Kapuni Urea Plant

Kapuni urea plant in the Southern Taranaki community has observed several milestones recently — 30 years of operation and employment at Kapuni, 20 years of ownership by Ballance fertiliser co-operative, a $30 million investment in maintenance and capital improvements and a renewed gas supply and resource consent to keep operating for a further two decades, producing approximately 260,000 tonnes of urea annually, saving the country about $100 million in foreign exchange or import replacement.

Kapuni was opened in 1982 as a Think Big project. These projects were launched by Prime Minister Rob Muldoon as a way for New Zealand to boost its infrastructure and decrease its reliance on imports.

Production has eliminated the need to import greater than 5 million tonnes of urea, saving billions of dollars in foreign exchange.

It was built to make use of ‘flared’ gas (otherwise wasted as burn-off) at the nearby gas fields. The plant is owned by New Zealand farmers – not by an overseas-based corporate.

Kapuni ammonia-urea plant uses 7 petajoules of natural gas annually, or 3-4% of total production from the Maui, Kapuni and Kupe fields. That is about the same amount of gas sold annually for domestic use in the North Island for cooking and heating.

80% of Kapuni’s urea production went for export initially, under Petrocorp and Petrochem. Agricultural demand for urea has now grown to 600,000 tonnes annually, outstripping Kapuni’s capacity, and its output is now all sold domestically. It was first a state-owned enterprise and then was owned by Fletcher Challenge for four years (1988 to 1992). The plant was purchased by BOP Fertiliser, now Ballance, in July 1992 and in 1997 underwent a large expansion programme, increasing production by 30%.

Kapuni now produces an average of 730 tonnes of urea each day, or 265,000 tonnes annually.

Initially anhydrous liquid ammonia is produced and stored on site. It is then combined with carbon dioxide in the urea synthesis reactor. Aqueous urea is then concentrated by evaporating water from the molten solution, which is then granulated in a mixed fluidised-spouting bed granulator. Ballance’s n-rich urea contains 46% nitrogen, 20% carbon, 27% oxygen and 7% hydrogen.

Kapuni had a fire in late 2011 which was followed by a 14-week shutdown and $3 million of repairs. Then in early 2012, it suspended production for 66 days for the three-yearly maintenance and capital upgrade during which a further $37 million was spent to ensure the plant keeps operating for the next two or three decades.

In addition to securing gas supplies through to 2020, following consultation with neighbours and the regional council, the Kapuni ammonia urea plant has been granted new operating permits by Taranaki Regional Council until 2035. The new resource consents provide for all discharges to air associated with the manufacture of ammonia and urea at the plant, and for the necessary water supply, treatment and discharge.

GoClear is an exhaust system additive and scrubbing agent that reduces pollutant nitrogen oxide (NOx) emissions from diesel engines. The liquid is held in a small tank and injected into the exhaust system of diesel engines where it reacts with gases as they pass through a catalytic converter, turning nitrogen oxide emissions into water vapour and nitrogen. Ballance has invested $1.5 million on the new Selective Catalytic Reduction (SCR) solution to produce GoClear, including three hundred thousand dollars on specialist analytical equipment, so it can produce the product to the international standards demanded by diesel truck manufacturers around the world.

With complex technical modifications to the Kapuni plant, aqueous urea solution is taken upstream from the granulator and mixed with ultra-pure water to produce a precise solution of high-purity aqueous urea. Ballance is now producing GoClear for the two main distributors in New Zealand, Yara and Orica.

The product is essential for new trucks running SCR technology to manage emissions control. Most European manufacturers, including Volvo, Mercedes, Scania, DAF and Iveco use SCR, as does Mack in the US. The SCR technology is used at about 4% the rate of diesel.

The ability to produce SCR solution locally also reduces the environmental footprint of the product, given that all supplies at present have to be imported along a lengthy supply chain.

Fonterra has recently taken delivery of many new Volvo trucks fitted with SCR technology and intends to buy more. Procurement category manager Guy Cooper said the company would have a fleet of 480 milk collection trucks by the end of November, including 113 using SCR technology. Fonterra’s entire fleet could be using SCR-type trucks within about three years.

GoClear is available to the public at McKeown Petroleum’s Gore and Oamaru fuel stops, and Z Sanson (as Z-DEC), and Z Mount Wellington and Caltex Bombay Hills.

Ballance and Orica have on-farm delivery systems available for filling tractors using SCR technology including New Holland, Claas, Case IH and Massey Fergusson. Farmers near Gore and Oamaru can buy directly from McKeown Petroleum’s fuel stops in smaller quantities.