Degree

Doctor of Philosophy (PhD)

Department

Cain Department of Chemical Engineering

Document Type

Dissertation

Abstract

Heterogeneous catalysis has been and continues to be highly studied due to being one of the cornerstones of the chemical industry. With an increasing demand for chemicals and rising costs, there is a growing need to adapt to changing feed stocks and increase production efficiency. Polymers, oxygenates, and other chemical intermediates are predicted to experience continued growth, corresponding to an increased need for olefines. Due to the abundance of shale gas, researchers and producers are interested in meeting this demand via the dehydrogenation of light alkanes.

While dehydrogenation catalysts are a valuable tool in olefin production, selectivity and deactivation remain a challenging problem. Pt has become the standard for dehydrogenation catalyst metal. Although highly active, the high cost and its affinity to coke have led researchers to devote significant time to optimizing the platinum dehydrogenation catalyst. Cheaper alternatives to Pt are being explored, with V as a possible candidate, but quick deactivation makes it challenging to implement.

New thinking has led to substituting traditional heating for new localized heating methods. By implementing radio-frequency induction heating (RF-IH), alternating magnetic fields can provide the energy for magnetic catalysts to heat locally. This approach has been adapted for multiple reactions such as pyrolysis, reforming of methane, and propane dehydrogenation, which displayed evidence of activity and selectivity improvements. Also, low-cost materials such as iron oxide are sufficient susceptors to reach the necessary temperatures. What is currently missing is a comparison to equivalent thermal reactions that provide insight into the effects of RF-IH.

This need is addressed by exploring the hydrogenation of oleic acid utilizing a magnetic catalyst. Compared to thermal heating, RF-IH displayed improved activity that could be attributed to thermal effects. However, the improved selectivity and reduction of coke-like products suggest possible non-thermal effects. These results suggest applying RF-IH to more challenging reactions. A magnetic core-shell-shell catalysis was synthesized to mimic a typical n-butane dehydrogenation catalyst. RF-IH’s improved selectivity while maintaining similar selectivity to the thermal runs further suggests the possibility of non-thermal effects. These results provide the motivation to continue investigating the effects of RF-IH and its benefits to heterogeneous catalysis.

Date

11-14-2023

Committee Chair

Dooley, Kerry M.

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