Decarbonization Measures for the Indian Aluminum Sector

Limiting carbon dioxide (CO₂) emissions while meeting the increasing demand is a major technological challenge faced by the aluminum industry. Approximately 98% of the energy used in the Indian aluminum (Al) sector comes from burning coal and furnace oil. The total primary energy and greenhouse gas emission intensities are calculated as 187.33 GJ/t of Al and 19.63 tonnes of CO₂e/t of Al. This work presents major decarbonization measures for the Indian aluminum sector, along with an economic assessment for each measure. A total of 14 decarbonization measures, classified as electricity conservation (e.g., copper collector bar), renewable energy (e.g., biodiesel for calcination), process change (e.g., inert anode smelting), fuel saving (e.g., mechanical vapor recompression), and clean electricity (e.g., nuclear energy), are analyzed. The decarbonization measures are compared on the basis of cost of abated carbon. It is found that the electrolysis process in the smelter (aluminum production) has a greater potential for decarbonization compared to the refinery (alumina production). The 100% graphitized cathode is the most significant energy-saving measure, whereas clean electricity is the most considerable CO₂ abatement measure. Together, all the measures can save 17.67 t CO₂e/t of Al, which is a 90% reduction at an additional cost of 209.15 $/t of Al. It is further observed that 22% of the greenhouse gas emissions can be abated without a net cost to the customer.