Rather high energy penalty of CO2 capture is the critical gap deterring the deployment of CCS technologies in last twenty years. Deeper understand of mechanism of energy consumption for CO2 capture will lay the basis for reducing the energy consumption. Accordingly, this paper introduced a thermodynamic analysis method with new criterion to reveal the mechanism of energy consumption in power system integrating CO2 capture from new angle. Coal-fired power plant with post-combustion had been taken as the typical case and some enlightening results had been achieved. Although energy consumption for separation process is generally recognized as the dominant part of capture penalty, deterioration of energy utilization in power system due to providing energy for CO2 separation is nonnegligible, which also exhibits attractive potential for energy saving in some cases. For separation efficiency improvement, the ceiling of 50% separation efficiency indicates as low as 5.9 percentage points penalty (with CO2 compression), and the CO2 capture cost of around 24 $/t CO2 can be anticipated for 50% separation efficiency.
Keywords CO2 capture, Energy consumption, Post-combustion, Evaluation