Refrigerant legislation imposes significant restrictions on the use of refrigerants. Imports of new refrigerants are limited by declining quotas, making the availability of some refrigerants more difficult. Alternatives to old refrigerants include the use of replacement refrigerants or the recovery and purification of old refrigerant. In this article, I will take a closer look at these options.
According to refrigerant legislation, all HFC-refrigerants in refrigeration and air conditioning systems must be recovered when the system is emptied. Recovered refrigerants with a GWP of more than 2500 can still be used until 2030. From 1 January 2020, the F-Gas Regulation prohibited the placing on the market of solid refrigerating appliances with a GWP of 2500 or higher for HFC refrigerant, apart from a storage temperature of -50 ° C or colder equipment. The same ban came into force at the same time for self-powered refrigeration appliances for professional use.
Substitute, lower GWP (Global Warming Potential) refrigerant blends such as R448A, R449A and R452A, which still contain HFC components, have been introduced to the market. These refrigerants can replace, for example, R404A quite well, but still have a fairly high GWP value (R452A GWP 2141).
As an investment, a replacement refrigerant is a low-cost option, but the side effect can be a decrease in the efficiency of the refrigeration unit and an increase in energy consumption. In self-powered appliances, the next restriction will take place in just over a year, when the GWP limit will be reduced to the 150 already used in household appliances. This significantly reduces the options available for new equipment.
The high purchase price of new systems places limitations
Looking at entirely new equipment, carbon dioxide (R744) and natural refrigerants (R290, R600, R600a) have emerged as viable alternatives. For R744, the high purchase price of the system itself has limited the prevalence of this option in restaurant and professional kitchen use. A good alternative is, for example, waterloop systems in which the refrigerant is R290 and the heat of condensate is transferred to the liquid circuit via a heat exchanger for further utilization.
Natural refrigerants are highly flammable, which limits their use with fillings of 150 g or more in cold and freezer rooms. In cabinets and refrigeration and freezing equipment, the filling limit has been changed to risk-based, whereby, for example, the maximum filling of R290 per circuit is 494 g.
There are a significant number of refrigeration appliances on the market that are not even halfway through their life and are based on high GWP HFC refrigerants such as R404A. The F-gas setting also allows them to be serviced with regenerated refrigerant until 1.1.2030. This provides a cost-effective alternative for maintaining systems and minimizing life cycle costs. There is currently no substitute refrigerant available, which provides a more energy-efficient alternative to such equipment in use than the refrigerant for which the equipment is designed.
There are three options to choose from
1. Fill the plant with the refrigerant recovered from it and, if necessary, add regenerated refrigerant to achieve the correct filling volume. The risk is that the recovered refrigerant contains impurities, or the mixture ratios of the mixture are no longer the same as the original. The solution is the cheapest in terms of maintenance costs but can pay off in terms of reduced service life. It can cause higher than normal operating pressures in the system, increased energy consumption and reduced cooling performance. This could pose a risk to food safety.
2. Replace the refrigerant with a suitable replacement refrigerant. The calculated GWP load of the plant’s refrigerant charge will decrease, but energy consumption may increase and refrigerant capacity may decrease. In addition, the recovered refrigerant must be delivered for recycling or disposal as hazardous waste, which increases costs. In addition, the new, replacement refrigerant refill is out of the declining refrigerant quota again and increases the chemical load on the environment in the form of a new refrigerant to be placed on the market.
3. The recovered refrigerant is delivered for regeneration and reused in the plant. Minimize the amount of hazardous waste generated and ensure energy efficient and reliable operation of the plant.
Regeneration is the most environmentally friendly option
Recovered and regenerated refrigerant plays a key role in helping industry respond to the phased downs of the F-Gas Regulation. Regenerated HFCs are “quota-free” and are therefore crucial to ensure that there is enough product on the market to meet demand, as a gradual reduction in quota affects availability.
The regenerated product can still be used, but the availability of these high GWP refrigerants depends entirely on the availability and demand of refrigerants which can be regenerated, provided that it does not exceed the amount that will be returned for reprocessing in the following years.
Refrigerants with a GWP of more than 2500 do include R404A, R507A, R422A, R422D, R428A and R434A. Although it is assumed that regenerated R404A may be available for some time, some other refrigerants may not be as easy to obtain from all suppliers. By using regenerated refrigerants, we can also reduce carbon footprint, because they reduce the need of new compensatory refrigerants.
Regenerated refrigerant is an ideal medium-term solution for systems that still use refrigerants> 2500 GWP. Other measures need to be taken in the long term. The use of regenerated refrigerant gives time to make decisions and obtain financing for new equipment that considers environmental and energy consumption as well as aspects of heat recovery and recycling.
Recycled or reclaimed?
Regenerated refrigerant is often incorrectly referred to as recycled refrigerant. The terms sound similar, but they are two different things. The regenerated refrigerant has been tested, purified, supplemented and analyzed to fully meet the properties and requirements of the new refrigerant.
Recycled refrigerant is only thoroughly purified and does not involve analysis or quality assurance in terms of specification or purity.
If the recovered refrigerant is returned to the system uncleaned, the unit may not operate in the same way as new or regenerated refrigerant. Non-regenerated refrigerant can cause an increase in energy consumption, a decrease in refrigeration capacity and predispose to malfunctions.
What is regeneration?
When the refrigerant is regenerated, its features are equivalent to new. Initially, it is analyzed to ensure that no foreign ingredients are left there which would prevent its regeneration. In rarer cases, there is a risk that the recovered refrigerant may be unrecoverable due to ingredients that do not belong there. Moisture or acid content in the refrigerant is not a problem.
After the initial analysis, the refrigerant is treated back as equivalent to the new in accordance with the AHRI 700 standard by distillation, purification and drying processes. A certificate of analysis is also issued for this. The process allows the treated refrigerant to be placed on the market as a reclaimed product. The waste status of the treated refrigerant is eliminated and thus regeneration reduces the amount of waste generated during maintenance and the environmental impact.
The F-Gas Regulation requires that all cylinders containing regenerated refrigerant be labeled, have a batch number and indicate where they have been reprocessed to facilitate traceability. All users and regeneration plants must keep records of the origin of the recovered refrigerants and where they have been delivered regenerated for use.
The use of regenerated refrigerant enables the life cycle design of existing plants so that plants can be renewed in a controlled manner for completely new systems and refrigerants without an unreasonable increase in the maintenance costs of usable plants. At the same time, the amount of waste generated is reduced in an environmentally responsible manner.