TY - JOUR
T1 - A numerical modelling study of SO2 adsorption on activated carbons with new rate equations
AU - Li, Ziyi
AU - Liu, Yingshu
AU - Wang, Haihong
AU - Tsai, Chuen-Jinn
AU - Yang, Xiong
AU - Xing, Yi
AU - Zhang, Chuanzhao
AU - Xiao, Penny
AU - Webley, Paul A.
PY - 2018/12/1
Y1 - 2018/12/1
N2 -
Modelling dynamic adsorption of sulfur dioxide (SO
2
) on activated carbons (ACs) is significant in guiding practical desulphurization processes and making highly efficient use of adsorbents in terms of the adsorption rate which largely depends on particle size. In this work, models derived from the Vermeulen and an improved linear driving force (LDF) rate equation were studied for the first time on SO
2
adsorption over AC particles with different sizes. For larger particles (≥3 mm), breakthrough curves predicted by the Vermeulen equation showed good agreement with experimental data, demonstrating that intraparticle diffusion resistance varied with particle size, feed concentration, adsorption time and location. For smaller particles (1 mm), a correction on the volume-averaged adsorption capacity as a function of adsorption time and saturation in the rate equation was developed to avoid the underestimation of adsorption rate due to the inappropriate parabolic concentration profile inherent in the conventional LDF model. By providing a concentration gradient and adsorption rate closer to actual values, the improved LDF equation was confirmed to provide excellent prediction results on 1-mm particles. Different modelling characteristics of the two models indicates varying effects of intraparticle diffusion on adsorption rate with particle size regarding the specificity of SO
2
physisorption on ACs.
AB -
Modelling dynamic adsorption of sulfur dioxide (SO
2
) on activated carbons (ACs) is significant in guiding practical desulphurization processes and making highly efficient use of adsorbents in terms of the adsorption rate which largely depends on particle size. In this work, models derived from the Vermeulen and an improved linear driving force (LDF) rate equation were studied for the first time on SO
2
adsorption over AC particles with different sizes. For larger particles (≥3 mm), breakthrough curves predicted by the Vermeulen equation showed good agreement with experimental data, demonstrating that intraparticle diffusion resistance varied with particle size, feed concentration, adsorption time and location. For smaller particles (1 mm), a correction on the volume-averaged adsorption capacity as a function of adsorption time and saturation in the rate equation was developed to avoid the underestimation of adsorption rate due to the inappropriate parabolic concentration profile inherent in the conventional LDF model. By providing a concentration gradient and adsorption rate closer to actual values, the improved LDF equation was confirmed to provide excellent prediction results on 1-mm particles. Different modelling characteristics of the two models indicates varying effects of intraparticle diffusion on adsorption rate with particle size regarding the specificity of SO
2
physisorption on ACs.
KW - Activated carbons
KW - Adsorption
KW - Breakthrough curve modelling
KW - Intraparticle diffusion
KW - Sulfur dioxide
UR - http://www.scopus.com/inward/record.url?scp=85050865901&partnerID=8YFLogxK
U2 - 10.1016/j.cej.2018.07.119
DO - 10.1016/j.cej.2018.07.119
M3 - Article
AN - SCOPUS:85050865901
SN - 1385-8947
VL - 353
SP - 858
EP - 866
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
ER -