Determine the energy in Mega-Joule (MJ) required to produce 300g of aluminium metal at 900°C after reduction of aluminium oxide (Al2O3) by means of carbon reductant in fused bath electrolyse cell. The molar mass of Al:27g/mol; Al2O3: 102g/mol; C:12g/mol and CO2:44g/mol and 1MJ =10-6J.
The reagents aluminium oxide and carbon reductant enter the reactor at 25°C and the off-gas CO2 leave the reactor at 700°C. The reaction of reduction is the following. 2Al2O3 + 3C =4Al + 3CO2