Abstract: The process accumulates heat from a relatively low temperature source to support an endothermic chemical reaction, partially separates the products of the reaction from the reactants, and then releases the accumulated heat in the reverse exothermic chemical reaction at a higher temperature simultaneously restoring the original chemical composition. The forward and reverse chemical reactions are slow enough to prevent substantial reaction during the separation and transfer of the chemicals, but they may be speeded by catalysts within the reaction chambers. The chemicals are separated by standard procedures such as sorption-desorption, distillation, freezing and melting, precipitation, extraction, centrifugation, and reactions with other materials.