Northvolt and Cinis to turn battery waste into sustainable fertilizer

Battery production waste could be the key sustainable ingredient to make crops grow faster. Northvolt, a Sweden-based battery manufacturer that was founded with circular production methods and sustainability written into its DNA, has partnered with Cinis Fertilizer, a Swedish startup company producing sustainable fertilizer from waste industrial products it sources from battery and paper manufacturers.

Per the agreement, the battery manufacturer will provide 200,000 tons of sodium sulfate per year to the fertilizer maker. The material is a type of salt that can be recovered during the battery manufacturing process. To this end, Northvolt has designed a new water treatment technology at its Gigafactory “Ett” in Skellefteå, Sweden, that has been developed with the precise setup of Northvolt’s cathode manufacturing steps in mind.

During the electrode active material production of its NMC cells, wastewater containing ammonia and metals is produced. The new facility can recover ammonia from this water for repurposing in battery manufacturing. After further filtration, the metals are removed leaving a slurry of highly concentrated sodium sulfate (Na2SO4). The slurry is then dried and crystalized before it is sent to Cinis for fertilizer production.

“This is just one example of the positive outcomes that can be achieved from making investments into circular manufacturing,” said Northvolt’s chief environmental officer, Emma Nehrenheim. “In this instance the material in play is salt, but in other areas of the Northvolt production process, our engineers are engaged in developing solutions to ensure that water, heat, energy, and other materials that would otherwise be wasted are instead recovered and recirculated to one purpose or another.”

The salt's off-taker is a Swedish startup company that has set out to produce the “world’s most environmentally friendly mineral fertilizer”. The company sources chloride-rich ash that paper and pulp mills collect in electrostatic precipitators, sodium sulfate from Northvolt, and Cinis also sources potassium chloride from other industrial facilities.

By sourcing the feedstock for their fertilizer from the industrial waste products of the pulp and paper industry as well as from battery manufacturing, Cinis Fertilizer says it can reduce the energy consumption of its operation by 50%. By repurposing the chemicals that are considered waste in other industries, the production of this fertilizer will produce 75% less carbon dioxide than conventional equivalents.

“We share a common goal with Northvolt: creating value-adding products for a fossil-fuel-free future,” said Cinis’ chief executive, Jakob Liedberg. “Through this new partnership, we will produce a fossil-free fertilizer with a close to zero carbon footprint, and make a unique contribution towards securing more sustainable agriculture.”

A precise date for the first delivery of sodium sulfate from Northvolt to Cinis has not been settled as part of the agreement. Within the next two years, Cinis will, however, build two fertilizer factories in northern Sweden, one of which will be next to the Northvolt Ett Gigafactory. The electricity required for fertilizer production will be renewable, the company says. For now, the wastewater treatment will only be deployed at the Swedish facility, as it is designed to handle the wastes of electrode active material production. There are no such processes undertaken at Northvolt's site in Poland, and therefore no opportunity to produce the sodium sulfate.

“Looking forward, Northvolt will always work to ensure that the environmental footprint of its activities is as low as possible; as and when Northvolt establishes additional active material production capacity, we look forward to building upon the foundation we already now have in place with the wastewater treatment technology at Northvolt Ett,” Northvolt's editorial manager, William Steel, told pv magazine.