A Detailed Process and Techno-Economic Analysis of Methanol Synthesis from H₂ and CO₂ with Intermediate Condensation Steps

In order to increase the typically low equilibrium CO₂ conversion to methanol using commercially proven technology, the addition of two intermediate condensation units between reaction steps is evaluated in this work. Detailed process simulations with heat integration and techno-economic analyses of methanol synthesis from green H₂ and captured CO₂ are presented here, comparing the proposed process with condensation steps with the conventional approach. In the new process, a CO₂ single-pass conversion of 53.9% was achieved, which is significantly higher than the conversion of the conventional process (28.5%) and its equilibrium conversion (30.4%). Consequently, the total recycle stream flow was halved, which reduced reactant losses in the purge stream and the compression work of the recycle streams, lowering operating costs by 4.8% (61.2 M€·a$^−$¹). In spite of the additional number of heat exchangers and flash drums related to the intermediate condensation units, the fixed investment costs of the improved process decreased by 22.7% (94.5 M€). This was a consequence of the increased reaction rates and lower recycle flows, reducing the required size of the main equipment. ... mehrTherefore, intermediate condensation steps are beneficial for methanol synthesis from H₂/CO₂, significantly boosting CO₂ single-pass conversion, which consequently reduces both the investment and operating costs.