Simultaneous CO₂/SO₂ Capture Characteristics of Three Limestones in a Fluidized-Bed Reactor

Abstract

Simultaneous CO 2 /SO 2 capture characteristics of three limestones were investigated in a pilot scale fluidizedbed reactor. For each of these sorbents, the measured CO 2 capture capacity decreased as the number of cycles increased and as the SO 2 concentration increased. On the other hand, the SO 2 capture increased with the number of cycles and the SO 2 concentration. The total calcium utilization decreased as the number of cycles increased, but the effect of SO 2 concentration on the total calcium utilization depended on the sulfation pattern of limestone. For one limestone (with unreacted-core-type sulfation), the total calcium utilization decreased with increasing SO 2 concentration. However, for the other two limestones (with uniform-type sulfation), the total calcium utilization was almost independent of SO 2 concentration for the range investigated. The results show that SO 2 reduces the CO 2 capture capacity of limestone and indicate that the sulfation patterns affect the CO 2 capture capacity.

Modelling of the kinetics of sulphation of CaO particles under CaL reactor conditions

“…The SO 2 can reach all the surfaces, ensuring a uniform sulphation of the particles. All of these patterns were found in the sulphation of fresh calcined limestones depending on the initial structural properties of the calcined sorbent [26,41,59]. However, in a postcombustion CaL system, there are other factors that can change the expected sulphation pattern.…”

The calcium looping cycle for CO2 capture from power generation, cement manufacture and hydrogen production

“…There is considerable variability in the reactivity and friability of natural limestones, which should be investigated before selecting a sorbent (Laursen et al, 2000;Ryu et al, 2006;Alvarez, 2007;Fennell et al, 2007a). These properties depend on impurities and the conditions / age of formation.…”

Investigation of SO2 Capture in a Circulating Fluidized Bed Carbonator of a Ca Looping Cycle

“…amine systems) is that the flue gas treated can contain a certain amount of SO 2 since CaO from calcined limestones is used in many commercial scale power plants 17 . Several works on sulfation phenomena in CaL systems have been published although these focus mainly on the effect of SO 2 on CO 2 carrying capacity during cycling 18,19,20,21,22,23,24,25 . These studies have referred to the negative impact upon SO 2 on sorbent capacity and the increasing decay of CO 2 carrying capacity of the sorbent during cycling due to the irreversible sulfation reaction of CaO.…”