(Ulsan = Yonhap News) Reporter Yongtae Kim = A technology has been developed to produce high-purity hydrogen and high-value-added chemical materials simultaneously using discarded solar panels, which are difficult to process.
The Ulsan National Institute of Science and Technology (UNIST) announced on the 6th that a research team led by Professor Baek Jong-beom from the Department of Energy and Chemical Engineering developed this highly efficient method.
Silicon can react with water to produce hydrogen and silica (silicon dioxide), but in reality, the reaction stops as a silica film forms on the surface immediately once the reaction starts, blocking water’s access. Consequently, hydrogen production does not reach the theoretical maximum yield.
The research team devised a method to remove this silica film without using strong chemicals. By placing silicon and water in a container with small beads and rolling it, the beads repeatedly break and peel off the silica protective film as they collide with the silicon particles.
Experimental results showed that about 1,706 mL of hydrogen was produced per gram of commercial silicon, which corresponds to 99.6% of the theoretical maximum yield.
This hydrogen production efficiency is up to five times higher compared to conventional thermochemical methods, which yield about 18-28% of the theoretical maximum.
Professor Baek Jong-beom stated, “The advantage is that we can produce hydrogen in an eco-friendly manner by utilizing silicon from discarded solar panels and also obtain silica that can be used industrially,” adding that “this can transform difficult-to-dispose waste panels into high-value-added resources, greatly helping to establish a resource-circulating economy.”
The research, supported by the National Research Foundation of Korea, was published online in the energy field journal “Joule” on the 27th of last month.