INCORPORATING COLD CHAIN
ASSOCIATIONS NEWS normality is restored ( or when the higher prices become the new normal ). It is also difficult to sell the concept of more efficient systems because there is an expectation that any additional capital cost will be funded by savings made . The capital cost is concrete , but the savings are forecasts and therefore subject to a degree of caution , scepticism or even cynicism . Worthy efficiency projects are sometimes stalled or even cancelled because the projected savings are dialled back to such an extent that the expenditure can no longer be justified in simple payback terms . Safety and reliability are even more difficult concepts to justify in terms of any additional expenditure required to achieve the objective . The cost of business disruption caused by an accident or the cost of product spoilage caused by plant downtime can be many times higher than the cost of the investment proposed but everyone hopes that it won ’ t happen to them . This exploration of the achievements of the last 30 years and the expectations for the next 20 will examine them in terms of all three of these factors : environmental , efficiency and safety .
They are not independent variables – each has an effect on the other two .
3 . NOTABLE ACHIEVEMENTS OF THE LAST 30 YEARS
The Montreal Protocol has been hailed as one of the most successful international treaties in history . It was published just 14 years after publication of the scientific paper that explained the magnitude of the problem .
It was then signed initially by 21 countries on the date of publication , 16 September 1987 , including Egypt , Togo , Ghana and Senegal in addition to the US , Mexico , Canada and many of the European Union countries . Over the following year a further 25 countries signed up including Morocco , Burkina Faso , Uganda and Congo as well as more European and South American countries . This meant that the treaty had sufficient international support to enter into force on 1 January 1989 . South Africa was the 52nd country to sign , on 15th January 1990 , and the Protocol has subsequently been ratified by every member of the United Nations ( UN ) as well as the Cook Islands , Niue , the Holy See and the European Union , one of the first universally ratified treaties in the history of the UN .
Since 1987 the Montreal Protocol has been amended nine times , initially speeding up the phase out of the most harmful substances , the CFCs such as R-11 and R-12 , then extending the original provisions to include HCFCs such as R-22 and most recently , in the Kigali Amendment of 2016 , broadening the scope to incorporate global warming substances such as HFCs , even though they have no ozone depleting potential . This was a very significant move because it recognised the success of the Montreal process in controlling and reducing emissions of harmful substances and adopted that mechanism to address the problem of climate change caused by man-made global warming . The Kyoto Protocol , adopted in December 1997 , had sought to control emissions under the UN Framework Convention on Climate Change but it was fundamentally unsuitable for application to working fluids in sealed systems because it was intended to
regulate planned emissions from power stations and other industrial sources .
This mechanism has resulted in three transition waves as new options have become available . At first the transition was from CFCs to HCFCs which with their lower ODP were said at the time to be “ part of the solution , not part of the problem ” ( a direct quote from a seminar run by one of the refrigerant manufacturers ). The second transition , which overlapped significantly with the first , was to working fluids that contained no chlorine and therefore had no effect on the stratospheric ozone layer . These were predominantly HFCs such as R-134a but the development of the UN Framework Convention on Climate Change through the 1990s leading up to the Kyoto Protocol in 1997 highlighted the fact that some of these fluids had a very high global warming potential . It took almost 20 years , from 1997 to 2016 , to formulate an acceptable mechanism within the UN framework for regulating the HFCs with high GWP but this has now been enacted in various jurisdictions around the world including the f-gas regulations in Europe and the AIM Act in the US . This prompted the third transition wave , from HFCs to HFOs – the so-called hydrofluoroolefins . This labelling is something of a marketing triumph since the HFOs are all HFCs ( hydrofluorocarbons ). Their key feature is that the carbon backbone of the molecule includes a double bond , which makes the molecule less stable and more likely to react with an external influence to break down into some other compound . The short atmospheric life of the HFOs means that they cannot have a strong influence on global warming because they don ’ t exist for long enough , but this has brought a new set of environmental concerns based on fears about what the HFOs turn into when they are no longer HFOs .
Moving from CFCs to HCFCs only required an adjustment of the existing technologies , needing greater care in designing oil management systems to cope with slightly reduced miscibility and designing for slightly higher operating pressures . The introduction of HFCs needed development of a new range of lubricants , the polyesters , because the absence of chlorine in the refrigerants reduced the lubricity of bearing surfaces and led to premature bearing failures when traditional mineral or synthetic oils were used . A spin-off benefit of the change of lubricant was that the new oils had less adverse effect in evaporators on the low temperature side of the system and so system efficiency could be improved as well . Operating pressures with some HFCs , for example R-32 and blends containing R-32 , are higher than required for R-22 so some system and component redesign was required . Moving from HFCs to HFOs has introduced additional difficulties , for example safe design of systems to avoid problems with the flammability of the new substances such as R-1234yf . It is fair to say that at each step of this development process the technical challenges have become more difficult and the margin for error in the process has diminished . With hindsight those early development steps look quite simple now , although they felt quite challenging at the time . CLA
Continued in Part 2 …
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