Following February’s feature highlighting green initiatives by supermarket chains to use CO₂ as a natural and carbon neutral coolant for in-house refrigeration, this month’s Hot Topic delves into another ‘cool’ issue – intransit natural refrigerants.

With the influx of eco-consciousness, a hike in diesel costs and buzz phrases such as ‘corporate responsibility’, supermarkets and transport companies are seeking cleaner, cheaper, greener refrigeration alternatives.

Gasworld asks industry insiders and international corporations whether natural refrigerants, such as liquid nitrogen and liquid or solid carbon dioxide, are the solution.

A recent study by the Centre for Energy and Built Environment Research at Brunel University revealed that 1.8% of a typical European country’s total carbon emissions are due to food transportation. While the food sector in general is responsible for 22% of the total. Similarly, external factors such as legislative reform have compounded the need for an eco-friendly alternative.

Thomas Roller, new CEO of Ukram Industries, remarked at the particular significance of this in the EU and North American regions where, “Governments, businesses and people are increasingly becoming aware of the need to cut the environmental costs of doing business.”

Nevertheless it is worth noting that use of the likes of liquid CO2 and nitrogen for intransit refrigeration is not new. It uses the same expendable refrigeration concept as food freezing and chilling process using direct refrigeration processes.

Rather than traditional methods of intransit refrigeration which run on diesel and are closed loop mechanical processes using HCFC’s and butane derivatives, expendable refrigeration systems release vaporised refrigerants into the insulated truck body to maintain cold temperatures.

This method is effectively pollution free; allowing the food sector to meet recent 2006 legislation on global warming, whilst also working towards stringent 2015 legislative deadlines. Similarly, the system is silent which enables vehicles to transport goods in built-up areas during the night without causing disruption or breaching noise pollution guidelines.

Roller confirmed, ‘One truck trailer fuelled by diesel releases 25 to 30 tonnes of CO2 during the course of the year. Multiply that with the number of diesel-fuelled refrigerated trucks that transport food globally and the quantity of CO2 emitted would be an astounding figure.”

Executive Director for Greenpeace International, Kumi Naidoo commented to business leaders in Davos, “Large enterprises have both an opportunity and responsibility to change the game”.

A source for the Intergovernmental Panel on Climate Change agreed, “Addressing Climate Change requires leadership and collaboration.” He also noted that natural refrigerants “make business sense”.

Cedric Hanson, Business Development Manager for Applications Technology at BOC, commented, “We recognise that cryogenic refrigeration is an important alternative to mechanical fridges particularly as the technology will develop further. There are many options for using cryogenics including refrigerated trolleys with liquid CO2 or dry ice, direct injection cryogenic systems and indirect cryogenic systems. All will have their place depending on the needs of our customers.”

Indeed with the EU offering corporations subsidies in the form of ‘carbon credits’, natural refrigerants do seem to “make business sense”. Judith Ball, Marketing Executive for ecoFridge, explained, “New EC regulations will see the statutory requirement for the reduction of fleet carbon output in the near future. With the combination of this and the ever increasing rise in diesel prices (nitrogen prices have stayed level for a long time) ecoFridge could be seen as the only viable alternative.”

Though in a formative stage, Hanson cited competition in the market place, “BOC has been selling cryogenics for chilling and freezing applications for many years and has considerable experience within the intransit refrigeration market with BOC Polarstream.”

Air Products also offered an equivalent during the 1970s and 1908s, “CryoGuard”. However, this enjoyed less success than the BOC Polarstream, particularly in the UK market.
Since February’s article, several leading international companies have invested in cryogenic refrigeration.

ASDA, a key European supermarket chain parented by Walmart, has become one of the first fleets to trial intransit natural refrigeration in Western Europe. Casino Group has invested in the same ecoFridge® technology, while elsewhere Coca-Cola has followed suit.

ASDA’s Network Transport Manager Chris Hall notes, “This is a major step towards ensuring that our fleet transport reduces costs, cuts emissions and lowers the overall environmental impact of food distribution. It also solves the problem of delivering chilled goods to our stores in residential areas – especially at night, due to the silent running nature of the technology.”

Similarly the multiplatform retailer, Casino Group has adopted this new technology within its French logistics operations. A spokesperson for Casino, Francois Herbrard of their Sustainable Studies department commented, “We decided to trial the systems in 2008 which have proved to be very successful.” He finished by describing nitrogen-expendable refrigeration systems as ‘one of the refrigeration technologies at the forefront of future design.’

These companies are illustrating the demand to turn greener leaves than simply switching from HCFC to HFCs; HFCs might not harm the ozone layer, but these third generation products still bear massive global warming potential. Natural refrigerants are staggeringly 1,430 times less damaging to the climate than a typical HFC.

Third party advice encourages such shifts. In an exclusive statement to gasworld, a spokeswoman from the UK’s Food Standards Agency, assured consumers and suppliers alike that the technology “is completely safe and there are no food safety risks at all.”

EcoFridge, the group offering natural refrigeration solutions to ASDA and Casino Group extolled the benefits of this green technology. Ball commented, “The use of liquid nitrogen for refrigeration is a very clean and environmentally friendly alternative to many other ‘green’ solutions available on the market today. Nitrogen makes up 78% of the air we breathe and produces no carbon emissions when released into the atmosphere. LN2 is also a by-product of the production of oxygen and uses a quarter of the amount of carbon to produce compared to other alternative fuels.”

Ball reiterated the food standards agency’s remarks about safety, saying, “Nitrogen is also completely safe when the correct safety practices are adopted as with ecoFridge. Unlike other gases there is no risk of explosion and if spilt, will be released into the atmosphere as vapour.”