Environmental assessment of cleaning systems in connection with heat treatment

Abstract

The cleaning processes before and after the heat treatment of steel are crucial of the quality of the final product. For the cleaning different systems based on alkaline detergents or solvents can be used. To analyse the environmental performance of those systems a process life cycle assessment was conducted with the aim to identify the cleaning system with the lowest environmental load. Furthermore it was of interest what kind of environmental impacts are caused and how they can be reduced. Therefore the results of the life cycle assessment were used to model possible improvement scenarios. In addition a literature study was conducted, where possible alternative cleaning systems were discussed theoretically. It was found difficult to identify one cleaning system which has the lowest environmental load as there are different factors, like the utilisation and the cleaning efficiency, which influence the environmental performance of the cleaning systems considerably. However it could be discovered that the electricity consumption was the major cause of the environmental load within all impact categories. Thus measures to decrease the electricity consumption were developed. The final assessment of the improvement scenarios turned out that a new utilisation of the cleaning machines or the use of label certified electricity would be the most favourable solutions to reduce the environmental impacts of the cleaning systems connected with the steel heat treatment.