Primary production of aluminium requires tremendous amounts of energy. The steam necessary for the Bayer Process is produced from fuel oil, coal or natural gas. The alumina is calcined at high temperature using fuel oil or natural gas. Coal gas is also widely used in China. Turning this to metallic aluminium requires vast amounts of electricity to be passed through the molten substance using a method of electrolysis called the Hall–Héroult process named after its French and American discoverers.
The process also produces greenhouse gases that affect global warming. According to the International Aluminium Institute, manufacturing new stocks of aluminium releases 1% of global human-induced greenhouse gas emissions. A top industry priority is to decrease these emissions through reduction measures, increased recycling and up-cycling.
More significant to our industry, however, is the use of aluminium in vehicles, aircraft, watercraft and trains. In fact, using lightweight aluminium components in vehicles is one of the most significant advances in automotive design and manufacturing. Every kilogram (2.2 pounds) of heavier material that is replaced by aluminium results in the elimination of 22 kilograms (44 pounds) of carbon dioxide over the lifetime of the vehicle. (Source: International Aluminium Institute)
Another promising application is the use of aluminium in fuel-cell-powered cars. Researchers at Purdue University recently discovered that aluminium could be used to produce hydrogen fuel efficiently. The process begins with aluminium pellets which are mixed into liquid gallium to produce liquid aluminium-gallium. When water is added, the aluminium reacts with the oxygen to form a gel. Hydrogen gas, which can be collected and used to power a fuel cell, is also produced.
Innovations such as these will increase the demand for aluminium and, of course, bauxite.
The International Aluminium Institute projects that the aluminium industry will be carbon neutral by 2020.