PAPER

Submitted for
First North American Conference & Exhibition:
Emerging Clean Air Technologies & Business Opportunities
Toronto, Ontario, Canada, September 26-30, 1994

Current Status of Fluoroiodocarbons (FICs) as CFC and Halon Replacements. Part 1.

Jon Nimitz, Ph.D., President
The Ikon Corporation
3300 Mountain Road NE
Albuquerque, NM 87106-1920 USA
Phone: (505) 256-1463; Fax: (505) 256-1003

Executive Summary
One of the most promising emerging technologies for replacing CFCs, HCFCs, and halons is the use of fluoroiodocarbons (FICs). FIC technologies, invented by the author, show promise of providing refrigerants, solvents, foam blowing agents, firefighting agents, aerosol propellants, and dielectric gases that are highly effective, nonflammable, have low toxicity, do not deplete stratospheric ozone, do not contribute to global warming or smog, and can in many cases be dropped in to existing equipment. This paper reviews the properties of FIC-based replacements to ozone-depleting substances and the current status of validation. Properties discussed include physical properties, performance, toxicity, environmental effects, flammability, thermal stability, cost, and availability. Business opportunities in FIC technologies are discussed.

Physical Properties
FICs contain carbon, fluorine, and iodine; some may contain hydrogen or other elements. The author has identified approximately 25 FICs of interest: selected properties of the four FICs of greatest interest at this time are shown in Table 1.

Table 1. Selected Properties of FICs

SYSTEMATIC NAME	OTHER NAMES	STRUCTURE	CONDENSED FORMULA	MOLECULAR WEIGHT	BOILING POINT, °C	LIQUID DENSITY (g/mL)
trifluoroiodomethane	trifluoromethyl iodide iodotrifluoromethane	CF3I	CF3I	195.91	-22.5	2.36
1,1,2,2,3,3,3-heptafluoro- 1-iodopropane	heptafluoro-1-iodopropane perfluoropropyl iodide 1-iodoperfluoropropane	CF3CF2CF2I	1-C3F7I	295.93	40.5	2.06
1,1,2,2,3,3,4,4,4-nonafluoro- 1-iodobutane	perfluoro-n-butyl iodide perfluorobutyl iodide iodoperfluorobutane perfluoroiodobutane nonafluorobutyl iodide	CF3CF2CF2CF2I	1-C4F9I	345.94	67.5	2.01
tridecafluoro-1-iodohexane	perfluorohexyl iodide 1-iodotridecafluorohexane 1-iodoperfluorohexane	CF3CF2CF2CF2CF2CF2I	1-C6F13I	445.95	117	2.05

Flammability
FICs have been shown by at least three research groups to be outstanding extinguishants, comparable to halons (Ref. 1). They inert hydrocarbons at about 3% concentration by volume of FIC in air. By adding sufficient FIC to a flammable refrigerant, solvent, foam blowing agent, or propellant (one from which it does not fractionate), the mixture is rendered nonflammable at all points during its evaporation. The author has only considered blends that win not fractionate and will not be flammable at any point during evaporation.

Performance
Previous papers have introduced FIC-based refrigerants (Refs. 2 and 3), solvents (Ref 4), and firefighting agents (Refs. 1, 5-7). An upcoming presentation will discuss their potential as high-R-value foam blowing agents (Ref 8).

One FIC-based refrigerant (called Ikon-12c) has been demonstrated successfully as a drop-in replacement for R-12 in three applications: a domestic refrigerator, an automobile air conditioner, and a transport refrigeration container. In all cases no changes were made to the mineral oil lubricant or system materials, and measured performance was virtually identical to CFC-12. The domestic refrigerator has been operating for over a year with no problems.

Ikon-12c has several advantages over HFC-134a, the main replacement for R-12 available today. Ikon-12c has a global warming potential (GWP) only 1/40 that of HFC-134a, requires no change of lubricant, and, because it has virtually identical vapor pressure, energy efficiency, capacity, and materials compatibility to R-12, Ikon-12c is a "drop-in" replacement and eliminates the need for retrofitting. Potential FIC-based replacements for R-22 and R-11 are under investigation.

Recent calculations show that rigid insulating foams (e.g., polyurethane and polyisocyanurate) blown with FICs are expected to have 10-40% better insulating abilities than those blown with CFCs or HCFCs. A test at Sandia National Laboratories demonstrated the effectiveness of two FIC-based agents for foam blowing. When FICs are produced in bulk, the expected payback time for FIC- containing insulation in refrigeration is about 2 years.

Laboratory testing has shown that FICs are highly effective solvents both alone and in nonflammable blends with conventional solvents. They were shown to remove a variety of difficult soils from metal and glass surfaces.

Environmental Effects
The ozone-depletion potentials (ODPs) of FICs will be extremely close to zero. Because FICs undergo rapid photolysis in sunlight, they have very short atmospheric lifetimes and only a minute fraction of the material released at ground level will reach the stratosphere. The best current estimate for the atmospheric lifetime of CF₃I is 1.15 days (Ref 9). Based on this lifetime plus a transit time of 90 days, the author has estimated the ODPs of FICs at less than 1 x 10^-15. This calculation does not take account of any rapid mixing of part of the troposphere with the stratosphere, and more accurate calculations of ODP are underway at Lawrence Livermore National Labs (LLNL) and the National Oceanographic and Atmospheric Administration (NOAA). Recent measurement of the rate of reaction of iodine monoxide (IO) with ozone at the National Institutes of Standards and Technology (NIST) show that the rate is very low and no cause for concern. Additional measurements of rate constants for atmospheric reactions and atmospheric modeling of FICs are underway.

The GWP of CF₃I has been determined to be about 5 times that of carbon dioxide, corresponding to about 10-5 relative to the standard CFC-11 = 1.0 (Ref. 9). This is an extremely low number, several thousand times lower than that of CFCs or halons, and about 100 times lower than that of HFC-134a.

Many chemicals are classified as volatile organic compounds (VOCs) that contribute to smog formation. Tropospheric (ground-level) ozone is one of the most dangerous components of smog. Addition of iodine to smog at levels near 0.1 ppm has been shown to decrease levels of undesirable tropospheric ozone and carbon monoxide (Refs. 10-12). Thus FICs appear to be "anti-VOCs," and their release would be expected to improve air quality in urban areas. They appear to provide the best of all possible worlds; destroying "bad" tropospheric ozone while leaving "good" stratospheric ozone intact. Testing is underway to quantify the "anti-VOC" effects of FICs.

Materials Compatibility
We have conducted laboratory compatibility tests of FICs with a range of polymers and metals. Reported compatibility information on selected CFCs, HCFCs, HFCs, halons, and FICs was compared, and this comparison indicates that FICs will have acceptable materials compatibility, comparable to that of CFCs, HFCs, HFCs, and halons (Ref. 13).

Thermal Stability
Laboratory and field tests of several FIC-based agents in a number of applications have shown that FICs have good thermal stability and would not decompose under most conditions of usage. Several stabilizers have also been identified that can further enhance the thermal stability.

Toxicity
Perhaps the major reason iodides have not been more fully investigated is that in general iodides are more reactive than bromides or chlorides. However, the FICs selected here have unusual stability and low toxicity because they have at least two fluorine atoms attached to the carbon bonded to the iodine atom. The presence of these fluorine atoms greatly stabilizes the molecules, making them hundreds to thousands of times less reactive and less toxic than would otherwise be the case.

Acute studies of CF₃I have been conducted under the direction of Major Gary Jepson at Armstrong Labs at Wright-Patterson AFB. Reported toxicity data on trifluoromethyl iodide (CF₃I) include the following: mice 15-minute LC₅₀ 27.4% by gas volume (74.9% by mass, mechanism of lethality: anesthesia), no lethality on exposure of mice to 6% by gas volume (30% by mass) for 72 hours, and one preliminary report indicates cardiac sensitization observed in a beagle at 0.4% by gas volume (2.7% by mass) under the test conditions of 10 times normal adrenahn levels. For heptafluoro-n-propyl iodide (CF₃CF₂CF₂I, 1-C₃F₇I), one report gives the 2-hour mice LC₅₀ as 404 g/m³ (corresponding to 25% by mass and 3.1% by volume) and another preliminary report gives the 15-minute rat LC₅₀ as 4.9% by gas volume (34.4% by mass). Some of these data are subject to verification.

Generally, the data show that FICs have low to moderate acute toxicity and indicate that human exposure to high concentrations for extended periods should be avoided. Additional studies of the toxicities of pure FICs and blends are planned.

Regulatory Approval
Trifluoromethyl iodide (CF₃I) has already been approved under the Significant New Alternatives Program (SNAP) by the U.S. EPA for use in unoccupied areas. Additional SNAP submittals are planned for other uses of FIC- based agents. Testing, classification, and approval by other organizations such as the Canadian Standards Agency (CSA), Underwriters Laboratories (UL) and the Air-Conditioning and Refrigeration Institute (ARI) will be sought provided market conditions warrant those actions.

Cost and Availability
Chemicals that are custom-made in research quantities are of necessity much more expensive (by factors of 30 or more) than those made in bulk. One year ago CF₃I was, like other FICs, available only in research quantities and relatively expensive (about $600/lb). Today it is available from three pilot plants in quantities of up to several thousand pounds at $75-100/lb. The ultimate cost is expected to be $10-20/lb, and blends will be even less expensive.

Additional Work Required
Additional work on FIC-based agents is required in several areas including performance, materials compatibility, thermal stability, toxicity, and improved synthesis and manufacturing.

Business Opportunities
The worldwide market for CFC and halon replacements is approximately $40 billion annually. It is anticipated that FIC technologies win capture a significant share of this global market.

Worldwide usage of CFCs and halons in 1986 is shown in Table 2 (Ref. 14). Data from 1986 represent demand with no limitations on production or use because 1986 is the year before international ratification the Montreal Protocol. Figures for worldwide production of individual CFCs for 1986 are given in Table 3 (Refs. 14 and 15).

Table 2. Worldwide Usage of CFCs and Halons in 1986

Use Sector	Metric Tons	Percent by Weight
aerosols	299.8	25.8
rigid & flexible foams	297.5	25.6
refrigeration & air conditioning	280.4	24.1
solvents & misc.	262.2	22.5
halons	25.0	2.0
Total	1164.7	100.0

Table 3. World Production of CFCs in 1986 by CFC

CFC	PRIMARY USES	1986 PRODUCTION (metric tons)
11	refrigeration, foams	415
12	refrigeration air conditioning	441
113	solvent	241
114	refrigeration	18
115	refrigeration	13
	TOTAL	1128

Fluoroiodocarbons (FICs) and their blends offer the promise of outstanding performance, nonflammability, negligible environmental impact, low toxicity, and the ability to drop in to existing equipment. The features and benefits of these products are outlined in Table 4. Because these are new chemicals for these uses, additional research and development will be required in several areas, including performance, thermal stability, materials compatibility, manufacturability, and toxicity. Research is underway on selected FICs in several of these areas.

Table 4. Features and Benefits of Ikon Products

Features	Benefits
Excellent fire extinguishants	Safety from flammability hazard
Clean evaporation	No residue or cleanup required
Essentially zero ozone-depletion potential	Freedom from restrictions under the Montreal Protocol and future regulations
Extremely low global warming potential	Freedom from future regulations on global warming gases
High energy efficiency for refrigeration	Savings on operating costs
High solubility for oils and greases	High solvent cleaning abilities
High refrigerating capacity	Lower capital costs from being able to use smaller units to achieve same capacity
Higher insulating ability than other foam	Savings on operating costs blowing agents

The Ikon Corporation has a number of U.S., Canadian, Mexican, and other international patents allowed and pending on FIC technologies, plus trade secrets and other know-how. The Ikon Corp. offers a nonexclusive license to manufacturers in return for a reasonable royalty against factory sales.

The Ikon Corp. also offers a research assistance package consisting of the quantity of the Ikon product you desire for testing, a visit to your site to discuss your needs, and ongoing consultation.

Ikon can assist the development of FIC technologies by providing information, guiding the research effort, planning, computer modeling of chemical properties, interpretation of experimental results, and assistance in designing improved syntheses of FICs.

Conclusions
FIC-based agents show promise as high-performance, nonflammable, nontoxic, environmentally safe drop-in replacements for CFCs, HCFCs, and halons. Significant amounts of validation work remains to be done. If work proceeds promptly and with adequate support, it is estimated that regulatory approval and bulk production of FIC-based agents can be achieved in about 12-24 months. The Ikon Corporation is seeking licensees to support further development and marketing of FIC technologies worldwide.

This technology offers:
• Drop-in or near drop-in replacements for many CFCs and halons
• Continued use of existing equipment without major retrofit
• Continued use of existing procedures
• Freedom from future regulations on ozone-depleting substances
• Freedom from future regulations on greenhouse gases
• Savings on capital and energy costs
• Increased safety in handling and use

  Potential use areas include the following:

• Refrigeration
  • cryogenic
  • laboratory
  • perishable goods storage
  • comfort cooling (automotive, commercial, residential, industrial)
• Foam Blowing
  • polyurethane
  • polystyrene
  • polyisocyanurate
  • specialty (e.g., single-container)
• Solvent Cleaning
  • electronics
  • metals
  • precision surfaces
• Firefighting
  • flooding
  • streaming
• Aerosol Propellants
  • consumer products (e.g., cosmetics, spray paints)
  • industrial products
  • sterilants
• Dielectric Gases for Electronics
  • dielectric gases for high-voltage, high-frequency electronics

References

1. Nimitz, J. S., High-Performance, Environmentally Sound Replacements for Halon 1301, report prepared for McClellan AFB under contract F04699-93-C-0004, December 1993, ETEC 93-3. Available from NTIS.
2. Lankford, L. H., and Nimitz, J. S., "A New Class of High-Performance, Environmentally Sound Refrigerants" Proceedings of the 1993 International CFC and Halon Alternatives Conference, Washington DC, October 20-22,1993.
3. Nimitz, J. S., and Lankford, Lance H., "Refrigerants Containing Fluoroiodocarbons (FICs)" Proceedings of the 1994 ASHRAE International Compressor Engineering Conference, Purdue University, W. Lafayette, IN, July 19-22, 1994.
4. Nimitz, J. S., and Lankford, L. H., "A New Class of Nonflammable, Environmentally Safe Solvents," Fourth Annual International Workshop on Solvent Substitution, Phoenix, AZ, Dec. 7-10, 1993.
5. Nimitz, J. S. "The Ultimate Halon Replacements are in Sight," Proceedings of the 1993 Halon Alternatives Working Conference, University of New Mexico, Albuquerque, NM, 11-13 May, 1993.
6. Nimitz, J. S., and Lankford, L. H., "Fluoroiodocarbons as Halon Replacements," Proceedings of the 1993 International CFC and Halon Alternatives Conference, Washington DC, October 20-22, 1993.
7. Nimitz, J. S., "Trifluoromethyl Iodide and its Blends as High-Performance, Environmentally Sound Halon 1301 Replacements," Halon Options Technical Working Conference, Albuquerque, NM, May 3-5, 1994
8. Nimitz, J. S., "New Foam Blowing Agents Containing Fluoroiodocarbons (FICs)," Proceedings of the SPI Polyurethanes Conference, Boston, MA, October 9-12, 1994.
9. Personal communication from Dr. Susan Solomon, NOAA, Boulder, CO, to Dr. Jon Nimitz, ETEC, Albuquerque, NM, March 1994.
10. Chameides, W. L., and Davis, D. D., "Iodine: Its Possible Role in Tropospheric Photochemistry," Journal of Geophysical Research, Vol. 85, 1980, pp. 7383-7398.
11. "Iodine May Be Smog Weapon," Chemical and Engineering News, Vol. 40, No. 39,1962,p.68.
12. Hamilton, W. F., Levine, M., and Simon, E., "Atmospheric Iodine Abates Smog Ozone," Science, Vol. 140, 1963, pp. 190-191.
13. Brown, M. W., Seals and Sealing Handbook, 3rd ed., Elsevier, Oxford, 1990
14. Waschek, C., "Ozone Protection Strategy and Implementation Guidelines," The Coca-Cola Company, Corporate Engineering Department, Atlanta, GA, June 1992
15. The Information Please Environmental Almanac, Houghton-Mifflin Co., New York, NY, 1993, p. 309.

For more information regarding this subject, please contact Dr. Nimitz at mailto:jnimitz@etec-nm.com