Self–activation and effect of regeneration conditions in CO2 – carbonate looping with CaO - Ca12Al14O33 sorbent

CO2 capture by solid sorbents through uptake–regeneration cycling is a promising option for high temperature removal of CO2 from combustion gases and synthesis/fuel gases. The present study investigates the influence of regeneration atmosphere and temperature on the CO2 uptake capacity during repeated cycling of CaO–based solid sorbents. The sorbents were synthesised to contain 75 and 85 %w/w of active phase (CaO) and binder (Ca12Al14O33) and were then subjected to cycling tests with repeated CO2 uptake and release in a thermogravimetric analyser TGA for up to 200 cycles. Test conditions were chosen to test high temperature CO2 capture at 600 °C in an atmosphere containing 14 and 25 %v/v CO2 (N2 balance). Three different regeneration conditions were tested: a) mild condition: regeneration at 900 °C in 14% CO2 or 100% N2; b) moderate condition: regeneration at 1000 °C in 14% CO2; c) severe condition: regeneration at 1000 °C in 86% CO2. Hydration of the sorbent during synthesis and prolonged carbonation prior to the cycling tests significantly improved the stability of the uptake capacity. Interestingly, the pretreated 75 %w/w CaO synthetic sorbent maintained a good uptake capacity up to the 150th cycle under severe regeneration conditions and even showed continuously increasing CO2 uptake capacity throughout the 150 cycle test with 25% CO2. The 75 %w/w CaO sorbent is thus an interesting candidate for future work on high temperature CO2 capture.

STENDARDO Stefano;  ANDERSEN Lars;  HERCE C; 

2013-08-16

ELSEVIER SCIENCE SA

JRC75299

1385-8947,   

http://www.sciencedirect.com/science/article/pii/S1385894713000855,    https://publications.jrc.ec.europa.eu/repository/handle/JRC75299,   

10.1016/j.cej.2013.01.045,