Innovative power generation systems using supercritical CO2 cycles

Supercritical carbon dioxide (sCO2) power cycle is an innovative concept for converting thermal energy to electrical energy. It uses sCO2 as the working fluid medium in a closed or semi-closed Brayton thermodynamic cycle. The sCO2 power cycles have several benefits such as high cycle efficiency, small equipment size and plant footprint (and therefore lower capital cost) and the potential for full carbon capture. Achieving the full benefits of the sCO2 cycle depends on overcoming a number of engineering and materials science challenges that impact both the technical feasibility of the cycle and its economic viability. For example, the design and construction methods of turbomachinery, recuperator and high-pressure oxy-combustor pose significant technical challenges. Other R&D needs include material selection and testing, and optimized power cycle configuration. Over the years, particularly in the last decade, R&D efforts have been growing worldwide to develop sCO2 cycle technologies for power generation. Significant progress has been made in developing sCO2 cycle power systems. Some small, low-temperature sCO2 Brayton cycle power systems are starting to emerge in the commercial market, and a natural gas-fired demonstration power plant using a sCO2 cycle called the Allam Cycle is under construction. This article describes the sCO2 cycles for applications in power generation from fossil fuels and reviews the recent developments in sCO2 power cycle technologies. © The Author 2017. Published by Oxford University Press on behalf of National Institute of Clean-and-Low-Carbon Energy.