Name
Tandem redox catalysts boost ethylene production by integrating ethane dehydrogenation with selective hydrogen combustion
Date & Time
Wednesday, October 2, 2024, 10:00 AM - 10:20 AM
Description

Commercial ethylene production from thermal cracking of naphtha or light alkanes has long been criticized for the intensive energy consumption, high CO2 emission, severe coke formation, and limited single-pass conversion due to thermodynamic constraints. Herein, tandem redox catalysts were adopted for intensified ethylene production via chemical looping oxidative dehydrogenation (CL-ODH) of ethane. The redox catalysts consist of Co/HZSM-5 serving as the ethane dehydrogenation catalyst and Ce0.02Bi0.98O acting as the selective hydrogen combustion (SHC) catalyst. The SHC capability of the Ce0.02Bi0.98O catalyst was first evaluated in the mixture of either H2/C2H6 or H2/C2H4, showing over 98% hydrogen combustion while negligible C2H6/C2H4 conversion (< 2%) at 600 ºC. When only the Co/HZSM-5 was used for CL-ODH of ethane, high ethane conversion (94%) can be achieved but significant coke (at 63% selectivity) was generated due to overcracking. By integrating the Co/HZSM-5 with Ce0.02Bi0.98O via mechanical mixing, 39% of ethane conversion at 80% of ethylene selectivity was eventually attained at 600 ºC. This result outperforms most of the redox catalysts (under similar reaction conditions) reported in literatures. The long-term stability of the redox catalysts was assessed for 100 reaction cycles, which showed no obvious activity degradation. Comparative experiments indicate that near 90% of in-situ hydrogen combustion can be achieved by tuning the intimacy between ethane dehydrogenation sites and selective hydrogen combustion sites of the catalysts. The insights gained herein can provide useful knowledge for the development of efficient tandem redox catalysts to intensify ethylene production in CL-ODH of ethane.

Location Name
Max Bell 252
Full Address
Banff Centre for Arts and Creativity
107 Tunnel Mountain Dr
Banff AB T1L 1H5
Canada
Session Type
Oral Presentation
Abstract ID
1063