石墨烯基渗透蒸发杂化膜的制备及其汽油脱硫性能研究

发布时间：2018-05-09 02:20

本文选题：杂化膜 + 石墨烯　；参考：《天津大学》2015年硕士论文

【摘要】：随着各国日益严格的环保法规的出台,开发高效、低能耗的非加氢脱硫技术是实现清洁油品生产的核心问题。渗透蒸发膜法脱硫技术是极具工业化应用前景的脱硫技术之一。开发高渗透性、高选择性、高稳定性的膜材料则是渗透蒸发法用于脱硫的重要需求。本研究以二维材料石墨烯纳米片(GNS)为填充物,分别以橡胶态高分子聚二甲基硅氧烷(PDMS)和半结晶态高分子聚醚共聚酰胺(Pebax 2533)为膜主体材料,通过物理共混法制备了杂化膜,并将其用于汽油脱硫。以克服trade-off效应、强化脱硫性能为目标,调控高分子主体与高分子-无机界面结构,实现杂化膜自由体积特性、结晶度优化;通过在石墨烯片层表面高效负载促进传递物质,实现促进传递机制的优化。在用于渗透蒸发脱硫过程中,以期实现较好的长期稳定性及分离性能。主要研究结果如下:1.通过将GNS引入PDMS高分子基质中制备了PDMS-GNS杂化膜。GNS的引入优化了高分子膜主体结构,提高了杂化膜的自由体积分数。GNS表面具有丰富的大π键,可与噻吩发生π-π相互作用,使噻吩沿GNS表面在PDMS-GNS界面区域快速传递。制备的PDMS-GNS杂化膜的渗透通量与富集因子分别为6.22 kg/(m2h)与3.58。与PDMS空白膜相比,在富集因子基本保持不变的前提下,通量提升了65.9%。2.通过将聚多巴胺/石墨烯纳米片(PDA/GNS)引入Pebax高分子基质中制备了Pebax-PDA/GNS杂化膜。多巴胺对氧化石墨烯还原修饰,优化了疏水性Pebax与GNS界面相容性。PDA/GNS的引入有效地降低了杂化膜结晶度,提高了自由体积分数,优化了Pebax膜主体结构。制备的Pebax-PDA/GNS杂化膜的渗透通量与富集因子分别为3.94 kg/(m2h)与7.73。3.利用多巴胺氧化还原和生物粘合的特点,在PDA/GNS表面负载Ag,生成粒径较小、分散较好、负载量较高的Ag@PDA/GNS颗粒,将其引入Pebax高分子基质制备了Pebax-Ag@PDA/GNS杂化膜。Ag@PDA/GNS颗粒的掺杂降低了杂化膜结晶度,优化了杂化膜自由体积性;由于银离子与噻吩之间较强的π-络合作用,促进了噻吩在高分子-无机界面区的快速传递。当Ag@PDA/GNS填充量为8 wt%时,杂化膜的溶胀度为12.9%,与Pebax空白膜(22.7%)相比降低了43.2%。在Ag@PDA/GNS填充量为6 wt%时,在硫含量为500 ppm,操作温度313 K,流速为40 L/h条件下,渗透通量与富集因子分别为4.42 kg/(m2h)与8.76。当操作温度上升到343 K时,渗透通量与富集因子分别达到为22.53 kg/(m2h)与6.07。
[Abstract]:With the introduction of increasingly stringent environmental laws and regulations in various countries, the development of non-hydrodesulfurization technology with high efficiency and low energy consumption is the core problem to realize clean oil production. Pervaporation membrane desulfurization technology is one of the most promising desulfurization technologies in industrial application. The development of membrane materials with high permeability, selectivity and stability is an important requirement for desulfurization by pervaporation. In this study, the hybrid membranes were prepared by physical blending method, using two-dimensional graphene nansheet GNS as filler, rubber state polymer polydimethylsiloxane (PDMS) and semicrystallized polymer polyether copoly amide (PEBax 2533) as main materials. And it is used for desulfurization of gasoline. In order to overcome trade-off effect and enhance desulfurization performance, the structure of polymer body and polymer-inorganic interface is regulated, the free volume characteristic of hybrid membrane is realized, the crystallinity is optimized, and the transfer material is promoted by high efficiency loading on the surface of graphene lamellae. The optimization of the mechanism of promoting transmission is realized. In order to achieve good long-term stability and separation performance in the process of osmotic evaporation desulfurization. The main results are as follows: 1. By introducing GNS into the PDMS polymer matrix to prepare PDMS-GNS hybrid membrane, the main structure of the polymer membrane was optimized, and the free volume fraction of the hybrid membrane was increased. The surface of the hybrid membrane had abundant large 蟺 bonds and could interact with thiophene. The thiophene was transported rapidly along the GNS surface in the PDMS-GNS interface region. The permeation flux and enrichment factor of PDMS-GNS hybrid membrane were 6.22 kg / m ~ 2 h and 3.58 kg 路m ~ (-2) h, respectively. Compared with the PDMS blank membrane, the flux increased by 65.9%, while the enrichment factor remained unchanged. Pebax-PDA/GNS hybrid membrane was prepared by introducing PDA / GNS into Pebax polymer matrix. The addition of dopamine to the reduction modification of graphene oxide optimized the compatibility of hydrophobic Pebax and GNS interface. PDA / GNS effectively reduced the crystallinity of hybrid membranes increased the free volume fraction and optimized the main structure of Pebax films. The permeation flux and enrichment factor of the Pebax-PDA/GNS hybrid membrane were 3.94 kg / m ~ (2 h) and 7.73.3 h, respectively. Based on the characteristics of dopamine redox and biological bonding, Ag@PDA/GNS particles with smaller particle size, better dispersion and higher loading amount were formed by loading Agon on the surface of PDA/GNS. It was introduced into Pebax polymer matrix to prepare Pebax-Ag@PDA/GNS hybrid membrane. The doping of Pebax-Ag@PDA/GNS particles reduced the crystallinity of hybrid membrane, optimized the free volume of hybrid membrane, because of the strong 蟺 -complexation between silver ions and thiophene. The rapid transfer of thiophene in the polymer-inorganic interface was promoted. When the content of Ag@PDA/GNS was 8 wt%, the swelling degree of hybrid membrane was 12.9, which was 43.2% lower than that of Pebax blank membrane (22.775%). The osmotic flux and enrichment factor were 4.42 kg / m ~ (2 h) and 8.76 at the condition of Ag@PDA/GNS filling rate of 6 wt%, sulfur content of 500 ppm, operating temperature of 313K and flow rate of 40 L / h. When the operating temperature reached 343 K, the osmotic flux and enrichment factor reached 22.53 kg / m ~ (2 h) and 6.07 kg 路m ~ (-2) h, respectively.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE624.55;TQ051.893

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