Greenhouse gas intensity of natural hydrogen produced from subsurface geologic accumulations

Natural geologic hydrogen (H2) could supply climate-friendly energy. We perform a prospective life cycle assessment (LCA) of generic natural H2 production and processing system, using engineering physics chemistry to estimate greenhouse gas (GHG) intensity. Our baseline case contains 85 mol % H2, 12% N2, 1.5% CH4. Well productivity, depth, other parameters use data from US wells. an open-source LCA tool model energy emissions. Site-boundary GHG intensity is ∼0.4 kg CO2 equiv/kg or ∼3 g equiv/MJ lower heating value (LHV) H2. The largest sources GHGs are fugitive emissions embodied Sensitivity analysis performed by examining varying compositions, reservoir parameters, methods. Results sensitive CH4 content: with 75% 22.5% emits 1.5 Other key drivers include process the handling disposing waste (non-H2) species.