Comparative Energy, Resource and Recycling Lifecycle Analysis of the Industrial Repair Process of Gas Turbine Burners Using Conventional Machining and Additive Manufacturing

Abstract

Laser beam melting (LBM), also known as selective laser melting, is a powder bed fusion type of additive manufacturing (AM) technology used to fabricate metal parts from metal powder. LBM is a promising technology that offers new opportunities for increasing resource efficiency. The aim of this study was to compare environmental impacts of conventional manufacturing methods with AM for a real industrial application. Analysis was performed on the repair process of a burner used in a Siemens industrial gas turbine. The results of this study show that the repair process based on AM provides significant reduction in material footprint (abiotic depletion potential), primary energy consumption, and carbon footprint compared to conventional machining and welding processes. Even though the AM process has increased power and inert gas consumption on the shop floor, the complete life cycle shows that the conventional processes have a much higher environmental footprint from material use upstream. Different recycling models of nickel-based alloy and stainless steel scrap strongly influence the cradle-to-gate life cycle footprint. The results show that an AM process can have a sustainability advantage if it is designed in a holistic cradle-to-gate approach. The study also shows potentials for the LBM machine developers for entry into the industrialization of AM. Energy reduction potentials were identified during the idle mode, during operation mode from the supply of cooling duty, and also related to inert gas consumption. Careful consideration of these potentials can further improve the primary energy footprint of the LBM process.