Natural gas fuelled chemical looping reforming with carbon dioxide capture technology for hydrogen generation: thermodynamic investigation

Chemical looping reforming with CO2 capture is a method for pure hydrogen generation with inherent separation of CO2. This technology involves the use of three interconnected reactors: an air reactor, a fuel reactor and a CO2 releasing reactor. The oxygen demanded in the fuel reforming is supplied by a solid oxygen carrier, which circulates between the fuel reactor and the air reactor. Fuel and air are never mixed, and pure H-2 and CO2 can be obtained from the outlet of the fuel reactor and the CO2 releasing reactor respectively. A thermal analysis of the process using NiO as an oxygen carrier was performed by simulating reactions using the Gibbs energy minimisation method. The promising systems were investigated further with respect to temperature, oxygen excess numbers, CaO/CH4 molar ratio and pressure changes in the fuel reactor as well as possible carbon formation in the fuel reactor. It is found that the process has the potential to achieve high efficiency in addition to CO2 capture.