Improving the carbon footprint of secondary nickel recovered from industrial wastes

The existing efforts on carbon footprint studies of manufacturing processes are focused largely on emissions assessment for product compliance reporting. Relatively little attention has been given to analyzing how process properties affect these emissions for carbon footprint reduction. Going beyond assessment calculation into carbon footprint improvement, this paper presents a method for modeling and identifying the key emission sources to deliver reduced carbon footprint of secondary nickel recovered from industrial wastes. A metrics-based carbon footprint model is developed and populated with activity data from a closed-loop nickel recovery process. Different scenarios are simulated to provide insight into how to improve the carbon emissions of the process. The results suggest that the carbon footprint of the nickel recovery process is more sensitive to energy consumption than to any other process inputs. As ~63%-82% of the total emissions of the process are from the use of energy, energy efficiency is therefore identified as the most critical measure to improve carbon footprint. A case study is included in the paper to illustrate the use of the proposed method.