Due to the gradual increase of the greenhouse effect, the emissions of CO2 need to be limited. In addition, as the concerns for air pollution increase, a clean combustion process becomes important. Chemical looping combustion (CLC) provides efficient power production and enables the efficient capture of CO2. In CLC two interconnected reactors are used, the fuel reactor (FR) and the air reactor (AR). Most of the corrosion studies so far concerning CLC have focused on conditions typical for the fuel reactor.
However, little is known about the corrosion in the AR. In this thesis, the behaviour of KOH and its effects on corrosion in the AR was investigated through experiments. Firstly, the melting point of KOH was determined by TGA. Corrosion experiments were carried out at 345 ℃, 380 ℃ and 415 ℃, with air and synthetic air without CO2, both below and above the melting point. Finally, the corrosion rate was determined,
and the corrosion products were analysed by SEM-EDX. The melting point of KOH was determined to be 363 °C by TGA measurements and thermodynamic calculations. The work revealed that KOH induces corrosion on both carbon steel and 10CrMo. The extent of the corrosion depended on the temperature and gas composition. The higher the temperature, the higher the corrosion, within a temperature range of 345-415 °C. Synthetic air without CO2 showed higher corrosion than the experiments conducted in air. In the experiments in air, some KOH converted to K2CO3 by the CO2 in the air
leading to a less corrosive deposit. The work showed that the presence of KOH on the steel surface in the air reactor can lead to excessive corrosion
