Productivity Enhancement for the Oxidative Coupling of Methane in Adiabatic Layered-Bed Reactors

Abstract

Ethylene production via oxidative coupling of methane (OCM) in adiabatic packed-bed reactors is a promising route within the context of natural gas valorization. However, the high exothermicity of OCM imposes low inlet temperatures and, hence, low space-time yields. Layered-bed reactors are proposed in the present work as a potential alternative to mitigate this issue. In this modeling investigation, a first layer of active Sr/La2O3 catalyst is followed by a second layer of more selective NaMnW/SiO2 catalyst. Optimized bed compositions and operating conditions are shown to lead to up to a 10 times higher space-time yield compared to a single-catalyst bed. The achieved values of ca. 15 molC2+ s–1 m r –3 are comparable to conventional values from steam cracking of ethane, suggesting layered-bed adiabatic configurations as a promising way forward for intensified ethylene production via OCM.

Computational Study on the Effect of Thermal Boundary Conditions and Axial Aspect Ratio on Catalytic Oxidative Coupling of Methane

“…In industry, packed-bed reactors are widely used for heterogeneous catalysis including OCM reactors. − Especially in the case of highly exothermic reactions, low reactor-to-catalyst pellet diameter reactors and pellet string reactors are used. , Heat must be efficiently transferred through the reactor to efficiently complete the complex exothermic–endothermic reaction set without hotspot formation. To achieve lower energy usage, higher yield, smaller reactor capital cost, and other aspects of sustainable processing, it is prudent to understand, quantify, and control the physical and chemical phenomena occurring in plug flow reactors.…”