Biogas Reformation in Geothermal Wells

Hydrogen energy and geological carbon retention using a biogas-geothermal wellbore
reformation tool

Enhancing overall resource efficiency contributes significantly to energy security. Biogas serves as
a critical energy asset within waste management by converting diverse organic wastes into highervalue
products. Through the establishment of integrated partnerships, sector coupling underscores
the synergies among geothermal energy, district heating, industry-related CO₂, urban biowaste, and
agriculture. This innovative geothermal approach — applied to wellbore biogas reformation —
facilitates hydrogen production alongside point-of-use geological carbon capture and storage (CCS).
The Carbon Injection and Gasification Geothermal (CIGG) methodology offers a direct and effective
pathway towards net zero by merging biogas reformation and carbon capture with low-grade district
heat geothermal systems. This approach streamlines the hydrogen generation and CCS systems by
eliminating unnecessary surface process steps, while incorporating reservoir heat storage and
recovery, thereby reducing process energy consumption, costs, and material use, and results in an
integrated, more energy efficient and sustainable solution.

To realise these synergies, a specialised wellbore tool for biogas (methane) reformation is under
development, designed to leverage the natural properties of a geothermal reservoir formation and
its fluids (i.e., heat storage, geothermal pressure, and temperature). The reformation’s resulting hot
CO₂ waste stream from this tool is injected into the reservoir, for heat storage and later recovery.
This mitigates the reservoir rock’s temperature depletion typically observed from long term
production of geothermal power fluids. Moreover, this immediate, in situ downhole CO₂ capture will
enable improved geothermal power efficiencies through enhanced heat recovery utilising the power
fluid. As geothermal wells generally possess a lifespan of 15 to 25 years, integrating these
processes bolsters long-term energy security. Overall, the CIGG process represents a mutually
beneficial advancement for both energy sectors and environmental stewardship.