The thermodynamic evaluation and process simulation of the chemical looping steam methane reforming of mixed iron oxides.

Steam reforming chemical looping (CL-SMR) using mixed iron oxides has the potential as an alternative to the current partial oxidation (POX) and steam reforming (SMR) processes. In this study, the use of FeMoO 4 , Fe 2 ZnO 4 and Fe 2 MnO 4 as oxygen carriers (OC) under the CL-SMR reaction scheme was proposed to overcome the current disadvantages of methane POX and SMR processes. This research is aimed at finding potential iron-based metal oxides for the production of syngas, which can be regenerated under favorable conditions in steam, while producing H 2 . Thermodynamic evaluation and process simulation of the CL-SMR reaction scheme using mixed iron-oxides was performed. Results indicate that FeMoO 4 , Fe 2 ZnO 4 and Fe 2 MnO 4 generated syngas at 750 °C, 730 °C and 600 °C, respectively. However, FeMoO 4 was not fully regenerated under favorable conditions, whereas Fe 2 ZnO 4 and Fe 2 MnO 4 were completely regenerated at 440 °C and 640 °C, respectively. Fe 2 MnO 4 showed the most favorable operating conditions among the studied OC towards the production of syngas. Preliminary experimental studies involved the synthesis of Fe 2 MnO 4 through a solid-state method using Fe 2 O 3 and MnO as precursors, which was characterized via XRD, while its redox performance was evaluated in a TGA CH 4 -H 2 O redox cycle, with reduction using CH 4 followed by the steam oxidation of OC. Results indicate that both reduction with methane and oxidation with water vapor using Fe 2 MnO 4 present reasonable reduction-oxidation rates to be used in the CL-SMR reaction scheme, verifying the feasibility of the theoretical study performed in the present investigation.