Transforming Urban Waste CO2 into Valuable Consumer Goods

European cities release substantial greenhouse gases. Waste incineration and wastewater treatment are significant municipal CO2 contributors in the EU.

These systems are crucial for health and urban living but emit challenging-to-reduce gases. What if this CO2 was not wasted?

An international research team sees an opportunity in urban carbon. Through the EU-funded WaterProof initiative, they’re working to capture and convert CO2 into formic acid, a versatile chemical for various industries.

This could transform emissions from waste processes into common products like cleaning agents or even leather goods.

Transforming a challenge into an asset

Climate action often targets renewable energy, electrification, and efficiency, but some emissions are tough to curb.

“Some emissions are difficult to stop,” said Annelie Jongerius, an electrochemist and Avantium programme manager, leading the research.

One approach is CO2 capture and underground storage. The WaterProof team proposes a circular method: reusing carbon instead of storing it.

“It would be nicer if we could use it,” Jongerius said. “We also need alternatives to fossil feedstocks for chemical production.”

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If you take CO2 from wastewater, turn it into a product, and then use that product to clean your toilet so it flows back into the wastewater system, you create a complete loop.

Facilities like those at Dutch waste company HVC, operating two large incinerators in the Netherlands, face this challenge.

“We have to take in whatever waste society produces,” said Jan Peter Born, HVC’s innovation manager. “We can’t regulate CO2 emissions, only encourage less consumption and more recycling.”

HVC currently captures and sells CO2 to greenhouse farmers to boost crop yields. However, this is not a complete solution.

“Most CO2 released to the plants ends up back in the air,” Born explained, noting it’s a delayed emission and that farmers achieve the reduction by avoiding gas-fired CO2 production.

The WaterProof researchers aim to extend this by turning carbon into long-lasting useful products.

Converting CO2 into household products

Central to WaterProof is an electrochemical process that turns captured CO2 into formic acid using renewable electricity.

“It’s one of the simplest conversions,” said Jongerius.

An electric current in a cell reduces CO2 to formic acid, utilizing renewable energy and reducing fossil raw material dependency.

The process might have extra benefits. In an electrochemical cell, dual reactions occur at both electrodes. While focusing on CO2 conversion, the team also explores reactions producing hydrogen peroxide and related compounds.

These substances can break down tough pollutants in wastewater, like pharmaceutical and pesticide residues. However, this part remains in early stages and isn’t in the current system demo.

The team tests CO2-derived formic acid in eco-friendly cleaners like toilet and surface cleaners.

“It performs exactly as conventional formic acid,” said Jongerius. “It’s the same molecule.”

Beyond cleaning, the project explores CO2-derived formic acid in leather tanning. It applies to all leather types, and they’re working with Icelandic company Nordic Fish Leather to market eco-friendly fish leather, a sustainable alternative to cattle-based leather.

Scaling for real impact

Though promising, scaling is the next hurdle.

Building on past EU research, the team is developing a large-scale pilot with multiple stacked electrochemical cells to increase CO2 processing. Success could lead to commercial plants.

The adaptable modular design suits various sites, from wastewater plants to incinerators. The goal is to demonstrate the WaterProof process by summer 2026, showing fossil-free production under real conditions.

Such systems could integrate into urban infrastructure, turning cities into chemical production hubs instead of emission sources.

Extracting value