Although use of ozone-depleting CFCs in industry has dramatically decreased, emissions of hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) have increased. These gases, which also have a greenhouse effect, have been used as replacements for CFCs. According to the European Commission, emissions of fluorinated gases were the equivalent of 65 million tonnes of carbon dioxide in 1995, an amount forecast to increase by 50% by 2010. Fluorinated gases account for 2% of EU greenhouse gas emissions, but their global warming potential is high. Reduction of such gases is therefore a priority. New zeolite/water adsorption technology is one method for reducing the emission of refrigerating gases and increasing energy efficiency.
Zeolite system can be used as an alternative to current, greenhouse gas producing, refrigeration systems. The project would demonstrate that this alternative is technically and economically viable. Several new transport containers using zeolite/water technology have been constructed during the course of the project, for each of the categories foreseen (food, beverages and medicine refrigerators). The project beneficiary, Dometic, considers applying the process to future types of refrigerators. (The zeolite/water adsorption technology was developed by ZEO-TECH).
The Zeolite project developed an entirely new system of refrigeration based on the unique properties of particles of natural zeolite. The capacity of zeolite crystals to adsorb large quantities of water vapour was exploited to create an autonomous refrigeration system requiring no continuous power source at the time of use. Zeolite-based refrigeration is an entirely new refrigeration system. It allows the preservation of perishables such as food or medicine for limited periods (more than 12 hours in the case of this project's prototypes) in an environment where no electricity supply is available. The system can be regenerated using a variety of energy sources, including renewable energies (electricity, gas, wood, solar collectors, etc.). It can also store energy indefinitely, which also represents an asset.
The project demonstrated the technology’s potential by developing field refrigeration containers for catering. Some minor technical problems still needed to be solved at the end of the project, however, before zeolite-based systems could be put on the market.
The environmental and energy-efficiency benefits of zeolite technology have been demonstrated under specific conditions. Based on natural elements (zeolites), the new systems have reduced the emissions of refrigerating gases. The new refrigerators are CFC-free systems that have eliminated gases having greenhouse effect. Compared to compressor based refrigerators that have a global warming potential (GWP), the zeolite systems create the advantage of having zero GWP, due the fact that no gases are used as cooling agents. Moreover, the ozone depleting potential (ODP) is kept at zero, as it is the case for the compressor system. The project showed that for the time being zeolite systems may be more energy consuming than alternative technologies. Nevertheless there is still enough scope to improve the energy consumption in order to bring it closer to the level of conventional refrigerators. After-LIFE communication would focus on the product's commercialisation – they are very likely to be marketed – and be accompanied by the publication of articles and participation at exhibitions, conferences and seminars.
The system will probably only find a niche market. It is more expensive both to construct and to operate than alternative systems. As a result, it is likely to be used only in cases where its unique autonomy is indispensable. Its versatility favours its use in remote areas or areas with poor infrastructure – for example, for the delivery of humanitarian aid (food or medicine)or by the military.