Minimizing Carbon Emissions in Metal Forming

Abstract

The present work deals with the calculation and the investigation of possible reductions of CO2 emissions in manufacturing a metal formed product. The industrial sector plays a significant role in the recent increase of the oncentration of Greenhouse Gases in the atmosphere, which is responsible for the advancing global warming. As an answer to fiscal and financial intervention of government policies aimed at counteracting this phenomenon, the environmental impact of products became a key aspect of a company’s strategy. However, literature still lacks effective methods and quantitative studies that look into the details of a single manufacturing process, discussing its environmental aspects and how they can be influenced by changes in the technological parameters. In an attempt to do that, an example of quantification and minimization of the carbon emissions occurring during the two manufacturing steps of the fabrication of an Al 6061 disc is provided. Electrical energy consumption occurring during the shearing and the upset forging of a billet was found by means of nonlinear finite element analysis and converted into CO2 emissions with a carbon emission signature value (CES). Environmental impact and frictional properties of both traditional lubrication and two non-conventional ecologically benign lubricants (palm oil ester and used cooking oil ester) were experimentally tested and are included in the study. A gradient-based optimization algorithm was implemented to determine the optimal geometry of the billet before the compression as well as the lubricant that minimize the total carbon emissions, within the proper technological limitations and constraints on the final product quality. A clear and effective method which would represent an auxiliary decision tool for a manufacturer in the metal forming sector is hereby presented. Results show that the selection of the manufacturing options can have an influence of more than 13% on the overall CO2 emission.