High-Temperature Electrostatic Precipitation: Fundamentals, Phenomena and Feasibility

Bürger, Patrick

• Publisher: Cuvillier Verlag
• Year: 2023
• Print ISBN: 9783736978393
• eBook ISBN: 9783736968394
• Edition: 1

Particle separation from hot gases is a challenging task, especially for nanoparticles. Therefore, it is usually avoided by quenching the hot gas to conduct particle separation at a more convenient temperature. In these cases, valuable high-caloric heat is either not utilized at all or only inefficiently because of particle deposition on the heat exchanger surfaces. Valuable potential is thus wasted, as high-temperature processes are already an essential part of many industries and become increasingly relevant for other industrial sectors (e.g., pyrolytic processes in the circular economy). To reduce operating costs and environmental impact, the efficient use of resources (especially fossil fuels) is an absolute necessity.To tackle this pending problem, the concept of high-temperature electrostatic precipitation is investigated in this doctoral thesis. In an electrostatic precipitator, particles are charged by charge carriers produced in a corona discharge near the discharge electrode. Charged particles migrate due to the electric field and subsequently precipitate onto the collection electrode.This doctoral thesis clearly demonstrates the feasibility of nanoparticle removal from hot gases at up to 1073 K (800 °C) using electrostatic precipitation while presenting novel insights into the charge carrier properties and their distribution, the influence of thermionic emission on the operation of electrostatic precipitators, and the fundamentals of particle charging at high temperatures.

Table of contents

• Abstract
• Zusammenfassung
• Acknowledgements
• Table of contents
• List of abbreviations
• List of symbols and constants
• List of indices
• 1 Introduction
• 2 Fundamentals of electrostatic precipitation
• 2.1 General working principle
• 2.2 Corona discharge
• 2.3 Current-voltage characteristics
• 2.4 Particle charging and precipitation
• 2.5 Dust resistivity and the phenomenon of back corona
• 3 State of knowledge
• 3.1 Research on high-temperature electrostatic precipitation
• 3.2 Influence of pressure, temperature, and gas composition on ESPs
• 3.3 Thermionic emission of charge carriers
• 3.4 Modelling of corona discharge, particle charging and ESP operation
• 4 Description of the HT-ESP modelling approaches
• 4.1 Modelling approach – 0D model with radius-averaged values
• 4.2 Modelling approach – 1D model with charge carrier distribution
• 5 Preliminary experiments on electronic charging
• 5.1 Experimental setup and aerosol properties
• 5.2 Experimental results – current-voltage characteristics
• 5.3 Experimental results – separation efficiency and specific input of energy
• 5.4 Experimental and simulation results – particle charge
• 5.5 Outlook on the application of electronic charging
• 6 High-temperature electrostatic precipitation
• 6.1 Design considerations
• 6.2 Experimental setup and methodology
• 6.3 Experimental results – Current-voltage characteristics in air and flue gas
• 6.4 Experimental results – The separation of Fe2O3 nanoparticles
• 7 Simulation results
• 7.1 0D modelling approach with radius-averaged values
• 7.2 1D modelling approach with charge carrier distribution model
• 8 Discussion
• 8.1 Comparison of the experimental results to previous HT-ESP research
• 8.2 Additional insights gained from the experimental results
• 9 Conclusion
• 10 Future perspectives
• References
• List of own publications
• List of student works
• List of figures
• List of tables
• Appendix
• A.1 Relevant parameters for the simulation results described in chapter 5.4
• A.2 Relevant parameters for the simulation results described in chapter 7.1