Reducing emissions and energy at New Zealand Steel

Two projects at New Zealand Steel’s Glenbrook site have led to substantial emissions reductions and have reduced demand for external electricity and gas.

Working with Alinta Energy, New Zealand Steel’s core supplier of steam and co-generated electricity, changes were implemented to improve off-gas and heat recovery in the Multi Hearth Furnace (MHF) afterburners, and to increase steam generation in the MHF boilers. These projects have increased electricity generation by 55,000 MWh per annum, reduced annual purchased electricity by 13 per cent, and lowered GHG emissions by approximately 6,500 tCO2-e per annum. 

Meanwhile, the Rolling Mill team implemented a new approach for continuous operation of the Rolling Mill reheat furnace under much tighter operating conditions. The result is improved yield, and savings in use of natural gas estimated at 62,000GJ per annum, equivalent to 3,700 tCO2-e.