アルミニウム一次地金の輸入元を考慮した環境負荷データの比較

抄録

Primary aluminum consumes much energy in its production process-es leading a great quantity of emissions. In Japan, 99 ‰ amount of primary aluminum is currently imported from other countries. In this work, Global Warming Potential (GWP) and Acidification Potential (AP) values for primary aluminum ingot produced in Brasilia, Russia, Australia, Venezuela, U. S. A., Norway and Island have been investigated. The average GWP and AP values for Japanese import mixtures were calculated. The mini-mum GWP and AP values for primary aluminum ingot produced with best available tech-nology have also been estimated.
It was found that GWP value of primary aluminum ingot produced in each country varied from 10.4 to 27.4 kg-CO₂ equiv./kg, while AP value varied from 0.0172 to 0.135 kg-SO₂ equiv./kg. The average GWP and AP values for Japanese import mixtures were 15.5 kg-CO₂ equiv./kg and 0.0516 kg-SO₂ equiv./kg, respectively. GWP value of primary alu-minum ingot could be reduced up to 6.32 kg-CO2 equiv./kg if it is produced with best available technology, and AP value could be reduced up to 0.0103 kg-SO₂ equiv./kg. The environmental impact of primary aluminum ingot widely varies according to which coun-tries primary aluminum ingot was produced in and which technology was used in its pro-duction process.