Studies of catalytic reactors

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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.