Perspectives on oxygen-based coal conversion towards zero-carbon power generation

Projections made by credible institutions indicate that coal will continue to provide a major fraction of the global electricity mix for many decades to come. Assuming the validity of these projections and building on this likely scenario, this perspective article proposes oxygen-based coal conversion as a sustainable pathway for zero-carbon power generation, albeit not without its own challenges. The century-old tradition of burning coal in air is no longer sustainable. Achieving zero-carbon coal power dictates full capture of CO₂ emissions. Unfortunately, renewable power is still far from fully displacing coal-based power despite major gains. Also, renewables are inherently non-dispatchable sources constrained severely by lack of utility-scale electricity storage. Moreover, prospects for total conversion of power generation to natural gas presents its own challenges due to uncertain impacts of hydraulic fracturing on the environment. It is highly likely that we will need both coal and natural gas for electricity production. Accordingly, this article proposes a roadmap that emphasizes rapid transitioning of coal-based (and natural gas-based) power generation from air-based combustion to oxygen-based conversion. The latter excludes nitrogen from entering the process stream and offers easy capture of CO₂ to achieve zero-carbon electricity generation with significant savings on water demand.