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CO2 Emissions of Metal Production Technologies in Relation to External
Factors.
B.W. Daniels and H.C. Moll
Center for Energy and Environmental Studies IVEM, Groningen University,
Nijenborgh 4, 9747 AG Groningen, The Netherlands
tel. +31 50 3634609; e-mail B.W.Daniels@fwn.rug.nl
Abstract
Enhanced radiative forcing (greenhouse effect), caused by antropogenic CO2 emissions, is considered a major
environmental problem for the 21st century. This paper discusses the possibilities to reduce the specific CO2
emissions of the base metal industry (represented by steel and aluminium, largest by production volume and
emissions) to 50% and 10% of the current values. By process analysis, the paper investigates the CO2 emission
reduction potential for important current and future production routes of steel and aluminium, for some scenarios
representing external parameters. Subsequently, the paper investigates the effects of recycling, applying
the technologies with the lowest emissions for each scenario. The reduction potential of metal production
strongly depends on the external parameters. Favourable external conditions greatly enhance the reduction potential
of production, and enable the desired reductions of CO2 emissions.
Introduction
The present western Europe 7 consumption of energy and materials and the accompanying emissions of greenhouse
gases substantially contribute to global resource depletion and global climate change. To contribute to
global sustainability (requiring global stabilisation at 1990 emission level by the year 2050, according to scenario
IS92a [13]), while leaving room for development outside the western world, substantial reductions of
greenhouse gase emissions in the western world are required (mainly CO2). Currently, the total production of
metals contributes for about 7%, or 250 Mt/yr, to the total CO2 emissions in western Europe. The total emissions
are likely to grow in the future, as aluminium consumption will probably grow substantially in the next
decades, and for steel a gradual growth is foreseen.
This paper will systematically investigate the emissions of current and future metal production technologies, in
relation to external factors. It will investigate whether it is possible to attain 2 and 10-fold reductions of CO2
emissions per tonne metal with these technologies.
An equitable distribution of CO2 emissions on a global level in 2050 requires a reduction to one fifth of the current
energy consumption and emission levels for OECD Europe [20]). It is the long term objective with which
to compare the reduction possibilities. Taking into account the expected growth of production, this implies a
ten fold reduction per tonne of metal. A twofold reduction per tonne of metal been is the intermediate goal,
which also indicates the efforts required to keep total emissions constant.
The paper discerns options that can be freely chosen by the individual companies and options for which the implementation
depends on external factors, as they require external infrastructure. For a number of scenarios, the
paper will present cost structure and CO2 emissions of selected metal production routes, of the subsectors iron
and steel, and aluminium. A general analysis, included in the discussion, focuses on the reduction potential of
the sector as a whole, taking into account changes in recycling percentages. This section will also compare the
possibilities for emissions reduction with the factor 2 and 10 reduction objectives. Finally, the paper will shortly
discuss the reduction potential not included in the present analysis.
Methodology: Production Routes and Scenarios
The costs and emissions analysis included 8 production routes for steel and 3 for aluminium, all having the liq-