Comparative Life Cycle Assessment of a centrifugal compressor impeller: Hybrid technology production versus welding production

Abstract

Sustainable development is one of the main objectives in the turbomachinery sector to achieve the climate neutrality targets set by 2050 protocols. The manufacturing industry consumes an average of 23% of global energy, significantly contributing to the generation of greenhouse gases and other pollutants. Therefore, it is crucial to research technological solutions aimed at reducing consumption for the benefit of the environmental sustainability of the products manufactured. This study presents a comparative environmental impact assessment using the Life Cycle Assessment (LCA) methodology to evaluate the sustainability of two technological alternatives used to produce centrifugal impellers in the industrial sector. The first process analyzed deals with making an impeller by welding the shroud to the impeller body. The second process involves producing the component from a semi-finished product, machined through milling and Electrical Discharge Machining (hybrid solution). The study has been conducted at Nuovo Pignone company. It is based on primary inventory data collected through specific measurement campaigns and modeled using the environmental database Ecoinvent v3.9. The results were produced using the ILCD Midpoint method, and four different impact categories were investigated: Climate Change, Human Toxicity, Cancer Effects, and Freshwater Ecotoxicity. The results demonstrate that the solution produced through hybrid manufacturing is generally less impactful compared to the welded one. The insight implemented in the work is functional in drafting suggestions for manufacturers and customers to reduce the environmental burdens of the examined product.