Functional equivalence of industrial metal cleaning processes comparison of metal cleaning processes within LCA

Abstract
In an LCA case study, the three most frequent industrial metal cleaning technologies were assessed: Cleaning based on aqueous cleaning agents, non-halogenated hydrocarbon solvents and halogenated hydrocarbon solvents. Beside optimisation analysis, the comparison of the cleaning processes was a main goal of the study. The function of metal cleaning processes can be described with a set of parameters called functional parameters. In order to compare different cleaning processes within LCA, it is a precondition that all relevant functional parameters be equivalent. However, metal cleaning processes from different companies normally differ in most of the functional parameters and, thus, are not functionally equivalent. Therefore, it is necessary to calculate the material and energy flows of the processes corresponding to a reference function as a basis for comparison. This can be achieved by simulating the processes according to the functional parameters with the help of a process model. For a general comparison of the technologies, it is also necessary to consider the assessed machines having the same level of optimisation and the same scale.