Doctoral Dissertation
Power conversion for electrified thermochemical reaction systems
Electrification of heating can both decarbonize hard-to-abate heavy industrial processes and also enable more modular, safer, and higher performance processes. Across all of heavy industry, the chemicals processing and manufacturing industry is the largest consumer of heat. As such, among the various electrified heating technologies, this dissertation focuses on inductively heated thermochemical reaction systems, as energy transduction through magnetic induction is inherently scalable due to its ability to deliver heat wirelessly and volumetrically. We begin by introducing a metamaterial-based reactor operating the reverse water-gas shift (RWGS) reaction, encompassing both the power electronics and reactor design. Specifically, we discuss the operation within an effective medium framework for co-design. We also present the design and implementation of a 1 kW, 6.78 MHz push-pull class-EF2 power amplifier achieving a peak drain efficiency of 94% with a synchronous resonant gate drive for SiC MOSFETs. The power amplifier is used to drive the reactor for the RWGS reaction (H2 + CO2 → H2O + CO). Next, we investigate switch-mode power conversion techniques for inductively heated fluidized beds, which present a dynamically varying load. We demonstrate the design and implementation of a 13.56 MHz class-E power amplifier achieving 92% efficiency at full load, capable of maintaining zero-voltage switching (ZVS) across the operating range. We then introduce a new class of chemical reactors that leverage supermodes to generate arbitrary axial temperature profiles within the susceptor. By integrating model predictive control (MPC), these systems are able to maintain stable, near-isothermal temperature distributions under intermittent electricity availability or maximize profits under varying electricity prices. Following this, we present two high-frequency power amplifier designs. The first is a 50 MHz GaN-based class-[phi]2 amplifier utilizing a CMOS-based resonant gate driver, achieving 90% drain efficiency, which is the highest reported efficiency at this frequency and power. The second is a series-stacked class-[phi]2 amplifier capable of high-speed power modulation, achieving modulation speeds on the order of 0.1 [mu]s. Finally, we provide a broader perspective on the principles and processes underlying electrified thermochemical reaction systems. We generalize thermochemical loads as resistive, capacitive, and inductive elements, and discuss associated power conversion strategies and electricity distribution architectures for large scale electrified chemical production.