Enhancement of CO2 Capture on Biomass-Based Carbon from Black Locust by KOH Activation and Ammonia Modification

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• 作者：Changming Zhang ; Wen Song ; Qingliang Ma ; Lijing Xie ; Xiaochao Zhang ; Hua Guo
• 刊名：Energy & Fuels
• 出版年：2016
• 出版时间：May 19, 2016
• 年：2016
• 卷：30
• 期：5
• 页码：4181-4190
• 全文大小：564K
• 年卷期：0
• ISSN：1520-5029

文摘

A novel biomass-based carbon material was successfully prepared from black locust by KOH chemical activation in combination with surface modification by heat treatment with ammonia solution for enhancing CO₂ adsorption. The textural and surface characteristics of the prepared activated carbons were analyzed with N₂ adsorption isotherms, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), elemental analysis, and X-ray photoelectron spectroscopy (XPS). The results show that the modified activated carbon possesses a high surface area of 2511 m²/g, a large micropore volume of 1.16 cm³/g, and a high nitrogen content of 7.21 wt %. The adsorption behavior of CO₂ onto all activated carbon samples was experimentally evaluated by a volumetric method at three different adsorption temperatures of 0, 25, and 50 °C under atmospheric pressure (1 bar). High CO₂ uptakes of 7.19 and 5.05 mmol/g at 0 and 25 °C were achieved for the sample AC-KOH-N due to its well-developed micropore structure and abundant basic nitrogen-containing functionalities. The thermodynamic parameters indicate that both physical adsorption and chemical adsorption mechanisms for CO₂ adsorption coexist in the sample AC-KOH-N. The sample AC-KOH-N also shows a good selectivity for CO₂/N₂ and fast adsorption kinetics that be easily regenerated with superior cyclic stability after multiple cycles. These results suggest that the obtained biomass-based activated carbon is promising for CO₂ capture.