On a unit basis, a ton of aluminum production requires ∼126 GJ of energy (Liu et al., 2016). The sources of energy associated with the entire process of aluminum production are coal, hydroelectricity, and natural gas (International Aluminium Institute (IAI), 2011).
The energy required to produce secondary aluminum is less than 6.5 percent of the energy required to produce primary metal. The theoretical and practical energy requirement for secondary aluminum is 0.39 kWh/kg. If the system boundaries are drawn around a secondary aluminum facility, the material entering and leaving is aluminum metal.
The energy requirements for aluminum production involve the evaluation of three factors: the minimum theoretical energy requirement to drive the reduction reaction forward, the energy requirement to maintain the system at constant pressure and temperature, and the energy requirement to change the temperature of the reactant and/or product.
Alumina refining and aluminum production are one of the most energy exhaustive processes, where primary aluminum production is ∼10 times more energy intensive than the secondary process (Liu et al., 2016). On a unit basis, a ton of aluminum production requires ∼126 GJ of energy (Liu et al., 2016).
According to Alcoa, the world’s largest producer of aluminium, the best smelters use about 13 kilowatt hours (46.8 megajoules) of electrical energy to produce one kilogram of aluminium; the worldwide average is closer to 15 kWh/kg (54 MJ/kg). Worldwide production of aluminium in 2010 was 41.4 million tonnes.
To put just this number into perspective, this is approximately the equivalent amount of energy as producing 200 kg of aluminium (around 15 kWh/kg ), 350 kg of beef (around 8.3 kWh/kg ) or 1400 kg of stainless steel (between 0.3−3.75 kWh/kg ). ...