Removal of CO₂by Calcium-Based Sorbents in the Presence of SO₂

Abstract

In an investigation of in situ CO2 removal for fluidized-bed combustion processes, seven calcium-based sorbents were tested for simultaneous CO2 and SO2 removal using both an atmospheric thermogravimetric reactor and a pressurized thermogravimetric analyzer. SO2 was found to impede cyclic CO2 capture because of pore blockage by sulfate products, resulting primarily from direct sulfation during the later stage of each cycle. The sorbents showed similar patterns during cocapture. Loss in sorbent reversibility could not be prevented but was improved by higher CO2 partial pressures.

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

“…Furthermore, a certain quantity of CaSO 4 in the CaL system is guaranteed depending on the amount of fresh makeup limestone and purge. Therefore, SO 2 will deactivate the CaO available for CO 2 capture [21][22][23]. The deactivation would be enhanced if methods of reactivation like recarbonation [24] or hydration [25] were used to reduce the make-up.…”

High temperature CO2 sorption using Ca(OH)2 in pilot scale packed column

“…The synthesis of calcium cyanamide was also carried out by using the reaction between CaO and CO2 [14]. Later, CaO was used to separate CO2 from coal-combustion flue gas [14][15][16][17][18]. More recently, CaO is used as a CO2 capture for zero-emission coal technology and HyPr-RING process [4,19] in novel coal gasification.…”

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.…”