ESCAPE approach for the sustainability evaluation of spent lithium-ion batteries recovery: Dataset of 33 available technologies

Using life cycle assessment to aid process development for hydrometallurgical recycling of end-of-life lithium ion batteries

The global stockpile of recyclable end-of-life (EOL) lithium-ion batteries (LIBs) is continuously increasing in size, while hydrometallurgical processes are starting to play an increasingly important role in EOL LIB recycling. To this end, this study aims to use life cycle assessment (LCA) to aid the process development of hydrometallurgical LIB recycling using hotspot analysis. The LCA investigation started by comparing three lixiviants (hydrochloric-, sulphuric-, and citric acid) and three metal recovery strategies (mixed precipitation, selective/sequential precipitation, and integrated solvent extraction-precipitation) using the ReCiPe H/H method. The sulphuric acid - mixed precipitation process was found to be the most environmentally friendly based on endpoint value. Across these nine different processes there were 633 midpoint hotspots identified with 64.3% originating from the hydrometallurgical recovery circuit, 20.5% from the leaching process and 10.7% from the dense media separation of copper and plastic in pretreatment. Pneumatic separation of copper and plastic was then proposed to replace dense media separation which led to a 14.3% decrease in the endpoint value of the pretreatment section. Subsequently, formic acid leaching and nanofiltration were suggested as solutions to the hotspots relating to leaching and metal recovery. The study then showed that formic acid leaching could potentially increase cobalt recovery (compared to sulphuric acid leaching) by 2.1%. Furthermore, utilising nanofiltration to aid metal recovery was found to potentially decrease sodium hydroxide and process steam consumption by 54.6% and 68.8% respectively.

Sustainability Analysis of Processes to Recycle Discharged Lithium-Ion Batteries, Based on the ESCAPE Approach

There are several recycling methods to treat discharged lithium-ion batteries, mostly based on pyrometallurgical and hydrometallurgical approaches. Some of them are promising, showing high recovery efficiency (over 90%) of strategic metals such as lithium, cobalt, and nickel. However, technological efficiency must also consider the processes sustainability in terms of environmental impact. In this study, some recycling processes of spent lithium-ion batteries were considered, and their sustainability was evaluated based on the ESCAPE "Evaluation of Sustainability of material substitution using CArbon footPrint by a simplifiEd approach" approach, which is a screening tool preliminary to the Life Cycle Assessment (LCA). The work specifically focuses on cobalt recovery comparing the sustainability of using inorganic or organic acid for the leaching of waste derived from lithium-ion batteries. Based on the possibility to compare different processes, for the first time, some considerations about technologies optimization have been done, allowing proposing strategies able to save chemicals. In addition, the energy mix of each country, to generate electricity has been considered, showing its influence on the sustainability evaluation. This allows distinguishing the countries using more low-carbon sources (nuclear and renewables) for a share of the electricity mix, where the recycling processes result more sustainable. Finally, this outcome is reflected by another indicator, the eco-cost from the virtual pollution model 99' proposed by Vogtländer, which integrates the monetary estimation of carbon footprint.

Environmental Impact of Surgical Masks Consumption in Italy Due to COVID-19 Pandemic

The COVID-19 pandemic suddenly changed the lifestyle of billions of people. Face masks became indispensable to protect from the contagion providing a significant environmental impact. The aim of this work is to propose possible solutions to decrease masks' impact on the environment. For this reason, different masks (surgical and fabric) were considered, and the CO2 emissions associated with the mask materials production were calculated. Carbon Footprint (CF) for each material composing the masks was evaluated through the database Ces Selector 2019. The software Qgis (version 2.18.20) allows us to elaborate the CO2 emissions maps for each Italian region. Finally, for surgical masks, which are often imported from abroad, the CF related to transport was considered. It results that fabric masks are a sustainable solution to prevent contagion. The total CO2 emission associated with the use of fabric masks from the beginning of the pandemic (March 2020) to December 2021 resulted in about 7 kton compared to 350 kton for surgical masks.