School of Chemistry and Biochemistry, Thapar Institute of Engineering & Technology, (Deemed to be University), Patiala, 147004, Punjab, India.
Department of Chemical Engineering, Thapar Institute of Engineering & Technology (Deemed to be University), Patiala, 147004, Punjab, India.
J Environ Manage. 2019 Nov 15;250:109457. doi: 10.1016/j.jenvman.2019.109457. Epub 2019 Aug 28.
Nitrogen and oxygen enriched carbons were prepared by the cost-effective synthesis route of carbonization of polyacrylonitrile (PAN) and subsequent KOH activation for CO capture. The effect of four impregnation mass ratios (KOH: PAN = 1-4) and activation temperatures (600-900 °C) on the synthesized carbon adsorbent properties was explored by different analyses. The X-ray photoelectron spectroscopy (XPS) revealed the existence of basic nitrogen and oxygen functionalities on the adsorbent's surface which increases the adsorption rate for CO by providing its basic sites. By increasing mass ratio (KOH:PAN) from 1:1 to 3:1, the surface area increased from 1152.4 to 1884.2 m g and the dynamic CO adsorption capacity also increased from 2.1 to 2.5 mmol g respectively, at 30 °C (approximately ten times the adsorption capacity of untreated PAN, 0.22 mmol g). Physisorption and exothermic nature of the process were confirmed by the decrease in the adsorption capacity of the adsorbents with the increase in adsorption temperature. Moreover, good cyclic stability and regenerability over 5 adsorption-desorption cycles were obtained for the adsorbents. The fractional order kinetic and Temkin isotherm models fitted best with the adsorption data. A heterogeneous interaction between CO and the surface of adsorbents was suggested by the isosteric heat of adsorption values. Combined with the simple method for the preparation of activated carbon adsorbents, efficient CO adsorption and excellent regeneration make it appropriate adsorbents for post-combustion CO capture.
氮气和氧气富碳材料是通过经济有效的聚丙烯腈（PAN）碳化和随后的 KOH 活化合成路线制备的，用于 CO 捕集。通过不同的分析方法，探索了四种浸渍质量比（KOH：PAN=1-4）和活化温度（600-900°C）对合成碳吸附剂性能的影响。X 射线光电子能谱（XPS）揭示了吸附剂表面存在碱性氮和氧官能团，通过提供碱性位来增加 CO 的吸附速率。通过将质量比（KOH：PAN）从 1：1 增加到 3：1，比表面积从 1152.4 增加到 1884.2 m²/g，在 30°C 时的动态 CO 吸附容量也从 2.1 增加到 2.5 mmol/g（未处理 PAN 的吸附容量约为 10 倍，0.22 mmol/g）。吸附剂吸附容量随吸附温度的升高而降低，证实了该过程为物理吸附和放热过程。此外，吸附剂在 5 次吸附-解吸循环中表现出良好的循环稳定性和可再生性。分数阶动力学和 Temkin 等温线模型最适合吸附数据。吸附热值表明 CO 与吸附剂表面之间存在非均相相互作用。结合高效 CO 吸附和出色的再生性能，这种简单的活性炭吸附剂制备方法使其成为适合用于燃烧后 CO 捕集的吸附剂。
