Catalytic limitations on alkane dehydrogenation under H₂deficient conditions relevant to membrane reactors

Abstract

Experimentally simulating H2 removal during catalytic ethane dehydrogenation indicates that ethylene yields may be limited due to coking reactions, and accelerated coking causes more rapid catalyst deactivation.

The Interplay between Process Conceptualization and Experimental Research─Accelerating and Guiding Catalysis to Process Breakthroughs

“…It is worthwhile to highlight that >96% of the H 2 needs to be removed to shift equilibrium to the ethylene yield targets. Experimental work has been recently reported to better understand the consequences to the catalyst from operating conditions demanded by the membrane reactor concept, including higher olefin and lower H 2 partial pressures . These results indicated that achievement of equilibrium conversion may not be feasible with the current catalysts in use.…”

Recent Progress in Metal-Molecular Sieve Catalysts for Propane Dehydrogenation

“…The permeation experiments indicate the H 2 /C 3 H 8 separation factor increases with higher temperature and reaches >3 at 600 °C . On the other hand, the undesired cracking and coke reactions would be also accelerated under the H 2 -deficient atmosphere . In this context, integrating a H 2 -permeable membrane and appropriate active species is promising for improving the propylene yield in industrial applications.…”

“…Potential active species for this technology are Pt and Co, which show higher propylene selectivity and anticoking capacity compared to other elements as summarized in Tables –. Moreover, future H 2 -permeable membrane PDH technology should carefully optimize the H 2 -permeable levels, which not only assess the thermodynamic advantages due to H 2 removal but also consider the cracking and coking reactions in H 2 deficient conditions …”

“…155 On the other hand, the undesired cracking and coke reactions would be also accelerated under the H 2 -deficient atmosphere. 158 158 In addition to activity, the cost and toxicity of catalysts were also crucial for industrial applications. Thus, the development of green and low-cost methods for the synthesis of efficient molecular sieve-based catalysts is always an endless story.…”

Porous Single‐crystalline Centimeter‐sized α‐Al2O3Monoliths for Selective and Durable Non‐oxidative Dehydrogenation of Ethane

“…The shale gas revolution has significantly lowered the cost of C 2 H 6 and stimulated great interest in exploiting its potential as a direct feedstock for C 2 H 4 production in recent years. Non-oxidative dehydrogenation of C 2 H 6 to C 2 H 4 has been considered as the potential route of the highest efficiency of carbon utilization; [5][6] however, it is still lack of efficient catalysts with high activity and stability in the high-temperature operation. As a case study, we therefore fabricate PSC α-Al 2 O 3 monolith with oxygen defects and explore their functionality towards non-oxidative dehydrogenation of C 2 H 6 to C 2 H 4 reaction.…”