Modelling of three-reactor system for chemical looping hydrogen generation: Identifying a suitable operating range

Abstract

Chemical-looping hydrogen generation can produce hydrogen from fossils fuels with inherent separation of CO2. In this article, a novel compact fluidized bed is used for CLHG to solve the problem of low fuel gas conversion causing by thermodynamic limit. Based on the compact fluidized bed, a modelling of three-reactor system for CLHG process is built to study the operating range of this system. The results show that the low limit of the system temperature is 650°C, or else unexpected reaction will occur in reactors. The system can achieve heat-integrated by mixing a certain amount of inert support into oxygen carrier and adjusting a suitable temperature different among reactors. Moreover, an operational range of the oxygen carrier recycle rate between 6 and 8 mol Fe/mol CH4 is recommended for more extensive operating region and relative higher CH4/H2 ratio can be obtain. Finally, a fitting formula described the operating range of this system is proposed to provide a reference for the experiment and simulation in further work.