Browsing by Author "Zhang, Chuanzhao"

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A numerical modelling study of SO2 adsorption on activated carbons with new rate equations
(2018-12-01)
Li, Ziyi
;
Liu, Yingshu
;
Wang, Haihong
;
Tsai, Chuen-Jinn
;
Yang, Xiong
Modelling dynamic adsorption of sulfur dioxide (SO2) 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 SO2 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 SO2 physisorption on ACs.
Research Progress of Gaseous Polycyclic Aromatic Hydrocarbons Purification by Adsorption
(2019-04-01)
Yang, Xiong
;
Li, Ziyi
;
Liu, Yingshu
;
Xing, Yi
;
Wei, Jinchao
Gaseous polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and mutagenic pollutants and also able to promote the growth of secondary particulate matters, which have attracted great attention in recent years. Control of PAHs emissions in exhaust gases using different techniques has been hot topics in the atmospheric environment field. Adsorption is one of the most effective ones and is well accepted by industries in gaseous pollutant removal in which the adsorbent characteristics play critical roles. In this paper, the latest advances in the field of PAHs adsorption are critically reviewed with special emphasis on adsorption-desorption characteristics and related applications. Studies on adsorption equilibrium, kinetics, and desorption properties of PAHs as special low-volatile gases on conventional activated carbons and novel mesoporous adsorbents are summarized and compared, showing the advantages of mesoporous adsorbents over traditional adsorbents in terms of the fast adsorption and facile desorption. The significant factors on the optimal balance between adsorption and desorption as well as the corresponding adsorbent materials are discussed in detail. This work can be a reference for further studies on adsorptive purifications of PAHs and other low-volatile gases.