Abstract: Methods and systems for producing hydrogen and capturing carbon dioxide are disclosed. In some embodiments, the methods include the following: mixing magnesium bearing minerals with one or more acids and/or chelating agents to form a magnesium-rich solvent including magnesium hydroxide; mixing a gas including carbon dioxide with the magnesium-rich solvent in a reactor possibly in the presence of one or more water-gas shift catalysts; increasing a temperature and a steam pressure inside the reactor until a substantial portion of the magnesium hydroxide in the solvent and the carbon dioxide and water in the gas react to form magnesium carbonate and hydrogen; and increasing pH in the reactor thereby increasing a rate that the solvent and the carbon dioxide react.

Abstract: A method for producing hydrogen gas is provided and comprises reducing a metal oxide in a reduction reaction between a carbon-based fuel and a metal oxide to provide a reduced metal or metal oxide having a lower oxidation state, and oxidizing the reduced metal or metal oxide to produce hydrogen and a metal oxide having a higher oxidation state. The metal or metal oxide is provided in the form of a porous composite of a ceramic material containing the metal or metal oxide. The porous composite may comprise either a monolith, pellets, or particles.