Hydrogen Generation from Waste Aluminum Foil AA 1235 Promoted by Sodium Aluminate in Sodium Hydroxide Solutions

Abstract

The primary barrier to hydrogen production through the aluminum-water reaction is the oxide layer which forms on the exterior surface of the aluminum. In this work, the passivation was minimized by optimizing the concentration of sodium hydroxide solution (0.3 - 0.5 M) promoted by NaAlO2 at room temperature reaction conditions. The aluminum used is waste aluminum foil AA1235 chips having dimensions of 20 mm x 30 mm. The results showed that the hydrogen production rate increases as the NaOH solution concentration increases. The higher the solution’s pH, the shorter the hydrolysis process of the alumina layer, hence the hydrogen production is faster. Adding NaAlO2 as a promoter could increase the hydrogen production rate compared to sole NaOH, i.e., 11.162 ml/minute and 9.86 ml/minute, respectively. This increase occurred significantly during the fast reaction stage. It indicates that the solution containing NaOH and NaAlO2 work synergistically whereby NaOH can accelerate the reaction rate in the aluminum core and NaAlO2 functions as the booster for producing Al(OH)3.