Integrated optimization of the CO2 hydrogenation to methanol process based on catalyst-to-system 3E performance mapping

CO2 hydrogenation to methanol is crucial for low-carbon development. Insufficient understanding of the interactions among catalyst properties, reactor operation, and energy integration hinders efficient conversion and overall system performance. To address these challenges, multi-level mapping models and a systematic optimization method based on energy, environmental, and economic (3E) analysis are developed to guide catalyst parameter optimization and system-level adjustments. By integrating separable reaction kinetics, energy/mass balances, and pinch/cascade analyses, a set of equations is developed to relate catalyst parameters, reactor and energy-system variables, and exergy efficiency, carbon intensity, costs, and operating time. Feasible catalyst parameter domains, their associated time-evolving reaction and energy system operating parameters, and corresponding 3E performance are determined through global exploration. A three-objective trade-off framework is developed to identify Pareto-optimal catalyst parameters and system operations. For a representative Pareto-optimal solution, coordinated optimization reduces product cost by 1.90 %, carbon emissions by 2.63 %, and increases system exergy efficiency by 1.42 % relative to the reference case. This equation-oriented approach provides a clear, efficient pathway for high-performance design and optimization of the CO2-to-methanol process, encompassing catalysts, reactors, and energy systems. It can be extended to other catalytic processes or hybridized with data-driven approaches to enable low-carbon transformation and adaptive operation.