Contact Energy’s proposed solution to the food-grade CO2 shortage

Food-grade CO2 is the essential ingredient to keep the bubbles in everything from lager to lemonade. Photo / 123RF

NZX-listed power generator Contact Energy says it may have a solution to New Zealand’s food-grade carbon dioxide (CO2) shortage.

Recent closures of CO2 sources in a number of markets have caused a worldwide shortage of food-grade CO2 - the ingredient essential for keeping the bubbles in everything from lager to lemonade.

This came on the back of the 2022 closure of the Marsden Point oil refinery, which supplied the majority of New Zealand’s food-grade CO2.

New Zealand is now having to import food-grade CO2, which is costly and in short supply.

Contact says its team at the Ohaaki geothermal site, near Taupō, had developed a way of capturing the small amount of naturally occurring carbon dioxide released during the generation process and converting it to food-grade quality.

Chief executive Mike Fuge said if plans to convert are successful, it could provide a solution to the bubbles crisis.

This week, Contact will invite potential partners to assist with capturing, cleaning and converting the CO2 emitted from Ohaaki power station to food-grade quality CO2.

Initial tests have proven positive, Fuge said.

“Not only will this initiative help reduce carbon emissions, including those from burning fossil fuels to ship CO2 to New Zealand, but it could also create around 40 jobs in the Taupō area and help solve New Zealand’s food-grade CO2 shortage by creating a home-grown source that will increase supply and lessen cost,” he said.

Geothermal operations produce relatively low levels of climate change gases.

The company said geothermal is one of the greenest and most sustainable forms of CO2.

Along with carbonating drinks, food-grade CO2 is used in packaging to preserve the freshness of food, as well as to keep medical supplies cool during transportation and in biofuel production.

Contact estimates about 65,000 tonnes of CO2 could be captured at its Ohaaki geothermal site every year - enough to fully supply the New Zealand market.

Ohaaki is one of several geothermal assets Contact has operating in the central North Island.

Jamie Gray is an Auckland-based journalist, covering the financial markets and the primary sector. He joined the Herald in 2011.