Journal of Industrial and Engineering Chemistry ( IF 6.1 ) Pub Date : 2021-07-29 , DOI: 10.1016/j.jiec.2021.07.035 Adarsh Bhat 1 , Maithri Venkat 1 , Xiaoyin Chen 1 , Hiroko Ohtani 2 , Kevin Ellwood 2 , Tony Misovski 2 , Johannes W. Schwank 1
This study elucidates the factors responsible for the deterioration of beaded activated carbon (BAC), used in the abatement of volatile organic compounds that stem from painting processes in industries. In practice, continuous use of adsorbents during periodic adsorption–desorption results in the formation of heel (non-desorbable polymeric complex) in its pore structures, rendering the adsorbent eventually unusable. Here, the adsorption–desorption characteristics of VOCs from porous BAC are investigated, and an effective surface modification strategy is developed to impede heel formation and extend the operational life of the BAC. This modification protocol increases porosity by up-to 55 % and modifies the functional groups on the BAC surface without altering its structural integrity. Consequently, the adsorption capacity of the BAC increased by nearly 38% while decreasing the peak desorption temperature by as much as 50 °C due to lowered adsorption strength. Additionally, to provide mechanistic insights, the resultant changes in porosity, surface morphology, and adsorption–desorption characteristics of the BAC are investigated by N2 physisorption, SEM, TGA, and DRIFTS. Finally, cyclic adsorption–desorption studies conducted under conditions mirroring the industrial setup proved that the percentage heel accumulation in surface modified BAC is significantly lower (≤ 3%) compared to unmodified BAC.
中文翻译:
珠状活性炭的化学表面改性:一种抑制 VOC 堆积的策略
这项研究阐明了导致珠状活性炭 (BAC) 变质的因素,该活性炭用于减少工业喷漆过程中产生的挥发性有机化合物。实际上,在周期性吸附-解吸过程中连续使用吸附剂会导致其孔隙结构中形成残留物(不可解吸的聚合物复合物),最终导致吸附剂无法使用。在这里,研究了多孔 BAC 对 VOC 的吸附-解吸特性,并开发了一种有效的表面改性策略,以阻止跟部形成并延长 BAC 的使用寿命。这种修改协议将孔隙率增加了 55%,并修改了 BAC 表面上的官能团,而不会改变其结构完整性。最后,由于吸附强度降低,BAC 的吸附容量增加了近 38%,同时将峰值解吸温度降低了 50°C。此外,为了提供机理见解,通过 N 研究了 BAC 的孔隙率、表面形态和吸附-解吸特性的变化。2物理吸附、SEM、TGA 和漂移。最后,在反映工业设置的条件下进行的循环吸附-解吸研究证明,与未改性 BAC 相比,表面改性 BAC 中的脚跟堆积百分比显着降低(≤ 3%)。