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Cleaner Technology Projects in Denmark 1997

Substitutes for Potent Greenhouse Gasses

Substitutes for Potent Green House Gases
Arbejdsrapport nr. 101, 1997, Miljøstyrelsen

In recent years the consumption of potent green house gases in Denmark has increased, whilst at the same time the consumption of CFCs, HCFCs and other substances, depleting the ozone layer, is approaching zero.

CFCs (halogenated chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), HFCs (hydrofluorocarbons), PFCs (fluorocarbons) and SF6 (sulphur hexafluoride) are all artificial substances, which were not found in nature until recently.

Furthermore, as these substances are relatively stable, their lifetime in the atmosphere is long. This applies in particular to the halogenated substances: CFCs, PFCs and SF6. The CFCs and HCFCs are ozone-depleting substances, which are subjected to an international convention, the Montreal Protocol, to guarantee of elimination of these substances. Except essential uses, Danish and EU legislation has now prohibited the use of CFCs. Additionally, the use of HCFC is decreasing in Denmark and will be brought to a complete stop before year 2002.

Especially the consumption of HFC-substances has increased. These substances are used as substitutes for CFCs and HCFCs for certain purposes, especially for refrigeration and blowing of polyurethane foam. However, it should be mentioned that more environmentally friendly alternatives have been introduced, e.g. hydrocarbons in aerosol cans, cyclopentane for district heating pipes and hydrocarbons, ammonia and water in various types of refrigeration systems.

Because HFCs, PFCs and SF6 contain neither chlorine nor bromide, these substances will not contribute to any depletion of the ozone layer. However, they are contributing to the green house effect. The regulation of green house gases will be conducted by the United Nation Climate Convention, yet details of such regulation are not finally settled. This topic will be discussed during the 3rd Meeting of the Parties of the Climate Convention in Kyoto, Japan in December 1997.

In 1995 the Danish consumption of HFC substances was approximately 740 tonnes, where the corresponding amount of SF6 was about 17 tonnes. If the entire amount of these substances was released to the atmosphere, the resulting impact would correspond to an increased emission of green house gases, corresponding to approximately 1.5 million tonnes of CO2. The HFCs, the PFCs and SF6 are registered on the Danish EPA’s list of 100 substances, non-desirable in the future.

In recent years various technologies have been discussed at conferences and seminars, in technical magazines and in daily newspapers. Many questions have been asked about how to find the most suitable technology, environmentally safe and safe to use. Examples worth mentioning are modern household refrigerators using two kinds of refrigerants, viz. HFC134a and hydrocarbon (isobutane).

Such discussions will continue many years from now. This is not only a matter between industry on the one side and green organisations on the other. This subject is being discussed very actively between people within different industrial branches, and discussions are often influenced by commercial interest.

It must be recognised that continuos development is taking place within the various technology areas mentioned in this report. Hence, some of the information value might appear slightly out of date. Should any relevant information not be considered in this report, DTI Energy would appreciate to receive further details of such information. This will be included in the final edition, which will be prepared at the end of 1998.

Author/ institution

Per Henrik Pedersen, DTI Energy

This report is subsidised by the National Council for Recycling and Cleaner Technology

ISSN no. 0908-9195
ISBN no. 87-7810-928-8

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