Techno-economic assessment of a chemical looping reforming combined cycle plant with iron and tungsten based oxygen carriers

Chemical looping reforming (CLR) is an efficient technology that transforms hydrocarbons into hydrogen (H2) and carbon dioxide (CO2) with the use of an oxygen carrier. The three-reactor CLR (TRCLR) uses natural gas as fuel similar to a conventional steam-methane reforming (SMR) process. In the current study, two of the most suitable oxygen carriers with base metals iron (Fe) and tungsten (W) are investigated. The model of the CLR unit integrated with a combined cycle power plant is developed using Aspen Plus. The results show that the W-based TRCLR plants are 4 %-points more efficient in terms of H2 production efficiency. In terms of electrical efficiency, the Fe-based TRCLR plant produces excess power at an efficiency of 1.6% whereas the W-based plant requires 3% of extra power from the grid. As a result, the Fe-based plant is 2.6 %-points more efficient than the W-based plant in terms of global efficiency. The costs of H2 production for the Fe and W-based plants are estimated to be $1.66/kg and $16.92/kg, respectively. Compared to the SMR process, the cost of H2 production from the Fe-based TRCLR plant is about 31% lower.