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Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi" - DEI

Microwave breakdown for waste-to-fuel conversion

The seminar will be given by Zoya Popovic, Distinguished Professor, University of Colorado, Boulder, USA, as part of the course "Technologies and Applications of Wireless Power Transfer"

  • Date: 25 May 2022 from 15:00 to 17:00

  • Event location: Room 3.6, viale Risorgimento 2, Bologna, and online on Microsoft Teams

  • Access Details: Free admission

Link to virtual room

Abstract

Microwave heating of waste results in breakdown that can lead to conversion of waste to fuel, and can be done using high-power magnetron sources. This talk presents a heating cavity for waste processing based on volumetric solid-state power combining. Heating waste mixtures with microwave energy rather than incineration results in faster breakdown and can therefore be more efficient. Here we address heating of mixed food waste materials with widely differing and temperature-dependent conductivities and permittivities. Uniform heating is desired, here accomplished with mode mixing within the loaded cavity, and by spatial power combining of solid-state power amplifiers (SSPAs). We present a loaded cavity heating comparison of two circuit-combined and spatially-combined 2.45GHz 70-W efficient GaN SSPAs with controlled relative phase. We show that the heating efficacy is improved by volumetric combining inside the waste loading where the two PAs are load-modulated through coupling inside the cavity. We investigate the temperature changes in several locations and for several common waste materials, and compare FEM electromagnetic field simulations with an analytical thermal model to FDTD multi-physics simulations that incorporate thermal dependence of material properties.

About the speaker

Zoya Popovic is a Distinguished Professor and the Lockheed Martin Endowed Chair in Electrical Engineering at the University of Colorado, Boulder. She obtained her Dipl.Ing. degree at the University of Belgrade, Serbia, and her Ph.D. at Caltech. She has graduated over 68 PhDs and currently advises 18 doctoral students. Her research interests are in high-efficiency power amplifiers, microwave and mm-wave circuits for communications and radar, medical applications of microwaves, quantum sensing and metrology, and wireless powering. She is a Fellow of the IEEE and the recipient of two IEEE MTT Microwave Prizes for best journal papers, the White House NSF Presidential Faculty Fellow award, the URSI Issac Koga Gold Medal, the ASEE/HP Terman Medal and the German Alexander von Humboldt Research Award. She was named IEEE MTT Distinguished Educator in 2013. She was elected a foreign member of the Serbian Academy of Sciences in 2006, and a Member of the US National Academy of Engineering in 2022.