A Corrosion Study on a Novel FeCrAl Alloy for Water Wall Applications in Waste-Fired Boilers
| dc.contributor.author | Rödbro, Joachim | |
| dc.contributor.department | Chalmers tekniska högskola / Institutionen för kemi och kemiteknik | sv |
| dc.contributor.department | Chalmers University of Technology / Department of Chemistry and Chemical Engineering | en |
| dc.contributor.examiner | Liske, Jesper | |
| dc.contributor.supervisor | Lindmark, Hampus | |
| dc.date.accessioned | 2024-08-27T14:23:27Z | |
| dc.date.available | 2024-08-27T14:23:27Z | |
| dc.date.issued | 2024 | |
| dc.date.submitted | ||
| dc.description.abstract | Today, as society faces greater challenges regarding waste handling, the European commission have putting out directives for waste handling called “waste hierarchy”. This includes converting waste to energy. There are several technologies available of which one is the so called CFB boiler, Circulating Fluidized Bed Boiler. In this boiler the waste fuel is combusted and the heat in the flue gas is used to heat water into steam inside heat exchangers. The steam can generate electricity via a steam turbine and the heat can be used in a district heating net. The heat exchangers, e.g., superheater tubes and water walls, inside the boiler is made of metallic components. One problem a CFB boiler is facing is that the water wall heat exchangers get exposed to both heavy metals and chlorine originating from the waste. This accelerates the corrosion rate of the water wall materials. The material is usually of low-alloyed steel and a method for increasing the corrosion resistance is to put a layer of Ni-based alloy on top of the material, a so called coating. However, because of the high cost of the Ni-based coating other cheaper materials are currently under consideration. One of these is Kanthal EF101. The aim for thesis is to evaluate the corrosion rate for Kanthal EF101 when exposed to two heavy metal compounds, PbO or PbCl2 and compare it with a Ni-based alloy (Alloy625) and low-alloyed steel (T22). For this, multiple factors must be considered for example thermodynamics, kinetics, the principles of oxide formation and influence of PbO and PbCl2. The experiments in this project were divided into three steps; sample preparation, exposure and analysis. All exposures were performed with a laboratory environment simulating the water-wall in a waste fired boiler and lasted for 168 hours. The analysis used SEM and EDX instruments to create backscattered images for classification of elements on the sample and investigate the oxide growth. The results showed that EF101 has similar good protection properties as the Ni-based alloy Alloy625 and much greater protection than the low-alloyed steel T22. The presence of chlorine increased the corrosion rate of the samples, as the samples exposed to PbCl2 was severely more corroded than the corresponding samples exposed to PbO. | |
| dc.identifier.coursecode | KBTX11 | |
| dc.identifier.uri | http://hdl.handle.net/20.500.12380/308492 | |
| dc.language.iso | eng | |
| dc.setspec.uppsok | PhysicsChemistryMaths | |
| dc.title | A Corrosion Study on a Novel FeCrAl Alloy for Water Wall Applications in Waste-Fired Boilers | |
| dc.type.uppsok | M2 | |
| local.programme | Kemiteknik 180 hp (högskoleingenjör) |