System design and thermo-economic analysis of a novel gas turbine combined cycle co-driven by methanol and solar energy

Methanol, known as “liquid sunshine”, is a versatile and low-carbon alternative to traditional fossil fuels. To effectively utilize methanol and solar energy, a novel gas turbine combined cycle (GTCC) integrated with a solar-driven methanol decomposition reaction (Solar MDR) process is proposed in this study. Based on the cascade utilization of chemical energy, methanol is first decomposed into syngas in the parabolic trough solar receiver-reactor (PTSRR) field, followed by the conversion of chemical energy into power through combustion. The methanol preheating process is comprehensively considered by integrating methanol evaporator into heat recovery steam generator (HRSG) and utilizing waste heat from the PTSRR to drive the methanol preheater and superheater. Thermodynamic analysis is conducted to evaluate the impact of solar integration on irreversibility and power output in the methanol-fueled GTCC system. The results indicate that the system co-driven by methanol and solar energy improves the methanol power generation rate from 3.17 kWh kg⁻¹ to 3.75 kWh kg⁻¹. The exergy efficiency of the system slightly decreases from 51.05 % to 50.42 % due to the integrated system incurring an additional 106.28 MW of loss and destruction, with solar integration contributing an extra 34.9 MW of exergy loss and 66.7 MW of destruction in the PTSRR field. The proposed system achieves a solar-to-electric efficiency of 43.93 % and a solar levelized cost of electricity (LCOE) of $75.7 MWh⁻¹, offering a competitive advantage over other solar thermal power technologies from thermo-economic perspectives.