Fueling a carbon-zero future: Igniting hydrogen production from petroleum reservoirs via in-situ combustion gasification

Hydrogen (H2) is increasingly recognized worldwide as a pivotal, clean energy carrier essential for decarbonizing various sectors, including transportation, power generation, and fuel-intensive industries. While hydrogen can be produced from diverse sources, the most common method is steam methane reforming, which however generates 9-10 kg carbon dioxide (CO2)/kg H2. Considering the dominant share of fossil fuels in global energy consumption, new technologies are imperative to expedite the transition to a cleaner hydrogen-based energy source. An emerging alternative for hydrogen production is to generate it directly from petroleum reservoirs via the insitu combustion gasification technology. This novel approach produces hydrogen by triggering reactions between hydrocarbons, rocks, and water within petroleum reservoirs. Hydrogen-selective membranes are used to separate the generated hydrogen with all undesired gases being sequestrated within the reservoir, making it a carbon-zero technology. With increasing experimental and simulation work, this technology shows promising potential for large-scale hydrogen generation in an environmentally friendly manner. This paper identifies the technological potential and scientific challenges, delves into the fundamentals of the process, and discusses its efficiency, costeffectiveness, and environmental benefits. Moreover, it highlights the importance and key aspects involved in fundamental fluid chemistry, reservoir geology, reactions, and engineering design to enhance the development and deployment of this technology. This paper aims to catalyze advancements of this new, clean technology and accelerate the transition from a fossil fuel-based economy to a carbon-zero economy.