Studies of catalytic reactors

氢气生产和净化的新工艺：我们在这个项目中的主要目标是研究生产用于燃料电池的高纯度高压氢气的新工艺。我们一直对高压操作感兴趣，它承诺通过对液体前体加压，在更高的压力下进行整个脱氢和净化，而不是在接近大气压的情况下对传统工艺产生的气态氢加压，从而显著节省成本。这样就节省了压缩氢产物的能量（或功）。在我的化学反应器工程实验室里，我最近指导了乙醇的蒸汽重整研究，并在乙醇和乙醛之间建立了一个循环，将合成气转化为氢气，几乎不需要进一步净化氢气。为此，设计并建造了一套高度自动化的高压反应器系统。乙醇蒸汽重整的目的是寻找一种有吸引力的催化剂。在最近完成的研究中，我们对这些催化剂进行了全面的表征，并研究了随着时间的推移性能的损失。我们的工作证实：1)乙醇脱氢生成氢和乙醛的过程在300°C下快速进行，选择性高；2)乙醛在250°C下很容易在cu基催化剂上氢化成乙醇。我们现在打算为乙醇重整和乙醛循环的高压操作寻找合适的催化剂。我们将尝试在环境压力下重现一些早期的测量结果，作为我们高压工作的基线。最初，实验将扩展到更高的压力（2至5巴）。对于催化剂的开发，我建议研究使用铜水滑石作为催化剂。

Novel Processes for Hydrogen Production and Purification: Our primary objective in this program already in place is to investigate novel processes for production of high-purity, high-pressure hydrogen for use in fuel cells. Our interest has been in high-pressure operation which promises significant savings by pressurizing liquid precursors and conducting the entire dehydrogenation and purification under increased pressure instead of having to pressurizing the gaseous hydrogen produced from conventional processes near atmospheric pressure. In this way, the energy (or work) of compressing the hydrogen product is saved. In my chemical reactor engineering laboratory, I have recently directed studies on the steam reforming of ethanol and in a novel process built on a cycle between ethanol and acetaldehyde that converts synthesis gas into hydrogen with virtually no further purification of the hydrogen. For these studies, a highly automated high-pressure reactor system has been designed and built. Steam reforming of ethanol has been directed at finding an attractive catalyst. In research recently completed, we have thoroughly characterized these catalysts and also studied loss of performance with time on stream. Our work confirms that 1) the dehydrogenation of ethanol to form hydrogen and acetaldehyde proceeds rapidly at 300°C with high selectivity and 2) acetaldehyde is easily hydrogenated to ethanol at 250°C on Cu-based catalysts. We now intend to find suitable catalysts for high-pressure operation in both the ethanol reforming and the acetaldehyde cycle. We will attempt to reproduce some earlier measurements at ambient pressure as a baseline for our high-pressure work. Initially, experiments will be extended to higher pressures (2 to 5 bar). For catalyst development, I propose to examine the use of Cu hydrotalcites as catalysts.