Power plants that utilize gas turbines for power generation and processes for lowering CO₂ emissions

摘要

Power plants and process for lowering CO₂ emissions generally includes extracting a portion of the recirculated CO₂-rich flue gas mid-way through the compression pathway of a gas turbine and removing the CO₂ in a separation unit. The remaining portion of the CO₂ rich flue gas (i.e., the portion of the recirculated flue gas that was not fed to the separation unit) is mixed with fresh air coming from an additional compressor-expander and then fed back to the compression pathway. As a result, flue gas recirculation increases the CO₂ concentration within the working fluid, leading to an additional increase in CO₂ partial pressure. As the concentration and partial pressure of CO₂ is increased, a lower energy penalty is observed to remove the CO₂. Moreover, a reduced volume is fed to the CO₂ separation unit during operation. Consequently, the size of the separation equipment can be reduced as well as the energy required for the separation process.