores surface. By comparing 1-pentanol conversion, selectivity to DNPE and initial reaction rates at 150degreesC it is concluded that gel-type S/DVB resins that swell moderately in the reaction medium, as CT-224, are the more suitable catalysts for the reaction. NR50, which is thermally stable up to 200degreesC, is the most selective catalyst tested but it is too much expensive for industrial use. Selectivity to DNPE decreases as temperature increases showing that side reaction of dehydration to I-pentene is more sensitive to temperature. Apparent activation energies for the dehydration reaction of 1-pentanol to DNPE were found to be about 100 kJ/mol. (C) 2002 Elsevier Science B.V. All rights reserved.