Assessment of CO2 Adsorption Capacity on Activated Carbons by a Combination of Batch and Dynamic Tests

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• 作者：Marco Balsamo ; Ana Silvestre-Albero ; Joaqu铆n Silvestre-Albero ; Alessandro Erto ; Francisco Rodr铆guez-Reinoso ; Amedeo Lancia
• 刊名：Langmuir
• 出版年：2014
• 出版时间：May 27, 2014
• 年：2014
• 卷：30
• 期：20
• 页码：5840-5848
• 全文大小：398K
• 年卷期：v.30,no.20(May 27, 2014)
• ISSN：1520-5827

文摘

In this work, batch and dynamic adsorption tests are coupled for an accurate evaluation of CO₂ adsorption performance of three different activated carbons (AC) obtained from olive stones by chemical activation followed by physical activation with CO₂ at varying times (i.e., 20, 40, and 60 h). Kinetic and thermodynamic CO₂ adsorption tests from simulated flue gas at different temperatures and CO₂ pressures are carried out under both batch (a manometric equipment operating with pure CO₂) and dynamic (a lab-scale fixed-bed column operating with a CO₂/N₂ mixture) conditions. The textural characterization of the AC samples shows a direct dependence of both micropore and ultramicropore volume on the activation time; hence, AC60 has the higher contribution. The adsorption tests conducted at 273 and 293 K showed that when CO₂ pressure is lower than 0.3 bar, the lower the activation time, the higher CO₂ adsorption capacity; a ranking of 蠅_eq(AC20) > 蠅_eq(AC40) > 蠅_eq(AC60) can be exactly defined when T = 293 K. This result is likely ascribed to the narrower pore size distribution of the AC20 sample, whose smaller pores are more effective for CO₂ capture at higher temperature and lower CO₂ pressure, the latter representing operating conditions of major interest for decarbonation of flue gas effluent. Moreover, the experimental results obtained from dynamic tests confirm the results derived from the batch tests in terms of CO₂ adsorption capacity. It is important to highlight the fact that the adsorption of N₂ on the synthesized AC samples can be considered to be negligible. Finally, the importance of proper analysis for data characterization and adsorption experimental results is highlighted for the correct assessment of the CO₂ removal performance of activated carbons at different CO₂ pressures and operating temperatures.