物理吸附储氢的最佳条件分析

发布时间：2018-04-26 13:10

  本文选题：固体储氢 + 物理吸附　； 参考：《西北师范大学》2015年硕士论文

【摘要】：化石能源已经濒临枯竭,同时由于其大量使用,给地球环境带来了巨大负面影响。寻找一种储量丰富、清洁、可再生的新型能源迫在眉睫。氢气是未来的一种理想燃料,但是它必须从水或其他化合物中生产出来,所以目前只能说是一种能量载体而非能源。要实现氢的大规模使用必须先解决氢气的生产和储存问题。在这些问题中,氢气的安全储运是氢能应用需要解决的一项关键技术,普通的压缩储氢和液态储氢花费大、存在安全隐患,而且其能量密度分别只有4.4 MJ/L和8.4 MJ/L,与汽油31.6 MJ/L的能量密度相差甚远。理想的储氢方法是固态储氢,即在常温常压附近将氢气吸附在某种固体材料上。美国能源部制定的未来储氢目标是质量百分比为7.5 wt%,体积密度为70g/L,操作温度为-40—85℃,压强为120 bar,6 kg氢气的充气时间小于3分钟,整个储存系统要安全、耐用、便宜。固体储氢可粗略分为两类:物理吸附和化学吸附。物理吸附的主要材料为大比表面积多孔材料,如活性炭,纳米结构材料和金属有机骨架化合物等,这类材料在77 K时有很大的氢气吸附量,但在298 K时其储氢量却不足1 wt%。物理吸附在室温下的储氢量之所以很低是因为它们与氢分子的相互作用太弱,其结合能小于10 kJ/mol。关于物理吸附的理想结合能,科学家们具有不同的观点,本文基于Langmuir单层吸附模型分析了压强、温度和吸附热对物理吸附的影响。推荐的物理吸附压强为50—100 bar,在室温下要实现最大吸附,其结合能必须达到-33.5 kJ/mol。
[Abstract]:Fossil energy has been on the verge of exhaustion and has brought great negative effects to the earth's environment due to its extensive use. It is urgent to find a new energy source which is rich in reserves, clean and renewable. Hydrogen is an ideal fuel for the future, but it must be produced from water or other compounds, so for now it can only be said to be an energy carrier rather than a source of energy. In order to realize the large-scale use of hydrogen, the production and storage of hydrogen must be solved first. Among these problems, the safe storage and transportation of hydrogen is a key technology to be solved in hydrogen energy application. The energy density is 4.4 MJ/L and 8.4 MJ / L, respectively, which is very different from that of gasoline for 31.6 MJ/L. The ideal hydrogen storage method is solid hydrogen storage, that is, hydrogen is adsorbed on a solid material near normal temperature and pressure. The future hydrogen storage target set by the US Department of Energy is 7.5 wts mass percent, 70 g / L bulk density, -40-85 鈩，

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