(672f) On the Dynamics of Electrification of Heterogeneous Catalytic Reactors

The production of high-volume chemicals, like hydrogen, ammonia, and small olefins need significant energy, traditionally met through combustion of natural gas, which yields considerable greenhouse gas emissions. In response, electrification methods such as Joule heating, are emerging as a potential alternative, providing means for rapid heating and greater control over kinetics. Despite the early development of mathematical theory underlying periodic control, experimental demonstrations have been limited, largely due to the significant inertia and slow intrinsic dynamics associated with such systems. Furthermore, the development of a comprehensive modeling framework capable of accommodating rapid, Joule heating with nonlinear temperature control functions, for catalytic reactors employing detailed microkinetic models, remains outstanding. Experimental demonstrations have also remained rare. We have recently demonstrated the impact of dynamic electrification.^1,2

This study seeks to assess the impact of dynamic operation via rapid pulse heating, leveraging state-of-the-art experimental technology and computation. Our results demonstrate a nuanced understanding of how Joule heating can boost system performance via forced time-varying input perturbation, leveraging Joule heating setups and theoretical advancements. Our fundamental modeling study reveals improvements in simple gas-phase systems using prototypical reactions, without requiring additional nonlinearities beyond those inherent in Arrhenius rate laws. Our modeling framework reveals general guidelines for leveraging pulsing to optimize system performance depending on the characteristics of a given reaction. Moreover, we elucidate the interplay between kinetics and thermodynamics in endothermic shale gas utilization chemistries through our experimental findings.

Overall, our findings serve as a foundation for future investigations into dynamic electrification as a promising alternative to traditional heating methods towards achieving enhanced performance.

References

1. Q. Dong, et al. Programmable heating and quenching for efficient thermochemical synthesis. Nature 605(7910), 470 (2022). DOI:10.1038/s41586-022-04568-6.
2. K. Yu, et al. Dynamic Electrification of Dry Reforming of Methane with In Situ Catalyst Regeneration. ACS Energy Letters, 1050-1057 (2023). DOI:10.1021/acsenergylett.2c02666.