UKCCSRC Call 1 project paper: Operational flexibility options in power plants 1 with integrated post-combustion capture

Flexibility in power plants with amine based carbon dioxide (CO2) capture is identified in the literature as a way of improving power plant revenues. Despite the prior art, the value of flexibility in power plants with CO2 capture as a way to improve power plant revenues is still unclear. Most studies are based on simplifying assumptions about the capabilities of power plants to operate at part load and to regenerate additional solvent after interim storage of solvent. This work addresses this gap by examining the operational flexibility of coal power plants with amine based CO2 capture, using a rigorous fully integrated model. The part-load performance, with capture and compression bypass, and with interim solvent storage with delayed regeneration, of two coal power plant configurations designed for base load operation with capture, and with the ability to fully bypass capture, is reported. With advanced integration options, including boiler sliding pressure control, uncontrolled steam extraction with a floating crossover pressure, constant stripper pressure operation and compressor inlet guide vanes, a significant reduction of the electricity output penalty at 50% fuel input is observed, from 458 kWh/tCO2 to 345 kWh/tCO2, compared to a reduction from 361 to 342 kWh/tCO2 at 100% fuel input. Advanced integration options for improved part-load allow for maximum additional solvent regeneration, although to a lower magnitude than conventional integration options. The latter can maintain CO2 flow export within 10% of maximum flow across 30% to 78% of MCR (Maximum continuous rating). One hour of interim solvent storage at 100% MCR is evaluated to be optimally regenerated in 4 hrs at 55%MCR, and 3 hours at 30% MCR, providing rigorously validated useful guidelines for the increasing number of techno-economic studies on power plant flexibility, and CO2 flow profiles for further studies on integrated CO2 networks. The paper is available at http://www.sciencedirect.com/science/article/pii/S1750583616300275, DOI: doi:10.1016/j.ijggc.2016.01.027.