Prospective life cycle assessment of titanium powder atomization

Abstract

The environmental sustainability of titanium powders production mainly depends by atomization that is the most diffused technology in this field, ensuring the environmental advantages of high mass flow rate, energetical efficiency and reduced waste which have greatly encouraged its diffusion on an industrial scale. However, few quantitative assessment studies have been proposed on atomization sustainability and none of them consider the many technological evolutions of atomization that the industries are working on. This study proposes a prospective life cycle assessment (LCA), of the ex-ante type, of future new Electrode Induction Gas Atomization (EIGA) and Plasma Rotating Electrode Process (PREP) that will produce Ti6Al4V powders in 2035. This time point, referring to a medium-term view is considered to ensure the relevance and the reliability of technology forecasts based on quantitative estimates. Both the systems have been modelled through data retrieved from patents to assess their future impacts. The prospective LCA shows that in the future EIGA the average impact, in each indicator, will be 50% lower for electrical consumption and 98% lower for argon consumption compared to future PREP. The future EIGA and future PREP are more sustainable than the mature EIGA (of the crucible and crucible-free type) and mature PREP (of the traditional and supreme-speed plasma type) currently on the market. The average impact reductions, respectively passing from future to mature EIGA and PREP, are 65% and 23% for electricity consumption and 11% and 28% for argon consumption. The variabilities in technological solutions, scalability and future scenarios about electricity and argon production scale all the impacts without reverse the ranking. At a structural level, the most sustainable solutions are the optimization of the geometries of the titanium bar in the future EIGA and the optimization of the disposition of the plasma gun in the future PREP. This study shows which technological advancement increase the sustainability of EIGA and PREP atomization process in the future and to what extent in the two cases.