Development and analysis of a novel power-to-gas-to-power system driven by the Allam cycle for simultaneous electricity and water production

The global energy sector faces dual challenges of reducing carbon emissions and managing the intermittency of renewable energy sources. Addressing the challenge of renewable energy intermittency, the power-to-gas technique emerges as a potent solution and the Allam cycle stands out as a remarkably efficient, semi-closed, supercritical carbon dioxide cycle, boasting a zero-carbon emission process. In the current study, the combination of the Allam cycle and power-to-gas technology yields a zero-carbon emission process, culminating in a highly efficient multi-generation system. This innovative system aims to generate power, methane, and freshwater simultaneously. The waste heat produced as a by-product of the Allam cycle is effectively utilized by integrating it with the multi-effect desalination-thermal vapor compression unit. The system's performance was evaluated using Engineering Equation Solver for exergy and economic assessments, while MATLAB incorporates an artificial neural network and moth-flame algorithm for multi-objective optimization. The optimization process operates under the influence of nine key decision variables, ensuring comprehensive analysis and robust decision-making. Based on the optimization results and Technique for Order Preference by Similarity to Ideal Solution method, the optimal solution for freshwater mass flow rate, exergy efficiency, and cost rate is determined to be 378.5 kg/s, 39.03 %, and 11,021 $/h, respectively. Finally, this innovative system demonstrates the potential to address renewable energy intermittency and carbon emissions simultaneously, offering a promising approach for sustainable energy generation and water production.