How much electricity does it take to produce one ton of Al?

Question

How much electricity (in kilowatt hours) does it take to produce one ton of aluminum, not counting the energy required to keep the furnace hot?

Answer 1

Here are two pieces of data from the link below.

- Recycling 1kg of aluminium saves up to 6kg of bauxite, 4kg of chemical products and 14 kWh of electricity.

- Recycling aluminium requires only 5% of the energy and produces only 5% of the CO2 emissions as compared with primary production and reduces the waste going to landfill.


If recycling 1 kg saves 14 kWh, and it only takes 5% of the energy to recycle, then producing 1 kg of Al takes 14 kWh ÷ .95 = 14.7 kWh. Let's round it up to 15 kWh per kg.


15 kWh per kg x 907 kg per ton = 13,605 kWh per ton.

Answer 2

The site; http://www.rocksandminerals.com/aluminum/process.htm says "About 6.2 kWH (kilowatt hours) of electricity is required to produce one pound of aluminum from alumina."
which would be 12,400kWh for one US ton (2000lbs) quite close to the first answer, but by a little more direct route.

http://electrochem.cwru.edu/ed/encycl/art-a01-al-prod.htm has some interesting information on the subject, in one illustration it is stated that the theoretical minimum is 6.36kW/kg and the text states that modern plants operate at about efficiencies "approaching" 50% , that agrees pretty well with the above number (6.36 / 50%) / 2.2 lb/kg = 5.8kW/lb. which is "approaching" the 6.2kW/lb above.