PROSPECTS OF OXYGEN AIR-SEPARATION PLANTS APPLICATION TO INCREASE EFFICIENCY OF STEAM TURBINE UNITS AND TO REDUCE CO2 EMISSIONS

Abstract

Currently, in the process of manufacturing electric power at large thermal power plants, CCS (Carbon Capture and Storage) technology is used, which reduces carbon dioxide emissions into the atmosphere by 90 % in the process of burning different fuels. We considered three major CCS-technologies: «Post-combustion capture»; «Pre-combustion capture» and «Oxyfuel combustion capture». Decrease of CO2  emissions occurs due to the removal of carbon dioxide from combustion gases by means of chemical processes of absorption / desorption. We analyzed new efficient technologies of CO2 extraction from combustion gases, such as «Advanced Amines Process» and «Сhilled Ammonia Process». It was concluded that «Oxyfuel combustion capture», based on the combustion of  fuel in pure oxygen with the simultaneous use of «Сhilled Ammonia Process» is the most advanced technology. It is possible to ensure a higher efficiency of large steam turbine plants by using thermochemical regeneration of heat of initial fuel with the simultaneous use of oxygen. This will allow manufacturing high-efficiency steam turbine plants (STP) with a complete CO2 capture, implementing the technology «Oxyfuel combustion» Absolute thermal efficiency of such STPs which equals 57,6 %, practically reaches the level of combined-cycle plants. In addition, oxygen required capacity of air separation plants will be from 3840  to 5600 t / day.