Explore the World Expo: Significance of the Event / Osaka Expo Venue to Showcase Japan’s Recycling Society; CO2-Absorbing Bacteria to Be Introduced

By Takeru Tsuzuki and Kazuki Sato / Yomiuri Shimbun Staff Writers

7:00 JST, December 25, 2024

This is the fourth installment of a series on the significance of the World Expo.

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A clear liquid in a flask turned opaque after carbon dioxide was injected into it. Bacteria in the liquid fed on the CO2 and multiplied.

Hydrogen-oxidizing bacteria, a common type of microorganism, use CO2 as a raw material for the creation of biodegradable polymers used to make plastics. When these polymers are no longer needed, they can be broken down by microorganisms.

Kaneka Corp., a major chemical company in Takasago, Hyogo Prefecture, has been researching such bacteria since the 1990s. Kaneka has developed the technology to produce bacteria that can absorb more CO2 and convert it into a greater variety of polymers. It can absorb 50 to 70 times more CO2 than algae. The company plans to begin experiments for mass production by 2030.

The world’s plastic production is estimated to be more than 400 million tons per year. As the majority of plastic is made using fossil fuels and not recycled, it is a cause of climate change and ocean pollution.

“The only raw material that can replace petroleum is CO2,” said Shunsuke Sato, 45, who is leading the research at Kaneka. “This will be a ‘straightforward’ technology that will help shape a recycling-oriented society.”

The results of this research will be introduced at the 2025 Osaka-Kansai Expo, which starts in April, as an advanced technology that Japan can be proud of. It will be one of the main attractions of the Japan Pavilion, which will have recycling as its theme.

The realization of a recycling-oriented global society is essential for pursuing sustainable economic growth while reducing the burden on the environment. The pavilion, which represents Japan at the Expo, will serve as a venue to convey this message.

Since ancient times, Japan has nurtured a culture that values recycling. Takayuki Shiose, 51, an associate professor at the Kyoto University Museum who has been involved in the creation of the Japan Pavilion, said: “Japan has a culture of restoration, as in ‘kintsugi,’ the art of repairing broken pottery. It is an important mission for Japan to convey to the world the kind of recycling that we should strive for.”

In addition to the Japan Pavilion, the Expo will also feature a number of other exhibits that focus on the concept of recycling. The highly efficient cultivation of algae, a raw material for biofuels, is demonstrated at one exhibit. Another explains the synthesizes of methane, a raw material for fuel gas used in homes, from CO2 and hydrogen. Japanese companies and research institutes will all showcase their latest technologies.

The theme of the Expo is “Designing a Future Society Where Life Shines.” The concept goes along with that of the Sustainable Development Goals (SDGs), a collection of 169 targets which the United Nations aims to achieve by 2030. Osaka won the bid to host the Expo in 2018 largely because the concept got the international community’s understanding.

However, the realization of the SDGs is a huge challenge. The Sustainable Development Solutions Network, an international research organization, estimates that only 16% of the 169 targets under the 17 goals are likely to be achieved.

What contribution can the Expo make?

“Japan, where the spirit of “mottainai” [too good to waste] is deeply rooted, has the technology and potential to lead the way in solving environmental problems,” said Toshiya Hoshino, 65, professor emeritus at Osaka University, who served as Japan’s ambassador to the United Nations. “We should make the Expo, which will bring together people from around the world, an opportunity to strengthen cooperation toward achieving the SDGs.”