Waste disposal especially of batteries is an energy consuming task that is not taken as seriously as should be. With the production of millions of electric vehicles (EVs) every year, the used-up batteries’ disposal poses a great risk of contaminating its surroundings.
Researchers from Japan’s Ritsumeikan University have developed a distributed recycling system that employs microwave-based heating for recycling old alkaline batteries.
This process offers an efficient and cost-effective alternative for recycling e-waste at the local level.
Distributed recycling systems involving small-scale recycling facilities offer a sustainable alternative to conventional recycling systems. Such a system can greatly reduce the energy requirements for transportation and has the potential to increase recycling rates.
In a new study, researchers from Ritsumeikan University, Japan, proposed a new small-scale distributed battery recycling system for used batteries. “The feasibility to decentralize the recycling of e-waste needs to be analyzed, considering the different characteristics of each municipality.
In this study, our focus is on obsolete alkaline batteries as waste product to be treated in a distributed recycling system,” explains Shoki Kosai, a member of the research team and the first author of the study. Their new system employed microwave irradiation, which offers selective, rapid heating and reduced energy consumption compared to furnace-based heating. The team’s findings were published in Resources, Environment and Sustainability, made available online on June 20, 2022 and published in volume 9 on August 31, 2022.
“Through the adoption of this system, areas, where natural resources are not available, will gain the opportunity to become suppliers of secondary resources. This system could also remedy the problem of metal recycling in developing countries,” concludes Kosai.
First, the researchers conducted an empirical study to explore the usability of this microwave-based technique in battery recycling system of spent alkaline batteries.
Then, they conducted an analytical case study to examine the effectiveness of distributed recycling systems in Japan. A total of 1,710 municipalities in Japan were considered in the study, which used energy consumption and greenhouse gas emissions as metrics for testing the effectiveness of the proposed recycling system.
The results of the empirical study showed that microwave-based heating achieved a recovery rate of 97% of manganese oxide and zinc from the alkaline batteries. This recovery rate is 1.5 times more than conventional electric furnace-based heating, while taking only half the time.
The analytical study also revealed highly optimistic results, as the team noted that a balance between centralized and distributed recycling systems can reduce annual energy consumption and greenhouse gas emissions across Japan by 26,500 GJ and 1.54 Gg-CO2eq, respectively.
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