过渡金属改性Y型分子筛吸附脱除低碳烃中二甲基二硫醚

发布时间：2018-04-15 15:20

  本文选题：脱硫 + 烯烃　； 参考：《化工进展》2017年06期

【摘要】：采用离子交换法制备了CoY、CuY、NiY分子筛,并在固定床吸附器上考察了工艺条件及原料烯烃含量对改性分子筛吸附脱除二甲基二硫醚性能的影响。采用密度泛函理论计算二甲基二硫醚及异丁烯在CoY、CuY、NiY分子筛上的竞争吸附行为。最后考察了高温水蒸气对吸附剂的再生效果。结果表明,CoY、CuY和NiY分子筛对二甲基二硫醚的动态饱和吸附硫容分别为47.5mg/g、36.3mg/g和40.2mg/g;其中CoY和NiY分子筛硫容量受烯烃含量的影响较大,CuY分子筛受影响较小。计算结果表明,吸附过程中S—S键的Mayer键级变化不大,烯烃中C=C键双键性质减弱。二甲基二硫醚在CoY、CuY和NiY分子筛上的吸附能分别为 59.5k J/mol、 22.2k J/mol和 30.4k J/mol,与实验数据吻合。吸附饱和后的分子筛经160℃水蒸气脱附60min后能够有效再生,且多次再生后吸附剂硫容仍保持在新鲜吸附剂的97%以上。
[Abstract]:CoYCU CuY NiY molecular sieve was prepared by ion exchange method. The effects of process conditions and olefin content of raw materials on the adsorption and removal of dimethyl disulfide by modified molecular sieve were investigated on a fixed bed adsorbent.The competitive adsorption behavior of dimethyl disulfide and isobutene on CoY CuY NiY molecular sieve was calculated by density functional theory (DFT).Finally, the regeneration effect of high temperature water vapor on adsorbent was investigated.The results show that the dynamic saturated adsorption sulfur capacities for dimethyl disulfide are 47.5 mg / g 36.3 mg / g and 40.2 mg / g for CoY and NiY molecular sieves respectively, and the sulfur capacity of CoY and NiY zeolites is greatly affected by olefin content.The calculated results show that the Mayer bond order of S-S bond changes little during the adsorption process, while the double bond property of C / C bond in olefins weakens.The adsorption energies of dimethyl disulfide on CoyniCuY and NiY zeolites are 59.5 k / mol, 22.2k J/mol and 30.4kJ / mol, respectively, which are in agreement with the experimental data.The adsorbed saturated molecular sieve can be effectively regenerated after desorption of 60min by water vapor at 160 鈩，

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