Productive and Sustainable H2 Production from Waste Aluminum Using Copper Oxides-Based Graphene Nanocatalysts: A Techno-Economic Analysis

Abstract

Hydrogen has universally been considered a reliable source of future clean energy. Its energy conversion, processing, transportation, and storage are techno-economically promising for sustainable energy. This study attempts to maximize the production of H2 energy using nanocatalysts from waste aluminum chips, an abundant metal that is considered a potential storage tank of H2 energy with high energy density. The present study indicates that the use of waste aluminum chips in the production of H2 gas will be free of cost since the reaction by-product, Al2O3, is denser and can be sold at a higher price than the raw materials, which makes the production cost more efficient and feasible. The current framework investigates seven different copper oxide-based graphene nanocomposites that are synthesized by utilizing green methods and that are well-characterized in terms of their structural, morphological, and surface properties. Reduced graphene oxide (rGO) and multi-layer graphene (MLG) are used as graphene substrates for CuO and Cu2O NPs, respectively. These graphene materials exhibited extraordinary catalytic activity, while their copper oxide composites exhibited a complete reaction with feasible techno-economic production. The results revealed that the H2 production yield and rates increased twofold with the use of these nanocatalysts. The present study recommends the optimum reactor design considerations and reaction parameters that minimize water vaporization in the reaction and suggests practical solutions to quantify and separate it. Furthermore, the present study affords an economic feasibility approach to producing H2 gas that is competitive and efficient. The cost of producing 1 kg of H2 gas from waste aluminum chips is USD 6.70, which is both economically feasible and technically applicable. The unit cost of H2 gas can be steeply reduced by building large-scale plants offering mass production. Finally, the predicted approach is applicable in large, medium, and small cities that can collect industrial waste aluminum in bulk to generate large-scale energy units.

Silver-Assisted Hydrogen Evolution from Aluminum Oxidation in Saline Media

“…Other feasible methods are mainly focused on the modification of aluminum composition and structure. That can be done via its melting together with various metals (e.g., Fe, Sn, Cu, Li, Ga, In, Sn) [ 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ] or ball milling with salts (e.g., NaCl, KCl, NiCl 2 , CoCl 2 ) [ 52 , 53 , 54 , 55 , 56 ], oxides and hydroxides (Bi(OH) 3 , AlOOH, Al(OH) 3 , Al 2 O 3 , TiO 2 , Co 3 O 4 , Cr 2 O 3 , MoO 3 , Bi 2 O 3 , CuO, Cu 2 O) [ 57 , 58 , 59 , 60 , 61 , 62 , 63 ], and metals (Cu, Bi, Sn, Pb, Fe, Ni, Zn, Ga, In) [ 56 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]. Experiments with aluminum granules and distilled water under 200–280 °C proved that aluminum vulnerability to oxidation was critically dependent on the amount of impurities in aluminum alloys and their nature [ 72 ].…”

Hydrothermal Oxidation of Coarse Aluminum Granules with Hydrogen and Aluminum Hydroxide Production: The Influence of Aluminum Purity

“…Previous studies have investigated the use of chemical additives for addressing this issue, including the use of alkalis [6][7][8][9][10] or salts [11] in aqueous solutions, as well as the activation of aluminum by various metals, silicon, graphite, chlorides, and oxides [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Xinren Chen et al have demonstrated a unique aluminum corrosion mechanism, which could have promising implications for its use in energy production [27].…”