Chemical Looping Combustion (CLC) of two Victorian brown coals – Part 2: Assessment of interaction between CuO and minerals inherent in coals during multi cycle experiments

Abstract

This paper is part two in a series of two papers on chemical looping combustion using Victorian brown coal. Part one described the assessment of interaction between CuO and minerals inherent in two Victorian brown coals during one cycle CLC experiments with CuO. This second paper describes the assessment of performance of CuO with the same two coals but in multicycle operations. The chemical and physical properties of CuO, such as reactivity and mass loss rate, have been investigated in five consecutive reduction and oxidation cycles with two brown coals. The experimental results are compared with thermodynamic simulation results using FACTSAGE. The percentage of combustion achieved using CuO and CuO conversion during multicycle operation are reported. Also investigated is the carbon deposition on CuO during CLC with both the coals during five cycles operation.The extent of Loy Yang coal combustion and reoxidation of CuO resulted in less than 0.3% weight loss per cycle. However, this value was around 2% per cycle for CuO–Morwell coal mixture reduction and re-oxidation of CuO in air. The high reactivity and conversion rate with high conversion of CuO was observed during cyclic operation. The percentage of combustion at the end of the 5th cycle with CuO was more than 97% with Loy Yang coal, as compared to 91% with Morwell coal. Fresh oxide particles and solid residues were characterized using SEM to illustrate surface morphological changes due to combustion.