A generic superstructure modeling and optimization framework on the example of bi-criteria Power-to-Methanol process design

This work presents a fully open-source superstructure optimization model for bi-criteria process design optimization. This model is implemented in the Open sUperstrucTure moDeling and OptimizatiOn fRamework (OUTDOOR). It combines mass, energy and cost balances with a more sophisticated heat integration concept with low computational effort and acceptable accuracy. The model is applied to a Power-to-Methanol (PtM) process design case study. A cost optimal methanol plant is identified at net production costs (NPC) of 892 €/t_MeOH and net production emissions (NPE) of -1.937 t_CO2-eq./t_MeOH. It utilizes CO₂ captured from refinery flue gas and hydrogen supply via. ambient pressure alkaline electrolysis. A plant configuration, designed for minimum CO₂ emissions yields costs of 979 €/t_MeOH with emissions of -2.191 t_CO2-eq./t_MeOH, using CO₂ from ambient air and refinery and cement factory flue gases. A sensitivity analysis on electricity prices forecasts cost competitive methanol at large production capacities and low electricity prices of 2 ct/kWh.