The production of hydrogen as an alternative energy carrier from aluminium waste

Abstract

Background: Aluminium dross is a valuable resource that is often redirected to landfill as there are no real viable solutions for the utilisation of this industrial waste. A study has been conducted to provide a recycling process where the dross is reacted with an alkaline solution in order to generate hydrogen with bayerite and gibbsite products. Methods: Samples of aluminium dross were obtained from two sources: aluminium dross obtained from an aluminium recycling facility, recycled dross (RD) in Qatar and aluminous dross samples which were to be directed to landfill, landfill dross (LD), also in Qatar. Quantities of each sample were weighed in amounts that would contain equal amounts of aluminium reacting with an aqueous NaOH solution to generate hydrogen. The generated hydrogen has been analysed and compared with that reported in the literature. Results: Certainly, the lower purity sample LD was treated at a lower standard than the recycled dross. The LD and RD samples generated 0.15 and 0.5 g/l Al, respectively, with the landfilled dross achieving a maximum flow rate of 0.8 l/min compared to an RD which generated hydrogen at 2 l/min. The results proved that both forms of aluminium dross possess the potential to provide an acceptable volume of hydrogen at relatively consistent flow rates. The RD sample provided higher flow rates, and the LD sample generated hydrogen at a lower but consistent flow rate for a longer period and at a volume rather close to that of the RD sample. XRD analysis of the resulting product also yielded promising results with the formation of bayerite and gibbsite, which would provide additional side products of market value; if this process will be conducted on a larger scale. Conclusions: This study has shown very promising results, with both dross samples allowing for an acceptable production of hydrogen. It has shown that the utilisation of dross can be a potentially economically viable process for a product that provides clean, renewable energy and residual aluminous products of a real market value.

Heat and power storage using aluminium for low and zero energy buildings

“…from soft drink cans for obtaining hydrogen in the presence of sodium hydroxide [22,23]. Also, heavily adulterated scrap aluminium, which is not suitable for recycling and secondary aluminium production can be used for hydrogen production [24]. However, aluminium alloy composition may have an influence on the conversion degree [10].…”

Gas quantity and composition from the hydrolysis of salt cake from secondary aluminum processing

“…Therefore, H 2 gas generation from the hydrolysis of SC in MSW landfills poses a particular concern from an engineering control perspective. On the other hand, it became a useful approach and opportunity to generate hydrogen from aluminum wastes as a new source of energy (David and Kopac 2012;Elsarrag et al 2017;Hiraki et al 2007;Huang and Tolaymat 2015;Li et al 2017;Shkolnikov et al 2011).…”

Studies on Water–Aluminum Scrap Reaction Kinetics in Two Steps and the Efficiency of Green Hydrogen Production

“…Instead of using chemical promoters, such as hydroxides, oxides, or salts, the authors of [5] dealt with ball milling as a pretreatment and carried out the reaction in hot water. In [6], the difference between Al dross obtained from an aluminum recycling facility (RD) and Al dross directed to landfills (LD) was studied. The authors reported that, with NaOH as the promoter, the RD and LD samples generated 0.50 and 0.15 L of H 2 per 1g of Al, respectively.…”