(439d) Methane to Syngas By Chemical Looping Using FE-NI Oxygen Carriers: Reactor Design and Process Modeling
In this paper, we focus on a systems-level analysis of a methane-to-syngas process utilizing a chemical-looping fixed bed reactor with mixed Fe-Ni oxygen carrier material mentioned above. The overall system is designed to produce a desired flow rate and composition of syngas (as measured by the amount of CO and H2 and the ratio of CO/H2) from natural gas, while maximizing the yield and minimizing the overall energy consumption and CO2 emissions. The system involves heating of natural gas and air (for reduction and oxidation steps, respectively), chemical looping reactor with alternating redox cycles, downstream cooling of gases with heat recovery, steam generation from waste heat and optionally, using steam for electricity generation. The model involves a detailed chemical looping reactor model, incorporated into the systems-level model. Reactor-level mass and energy balance calculations will be performed to calculate the effect of operating conditions such as flow rates, solids conversion and temperature on the final product composition, selectivity and yields of different components and solids inventory. The systems-level model includes thermodynamic calculations of individual process components such as blowers, compressors and heat recovery equipment, as well as steam turbines. The overall system efficiency and CO2 emissions will be calculated for a design syngas flow rate and composition. Using sensitivity analysis on the process parameters, we will identify operating conditions required to improve process performance. The results will be compared to the conventional alternatives such as SMR and POX processes.