Thermodynamic and kinetic analysis of CuO-CaSO4 oxygen carrier in chemical looping gasification

Highlights: • A novel way is proposed to prepare CuO-CaSO₄ oxygen carrier with the industrial wast. • Thermodynamics insights into CuO-CaSO₄ the redox process by FactSage software. • Activation energy has confirmed CuO-CaSO₄ can reduce reaction temperature. • The rational mechanism is proposed and parameters have been calculated. -- Abstract: Chemical looping gasification (CLG) is an efficient coal gasification method and an emerging technology. In this process, the oxygen is from oxygen carriers such as CuO-CaSO₄. The great reactivity characteristic of CuO-CaSO₄ compound oxygen carrier has been confirmed by previous work. And, thermodynamics and kinetics are the vital parts of CLG process. To better understand the process of CLG with CuO-CaSO₄, the thermodynamics and kinetics of CuO-CaSO₄ CLG process has been investigated. In this work. A novel way was proposed to prepare to CuO-CaSO₄ oxygen carrier with the industrial wast phosphogypsum (PG). And it showed that the molar ratio of PG to Cu element should be around 2. Activation energy was investigated by isoconversion method. In the CLG process, Activation energy was 86.4556 kJ/mol with CuO-CaSO₄, However the activation energy was 145.6092 kJ/mol, when applied PG as oxygen carrier. Deeper studies showed that the mechanism of CLG with CuO-CaSO₄ was controlled by product layer diffusion mechanisms of Shrinking Core Model (SCM) model. Therefore, theses phenomena indicate that CuO-CaSO₄ is a recommended oxygen carrier in chemical looping technology.