Carbon dioxide is one of the biggest causes of greenhouse gas emissions, but a new processing plant in Northland will turn some of that waste into a clean and useful resource for primary industries.
Out of a chimney at Refining New Zealand, carbon dioxide pumps into the atmosphere -- but just across the road from it at Marsden Point, the new processing plant hopes to convert that waste into something valuable.
"We're intercepting a stream of CO2, which would be omitted to the atmosphere, and we're recycling that for further use in the industry," says BOC South Pacific's Colin Isaac.
The carbon dioxide comes out as a by-product of Refining New Zealand's oil operations.
The new, $40 million processing plant will purify the gas so it can be used for carbonating drinks, chilling food and packaging.
"They may be using it for modified atmosphere packaging, so it protects products -- typically milk, milk products for export," says Mr Isaac.
Instead of going into the air, that dirty carbon dioxide is put into a pipe that runs under the ground from the refinery, across to the processing plant.
From there, all those impurities are removed and that carbon dioxide is purified. It's put into trucks and those trucks deliver the pure CO2 to customers.
It has the benefit of not only putting Refining New Zealand's waste to use, but making it money.
"We compete with overseas refineries, and so we need to push the dial all the time to ensure that we stay profitable and competitive," says Refining NZ chief executive Sjoerd Post.
At the end of the process, the pure CO2 generally becomes part of the by-product, like in fizzy drinks or fertilisers.
Sometimes it can escape back into the environment -- but experts say its better going out in a processed, purified form than as untreated waste, which is damaging to the atmosphere.