Blue Hydrogen vs. Green Hydrogen: A Techno-Economic and Environmental Showdown in Heavy Industry Decarbonization

The global imperative to decarbonize hard-to-abate (HTA) industrial sectors including steel, chemicals, and refining has positioned hydrogen as a cornerstone of the low-carbon transition. Two primary clean hydrogen pathways have emerged: green hydrogen, produced via renewable-powered electrolysis, and blue hydrogen, derived from natural gas with carbon capture and storage (CCS). While both offer substantial emissions reductions compared to conventional fossil-based hydrogen, they entail fundamentally different techno-economic profiles, environmental footprints, and scalability trajectories. This study presents a comprehensive comparative analysis of blue and green hydrogen pathways across key industrial applications, integrating techno-economic assessment (TEA), life-cycle environmental evaluation, and scenario-based cost projections. The findings reveal that green hydrogen exhibits superior long-term economic performance, with costs projected to reach $2.00-3.50/kg by 2030, driven by rapid electrolyzer cost reductions and declining renewable electricity prices. However, blue hydrogen maintains a near-term cost advantage at $1.50-2.50/kg, though this is contingent upon high CCS capture rates (93-97%) and low upstream methane leakage. Critically, the climate benefits of blue hydrogen are significantly undermined by methane leakage rates observed in major gas-producing basins (2.8-3.1%), resulting in lifecycle emissions of 3.5-5.5 kg CO₂e/kg H₂ on a 20-year GWP basis . The green hydrogen-dominant scenario demonstrates superior mitigation economics, saving $115.5 billion compared to blue-dominant pathways while achieving comparable decarbonization outcomes . These results underscore the need for nuanced, sector-specific policy frameworks that account for regional resource endowments, infrastructure readiness, and long-term cost trajectories.