Hydrogen Production via Activated Waste Aluminum Cans and Its Potential for Methanation

Abstract

The production of hydrogen via aluminum waste can powder (AWCP) prepared via disintegration and mechanochemical activation using metals was explored. AWCP and its composites were reacted in 1 M NaOH to produce hydrogen at standard temperature (25 °C) condition. Ternary AWCP (3% Sn–3% Mg) composite produced the highest amount of H2 (660 mL/0.5 g in 660 s) in terms of weight percentage of AWCP used as compared to the best binary AWCP (3% Sn) with 680 mL of H2 produced in 240 s. The activation metals contributed microgalvanic activity in AWCP, which in result yielded higher hydrolysis of AWCP. The undoped AWCP, binary, and ternary composites were tested for batch methanation at 220 °C using CO2 gas and Ni based catalyst. H2 produced from aluminum–water reaction was successfully used to produce CH4 via continuous methanation process. However, not all the H2 produced participated in the reaction. This was mainly due to the role of gas hourly space velocity and the performance of the catalyst. Undoped AWCP performed better than binary and ternary composite despite higher amount H2 produced due to the gas hourly space velocity. The potential of AWCP as a raw material for H2 production and simultaneous methanation has led to a promising solution of producing clean, sustainable, and economical energy for the future.