Large Business Joint Winners - NZ Steel and Energy For Industry
NZ Steel, Energy For Industry and Winstone Pulp were the joint winners of the Large Business Award.
NZ Steel - Retrofitting a pipe mill for energy efficiency
New Zealand Steel Ltd produces a large range of steel solutions for local and export markets. As part of their ongoing energy efficiency improvement programme, the company modified their hollow sections pipe mill, which gave them a higher rate of product throughput and a reduction in natural gas consumption.
Though the pipemill is only a small component of New Zealand Steel's operation, the improvements have resulted in energy savings of $102,000 per year. With the additional revenue for 2008 from the increase in production, the total benefits are worth over $4 million.
The total cost of the project was $520,000, with a payback of less than two months.
The modification resulted in a reduction of gas use from 2.5 to 1.6 gigajoules of natural gas for each tonne of production - a 35% reduction. The throughput for the pipe increased from 3.8 to 6 tonnes for each hour the pipe mill was operating.
This project demonstrates that it is not always necessary to replace old technology with new, and that retrofitting can produce great results.
Energy For Industry and Winstone Pulp - Karioi Pulp Mill refiner heat recovery project
Results of an energy audit prompted Energy for Industry to install a heat recovery plant for Winstone Pulp International at its Karioi Pulp Mill in Ohakune. The plant recovers waste heat from pulping refiners and as a result, the mill's use of LPG for heat generation has been dramatically reduced.
The mill is expecting to save over $2 million a year in fuel costs. The LPG reduction equates to 120,000 gigajoules which equates to a 6,000 tonne reduction in CO2 emissions each year.
The overall cost of the project was $3.6 million with an anticipated payback of approximately two years. But given the actual performance of the plant, the payback period is likely to be shorter.
This system is easily replicable at other wood pulp mill operations that use thermo mechanical refiners to produce pulp.
The project serves as a excellent example of the value of businesses completing energy audits, even if they are already energy efficient and taking steps to reduce emissions.
