Vapor-phase ethyl tert-butyl ether (ETBE) synthesis was carried out in a fixed-bed flow reactor in the presence of three different kinds of heteropolyacid catalysts and four different kinds of ion-exchange resins. An activity change in the order of silicotungstic acid > tungstophosphoric acid (Dawson) > tungstophosphoric acid (Keggin) was observed with heteropolyacids and Amberlyst 15 > Lewatit K-2629 > Amberlyst 35 > Amberlyst 16 with ion-exchange resins. In ETBE synthesis over heteropolyacid catalysts, diethyl ether and ethylene (valuable petrochemical feedstocks) formation was also observed at temperatures above 368 K. DRIFTS analysis of pyridine-adsorbed samples revealed changes in acidity in accordance with activity. The significance of Brønsted acidity on the catalyst activity was illustrated. The inhibiting effect of water on ethanol adsorption and hence the catalyst activity was demonstrated by interpretation of experiments conducted using Amberlyst-15. Conversion of diluted ethanol to ETBE in the presence of Amberlyst 15 was found to be higher than the results obtained with pure ethanol using Amberlyst 16 and Amberlyst 35.

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in Wiley Online Library (wileyonlinelibrary.com).Vapor phase ethyl-tert-butyl ether (ETBE) production was conducted in the presence of Cesium salts of silicotungstic acid (Cs-STA), activated carbon supported silicotungstic acid (AC-STA), and activated carbon supported Cesium salts of silicotungstic acid (AC-Cs-STA) catalysts. Isobutene (IB) conversion to ETBE at 373 K were determined as 0.16 and 0.2 for STA and AC-STA catalysts on constant space time basis. This increase of activity is one of the highlights of this study considering that STA loading in AC-STA catalysts had been adjusted to 40%. IB conversion to ETBE obtained at 373 K in the presence of AC-STA catalyst was found to be close to equilibrium. Stability of the synthesized catalysts were tested by applying a washing procedure with ethanol. Repeated ETBE synthesis with thoroughly washed samples indicated quite stable and active catalyts.