Continuous operation characteristics of chemical looping hydrogen production system

•300Wth TRCL unit was successfully operated for 13h using oxygen carrier (OC).•94% CH4 conversion was achieved in a moving bed operation of the fuel reactor.•High purity (>99.9%) H2 was generated in the steam reactor (SR) in TRCL operation.•Carbon-deposited OC generated additional H2, lowering purity of H2 in the SR.•The OC showed high durability and maintained its physical and chemical properties. Three-reactor chemical looping (TRCL) is a hydrogen and electricity production technology with inherent separation of carbon dioxide by use of the iron-based oxygen carrier particles. In this study, an integrated continuous operation test unit (300Wth) using 20wt% Fe2O3/ZrO2as an oxygen carrier was successfully operated over 13h. The average CH4 conversion was 94.15% in a fuel reactor in a moving bed mode. Nearly pure hydrogen (99.95%) was obtained from a steam reactor (SR). The steam conversion to H2 was around 63% of the thermodynamic limit in the SR. The hydrogen containing CO was observed from the SR when the carbon deposited particles were introduced into the SR. During the continuous operation, the oxygen carrier particles maintained its physical and chemical properties with high durability in the TRCL system.