Simulation of the carbonate looping power cycle

Abstract

Abstract Carbonate Looping is a promising post-combustion capture process involving the separation of CO 2 from the flue gas of a coalfired power plant at high temperatures (600–700 ∘ C) using the reversible exothermic CaO carbonation reaction and the endothermic calcination reaction of CaCO 3 . The core of the carbonate looping process is a dual fluidized bed reactor in which the CO 2 acceptor material (CaO) is transported between the carbonator (CO 2 absorption) and regenerator (CO 2 desorption). Due to the heat requirements for the regenerator, the carbonate looping acts as a CO 2 separation unit and an add-on power plant, thereby offering the opportunity for increasing the site electricity production while inflicting only a low electric efficiency penalty on the total power plant. However, the quantity and quality of the Carbonate Looping heat sources differ significantly from a conventional coal-fired power plant. This paper presents the design and simulation of the carbonate looping steam cycle for a large coal-fired plant. The simulation involves the coupling of the carbonate looping reactor model from Aspen Plus with the steam cycle in EBSILON Professional code which is a mass and energy balance cycle calculation program specifically tailored for steam cycle calculations. The resulting simulation includes penalty deduction for the Air Separation Unit and the CO 2 conditioning unit, resulting in a net efficiency of 39.2% and while increasing the net power input from 1052 MWe to 1533 MWe, an addition of 481 MWe for the retrofitted power plant.