Hydrogen Production From the Scrap Aluminum Beverage Can Chips and Valorization of Byproduct Residue for CO2 Capture

Abstract

Abstract. In this study, we demonstrate the use of beverage cans collected from municipal waste as a source of aluminum to produce hydrogen. X-Ray fluorescence analysis of the decoated beverage can indicates that it contains about 95.0% aluminum. The influence of various physicochemical factors, including chip size, reaction temperature, and the concentration of promoters, co-promoters, and water sources, on the reaction rate and overall hydrogen yield was investigated systematically. By comparing with different promoters, the results demonstrate that hydroxide promoters show encouraging results of the initial removal of the passivating oxide layer, and the combination of sodium hydroxide with the boehmite gives a very high rate of hydrolysis reaction and generates hydrogen at a rate as high as 467.78 mLSTP min−1 g−1 with a purity greater than 99.9% at 80 °C. It is further demonstrated that the generated byproduct, identified as aluminum trihydroxide mainly, can easily be transformed into different crystallographic phases after calcination at higher temperatures. The specific surface area, pore volume, and average pore size of the calcined byproduct were about 197 m2/g, 0.52 cm3/g, and 11.0 nm, respectively. Furthermore, the CO2 uptake capacities of polyethylenimine (PEI)-modified adsorbents from calcined byproduct, commercial gamma-alumina, and zeolite 13X were measured and compared to verify the suitability of the adsorbent prepared from calcined byproduct. The PEI-impregnated byproduct adsorbent exhibited a maximum CO2 uptake of 1.84 CO2/g sorbents at 75 °C in a 9.66% CO2/N2. The results suggest that the byproduct residue can potentially be used for various adsorption applications.