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Evaluation of the possibilities of substituting potent greenhouse gases (HFCs, PFCs and SF₆)

Preface

In the mid 1990s, an increase occurred in the Danish consumption of potent greenhouse gases concurrently with the phase-out of CFC, HCFC and other ozone-layer depleting substances.

Substitution of CFC

It was especially the use of HFC substances that increased. These substances are used as substitution of CFC and HCFC for certain purposes within refrigeration and as blowing agent of polyurethane foam. Simultaneously, another development occurred as more environmental alternatives were developed for many purposes, e.g. hydrocarbons in aerosol cans, cyclopentane in insulating foam in refrigerators and district heating pipes as well as hydrocarbons, ammonia and water in different types of refrigeration systems.

Synthetic produced substances

CFCs (fully halogenated chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), HFCs (hydrofluorocarbons), PFCs (fully halogenated fluorocarbons) and SF₆ (sulphur hexafluoride) are all synthetic produces substances. In addition, the substances are quite stable and have a long life in the atmosphere. This applies particularly to the fully halogenated substances, i.e. CFCs, PFCs and SF₆.

Ozone depleting substances

CFCs and HCFCs are ozone depleting substances and are included in an international convention (the Montreal Protocol), which ensures a phase-out of these substances. The consumption of CFC is (with few exceptions) prohibited in Denmark. The Danish consumption of HCFC is decreasing and must be phased out completely by 2002.

HFCs, PFCs and SF₆ do not contribute to the depletion of the ozone layer, as the substances do not contain chlorine or bromine. On the other hand, they contribute to the greenhouse effect. The UN Framework Convention on Climate Change regulates the greenhouse gases. The substances, which the countries have to reduce the emission of, are on the list of greenhouse gases (in the Kyoto Protocol). The substances are treated equally with carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O).

Danish consumption

In 1999, the consumption of HFCs was approx. 980 tons in Denmark. The corresponding consumption of SF₆ was approx. 13 tons, while the consumption of PFCs was approx. 8 tons.

This is the reason why the present project has been subsidised by the Danish Environmental Protection Agency.

Phase-out of HFC

The Danish Environmental Protection Agency has just published a draft statutory order on phase-out of potent greenhouse gases (HFCs, PFCs and SF₆). These substances have a GWP (Global Warming Potential) from 140 to 23,900 compared to CO₂, which per definition has a GWP of 1.

In the course of a number of years, it is expected that the emission of these substances will reach what corresponds to approx. 2.5 to 3% of the emission of CO₂ in Denmark. This is the reason whey the government wants to limit the consumption and thus the emission of these substances.

In connection with the Budget for 2001, a tax was introduced on HFC, PFC and SF6. It was decided that an investigation should be carried out in the course of 2001 determining where an additional effort should be made to phase out the use of the substances as fast as possible with the lowest additional costs possible.

What is meant by additional effort is support for development of new technology, construction and test of demonstration system, development of education on the use of new refrigerants and forced implementation for the benefit of the environment, etc.

The Danish Technological Institute has prepared the reports "Erstatning af kraftige drivhusgasser" (Substitution of potent greenhouse gases) for the Danish Environmental Protection Agency (Environmental project no. 456, 1999) and "Ways of Reducing Potent Greenhouse Gases" for the Nordic Council of Ministers (Tema Nord 2000:552).

This report should be seen as part of the two above-mentioned reports, as this work focuses on areas where the situation is changed, or where there are special problems. Importance is attached to the field of commercial refrigeration in particular where the problems are the greatest and most complex.