Mechanism for self-reactivation of nano-CaO-based CO2 sorbent in calcium looping. (1st March 2015)

• Record Type: Journal Article
• Authors: Lan, Peiqiang; Wu, Sufang
• Is Part Of: Fuel. Volume 143(2015)
• Page Start: 9
• Page End: 15
• Publication Date: 2015-03-01
• Subjects: CO2 sorption -- Calcium looping -- CaO-based sorbent -- Self-reactivation -- Nano-CaO; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2014.11.004
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Increasing carbonation temperature and time favors self-reactivation occurring. Nano-CaO-based sorbent exhibits self-reactivation within 5 min. Nano-CaO-based sorbent shows conversion of 68% after 50 cycles. A grain–core–pore model is proposed to explain the self-reactivation of sorbent. Abstract: This study investigated the mechanism for self-reactivation of nano-CaO-based CO2 sorbents. Nano-CaO, nano-CaO mixed with MgO, and CaTiO3 -coated nano-CaO were prepared as CO2 sorbents to study. The influences of calcium looping conditions on self-reactivation of the sorbents by TGA. The research results showed that the self-reactivation will be found under a lower calcining temperature and short calcination holding time of the nano-CaO-based CO2 sorbents. The additive decreased the carbonation holding time to 5 min for self-reactivation and maintained the excellent durability of the nano-CaO-based sorbents. The nano-CaO-based sorbents exhibited self-reactivation with >50% conversion for >50 cycles under calcination conditions of 850 °C in 50% CO2 (N2 balance). A new grain–pore–core model was proposed for the self-reactivation process. This model considers the changes in the grains and structures of sorbents during pre-calcination and subsequent carbonation–calcination cycles.