Supercritical Carbon Dioxide-Based Power Cycles

Abstract

Thermal-based energy resources including fossil fuels as well as renewable sources such as solar and biomass involve a wide range of heat source temperatures. Effective utilization of all these resources demands judicious choice of thermodynamic cycles to convert the heat into electric power. In this context, supercritical carbon dioxide (S-CO2) working in a closed Brayton cycle loop is found to be suitable for temperatures normally realized from concentrating solar as well as biomass combustion. The present study discusses the work reported in literature on the thermodynamic performance of some basic variants of the CO2 cycle, such as the subcritical, transcritical, and the supercritical cycle. Comparative thermodynamic analysis of the cycles shows that S-CO2 is the best performer, and it has the potential to replace steam in conventional thermal power plants, solar thermal, as well as nuclear plants. The major advantages of S-CO2 Brayton cycle over steam Rankine cycle are discussed. Some technological challenges for ultimate scale-up and commercialization are identified, in the form of development of critical components and subsystems.