Solid oxide fuel cells with integrated direct air carbon capture: A techno-economic study

Direct air carbon capture, as a negative emissions technology, is pivotal to lowering carbon dioxide concentration in the atmosphere. Accompanying the development and application of this technology, the high energy demand and substantial capital cost associated with direct air carbon capture have been persistent concerns. This paper aims to analyse the technical and economic feasibility of utilising a hydrogen fed solid oxide fuel cell as a source of both electricity and high-grade heat for the process of direct air carbon capture. It is vital that a renewable form of hydrogen production is used for this process to be sustainable, therefore a renewable hydrogen fed 50 MW solid oxide fuel cell is modelled, integrated with a direct air carbon capture process, resulting in a system with the capacity to remove carbon dioxide just over 270 kt/year directly from the air. The current levelised cost of capture for the system varies widely with the price of renewable hydrogen production, with an estimated range of 314-1,505 pound per tonne of carbon dioxide captured. As the cost of renewable hydrogen declines in the future, such a process could become a feasible alternative to natural gas fed direct air capture, with a 2050 levelised cost of capture anticipated to be 191 pound per tonne.