Ten Years of the New Zealand Used Oil Recovery Programme
New Zealanders produce 30 million litres of waste oil each year. The safe disposal of this material presents a significant environmental issue. Approximately half of this oil is burned in three cement kilns located on Cape Foulwind, near Westport.
Ten years of environmental monitoring data is employed to investigate if the practice of burning used oil in cement kilns is consistent with environmental best practice given the limited options for disposal of this waste material in New Zealand. Emission data is used to determine whether the introduction of used oil into the fuel stream of a cement kiln has any significant effects on the emissions to air.
The emission monitoring results show that the co-processing of used oil has little effect on the emissions of trace metals and dioxins from the kiln stacks, and that the levels of such emissions are well within limits that are recognised on an international basis.
Keywords: Heavy metals, dioxin, furan, emissions, cement kiln, used oil.