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Abstract
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For syngas production, the combustion of fossil fuels produces large amounts of CO2 as a greenhouse gas annually which intensifies global
warming. In this study, chemical looping combustion (CLC) has been utilized for the elimination of CO2 emission to atmosphere during
simultaneous syngas production with different H2/CO ratio in steam reforming of methane (SR) and dry reforming of methane (DR) in a
CLC-SR-DR configuration. In CLC-SR-DR with 184 reformer tubes (similar to an industrial scale steam reformer in Zagros Petrochemical
Company, Assaluyeh, Iran), DR reaction occurs over Rh-based catalysts in 31 tubes. Also, SR reaction is happened over Ni-based catalysts
in 153 tubes. CLC via employment of Mn-based oxygen carriers supplies heat for DR and SR reactions and produces CO2 and H2O as raw
materials simultaneously. A steady state heterogeneous catalytic reaction model is applied to analyze the performance and applicability of the
proposed CLC-SR-DR configuration. Simulation results show that combustion efficiency reached 1 at the outlet of fuel reactor (FR). Therefore,
pure CO2 and H2O can be recycled to DR and SR sides, respectively. Also, CH4 conversion reached 0.2803 and 0.7275 at the outlet of SR and
DR sides, respectively. Simulation results indicate that, 3223 kmol·h?1 syngas with a H2/CO ratio equal to 9.826 was produced in SR side of
CLC-SR-DR. After that, 1844 kmol·h?1 syngas with a H2/CO ratio equal to 0.986 was achieved in DR side of CLC-SR-DR. Results illustrate
that by increasing the number of DR tubes to 50 tubes and considering 184 fixed total tubes in CLC-SR-DR, CH4 conversions in SR and DR
sides decreased 2.69% and 3.31%, respectively. However, this subject caused total syngas production in SR and DR sides (in all of 184 tubes)
enhance to 5427 kmol·h?1. Finally, thermal and molar behaviors of the proposed configuration demonstrate that CLC-SR-DR is applicable for
simultaneous syngas production with high and low H2/CO ratios in an environmental fr
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