This work presents an optimized design of a methyl diethanolamine CO 2 capture unit for clean hydrogen production via steam methane reforming of natural gas, where CO 2 is captured from the pressurized water-gas shifted syngas. We propose a modified version of the standard MDEA-based CO 2 capture process flowsheet, and we optimize the operating conditions by solving a multi-objective optimization problem to minimize energy consumption while maximizing the CO 2 capture rate. In this paper, we opted to model the CO 2 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 metres and productivity ranges between 0.74 t CO 2 /m 3 h at a capture rate of 90% and 0.35 t CO 2 /m 3 h for a CO 2 recovery of 99.8% respectively. • We propose a modified process configuration for an MDEA-based CO 2 capture unit for low-carbon H 2 production via steam methane reforming of natural gas. • The optimal set of operating conditions that minimizes the energy consumption of the process while maximizing the CO 2 capture rate are found by solving a multi-objective optimization problem. • Feasible column designs, with packing heights below the threshold of 15 metres, are possible even at high capture rates ( > 98 % ).