SO2 and CO2 co-capture from heavy fuel oil power plants: The influence of calcium looping cycles on limestone derived sorbent capture efficiency

Abstract

Although phasing out heavy fuel oil (HFO) usage as a power source is unlikely while the world remains reliant on petroleum products, literature on CO2 capture technology implementation at HFO-fired power plants is scarce. Calcium looping (CaL) is an advanced post-combustion CO2 capture technology that utilizes limestone-derived CaO to simultaneously concentrate CO2 and capture SO2. As sorbent is cycled between CO2 capture and CaO regeneration, its capture capacity decays. In this study, samples of two structurally distinct limestones were cycled in the presence of: (1) steam, (2) both steam and SO2. Samples at different stages of activity (Xmax = 0.6, 0.3 and 0.1) were collected and used to explore the effect of sorbent cycling and CaSO4 content on CO2 and SO2 co-capture from synthetic HFO flue gas. Bubbling fluidized bed (BFB) reactors equipped with effluent line sampling for continuous CO2, SO2, and O2 gas analysis were used. This data can be used to estimate required design parameters for CaL implementation at HFO-fired power plants, and provides further insight into the relationship between sorbent morphology and carbonation/sulfation behavior.