(104d) Carbon Membrane Reactor for Alkane Dehydrogenation

Non-oxidative alkane dehydrogenation is an important technology for on-purpose production of alkene and hydrogen (H₂), commonly used as building blocks in the chemical industry. The reaction, however, faces three major challenges: the single-pass conversion is limited by thermodynamics, the catalyst deactivates quickly through sintering and/or coking, and the process heat from fossil fuel firing produces copious CO₂ emissions. In this talk, we present our recent work on carbon membrane reactor that integrate a carbon molecular sieve membrane and a zeolite supported metal catalyst to achieve high alkane conversion, high catalyst stability and low CO₂ emissions. These effects originate from lowering reaction temperature by using catalysts with low threshold temperature and up-shifting reaction equilibrium far beyond thermodynamic limit by H₂-permeable carbon membrane. Using propane (C₃H₈) dehydrogenation as an example, the membrane reactor enables ~37% C₃H₈ single-pass conversion (3-fold higher than equilibrium conversion) and >95% C₃H₆ selectivity at 450°C (i.e., ~150°C lower than typical commercial condition), and ~20% reduction in CO₂ emissions. Further, we demonstrate that the technology applies to ethane dehydrogenation, establishing a new paradigm toward electrified green and sustainable chemical manufacturing.