Public Defence: Gudny Øyre Flatabø

Flatabø is defending her in PhD degree in process, energy, and automation engineering. Her thesis explores processes for more sustainable treatment of organic waste like sewage sludge.

30 Oct

Practical information

  • Date: 30 October 2024
  • Time: 10.00 - 15.30
  • Location: Porsgrunn, Room A-271 and Zoom
  • Download calendar file

    • Link to digital participation: Zoom.

    Programme

    10.00 Trial lecture: Enhancing Anaerobic Digestion Efficiency and Sustainability Through Biochar Integration: Mechanisms and Applications.

    12.30 Public defence: "Organic Waste Pyrolysis and Its Integration with Anaerobic Digestion: Emissions, Pollutants, and Methane Production".

    Evaluation committee

    • First opponent: Werner Fuchs, professor, BOKU University, Austria.
    • Second opponent: John Morken, professor, NMBU, Norway.
    • Administrator: Leila Ben Saad, associate professor, Universitety of Sout-Eastern Norway.

    Supervisors

    • Main supervisor: Wenche Hennie Bergland, associate professor, Universitety of Sout-Eastern Norway.
    • Co-supervisors: Carlos Dinamarca, professor II, Universitety of Sout-Eastern Norway and Dr Pål Jahre Nilsen from Scanship.
Any questions?

Gudny Øyre Flatabø is defending her thesis for the degree philosophiae doctor (PhD) at the University of South-Eastern Norway. portrett av doktorgradskandidat gudny ø flatabøThe doctoral work has been carried out at the Faculty of Technology, Natural Sciences and Maritime Sciences.

You are welcome to join both her trial lecture and public defence.

Summary

This thesis explores a new way to manage organic waste, especially sewage sludge, a type of organic waste from wastewater treatment plants. Sewage sludge often contains harmful pollutants that are tough to break down, like PFAS, PCBs, and dioxins.

The research focuses on combining two processes:

1. Pyrolysis
This process involves heating dry sewage sludge (or other dry organic materials) at high temperatures without oxygen, turning it into biochar—a charcoal-like substance. Pyrolysis not only reduces harmful pollutants like PFAS, PCBs, and dioxins by over 95% in the biochar compared to the original material, but also locks away carbon. By trapping carbon in a stable form, biochar helps avoid carbon dioxide releasing into the atmosphere, being a potential tool to reduce climate change.

2. Anaerobic Digestion 
Using microorganisms to break down wet organic material in the absence of oxygen, producing biogas (mainly methane) that can be used to replace fossil fuels.

While pyrolysis effectively reduces the pollutants in the solid biochar, the liquid byproduct (pyrolysis condensate) still contains high levels of harmful substances. This means we need to handle this liquid carefully to prevent environmental contamination.

By integrating pyrolysis and anaerobic digestion, we can recover energy and nutrients from sewage sludge and lessen its impact on the environment. However, challenges remain in figuring out how to manage the leftover pollutants in the pyrolysis condensate, as we may risk spreading these into water bodies.

The practical takeaway from this research is that using both pyrolysis and anaerobic digestion together could lead to more sustainable ways to treat organic waste like sewage sludge. It points the way toward waste management strategies that not only dispose of waste but also recover valuable resources and protect the environment.