This category provides an 'alternative method' for calculating aluminium-related CO2 emissions, based on the carbon content of materials consumed. This methodology is sourced from the WRI Greenhouse Gas protocol worksheets but ultimately derives from the Aluminum Sector Greenhouse Gas Protocol published by the International Aluminium Institute.
To use this category, create a profile item (there are no drill choices) and specify the required profile items (shown below). The returned value represents CO2 emissions related to the process data provided.
The carbon content of each material is calculated by multiplying the quantity of material by the fraction of carbon which is represented by carbon. These quantities are then added together along with the carbon content of the purchased anodes. The carbon content of sold anodes and the quantity of carbon by-products and waste are then subtracted to give the total carbon content of the whole process. The factor 44/12 (the mass ration of carbon and CO2) is then used to convert this quantity of carbon into a quantity for CO2 emitted.