金属镍中空纤维膜的制备与透氢性能研究

发布时间：2018-03-13 01:19

  本文选题：金属镍　切入点：相转化　出处：《天津工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：氢气是重要的石油化工原料,作为清洁能源能有效缓解由于温室气体排放造成的环境污染。传统金属钯及其合金膜在氢气分离应用中存在着成本高、不耐高温、极易氢脆等缺点,金属镍膜克服了传统钯膜这些缺点,对于重整气分离氢有很大应用前景。本文运用干湿纺丝法制备了金属镍中空纤维膜前驱体,并探索了纺丝条件对膜厚度的影响,进一步通过烧结技术得到致密的金属镍中空纤维膜。结合机械强度、XRD、SEM等表征手段对所得到的金属镍中空纤维膜进行表征,并对金属镍中空纤维膜进行了透氢测试。首先成功制备了金属镍中空纤维膜前驱体,实验结果表明在含氢气混合气的气氛下,经过1400℃左右烧结3小时,能够得到所需的致密的金属镍中空纤维膜。透氢测试在温度高达1000℃下进行,原料气是含氢的混合气,氮气作为吹扫气。氢气渗透经过致密金属镍中空纤维膜的控速步骤主要是通过氢原子扩散控制。金属镍膜的厚度在256μm,在1000℃下氢气的渗透通量能够达到7.66× 10-3 mol m~(-2) s~(-1),并且达到100%的氢气选择性。金属镍膜在含CO_2、CO、水蒸气的气氛下表现高的氢气选择稳定性,显示其在高温下烃重整制氢中潜在的应用。然后通过控制芯液流速和空气距这两个纺丝条件制备出了不同厚度的金属镍中空纤维膜。实验表明在纺丝的过程中留有一定的空气距有利于形成具有更高机械强度的中空纤维膜。金属镍中空纤维膜的透氢通过西韦特方程进行描述,这表明可以通过进一步减小膜的厚度来减小扩散的阻力来提高膜的透量。通过顺流模式切换到逆流模式中空纤维膜的透氢速率能提高4-8%。金属镍中空纤维膜在不同操作条件下的透氢结果可以通过数学模型的计算进行预测。
[Abstract]:Hydrogen is an important petrochemical raw material. As a clean energy, it can effectively alleviate the environmental pollution caused by greenhouse gas emissions. Traditional palladium and its alloy membrane have high cost and high temperature resistance in hydrogen separation. Metal nickel membrane overcomes these shortcomings of traditional palladium membrane and has great application prospect for hydrogen separation by reforming gas. In this paper, nickel hollow fiber membrane precursor was prepared by dry and wet spinning method. The influence of spinning conditions on the membrane thickness was explored, and the dense nickel hollow fiber membrane was obtained by sintering technology. The metal nickel hollow fiber membrane was characterized by means of mechanical strength and XRDX SEM. Firstly, the metal nickel hollow fiber membrane precursor was successfully prepared. The experimental results showed that the precursor was sintered at 1400 鈩，

本文编号：1604178