Highly selective conversion of bioethanol into lower olefins over Ni-ion loaded mesoporous silica catalysts

PETR 51

Kouji Kasai, k.kasai@org.res.titech.ac.jp, Teruki Haishi, Takashi Yamamoto, yamamoto@res.titech.ac.jp, and Masakazu Iwamoto, iwamoto@res.titech.ac.jp. Chemical Resources Laboratory, Tokyo Institute of Technology, 4259-R1-5 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan
Ni-ion loaded silica MCM-41 (Ni-M41) catalyzed selective ethanol conversion to lower olefins in the gas-phase flow-type reaction at an atmospheric pressure. The degree of ethanol conversion was ca. 100% at 673 K and the yields of ethene, propene, butenes, and acetaldehyde were 67, 16, 5, and 7%, respectively. No deactivation was observed during the continuous service of 10 h. The activity at 673 K was almost independent on the partial pressure of ethanol in the range 2.8 – 12.8 kPa. The coexistence of 0 – 25wt% of water in the gas-phase little affected the activity and selectivity of Ni-M41. The temperature or contact time dependence of the reaction concluded the reaction mechanism that ethanol was first dimerized to form diethylether, and resulting ether was further converted to ethene. Ethene was then dimerized to 1-butene, which was isomerized to 2-butenes. Finally, the metathesis of butenes and ethene resulted in the formation of propene.