Attrition analysis of oxygen carriers in combustion appliances
Typ
Program
Kemiteknik 180 hp (högskoleingenjör)
Publicerad
2023
Författare
Sandell, Erik
Hertzberg, Mattias
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Carbon capture and storage (CCS) is a technology which can help reduce emissions
of CO2 into the atmosphere and thereby reduce environmental impacts. Ideally, this
is implemented by storing pure CO2 gas in stable geological structures. However,
this can be challenging to achieve due to emissions often being a mixture of CO2,
nitrogen and other byproducts. Chemical looping technology (CLT) can simplify
this process by implementing an oxygen-carrying material instead of air to supply
oxygen for the reaction. This removes nitrogen from the combustion process and
resulting exhausts which consists of CO2 and water. The oxygen-carrying material
used in CLT is often metal oxide particles circulated between two fluidized bed reactors.
The harsh conditions in the systems lead to attrition of the particles and
future implementation of this technology requires a material that is inexpensive,
well suited for the reactions, and with a long lifespan in the process.
Therefore, this study aims to analyze the attrition rate of different oxygen carrier
materials, namely, ilmenite, iron sand, mill scale, LD slag, and synthetic ilmenite.
Each material was also examined at different reduction degrees.
The most attrition-resistant materials were ilmenite and iron sand and the least resistant
were LD-slag and synthetic ilmenite. Most materials were not considerably
affected by reduction. Mill scale showed increased attrition in partially oxidised and
highly reduced states with cracks forming in the particles visible in SEM imagery.
Beskrivning
Ämne/nyckelord
attrition , fluidized bed , mechanical strength , chemical looping gasification , CLC , OCAC , combustion , oxygen carrier