Optimal design of an MDEA CO₂ capture plant for low-carbon hydrogen production - A rigorous process optimization approach

This work presents an optimized design of a methyl diethanolamine CO₂ capture unit for clean hydrogen production via steam methane reforming of natural gas, where CO₂ is captured from the pressurized water-gas shifted syngas. We propose a modified version of the standard MDEA-based  CO₂ capture process flowsheet, and we optimize the operating conditions by solving a multi-objective optimization problem to minimize energy consumption while maximizing the CO₂ capture rate. In this paper, we opted to model the  CO₂ capture plant using an equilibrium-based approach. To validate the optimization results obtained and to verify the absorber and desorber dimensions, we sized both columns. Packing heights remain below the threshold of 15 meters and productivity ranges between 0.74 tCO₂/m³h at a capture rate of 90% and 0.35 tCO₂/m³h for a  CO₂ recovery of 99.8% respectively.