Hydrogen at the Source: Unlocking Clean Energy from Bitumen with Advanced Thermal Recovery

Abstract This study investigates the feasibility of generating hydrogen directly from various crude oil types—ranging from light and waxy oils to bitumen—using both microwave-assisted combustion and conventional combustion methods. The objective is to evaluate the efficiency of each approach and assess the potential to convert diverse petroleum resources into hydrogen while enabling in situ retention of carbon-rich byproducts (e.g., CO2, CH4), offering a novel low-emission pathway for energy transition. Laboratory-scale pseudo-reservoirs were prepared by mixing crude oil and brine (50:50 pore volume) with Ottawa sand and packing the blends into core holders. The tested oils varied widely in physical properties, with API gravities from 4.5 to 52 and viscosities between 4 cP and 178,500 cP. Thermal stimulation was applied using either microwave assisted or conventional combustion with continuous air injection, and real-time temperature profiles were recorded. Gas samples were collected and analyzed using gas chromatography (GC), with a focus on hydrogen, carbon dioxide, carbon monoxide, methane, and other gaseous products. Results from five experiments showed that hydrogen production occurs only when oxygen is present and is highly influenced by heating rate and oil composition. Microwave-assisted combustion consistently achieved earlier gas evolution and produced higher hydrogen yields, particularly from heavier oils such as bitumen. Fourier Transform InfraRed (FTIR), dielectric property, and Thermogravimetric Analyzer and Differential Scanning Calorimetry (TGA/DSC) analyses confirmed that both molecular structure and the presence of polar compounds and clay minerals enhance microwave absorption. These findings demonstrate that microwave-assisted combustion offers a promising approach for subsurface hydrogen generation, enabling selective gas production while retaining unwanted byproducts underground, contributing to cleaner energy recovery strategies.