Process simulation and thermodynamic analysis of a chemical looping combustion system using methane as fuel and NiO as the oxygen carrier in a moving-bed reactor

Abstract

This study provides a comprehensive evaluation and sensitivity analysis of the methane chemical looping combustion process in Aspen Plus, using a micro-reactor system and nickel oxide supported by alumina as the oxygen carrier. The effect of various parameters and limitations was investigated and thermodynamic evaluations made so that the outcomes of this study should be beneficial for scaling up the CLC process using a nickel-based oxygen carrier. By varying the fuel reactor temperature from 700 °C to 1200 °C, the maximum achievable conversion of methane to carbon dioxide was estimated to be 61.19%. The effect of the fuel reactor pressure (20 bar to 40 bar) on the conversion of methane remained constant. However, the reduction of oxygen carrier with hydrogen was slower than methane when the fuel reactor pressure varied from 20 bar to 40 bar. Once the entering carriers flow rate varied (1 ×10-8 kmol/s to 1 kmol/s), methane conversion decreased from 100% to nearly 50%. However, this study’s results showed a good agreement with the reported experimental results in the literature.