Progress towards the industrial implementation of hydrogen purification processes

E.M. BORZONE; A. BARUJ; G. MEYER

Rio de Janeiro

Conferencia; 22nd World Hydrogen Energy Conference (WHEC 2018); 2018

The Hydrogen Laboratory Coppe ? Federal University of Rio de Janeiro

Hydrogen is an important consumable in many processes found in the oil, chemical, food and metallurgical industries, among others. In the case of heat treatments for surface reduction, commonly found in the metallurgical industry, the gas acquires a small proportion of contaminants during its use and is usually discarded immediately after. The recovery of this gas could represent a considerable improvement on the global production costs. However, the hydrogen purification systems commercially available, such as PSA, have been developed for hydrocarbon-based production scale and are not suitable at the mid- to small- scale scenarios that can be found in other industries. On the other hand, PSA is also not suitable to eliminate inert gas contaminants. Thus, there is an opportunity for developing hydrogen purification systems oriented to applications in these scales. We have developed, at a prototype scale, two different hydrogen purification processes that work in a continuous flow schema, aiming to their application in particular cases related to the nuclear industry. One of them is based on the use of hydride forming materials, and the other in dense metallic membranes made of palladium alloys. Both processes are potentially convenient in scenarios where commercially available solutions are not. Specifically, we are aiming at an ongoing technical assistance project with FAE SA. This company uses important amounts of high-purity hydrogen as a surface reduction agent in metallic products production processes. During this process, the gas is contaminated with small amounts of impurities and then burnt in a stove and vented. The project goal is to purify this hydrogen-rich gas and the subsequent reinjection of the recovered hydrogen at the process inlet as a way to reduce production costs.Along this line of work, we installed in the production facility, at a pilot scale, a modular purification prototype allowing the implementation of the two proposed processes. The objective was to obtain operational information to choose the most convenient option for the full-scale model and to identify the design improvements that could be necessary. For this stage we processed about 1% of the gas flow. In this work, we present the detailed design of the modular device, the experimental sequence implemented for both options, the main results obtained, and the criteria considered for their evaluation.