Towards less carbon-intensive blue hydrogen: Integrated natural gas reforming and CO2 capture approach

As hydrogen emerges as a key enabler in the global transition to sustainable energy, blue hydrogen production technologies are gaining increased attention. While existing studies have evaluated the environmental and economic feasibility of blue hydrogen, a comprehensive and innovative assessment remains essential. This study introduces a novel integration of three natural gas reforming techniques: Steam Methane Reforming (SMR), CO2- based Autothermal Reforming (ATR), and Steam-based ATR, where the CO2-concentrated stream from SMR is utilized as feedstock for ATR-an approach not widely explored. A detailed thermodynamic analysis and process simulation are conducted for a 1 Mt/year hydrogen production plant, integrating a point-source CO2 capture system. The high-CO2 concentration stream from the reforming system is directed to an MEA-based capture unit for carbon capture, utilization, and storage (CCUS), significantly reducing greenhouse gas (GHG) emissions. A heat exchanger network is designed to minimize energy consumption, offering operational savings and enhanced process efficiency. Results indicate that at a 50 % CO2 capture rate, the carbon intensity is 3.13 kg CO2-eq/kg H2, which reduces to 1.25 kg CO2-eq/kg H2 at a 80 % CO2 capture rate. The benchmarked cost of hydrogen production ranges from US$1.0/kg H2 for carbon intensities of 0.45-1.5 kg CO2-eq/kg H2, decreasing with higher carbon intensity. Gas composition analysis across reforming techniques maximizes hydrogen yield while minimizing byproducts. Additionally, thermal management, pinch analysis, and sensitivity analyses provide valuable insights into system dynamics, identifying inefficiencies and opportunities to further enhance performance.