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Gewählte Doctoral Thesis:

Patrizia Stutzenstein (2020): OPTIMIERUNG VON HYDROTHERMALER KARBONISIERUNG UND NACHFOLGENDER PROZESSWASSERAUFBEREITUNG FÜR DEN EINSATZ VON FLÜSSIGEN RESTSTOFFSTRÖMEN.
Doctoral Thesis - Institut für Verfahrens- und Energietechnik (IVET), BOKU-Universität für Bodenkultur, pp 100. UB BOKU obvsg

Data Source: ZID Abstracts
Abstract:
100 years after Bergius developed the hydrothermal carbonization (HTC) process it was taken up again as a research topic concerning the use of hydrochar as a solid fuel and fertilizer. The high amounts of process water with high organic load are the main limitation when it comes to HTC of sewage sludge for dewatering. Concerning hydrochar as fertilizer or soil amendment, its long-term effects in soil are not fully understood yet and the hydrochars composition varies to a high degree. According to these limitations the current work consists of two parts: the influence of the process parameters on hydrochar from anaerobic digestate as fertilizer/soil amendment and the fate of the process water. To asses the influence of the process parameters on the hydrochar design of experiments was used and the optimal process conditions were determined. The recovery of nutrients was maximized at T = 180°C, while the highest carbonization was reached at T = 220°C. To reduce the process waters’ organic load, it was subjected to wet oxidation. Nitrate compounds were used as oxidizing agents. A combination of HTC and wet oxidation can result in energetic and economic benefits. High operational costs during wet oxidation are caused by the oxidizing agent and the heating energy. Result show that iron nitrate is a possible alternative to oxygen as an oxidizing agent.

Betreuer: Pfeifer Christoph
1. Berater: Wenzel Walter

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