Enhanced ethylene production from methane via rapid pulsed joule heating under non-oxidative conditions

초록

Non-oxidative upgrading of methane to value-added chemicals, such as ethylene, provides a carbon-efficient route for the petrochemical industry. However, conventional thermochemical processes operating under nearequilibrium continuous heating conditions are constrained by low productivity, inferior selectivity, rapid catalyst deactivation, and high energy consumption. Accordingly, in this study, a rapid pulsed Joule heating (RPJH) reactor was employed to convert methane to ethylene under non-oxidative conditions. Temporally modulated heating-quenching cycles, occurring in milliseconds, enhanced the ethylene selectivity by suppressing consecutive C-C couplings that led to coke formation. A simplified kinetic analysis supported that limiting the effective high-temperature exposure suppressed secondary dehydrogenation and carbon-growth pathways. Consequently, the RPJH system achieved a 47-fold higher electrical energy utilization than that in the case of conventional continuous heating. Coupling the RPJH reactor with a Pd/CeO2 hydrogenation zone further increased the ethylene yield by 1.3 times through the transformation of residual acetylene. This study demonstrates that the RPJH approach enables highly energy-efficient methane upgrading under dynamic electrified conditions and can be extended to other endothermic reactions requiring rapid thermal control.

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