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First CFC- Substitute Production Plant Comes on Stream

by James Lock
****ICI's research aims to identify a family of environmentally acceptable alternative chemicals to replace CFCs in vital applications. New techniques have been developed to cut development time to a minimum.****
THE world's first commercial plant for the production of a new. ozone-friendly chlorofluorocarbon (CFC) substitute has opened in Britain at ICI chemical fit polymers' site in Runcorn, northwest England. Such is the importance attached to It. that the official opening ceremony was performed by Prime Minister John Major early this year.
Tfie replacement chemical I* K1EA 134a rklea" is Greek for green and verdant), the first CFC substitute developed by ICI for use In refrigeration and air-conditioning systems. The new £30 million plant actually started production in October 1990.
At the launch, company chairman Sir Denys Henderson said the exciting product, which was brought on-stream in less than half the time normally required to develop a new chemical, provided a solution to a pressing environmental problem.
The Prime Minister emphasised the United Kingdom's strong commitment to protecting the ozone layer in the Earth's atmosphere. He recalled that it was a British scientist — Dr Joseph Farman of the British antarctic Survey tn 1982 — who discovered the hole in the ozone layer at the South Pole.
It was the United Kingdom's ozone conference in 1989 that actually brought the issue into higher profile and ted to the strengthening of the internationally agreed Montreal protocol of 1987 to phase out CFCs. The Protocol was farther strengthened at the succeeding ozone conference tn London in 1990. and a large number of countries now support it.
Mr Major said there was agreement in the more technologically advanced countries to cover the costs of developing nations as they become signatories to the protocol.
Effective Teamwork
ICI has been producing its wide range of Arcton refriger ant gases for more than 40 years and is a leading supplier to the industry. Under the teyms of the Montreal Protocol. CFC gases are to be phased oul by the year 2000. ICI has undertaken a £100 million fluorocarbon research programme for the development of a family of ozone-friendly CFC alternatives. KLEA 134a is the first of these.
The completion of the first KLEA 134a plant three months ahead of schedule was achieved largely by effective . teamwork and a clear understanding of the project philosophy by all involved. A project task-force comprising process, project, functional and commissioning personnel was set. up at Id's chemical and polymer research headquarter* at Runccrn.
The proximity In northwest England of the company's other chemists and engineers speeded up decision-making and problem-solving, which ateo involved close cooperation with Snamprogetti Ltd (SPL) of Basingstoke, near London, several of whose engineers were
seconded to the ICI team.
The task force at Runcorn prepared a front-end design package, comprising process specification, process and instrumentation diagrams, hazard studies, equipment mechanisation. plan! layout and pro-
ject standards. The centre of activity then moved to Basingstoke, where detailed engineering was carried out. Equipment procurement was by SPL, which also carried out day-to-day construction management and sujiervision under the control of Id's engineering construction group.
New Techniques
During the project a core team, comprising project, process, construction, commissioning. project control and SPL personnel, regularly reviewed the tight programme to check that the project remained on course and the rest of the team was aware of any changing requirements.
Meanwhile, work is in progress on a pilot plant at Widnes, northwest England, to improve KLEA 134a.
At the same time. ICI has set up a fluorochemical tech-
nical team in which 100 scientists are actively Involved, and some 200 engineers will be working on the construction of the new plants.
Id's research alms to Identify a family of environmentally acceptable alternative chemi-
cals to replace CFCs in vital applications. New techniques have been developed to cut development time to a minimum.
The company is working on the ones most urgently needed. KLEA 134a is a chlorine-free replacement for R12. the general purpose CFC coolant used tn domestic refrigerators. air-conditioners and small commercial chillers, but It is not suitable for larger industrial systems or for low-temperature supermarket freezers.
Having started up the 134a plant In Britain. Id's design of a larger, £90 million 10.000 tonnes/year pant to be built at St Gabriel, Louisiana, in the United States, is at an advanced stage, and the plant 1s scheduled to come on stream in 1992.
The development of a range
of alternatives to CFCs is extremely important but will take time. Two fast solutions have been found — butane and HCFC 22 (R22) are being used as propellants for the aerosols currently advertised as "ozone friendly".
For the longer term, however. It seems likely that CFCs will be replaced by hydrofluoroalkanes (HFAs), of which HFA 134a is the first example. HFAs arise either by eliminating the chlorine completely from a CFC—for example CF3CCI2F would become CFgCHgF (tetrafluorethane) — or by substituting a hydrogen for one or more of the chlorines In a CFC.
In the first instance, because there Is no longer any chlorine in the molecule. It no longer poses an environmental problem. In the second, the hydrogen Introduces Instability Into the molecule and reacts with the OH (hydroxyl) naturally present in the lower at mospnere. forming water and leaving behind the rest of the molecule, which itself reacts with water arid oxygen. Pilot Plant
Having made the substitution. it is a matter of finding the right HFA for each application. Individual HFAs do not possess all the properties possessed by the CFCs, so there will be no "drop in" substitutes as such. The product most closely matching the needs of an application will be specially developed for it.
Synthetic Lubricant
ICI explains that, for example. In an automobile air-conditioning system the temperature needs to drop to a comfortable level in a few seconds whereas, tn a building, the need Is for a less dramatic drop, though it Is desirable to hold the temperature constant for many days. User industries may need to re-englneer iheir existing equipment and in some cases Introduce new processes.
A great deal of work has been done already tn cooperation with those industries to ensure new products will perform properly in refrigerator compressors, for example. Id's own lubricants business has developed a new synthetic lubricant specifically to work with KLEA 134a in refrigeration applications.
ICI now has a pilot plant at Widnes for HCFC123 and Is ex ploring the use of both ft and HCFCI41b as replacements for various uses of CFC 11 tn appli-
cations such as polyurethane foams and in air-conditioning, centrifugal chillers and centralised systems for shops, hotels and offices, while various mixtures are being considered to replace R502.
Another CFC manufacturer, the ISC division of Rhong^ Poulenc Chemicals (formerly ISC Chemicals of RTZ Group) of Bristol, southwest England, has developed its new refrigerant. Isceon 69-S. as an immediate replacement for R502. the main refrigerant used in supermarket freezers, cold stores and food transportation. R502 is itself a blend of R22 and (fuliy-thlori-nated) CFC 115, which is a major component of R502. and has an ozone depiction potential (ODP) slightly less than R22.
Isceon 69-S itself is a mixture of R22. R218 and R290 and has an ODP much lower than that of R502, which is scheduled to be phased out over the nest five or six years under the terms of the Montreal Protocol.
Dr Forbes Pearson, technical director of star Refrigeration of Glasgow. Scotland, who carried out the comparative trials, comments “This refrigerant is an exciting find as ft is so close In performance to R502 that it can be considered, as a drop-in replacement. 4t is compatible with conventional mineral oil lubricants.”
R22. a hydrofiuorocarbon. lias an ODP five times lew than R502. but compressors designed to run on R5O2 do not work with R22 Sainsbury, the British supermarket group, which Is testing Isceon 69-S. is planning to use HFA 134a as a coolant In Its chiller cabinets (kept just above freezing point)
and R22 for the frozen food cabinets.
The price will be three times that of R502. but much less than the cost of replacing compressors.
Environmental Effects
Elsewhere, tests with particular significance for the success of the ventures are being carried out Under the umbrellas of alternative fluorocarbons environmental acceptability studies (AFEAS) and the programme for alternative fluorocarbon toxicity testing (PAFT), the former manufacturers of CFCs — who will now produce the HFAs — have pooled the resources of 14 laboratories to speed up assessment of the toxicology of the new products and their environmental effects.
AFEAS looks at the effects of new chemicals on the environment — their effect on the stratosphere, the troposphere, their contribution to global warming, how they break down and how their breakdown products affect the environment. PAFT is conducting a two-year carcinogen programme. as well as assessing single high-level exposure, the potential to affect living organisms in the environment, the risk of birth defects, the effect on reproductive capacity, and long-term toxicity.
In addition. ICI has funded the work of independent scientists at a variety of Institutions. including Professor Sherwood Rowlarid and Dr Mario Molten of the University of California, the original identifiers of the problem In 1974 The result is that there is going to be a significant toxicological database relating to these chemfcate. Including details of their environmental safety