Techno-economic assessment of natural hydrogen produced from subsurface geologic accumulations

Hydrogen produced from renewable energy sources is widely regarded as a crucial component of a clean energy system. However, the scaling of the 'green hydrogen' economy currently faces both technological and cost related impediments. Conversely, natural hydrogen could present an alternative source of low-cost and lowcarbon energy. This frontier in geoscience is being unlocked and the production of hydrogen from this native source has already commenced in Mali. In the current study, we performed a techno-economic assessment (TEA) of the natural hydrogen production system (NHPS) to establish the resource parameters that could make the production feasible and economically viable. The production system encompassing geological, physical, chemical and engineering processes was modelled. The total capital and project costs associated with the production system for a defined geological scenario was A$207 million, with an operating expenditure of A$1.64/kg (US $1.10/kg) of hydrogen produced. The levelised cost of hydrogen (LCOH) for the hypothetical facility operating at a gas mixture flowrate of 160,000 kg per day (with 83 mol% hydrogen concentration) over a 30-year project life was A$2.97/kg (US$1.99/kg). Changes in key production parameters were evaluated in a sensitivity analysis to gauge their impact on the process. Notably, hydrogen concentration and production flowrates emerged as crucial factors influencing economic viability. This preliminary assessment suggests that the novel energy source holds promise for fostering the sustainable development of the hydrogen economy globally. Furthermore, natural hydrogen production may also have additional socio-economic and environmental benefits to sustain interests in the growing hydrogen industry.