Abstract: A high-temperature decomposition reactor is provided. The reactor includes a reaction vessel, a furnace, and an insulation layer. The reaction vessel includes an inner volume configured to contain a quantity of carbonated medium while the quantity of carbonated medium transitions to a quantity of carbonation medium. The furnace is disposed around the reaction vessel and includes a furnace material. The furnace material is configured to simultaneously absorb heat and transmit heat. In some instances, the furnace material transmits heat to the inner volume to heat the carbonated medium. The insulation layer is disposed around the furnace and configured to prevent thermal losses from the reactor.