Chemical looping combustion of Victorian brown coal using NiO oxygen carrier

Abstract

This study is part of a program assessing the suitability of chemical looping for direct combustion of Victorian brown coal. The performance of NiO as an oxygen carrier in presence of a dried Victorian brown coal was assessed during five alternating cycles of reduction and oxidation in a CO 2 environment using a TGA. The experiments indicate a 4.4–7.5% weight loss of the oxygen carrier per cycle. Preliminary SEM-EDX and FACTSAGE predictions also indicate weight loss, but not to the same extent. The percentage of combustion of coal achieved at the 5th cycle was approximately 67%. Cycle 2 showed maximum reactivity (during reduction) with a decreasing trend during the subsequent cycles. These initial experiments did not reveal much agglomeration between ash and NiO although longer duration experiments are required to explore this issue further.