Flexible Oxy-Fuel Combustion for High-Penetration Variable Renewables
GE Research will optimize an oxy-combustion natural gas-fired turbine—the Allam-Fetvedt cycle—for flexible generation on a grid with high (VRE) penetration at near-zero carbon emissions. The team will use gas or liquid buffering tanks and tight thermal integration between the air separation unit (ASU) and the oxy-combustion turbine. The proposed technology easily separates the CO2 and H2O in the flue gas of an oxy-combustor. The post-combustion outlet gas is more easily separated into water and CO2 to the pipeline, thereby lowering the electricity costs of grids with high levels of VRE. The system’s flexibility can be improved by taking advantage of times when the electricity cost is low to produce the O2 needed for the combustor and turning down the ASU at times when electricity costs are high. If optimized, such a system has the potential to produce electricity with near-zero CO2 emissions at a reasonable cost.
Improvements in the design and processes of CCS-equipped plants in high VRE environments could dramatically reduce the cost of a net-zero carbon system. Benefits include: