当前位置: X-MOL 学术Ind. Eng. Chem. Res. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Heel Buildup during Thermal Desorption of Volatile Organic Compounds off Beaded Activated Carbon in the Presence of Oxygen Impurity
Industrial & Engineering Chemistry Research ( IF 3.8 ) Pub Date : 2022-01-18 , DOI: 10.1021/acs.iecr.1c04320
Seyed Mojtaba Hashemi 1 , Mohammad Feizbakhshan 1 , Zaher Hashisho 1 , John H. Phillips 2 , James E. Anderson 3 , Mark Nichols 3
Affiliation  

The presence of low-level oxygen in the purge gas during thermal regeneration triggers chemical reactions resulting in heel formation, which reduces the adsorption capacity and lifetime of the adsorbent. In this study, the effect of regeneration purge gas oxygen impurity on adsorption/regeneration of five aliphatic and six aromatic volatile organic compounds on activated carbon was investigated. Compounds were tested in five-cycle adsorption/regeneration experiments, with regeneration at two different levels of oxygen in nitrogen (≤5 and 10,000 ppm). Comparison of results for the different adsorbates showed that the effect of the oxygen content in the purge gas is dependent on the nature of the adsorbate. The increased oxygen concentration resulted in higher heel formation for alkyl-substituted aromatic adsorbates but less so for benzene and aliphatic adsorbates. Derivative thermogravimetric analysis of the regenerated samples showed extensive chemisorption of species for adsorbates with the highest heel formation, while physisorption was the dominant heel formation mechanism for the other adsorbates with less heel formed. The results suggest that the presence of oxygen in the regeneration purge gas at high temperature promotes chemical reactions between oxygen and the adsorbate, which adversely affect thermal regeneration efficiency, depending on the functionality and nature of the adsorbate.

中文翻译:

在氧杂质存在的情况下,珠状活性炭上的挥发性有机化合物热解吸过程中的脚跟堆积

在热再生过程中,吹扫气体中存在的低含量氧气会引发化学反应,导致形成尾状物,从而降低吸附剂的吸附能力和使用寿命。在这项研究中,研究了再生吹扫气中的氧杂质对五种脂肪族和六种芳香族挥发性有机化合物在活性炭上吸附/再生的影响。化合物在五循环吸附/再生实验中进行了测试,在氮气中两种不同水平的氧气(≤5 和 10,000 ppm)下进行了再生。不同吸附物的结果比较表明,吹扫气体中氧含量的影响取决于吸附物的性质。增加的氧浓度导致烷基取代的芳族吸附物形成较高的尾随物,但苯和脂肪族吸附物的形成较少。再生样品的衍生热重分析表明,对于具有最高鞋跟形成的吸附物,物质的广泛化学吸附,而对于其他形成较少鞋跟的吸附物,物理吸附是主要的鞋跟形成机制。结果表明,高温下再生吹扫气体中氧气的存在促进了氧气和吸附物之间的化学反应,这对热再生效率产生了不利影响,具体取决于吸附物的功能和性质。再生样品的衍生热重分析表明,对于具有最高鞋跟形成的吸附物,物质的广泛化学吸附,而对于其他形成较少鞋跟的吸附物,物理吸附是主要的鞋跟形成机制。结果表明,高温下再生吹扫气体中氧气的存在促进了氧气和吸附物之间的化学反应,这对热再生效率产生了不利影响,具体取决于吸附物的功能和性质。再生样品的衍生热重分析表明,对于具有最高鞋跟形成的吸附物,物质的广泛化学吸附,而对于其他形成较少鞋跟的吸附物,物理吸附是主要的鞋跟形成机制。结果表明,高温下再生吹扫气体中氧气的存在促进了氧气和吸附物之间的化学反应,这对热再生效率产生了不利影响,具体取决于吸附物的功能和性质。
更新日期:2022-01-26
down
wechat
bug