Even though there are various methods for generating hydrogen from water such as electrolysis and photocatalytic methods, the primary challenge in the whole process remains safe and economical storage of hydrogen. Using aluminum, however, seems to be a solution to this challenge. Chemical and physical properties of aluminum favor production of hydrogen gas especially on alloys of aluminum. When aluminum is modified through plasma activation process, the hydrogen production process becomes more efficient. This is because the activation process induces the effects of hydrophilicity which enables the metal to sink in water. It aids polar molecules formation leading to high surface tension and formation of hydrogen bonds hence allowing the metal sink.
Researchers from Center for Hydrogen Energy Technologies at Lithuanian Energy Institute and led by Dr. Darius Milcius investigated the effect of plasma-modified aluminum on hydrogen production. Their experiments involved plasma treatment and analysis using XRD and XPS analysis methods as well as measurements of the hydrogen volumes produced. Due to its effectiveness and efficiency, the work has been published in Energy Technology journal.
The research team was able to measure the amount of hydrogen produced. Inert gas fusion was used to facilitate the measurement due to high reactive nature of hydrogen. From the tests, it only required one minute from the start of the reaction to start generating hydrogen. The process is, however, longer and could continue for approximately 20 minutes before the reaction completes.
Aluminum was chosen by the authors due to its advantages. First, it is cheap and readily available as compared to other metals which could have however been used as well. Aluminum oxide is a highly reactive metal quickly oxides to form a protective layer. The layer prevents any reaction between aluminum and water to take place. As a result, aluminum was modified to gain hydrophilic property that enables it to sink in water and hence inducing the required reaction. The best practice is to perform the plasma-activation process under low temperatures.
The reaction between aluminum and water involves three phases. According to the authors, the first phase otherwise known as induction time refers to the period from which the metal is immersed in water up to the time when hydrogen generation begins. First reaction stage follows. Most of the reactions take place since the oxide layer preventing reaction no longer exists. In the final step, all the reactions are completed and required end products formed. A modified aluminum plasma performs very well and produces a significant amount of end
Darius Milcius and his research team are focused on revolutionizing hydrogen production. The method is inexpensive, provides a better way of harnessing and storing produced hydrogen or oxygen and hence should be adopted by technologists, chemists and other scientists and researchers. The reaction between water and plasma-modified aluminum is environment-friendly due to limited pollution effects as compared to other available methods. Another added advantage is that other products such as aluminum can also be produced through this kind of reaction.
Urbonavicius, M., Varnagiris, S., & Milcius, D. (2017). Generation of Hydrogen through the Reaction between Plasma-Modified Aluminum and Water. Energy Technology, 5(12), 2300-2308.Go To Energy Technology