高性能碳素材料杂化炭膜的制备及基础应用研究

发布时间：2018-01-07 10:27

  本文关键词：高性能碳素材料杂化炭膜的制备及基础应用研究　出处：《沈阳工业大学》2017年硕士论文　论文类型：学位论文

  更多相关文章： 杂化炭膜 磁场 气体分离性 炭膜反应器

【摘要】：膜技术是近半个世纪发展起来的一种分离技术,具有分离效率高、操作简单、能耗低等优点,得到了广泛的应用。然而,市场上传统的有机膜热稳定性、化学稳定性和分离性较差,迫切需要开发新型高性能膜材料。炭膜是一种新型无机膜材料,近几十年得到广泛关注,它既可以克服有机膜的缺点,又具有良好的分离性能。然而,炭膜存在的造价高、质地脆等问题,严重制约了大规模工业化应用。鉴于此,本文制备了具有较高强度的支撑炭膜,同时通过掺杂碳素材料优化微观结构与分离性能;另外,研究了其在强化甲醇制氢反应的应用。首先,以BTDA-ODA型聚酰亚胺为前驱体材料,以石墨烯、碳纳米管和活性炭纤维等多种碳素材料为掺杂剂,制备了非支撑杂化炭膜;采用TGA、FTIR、XRD、SEM等先进手段分析了前驱体在热解过程中的热解行为、表面元素或官能团变化,及所得炭膜微观形貌和结构的演变。通过磁场优化炭膜的微观结构和制备工艺过程。再以高机械强度的多孔炭板为支撑体,通过旋涂成膜法,经干燥成膜及炭化等步骤制备得到支撑炭膜。考察了支撑体成型压力、掺杂剂用量、渗透温度、渗透压力等条件对支撑炭膜微结构及气体分离性的影响。最后,将所制备支撑炭膜用于强化甲醇重整制氢反应过程,研究了反应温度、反应时间、催化剂载体、炭膜分离性等因素对反应转化率和收率的影响。结果表明:(1)在成膜过程中,外加磁场有利于提高最终所制备炭膜的气体渗透性。当磁场强度为10Gs时,炭膜的渗透性分别为546Barrer(H2)、349Barrer(CO2)、148Barrer(O2)、24Barrer(N2);同时,选择性分别为22.5(H2/N2)、6.1(O2/N2)、14.4(CO2/N2)。(2)非支撑碳素材料杂化炭膜的气体分离性能大多分布于Robeson图上限,极具有商业价值。(3)石墨烯与母体兼容性良好,可大幅度提升炭膜的气体渗透性。当石墨烯质量分数为0.3%时,支撑炭膜对H2、CO2、O2、N2的渗透性分别达5229Barrer、1315Barrer、1123Barrer、529Barrer,对H2/N2、CO2/N2和O2/N2选择性分别为9.9、2.5和2.4。(4)在甲醇水蒸气重整制氢反应中,固定床反应器的最佳反应温度为260oC时,甲醇转化率为71.33%,H2收率为21.39%;炭膜反应器的最佳反应温度为280oC时,甲醇转化率与H2收率分别为93.29%和29.15%。
[Abstract]:Membrane technology is a separation technology developed for nearly half a century, has a high separation efficiency, simple operation, low energy consumption, has been widely used. However, the traditional market of organic film thermal stability, chemical stability and separation is poor, it is urgent to develop a new high performance membrane material is a new type of carbon membrane. Inorganic membrane materials, has received extensive attention in recent decades, it can overcome the shortcomings of the organic film, and has a good separation performance. However, the high cost of carbon membrane, crisp texture and other issues, has seriously restricted the application of large-scale industrialization. In view of this, supported carbon membranes with high strength were prepared at the same time by doping carbon materials to optimize the micro structure and separation performance; in addition, the research on its application in the enhancement of hydrogen production by methanol reaction. Firstly, the BTDA-ODA type polyimide precursor materials, graphene, carbon nanotubes The activated carbon fiber and other carbon materials as doping agent, non supported hybrid carbon membranes were prepared using TGA, FTIR; XRD, SEM and other advanced means the pyrolysis behavior of the precursor in the pyrolysis process were analyzed, the surface elements or functional groups, and the evolution of the morphology and structure of carbon membrane. Through magnetic field optimization carbon membrane microstructure and preparation process. Using porous carbon plate with high mechanical strength as support, by spin coating method, drying and carbonization of film prepared by supported carbon membranes was studied. The supporting body molding pressure, amount of dopant, infiltration temperature, pressure and other conditions penetration of the supported carbon membranes microstructure and gas separation. Finally, the system used to strengthen the methanol reforming process to prepare supported carbon membranes, the reaction temperature of reaction time, catalyst carrier, carbon membrane separation and other factors on the reaction conversion rate and yield 鐨勫奖鍝，

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