Carburization behaviour of Mn–Cr–O spinel in high temperature hydrocarbon cracking environment

Abstract

This investigation was initiated to understand chemical stability of MnCr 2O 4 spinel in high temperature carbonaceous reducing environments. MnCr 2O 4 and Cr 2O 3 were comparatively tested at 1050 °C for various time periods up to 100 h. It was found that the resistance to carburization of MnCr 2O 4 is better than Cr 2O 3, and the carbide conversion rate of MnCr 2O 4 was slower than Cr 2O 3. The more porous structure of Cr 2O 3 than MnCr 2O 4 after carburization was observed. MnCr 2O 4 spinel was proved to be more stable than Cr 2O 3 in carburizing environments according to the results of thermodynamic calculation. After further carburization, coke formation was built up in MnCr 2O 4 due to the catalytic effect of Mn 7C 3 converted from MnO.