Jankovic Jelena, Lukic Jelena, Kolarski Dejan, Veljović Djordje, Radovanović Željko, Dimitrijević Silvana
Electrical Engineering Institute Nikola Tesla, University of Belgrade, Koste Glavinica 8a, 11000 Belgrade, Serbia.
Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia.
Materials (Basel). 2023 May 4;16(9):3522. doi: 10.3390/ma16093522.
Elemental sulfur (S) is a corrosive sulfur compound which was found to be extremely reactive to silver, causing intensive silver sulfide (AgS) deposition on on-load tap changer (OLTC) contacts in power transformers. A highly selective adsorbent (HSA), called Tesla'Ssorb, for the removal of S from mineral insulating oils was prepared from raw material (RM) using the novel procedure. In this study, the adsorption properties of HSA for the removal of S from the oil were determined. RM and HSA were characterized using various techniques, such as field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD). The performance of HSA was determined by adsorption equilibrium, thermodynamic, and kinetic study through batch experiments, at various temperatures and initial concentrations of S. The obtained results were analyzed by Langmuir and Freundlich adsorption isotherms and it was found that equilibrium data were fitted better with the Langmuir isotherm model. The maximum adsorption capacity was 4.84 mg of S/g of HSA at 353 K. Thermodynamic parameters, such as enthalpy (ΔH°), Gibbs free energy (ΔG°), and entropy (ΔS°), were calculated and it was found that the sorption process was spontaneous (ΔG° < 0) and endothermic in nature (ΔH° > 0). It was found that the adsorption of S follows pseudo-second-order kinetic model, and the activation energy indicated the activated chemisorption process.
元素硫（S）是一种腐蚀性硫化合物，被发现对银具有极强的反应性，会在电力变压器的有载分接开关（OLTC）触点上导致大量硫化银（AgS）沉积。使用一种新方法从原材料（RM）制备了一种用于从矿物绝缘油中去除S的高选择性吸附剂（HSA），称为特斯拉吸附剂。在本研究中，测定了HSA从油中去除S的吸附性能。使用各种技术对RM和HSA进行了表征，如场发射扫描电子显微镜（FESEM）、能量色散X射线（EDX）和X射线衍射（XRD）。通过在不同温度和S初始浓度下的间歇实验，通过吸附平衡、热力学和动力学研究确定了HSA的性能。所得结果通过朗缪尔和弗伦德利希吸附等温线进行分析，发现平衡数据与朗缪尔等温线模型拟合得更好。在353K时，最大吸附容量为4.84mg S/g HSA。计算了热力学参数，如焓（ΔH°）、吉布斯自由能（ΔG°）和熵（ΔS°），发现吸附过程是自发的（ΔG°<0）且本质上是吸热的（ΔH°>0）。发现S的吸附遵循准二级动力学模型，活化能表明了活化化学吸附过程。
