Technical, environmental, and economic feasibility investigation of an innovative dry washing process for metal degreasing

Industrial washing is essential in manufacturing and many other technological fields. Nowadays, steam washing is the most common technique. However, it involves chemical solvents which are potentially noxious for the environment and difficult to be disposed of. Therefore, there is a growing demand for alternative washing techniques that would ensure low operating costs, extensive productivity, high efficiency, environmental sustainability, good compatibility with different materials, and safe operating conditions. A fluidized bed (FB) represents a promising alternative to satisfy market requirements. In this study, a prototype of FB machine for the degreasing of pressure vessels was designed, built, and compared to the current solvent washing machine. The scope of the work is to assess the technical, environmental, and economic feasibility of a FB device for industrial washing. The analysis of variance (ANOVA) was carried out to detect the process parameters influencing the cleaning. The optimal process parameters were identified based on the experimental results. Life cycle assessment (LCA) and cost analysis were performed to evaluate environmental impacts, and operating costs. The results confirmed the validity of FB technology as an alternative to current washing techniques thanks to its higher cleanness, minor environmental impact and costs, and comparable productivity.