Abstract:
A series of adsorbents (activated carbons, ACs) were synthesized by physical and chemical activation of olive stones (OS) and their textural and chemical characteristics determined by complementary techniques such as N2 and CO2 physisorption, pH of the point zero of charge (pHPZC), HRSEM or XPS. Samples with a wide range of physicochemical properties were obtained by fitting the activation procedure. The performance of these adsorbents in filters working under dynamic conditions was studied by determining the corresponding breakthrough curves for the ethylene removal. The physicochemical transformations of OS during activation were related with the adsorptive performance of derivative ACs. Results were compared to those obtained using commercial carbons, in particular ACs, carbon black or carbon fibers, in order to identify the properties of these materials on influencing the adsorptive performance. In general, ACs from OS perform better than the commercial samples, being also easily regenerated and properly used during consecutive adsorption cycles. CO2-activation showed to be the best synthesis option, leading to granular ACs with a suitable microporosity and surface chemistry. These results could favour the integration of this type of inexpensive materials on devices for the preservation of climacteric fruits, in a clear example of circular economy by reusing the agricultural residues.
摘要:
一系列吸附剂(活性炭,ACs)是通过橄榄石(OS)的物理和化学活化合成的,它们的质地和化学特性是通过N2和CO2物理吸附等互补技术确定的,电荷零点的pH值(pHPZC),HRSEM或XPS。通过拟合活化程序获得具有广泛理化性质的样品。通过确定去除乙烯的相应穿透曲线,研究了这些吸附剂在动态条件下工作的过滤器中的性能。活化过程中OS的物理化学转化与衍生AC的吸附性能有关。将结果与使用商业碳获得的结果进行比较,特别是AC,炭黑或碳纤维,为了确定这些材料的性质对吸附性能的影响。总的来说,操作系统的AC比商业样本表现更好,在连续的吸附循环中也容易再生和适当使用。CO2活化被证明是最好的合成选择,导致具有合适的微孔性和表面化学性质的颗粒状AC。这些结果可能有利于将这种廉价材料集成到更年期水果保存设备上,在循环经济的一个明显的例子中,通过重复使用农业残留物。