BOC, the New Zealand unit of the world's largest industrial gas company, says a deal with NZ Refining gives it a second source of carbon dioxide (CO2) it can process to meet growing demand from the dairy, food processing and beverage industries.
The local unit of Germany's DAX 30-listed Linde Group estimates current New Zealand consumption of liquid CO2 is about 60,000 tonnes a year
BOC is building a $40 million processing plant at Marsden Point, after agreeing to a 15-year contract to take carbon dioxide from New Zealand Refining's plant, which will have capacity of more than 50,000 tonnes of saleable, food-grade liquid CO2 a year, allowing for demand to almost double.
"There is significant forecasted growth in the demand of CO2 in New Zealand," BOC said in an email. "An example of this is the major NZ dairy industry, which requires significant volumes of CO2 for the modified atmosphere packing of its products for export to the rest of the world."
BOC currently sources CO2 from a third party supplier it didn't name and said the Marsden Point plant will give it a second source of the industrial gas "to enhance the reliability of supply and volume available of CO2 to BOC's customers."
NZ Refining, which supplies about 80 percent of New Zealand's refined fuels, is able to show a consequent 50,000 tonne a year reduction in its CO2 emissions, adding to the 120,000 tonne reduction it expects from its Te Mahi Hou project due to come on stream next year.
To turn the feedgas into food-grade CO2, it is pressurised to 20 times atmospheric pressure (20bar), dried and purified and then cooled to about -25 degreesC where it condenses to a liquid and can be distilled.