Premium
Study of Al 2 O 3 addition to synthetic Ca‐based sorbents for CO 2 sorption capacity and stability in cyclic operations
Author(s) -
Karami Davood,
Mahinpey Nader
Publication year - 2015
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.22108
Subject(s) - sorbent , sorption , sintering , carbonation , materials science , chemical engineering , precipitation , particle size , mixing (physics) , chromatography , chemistry , adsorption , composite material , organic chemistry , physics , quantum mechanics , meteorology , engineering
Synthetic CaO sorbents were prepared using alumina as a sintering inhibitor via a simple precipitation method. The effects of three mixing procedures on the physical properties and CO 2 capture performance of the sorbents were examined. The cyclic CO 2 capture performance of the sorbent derived from the precipitation of calcium salts over colloidal alumina (highly dispersed alumina gel) showed the best performance of the three mixing methods. It was found that variation of alumina‐to‐CaO ratios did not significantly change the sintering influence on the sorbent capacity in cyclic operations. CaO particles homogeneously mingled with alumina at higher ratios. Sintering prevention, however, was not observed. This important observation indicates that alumina appeared to merely act as a binder for the fabrication of mechanically enhanced strength particles that are suitable for large‐scale operations. It was determined that CO 2 uptake was not dependent on either the mixing technique or the type of synthetic materials incorporated into a sorbent in cyclic operation. The sorbent derived from the precipitation of calcium salts over colloidal alumina with an alumina‐to‐CaO ratio of 20:80 achieved the highest CO 2 uptake of 13.1 moles/kg sorbent for half an hour of carbonation in the first cycle and retained a sorption capacity of 6.5 moles/kg sorbent after 17 successive cycles (50 % activity loss), which is in agreement with the reported results. It was demonstrated that the quantity of CO 2 uptake increased moderately with decreasing sorbent particle sizes. The effect of pressure on sorbent CO 2 uptake was insignificant.