Design and optimization of stand-alone triple combined cycle systems using calcium looping technology

In our approach, the “stand-alone” process is an off-the-grid electricity system or a fuel processor without external energy supplies. A syngas producer is developed as a stand-alone SMR + CaL process using a combination of a steam methane reformer (SMR), a calcium looping (CaL) and a pre-burner to enhance CO₂ concentration of exhaust gas and produce syngas for power generation. A stand-alone triple combined cycle system (TCCS), which mainly consists of a solid oxide fuel cell (SOFC), Brayton-Rankine combined cycles, and a syngas producer, is developed as a high efficiency power generation system with CO₂ capture by adding a post-burner and using the specific water/heat exchanger networks. Based on optimal operating conditions by solving two optimization algorithms, the simulation shows that the total power efficiency of the stand-alone TCCS is up to 60.56% and its CO₂ emissions per kWh of electricity is down to 7.18 gCO₂.