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Chemical Looping Combustion technology involves circulating a metal oxide between a fuel zone where methane reacts under anaerobic conditions to produce a concentrated stream of CO 2 and water and an oxygen rich environment where the metal is reoxidized. Although the needs for electrical power generation drive the process to high temperatures, lower temperatures (600-800 C) are sufficient for industrial processes such as refineries. In this paper, we investigate the transient kinetics of NiO carriers in the temperature range of 600 to 900 C in both a fixed bed microreactor (WHSV ¼ 2-4 g CH 4 /h/g oxygen carrier) and a fluid bed reactor (WHSV ¼ 0.014-0.14 g CH 4 /h per g oxygen carrier). Complete methane conversion is achieved in the fluid bed for several minutes. In the microreactor, the methane conversion reaches a maximum after an initial induction period of less than 10 s. Both CO 2 and H 2 O yields are highest during this induction period. As the oxygen is consumed, methane conversion drops and both CO and H 2 yields increase, whereas the CO 2 and H 2 O concentrations decrease. The kinetics parameter of the gas-solids reactions (reduction of NiO with CH 4 , H 2 , and CO) together with catalytic reactions (methane reforming, methanation, shift, and gasification) were estimated using experimental data obtained on the fixed bed microreactor. Then, the kinetic expressions were combined with a detailed hydrodynamic model to successfully simulate the comportment of the fluidized bed reactor.

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