Abstract: Described is the use of a mineral comprising a metal carbonate fraction and a fuel fraction, such as oil shale or coal shale, in a calcination process. The disclosed process can advantageously result in carbon dioxide being removed from the atmosphere. Further, in the process, heat energy generated during calcination can be used to separate oxygen from air, so that the oxygen can be fed back into the system. Alternatively or in addition, heat energy may also be used to compress the gaseous carbon dioxide generated from the calcination process.

Abstract: A process comprising the following steps: a) calcination of a metal carbonate by combustion of a fuel in the presence of a mixture of oxygen, water vapour and carbon dioxide, to generate a metal oxide, water vapour, carbon dioxide and heat; b) using the heat generated to drive an oxygen generation reaction; and c) use of the oxygen generated in step b) in calcination step a). The use of the process on carbon dioxide sequestration and/or in oxygen generation.