ABSTRACT

Currently dioxide carbon and methane as the most important greenhouse gases are constantly being emitted to the atmosphere. Thus, to reduce the detrimental effects resulting from these gases, they must be captured and separated. In this regard, novel and low- cost nanoadsorbents based on cotton pulp, jute, and kenaf as carbon fibers were successfully synthesized and fabricated. In order to provide a micro-mesoporous structure, cotton pulp, jute, and kenaf as carbon fibers were carbonized at 600°C and then activated with KOH/C (named CP-AC, J-AC, and K-AC samples). The physicochemical properties of the fabricated nanoadsorbents were characterized by BET, FTIR, XRD, and ESEM analyses. Compared to the other nanoadsorbents used, J-AC nanoadsorbent displayed an enhanced CO₂ adsorption capacity at the pressure of 1 bar (5.7 mmol/g) and 35 bar (18.4 mmol/g). The fabricated nanoadsorbents created a high surface area (up to 1978 m²/g) with a pore volume of up to 0.95 cm ³/g. Several isotherm models were utilized to investigate the adsorption behavior of gases. It was found that Dual site Langmuir-Freundlich model better fitted the experimental data. The ideal adsorbed solution theory (IAST) was employed to calculate the adsorption selectivity and with the results revealing a considerable CO₂/CH₄ selectivity. The results also indicated that the fabricated nanoadsorbents at low pressures compared to the nanoadsorbent used in the literature have higher adsorption capacity for CO₂. To summarize, the synthesized nanoadsorbents provided an excellent adsorption capacity. Thus, they could be considered for CO₂ and CH₄ adsorption.

摘要

目前，作为最重要的温室气体的二氧化碳和甲烷不断地排放到大气中。因此，为了减少由这些气体引起的有害影响，必须将它们捕获并分离。在这方面，成功地合成和制造了基于棉浆，黄麻和洋麻作为碳纤维的新型低成本纳米吸附剂。为了提供微介孔结构，将棉纤维，黄麻和洋麻作为碳纤维在600°C下碳化，然后用KOH / C活化（命名为CP-AC，J-AC和K-AC样品）。通过BET，FTIR，XRD和ESEM分析表征了制备的纳米吸附剂的理化性质。与使用的其他纳米吸附剂相比，J-AC纳米吸附剂显示出增强的CO ₂在1 bar（5.7 mmol / g）和35 bar（18.4 mmol / g）的压力下的吸附容量。所制备的纳米吸附剂产生了高表面积（高达1978 m ² / g），孔体积高达0.95 cm ³ / g。利用几种等温模型研究气体的吸附行为。发现双站点Langmuir-Freundlich模型更好地拟合了实验数据。理想的吸附溶液理论（IAST）用于计算吸附选择性，结果显示出相当高的CO ₂ / CH ₄选择性。结果还表明，与文献中使用的纳米吸附剂相比，低压制备的纳米吸附剂对CO _2的吸附能力更高。。综上所述，合成的纳米吸附剂具有出色的吸附能力。因此，可以考虑它们对CO ₂和CH _4的吸附。