While firefly squid, copperware, and glass are likely the first things to come to mind when you think of famous products from Toyama Prefecture, another that might surprise you is aluminum. In Toyama Prefecture, the refining of aluminum got its start thanks to the plentiful electricity generated by the hydroelectric power facilities Kurobe Dam. Even today, 30% of Japan's aluminum extrusion products are shipped from Toyama Prefecture. Right now, in a laboratory at the University of Toyama in Takaoka City, research is being conducted on cutting-edge aluminum recycling that has yet to be put to practical use anywhere in the world. And it is the power of NEC's data science and artificial intelligence (AI) that is contributing significantly to this upcycling initiative.

Toward the promotion of decarbonization: Embarking on a challenging project at Japan's leading aluminum recycling research facility

In February 2024, a system NEC provided to the University of Toyama went live, marking a major step forward in state-of-the-art aluminum recycling research. Serving as the stage for this research is Collaborative Research Building for high Metals, University of Toyama, which officially opened in October 2023 on the Takaoka Campus of the University of Toyama. This research facility—where industry, academia, and government work together—is outfitted with a melting and refining system, extruder, electron microscope, and other equipment that is among the most advanced used in a university setting in Japan. The data obtained using this equipment can be gathered and analyzed collectively by the materials informatics system provided by NEC. The aim of all this is to make the upcycling of aluminum a reality.

The recycling of empty cans is probably what first pops into your head when you think of aluminum. The recycling of products within the same category (e.g., the recycling of aluminum cans to reproduce aluminum cans) is referred to in Japan as closed-loop recycling and the technology behind this has reached full maturity. In Japan, the recycling rate for aluminum cans is more than 90%(*). In contrast, recycling aluminum from another product category into wrought aluminum alloys and other materials used for automobile bodies and other purposes for which impurities are strictly controlled is referred to as upcycling and is considered extremely difficult.

Economic security is one of the reasons upcycling is important. Demand for lightweight wrought aluminum alloys is on the rise due to the growing popularity of electric vehicles (EV), which need to be light in weight. However, the current reality is that bauxite—the raw material used to produce aluminum—is primarily produced overseas, and Japan is dependent on imports for virgin aluminum. Another reason is the environment. It takes a tremendous amount of electricity to produce aluminum from bauxite, and approximately 10 tons of CO2 is emitted for every ton of aluminum produced. On the other hand, recycling uses just 3% of the electricity it takes to newly produce aluminum from bauxite. From the perspectives of economic security, energy conservation, and decarbonization, there is a pressing need to realize upcycling as quickly as possible.

"Aluminum has unusual characteristics" – Focusing on the power of NEC's data science

Upcycling is already being carried out for iron and other metals. As for why the recycling of aluminum has proven particularly difficult, Professor Toshiya Shibayanagi, director of the Aluminum Research Center (ARC), explains, "All metals have different characteristics. Aluminum is an unusual metal in that it has a hard time releasing impurities once it has absorbed them. In other words, impurities cannot be extracted from aluminum using the kinds of processes utilized for other metals."

What kind approach is being taken by the University of Toyama and NEC to address this issue? The two parties decided to focus on an approach driven by data science to recycle aluminum scraps containing various impurities.

In materials science, data science is used to statistically identify important properties in materials that collectively possess many properties. There is no way to know how aluminum scrap was made, and it contains varying percentages of iron, silicon, and other impurities. It is important to predict early on what will happen to aluminum during the recycling process and optimize the recycling process based on this prediction. According to Professor Shibayanagi, who strongly believes there are limitations when it comes to human-designed processes, "Data science is vital when it comes to designing the ideal recycling process based on the limited information we have on the scrap we're dealing with."

Becoming a pioneer not only for the sake of Japan but also for the world

In 2021, NEC established a data science course at the University of Toyama. This connection led Professor Shibayanagi and his colleagues to pay close attention to NEC's data science expertise and AI, particularly machine learning technologies, ultimately spurring this latest joint research project. Professor Shibayanagi has high hopes for the project, saying, "If we're able to achieve the recycling of aluminum, it will not only be beneficial for Japan but also enable us to provide technology to people in the countries that need it. We're not conducting this research for the sake of research, but instead striving to create something society actually needs."

Toshiyuki Ikeda, the GX Agenda Leader of the Cross-Industry Business Unit supporting this joint research project on behalf of NEC, told us, "Since our image is so strongly associated with IT, aluminum recycling is very unlikely to come to mind when you think of NEC." However, he also explained the significance of this project, saying, "NEC can help solve the world's environmental problems by using AI and other NEC technologies to visualize recycling processes and impurities." Although researchers around the world are working on the recycling of aluminum, it has yet to be achieved. "This is precisely why we feel it is absolutely worthwhile to be taking on this challenge," says Ikeda.

This aspiration is yet another way in which NEC is striving to achieve its Purpose of "creating the social values of safety, security, fairness and efficiency to promote a more sustainable world where everyone has the chance to reach their full potential."

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