TY - THES

T1 - Corrosion of passive alloys in aqueous solutions at different pH values

AU - Todeschi, Federico

N1 - no embargo

PY - 2023

Y1 - 2023

N2 - Now a day with the problems of the climate change and the high price of the fossil materials, it is very important found new more eco-friendly way to produce plastic and fuel in addiction to improve circularly economy.ReOil is a process developed by OMV (Österreichische Mineraölverwaltung) that want to solve this problem by the production of synthetic crude oil from the plastic wast by pyrolysis process.The products exit from the pyrolysis process couldn’t be directly distilled to produce the refinery products, but they need a series of washing steps to remove unreacted materials and the unwanted products. In the washing steps are use aggressive solutions at the different pH.In this thesis are analyzed nine different materials two nickel alloys (2.4605, 2.4819) and seven stainless steel (1.4404, 1.4539, 1.4562, 1.4462, 1.4410, Sanicro 35, Böhler P569) in the washing solution from the OMV ReOil plant, to select the most correct material for each washing step. Acidic wash, neutral wash, alkaline wash are the name of the ReOil washing solutions delivered from OMV sampled from the working line in the three washing steps and that are use as electrolyte.In this thesis the investigate materials are valuated by potentiodynamic measurements at 50 and 90°C, immersion test and autoclave test, and also to have a more meaningful results the materials are also tested in artificial electrolytes, at different pH from 1 to 4, similar to the OMV acidic wash solution, because this solution is the most critical electrolyte from the delivered from OMV.In the conclusion of the thesis are shown the results of all that tests and the material recommended for each steps, that can be summarized in: Sanicro 35 for acidic wash, 1.4410 for neutral wash and 1.4404 for the alkaline wash.

AB - Now a day with the problems of the climate change and the high price of the fossil materials, it is very important found new more eco-friendly way to produce plastic and fuel in addiction to improve circularly economy.ReOil is a process developed by OMV (Österreichische Mineraölverwaltung) that want to solve this problem by the production of synthetic crude oil from the plastic wast by pyrolysis process.The products exit from the pyrolysis process couldn’t be directly distilled to produce the refinery products, but they need a series of washing steps to remove unreacted materials and the unwanted products. In the washing steps are use aggressive solutions at the different pH.In this thesis are analyzed nine different materials two nickel alloys (2.4605, 2.4819) and seven stainless steel (1.4404, 1.4539, 1.4562, 1.4462, 1.4410, Sanicro 35, Böhler P569) in the washing solution from the OMV ReOil plant, to select the most correct material for each washing step. Acidic wash, neutral wash, alkaline wash are the name of the ReOil washing solutions delivered from OMV sampled from the working line in the three washing steps and that are use as electrolyte.In this thesis the investigate materials are valuated by potentiodynamic measurements at 50 and 90°C, immersion test and autoclave test, and also to have a more meaningful results the materials are also tested in artificial electrolytes, at different pH from 1 to 4, similar to the OMV acidic wash solution, because this solution is the most critical electrolyte from the delivered from OMV.In the conclusion of the thesis are shown the results of all that tests and the material recommended for each steps, that can be summarized in: Sanicro 35 for acidic wash, 1.4410 for neutral wash and 1.4404 for the alkaline wash.

KW - Corrosion

KW - stainless steel

KW - acidic environment

KW - neutral environment

KW - alkaline environment

KW - nickel alloys

KW - immersion test

KW - autoclave test

KW - Potentiodynamic measurement

KW - duplex stainless steel

KW - sanicro

KW - Korrosion

KW - Edelstahl

KW - saures Milieu

KW - neutrales Milieu

KW - alkalisches Milieu

KW - Nickellegierungen

KW - Immersionstest

KW - Autoklaventest

KW - potentiodynamische Messung

KW - Duplex-Edelstahl

KW - Sanicro

U2 - 10.34901/mul.pub.2024.022

DO - 10.34901/mul.pub.2024.022

M3 - Master's Thesis

ER -