DuPont has announced the development of a new, lower global warming potential (GWP) refrigerant for use in commercial refrigeration systems. Opteon™ XP10 is based on HFO-1234yf, which has recently received acceptance for use in mobile air conditioning. It is characterized by its lower GWP (close to 600) when compared to HFC-134a, as well as its similarity to R-134a in terms of thermodynamic properties.

Initial test results indicate that it is suitable for use as an alternative refrigerant for new, medium-temperature commercial refrigeration systems based on R-134a technology or as a replacement for R-134a in existing systems.

First pilot projects with food retailers such as Aldi Süd, and Penny (both in Germany) and Spar (in Austria) have been encouraging in terms of operating performance and ease of use, according to a press release issued in October at the Chillventa 2010 trade show in Nuremberg, Germany. DuPont is considering an initially limited commercial launch of XP10 in the European Union between 2012 and 2013, and will monitor market interest to define the exact timing for its commercial introduction, according to the release.

Also, according to the press release, “The carbon emissions associated with the R&AC [refrigeration and air conditioning] industry are not only a direct consequence of the refrigerants themselves, but are also produced indirectly as a result of the energy consumed by the refrigeration systems in which they are used. The food retail industry is one of the major operators of such equipment. This is one of the reasons why food retailers in many EU countries are being proactive in their quest to reduce the carbon footprint of their operations, including the adoption of refrigeration technologies and refrigerants that deliver reduced direct and indirect carbon emissions.

“The search for more sustainable refrigerants and energy-efficient refrigeration systems are part of this effort, and DuPont is playing a leading role to help reduce the total carbon footprint of R&AC systems in preparation to meet current and future regulations.”

A NEXT STEP

“As with our range of DuPont™ Isceon® 9 Series (of HFC) refrigerants, which have since become almost an industry standard for the replacement of R-22, we are pleased to announce a further milestone in our quest to help reduce the environmental impact of R&AC systems with the development of a new lower GWP refrigerant technology for use in commercial refrigeration systems,” commented Thierry Vanlancker, global business director for DuPont Fluorochemicals.

Development work has also revealed that XP10 offers the opportunity to be used alongside CO2 in hybrid systems - XP10 for medium temperatures and CO2 for low temperatures. Studies show that such a solution would provide retailers with a 90 percent reduction in direct carbon emissions and a minimum 50 percent reduction in the total carbon impact of retail commercial refrigeration systems when compared to the current global industry standard direct expansion (DX) technology based on HFC-404A.

“We are already seeing retailers in some countries migrating from R-404A DX technology to 134a/CO2 hybrid systems in order to improve system energy efficiency and to reduce their overall carbon impact. XP10 is an efficient and logical choice in making a further step change reduction in carbon impact,” said Pascal Faidy, business and market manager, DuPont Fluorochemicals Europe, Middle East, Africa (EMEA).

It was stated that XP10 can also be used in stand-alone systems for smaller applications where hybrid systems are not practical, such as in discounter applications. A further benefit, it was reported, is that by adopting this new refrigerant technology in combination with systems using other low-carbon refrigerants such as CO2 or hydrocarbons, retailers can make a significant contribution to achieving the EU’s 20-20-20 targets (a 20 percent cut in emissions of greenhouse gases by 2020, compared with 1990 levels; a 20 percent increase in the share of renewables in the energy mix; and a 20 percent cut in energy consumption).

POSITIVE RESULTS

With regard to the development and market testing of XP10, DuPont is conducting laboratory-based compressor and system tests in cooperation with several equipment manufacturers. A series of field trials in food retail operations both within and outside Europe are also being conducted.

For instance, Spar Österreich of Salzburg, Austria, has been using XP10 for the medium-temperature section of an R-134a/CO2 cascade system at a supermarket in Kundl/Tyrol since July 2010. Apart from a replacement of the filter drier and a reprogramming of the Frigolink HKS regulator with the corresponding data for XP10, no further change of components or oil was required. The refrigerant charge measured before and after the conversion came in at 83 kg (183 pounds). In line with DuPont recommendations, a minor adjustment to the expansion valve was made to ensure the correct superheat setting. The refrigeration system has shown no sign of leakages or other problems since recommencing operation, the DuPont press release said.

In Germany, Aldi Süd GmbH & Co. KG of Moenchengladbach, converted an R-134a-based refrigeration system to XP10 as part of a second pilot project started in May 2010. Following removal of the original R-134a refrigerant, the system was charged with the corresponding amount of XP10 and restarted. Neither an oil change nor a replacement of components was required. Service contractors carried out a minor adjustment of the expansion valve to ensure the correct superheat setting. Measurements taken before and after the conversion showed a slight fall in energy consumption (approximately 2 to 3 percent) with XP10 when compared to R-134a at the same external temperatures.

“We believe that the extension of our field trials will prove that our new development has the potential to become a competitive and sustainable global technology standard that will enable the retail supermarket sector to meet their carbon footprint reduction goals,” said Faidy.

Publication date: 12/06/2010