Lithium orthosilicate (Li4SiO4) is one of the most promising materials for CO 2 capture from flue gas at high temperature due to its high reactivity. Improved sorption properties can be obtained by appropriate doping. In this study, different lithium orthosilicate based sorbents, pure and modified with potassium carbonate, obtained using amorphous and crystalline silica were prepared and characterized by scanning electron microscopy and X-ray diffraction. The CO 2 adsorption properties were investigated by thermogravimetric analysis under a flux of 4vol.% CO 2 (atmospheric pressure) in a range of temperature of 500-600°C. To investigate the durability, multiple CO2 sorption/desorption cycles were performed on selected samples. The influence of different operating parameters such as sorption temperature, type of silica, doping method with K 2CO 3 on CO 2 sorption capacity has been investigated. At optimal experimental conditions (580°C, Li 4SiO 4 from crystalline quartz with simple addition of 10mol% K 2CO 3) the CO 2 sorption capacity was 270mg CO2/g sorbent (corresponding to 80% conversion of Li4SiO4) after 2h. The selected sorbent maintained its original sorption capacity after multiple adsorption/desorption cycles.
High-Temperature and Low Concentration CO2 Sorption on Li4SiO4 based Sorbents: Study of the Used Silica and Doping Method Effects
SEGGIANI, MAURIZIA;PUCCINI, MONICA;VITOLO, SANDRA
2011-01-01
Abstract
Lithium orthosilicate (Li4SiO4) is one of the most promising materials for CO 2 capture from flue gas at high temperature due to its high reactivity. Improved sorption properties can be obtained by appropriate doping. In this study, different lithium orthosilicate based sorbents, pure and modified with potassium carbonate, obtained using amorphous and crystalline silica were prepared and characterized by scanning electron microscopy and X-ray diffraction. The CO 2 adsorption properties were investigated by thermogravimetric analysis under a flux of 4vol.% CO 2 (atmospheric pressure) in a range of temperature of 500-600°C. To investigate the durability, multiple CO2 sorption/desorption cycles were performed on selected samples. The influence of different operating parameters such as sorption temperature, type of silica, doping method with K 2CO 3 on CO 2 sorption capacity has been investigated. At optimal experimental conditions (580°C, Li 4SiO 4 from crystalline quartz with simple addition of 10mol% K 2CO 3) the CO 2 sorption capacity was 270mg CO2/g sorbent (corresponding to 80% conversion of Li4SiO4) after 2h. The selected sorbent maintained its original sorption capacity after multiple adsorption/desorption cycles.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
