A Low Temperature Solar Thermochemical Power Plant With $CO2$ Recovery Using Methanol-Fueled Chemical Looping Combustion

A novel solar-hybrid gas turbine combined cycle was proposed. The cycle integrates methanol-fueled chemical-looping combustion and solar thermal energy at around $200°C$⁠, and it was investigated with the aid of the energy-utilization diagram (EUD). Solar thermal energy, at approximately $150°C–300°C$⁠, is utilized to drive the reduction in $Fe2O3$ with methanol in the reduction reactor, and is converted into chemical energy associated with the solid fuel FeO. Then it is released as high-temperature thermal energy during the oxidation of FeO in the oxidation reactor to generate electricity through the combined cycle. As a result, the exergy efficiency of the proposed solar thermal cycle may reach 58.4% at a turbine inlet temperature of $1400°C$⁠, and the net solar-to-electric efficiency would be expected to be 22.3%. The promising results obtained here indicate that this solar-hybrid combined cycle not only offers a new approach for highly efficient use of middle-and-low temperature solar thermal energy to generate electricity, but also provides the possibility of simultaneously utilizing renewable energy and alternative fuel for $CO2$ capture with low energy penalty.