Comparison of doped ZSM-5 and ferrierite catalysts in the dehydration of bioethanol to ethylene in a flow reactor

This study describes the performance of ten zeolite catalysts, doped with various elements, in the dehydration of bioethanol. As acidic catalysts are known as profitable for this reaction, ZSM-5 and ferrierite (FER) based catalysts were selected to use. The synthesized catalysts were characterized by different analytical methods (XRF, XRD, DRIFT, N2-physisorption and TPD-NH3). A high space velocity (15 h−1) and low temperature (220 °C) were used to study the differences on catalyst activity. The Ti-deZSM-5 was the most active catalyst with 48% conversion. Subsequent the screening tests were carried out in a flow micro-reactor at different operating conditions (220–250–280 °C and WHSV 7–11–15 h−1). Ti-deZSM-5 showed the highest bioethanol conversion (96%) and selectivity to ethylene (88%) at 280 °C and WHSV of 7 h−1 while in the case of FER it resulted in very small or no selectivity to ethylene. The results show that catalysts from the ZSM-5 group are more suitable for the dehydration of bioethanol to ethylene than FER catalysts.