Two Home Runs for Honeywell: Chemistry to Save the Ozone Layer without Global Warming

Ian Shankland

2Nov 6, 2019

My Talk Today

1. Why & where CFCs were used

2. Ozone depletion and CFC replacements

3. Global warming - replacing the CFC replacements

Chemistry That Saves The Ozone LayerAnd Reduces Global Warming Impact

3Nov 6, 2019

Top 20 Engineering Achievements*

*National Academy of Engineering

4Nov 6, 2019

The Ice Man Cometh

• 1800s: winter ice harvesting

• Ice deliveries for the home icebox

• Ice used in food transportation

• Late 1800s to early 1900s: mechanical refrigeration for breweries and ice making

• Primary refrigerant was ammonia

5Nov 6, 2019

Mechanical Refrigeration For The Home

Pre-1930 Refrigerants• Methyl chloride: toxic & flammable• Ethyl chloride: toxic & flammable• Sulfur dioxide: toxic• Butane: flammable• Ammonia: toxic & flammable

• Significant safety issues limited the wide adoption of refrigeration and air conditioning

• Many issues, including fatalities from leaking refrigerants like CH3Cl and SO2

6Nov 6, 2019

1929 Cleveland Hospital Fire

• Methyl chloride gas escaped, causing a disastrous explosion in a Cleveland hospital

• More than 120 deaths• Fatalities attributed to fire and inhalation

of CH3Cl and other noxious gases from celluloid x-ray film combustion

• This, and other incidents, lead to pressure to ban refrigerants

Strong Need For Safe Refrigerants

7Nov 6, 2019

CFCs (ChloroFluoroCarbons) Invented

• 1931: CFC-12 commercialized for refrigeration• Nonflammable• Low toxicity• Excellent thermodynamic properties• Excellent energy efficiency• Chemically stable

Thomas Midgely

Fluorocarbon Numbers4-digit code: CFC-12 0012

Add 90 01020102 = 0 double bonds, 1 C, 0 H & 2 FAll other available valence positions filled with Cl0102 = CF2Cl2

8Nov 6, 2019

Glossary

• CFC: Chlorofluorocarbon• HCFC: Hydrochlorofluorocarbon• HFC: Hydrofluorocarbon

• ODP: Ozone Depletion Potential – Potential of a substance to deplete stratospheric ozone relative to that

of the same mass of CFC-11 (ODP = 1)

• GWP: Global Warming Potential– Ratio of atmospheric warming (radiative forcing) caused by a substance

relative to the same mass of CO2 (GWP = 1) over a 100 year time horizon.

9Nov 6, 2019

CFC-12: Refrigeration, car air conditioning, aerosols, freezing food, medical equipment sterilization, polystyrene foam, chillers

CFC-11: Polyurethane foam insulation, large water chillers

CFC-113: Solvents for cleaning electronics, metals, medical devices, aerospace parts

HCFC-22: Home & building air conditioning, supermarket refrigeration

1931 – 1970s: Other CFCs & Uses Developed

10Nov 6, 2019

Stratospheric Ozone Layer• Ozone (O3) layer protects the

earth from ultraviolet radiation• Ozone levels vary naturally – day/night,

summer/winter & solar cycles• Stratospheric ozone at 1 atmosphere

pressure and 0°C would be 3 mm thick(300 Dobson units)

• 1960s: Research on atmospheric impact of supersonic aircraft • 1973: J. Lovelock detects CFCs in the atmosphere• 1974: S. Rowland & M. Molina warn of ozone depletion from CFCs• 1978: U.S. bans CFCs in most aerosols• 1985: Antarctic ozone hole discovered• 1987: Montreal Protocol on Substances that Deplete the Ozone Layer• 1995: Crutzen, Molina & Rowland awarded Nobel Prize for Chemistry

11Nov 6, 2019

Ozone Destruction

• CFC-12 (CF2Cl2) Chemically stableAtmospheric lifetime ~ 120 years

• CFC-12 reaches the stratosphere

• Ultraviolet radiation breaks the C-Cl bond

• Cl atoms catalytically destroy ozone

12Nov 6, 2019

CFC Replacements

• CFCs phased out in the 1990s (later in developing countries)

• Many industries impacted:– Air conditioning, refrigeration, electronics, medical, aerospace,

building construction, personal care products, pharmaceutical, fire extinguishing and more

• Conservation & switching to other materials, e.g. hydrocarbons decreased CFC usage

• However, the need for environmentally safer materials with attributes similar to the CFCs still existed

13Nov 6, 2019

Exemplary CFC Replacement Attributes

• Use in existing equipment• Energy efficient

Functional in the Application

• Low toxicity• Acceptable flammability

Safe in Use

• Very low or zero ODPReduced global warming impact

EnvironmentallyAcceptable

• Economically Viable

• Commercially AvailableViable

Technology

14Nov 6, 2019

CFC Substitute Environmental Criteria

• Minimal to zero ODP– Preferably no Cl or Br

• Atmospheric breakdown products thatdo not create environmental issues

• Initial choices were HCFC or preferably HFC materials– HFCs have zero ODP and reduced

GWP values compared to CFCs– HCFCs offered significant

reductions in ODP

Partially halogenated alkanes react with trace components present in the troposphere

RF-H + ·OH à RF· + H2ORF· à à à

RF-H = HFC or HCFC

ODPHFC-134a 0

HCFC-22 0.05HCFC-141b 0.11

CFC-12 1.0

EnvironmentallyAcceptable

15Nov 6, 2019

CFC Substitute Toxicological Testing

• Acute Toxicity

• Environmental Toxicity

• Genotoxicity (Mutagenicity)

• 4-Week Inhalation Test

• Sub-chronic (13-Week) Inhalation Test

• Developmental Toxicity (Teratology)

• Reproductive Toxicity

Testing Programs Require 2-6 Years To Complete… Required By Regulatory Agencies

Safe In Use

16Nov 6, 2019

Vapor Compression Refrigeration

• Thermodynamic properties• Transport properties• Refrigeration capacity• Energy efficiency• Dielectric properties

• Lubricant miscibility• Chemical stability with lubricant, metals,

polymers, trace amounts of water• Thermal stability• Acceptable flammability properties

Exemplary Complex & Multi-Dimensional Performance Requirements

Functional In The Application

17Nov 6, 2019

Non-Ozone Depleting Materials

• New molecules developed:– No chlorine = no ozone depletion– (No bromine = no ozone depletion)– Shorter atmospheric lifetimes

• Thorough testing by manufacturers – Safety (low toxicity & nonflammable)– Environmental properties– Safe & efficient manufacture– Performance testing

• Thorough testing by end users– Safety– Performance– Reliability

EXAMPLE• HFCs: Hydrofluorocarbons• HFC-134a: CF3CFH2

– ODP=0– GWP =1,430 vs 10,900 for CFC-12

• Replaces CFC-12– Very safe– Good energy efficiency– But not a “drop-in”– More complex manufacturing

18Nov 6, 2019

Non-Ozone Depleting Substances 1990-2005

• HFC-134aCF3CFH2

• HFC-125 CF3CF2H

• HFC-32 CF2H2

• HFC-143a CF3CH3

• HFC-245faCF3CH2CF2H

• HFC-365mfcCF3CH2CF2CH3

Automobile Air Conditioning Appliances

Pharmaceutical Applications

Home Air Conditioning

Supermarket RefrigerationCommercial Air

Conditioning

Aerosols Foam Insulation Appliances

19Nov 6, 2019

Stra

tosp

heric

Cl +

Br

1980 2100

2006 “The combined stratospheric abundances of the ozone-depleting gases show a downward trend from their peak values of the late 1990s, which is consistent with surface observations of these gases and a time lag for transport to the stratosphere.”Scientific Assessment Of Ozone Depletion: 2006

Developed Economy Countries:

• CFCs phased out

• HCFCs phased out

Developing Economy Countries:

• CFC phase-out complete 2010; some concern about compliance

• HCFC freeze at ’09/’10 levels in 2013and 97.5% reduction by 2030

The Montreal Protocol Is Working

Scientific Assessment Of Ozone Depletion: 2006

20Nov 6, 2019

The Polar Ozone Holes

Phys.org Feb 10, 2013 — Satellites show that the recent ozone hole over Antarctica was the smallest seen in the past decade. Long-term observations also reveal that Earth's ozone has been strengthening following international agreements to protect this vital layer of the atmosphere.

21Nov 6, 2019

2019 Antarctic Ozone Hole

• “Ozone hole season”: Sep-Nov• Ozone hole is unprecedentedly

small area for this time of year

22Nov 6, 2019

The Greenhouse Effect

Solar RadiationAbsorbed By The Earth’s SurfaceSome Radiation Is Reflected

1

22

1

Greenhouse Gases (GHGs)• CO2

• Methane & Nitrous Oxide• Halocarbons – Including HFCs

Greenhouse Effect è Global Warming è Climate Change

Earth’s Surface Warms & Re-emitsGreenhouse Gases Trap Radiation

Radiative Forcing = (EnergyIn – EnergyOut)/m2s

23Nov 6, 2019

Global Warming Potential Values

GWP100

HFC-152a CH3CHF2 140

HFC-32 CH2F2 650

HFC-245fa CF3CH2CHF2 950

HFC-365mfc CF3CH2CF2CH3 900

HFC-134a CF3CH2F 1,440

HFC-125 CF3CHF2 2,800

HFC-143a CF3CH3 3,800

Major HFC Products

24Nov 6, 2019

Climate Change Regulations

Growing GHG Emissions• Main Culprit Is CO2

• HFCs Are “Visible” Due To High GWP

EU F-Gas Directive• Mobile Air Conditioning Directive

– 2011: GWP<150 New Platforms– 2017: GWP<150 All New Vehicles

• GWP < 150 for certain aerosol applications July 2008 & July 2009

Kyoto Protocol• 5.2% Average GHG Reduction• Creates Emissions Trading Markets`

1

2

3

4

5

6

01990 2010 2030 2050

CarbonDioxide

CFCs HCFCsMethane

Nitrous Oxide

HFCs

Rad

iativ

e Fo

rcin

g, W

m-2

Business As Usual ModelBusiness As Usual Scenario UNEP / EPA Scenario for HFCsIPCC (IS92a) Scenario for other gases

25Nov 6, 2019

Representative Property Data For Select Low GWP Materials

Structure Atmos Life GWP VOC

Status*

1234yf 10.5days <1 Non-VOC

1234ze (E) 16.4days <1 Non-VOC

1233zd (E) 20days 1 Non-VOC

*Volatile Organic Compound (VOC) status

Materials Must Meet Many Other Complex Requirements Before Acceptance

26Nov 6, 2019

Life Cycle Analysis (LCA) : Automobile Air Conditioning

0

500

1,000

1,500

2,000

2,500

3,000

3,500

134a1234yf CO

2134a1234yf CO

2

Phoenix

Tokyo

LCA

, kg

CO

2e

Source: T. Ikegami, K. Inui, K. Aoki(JAMA), 2008 SAE Alternative Refrigerant System Symposium, Phoenix June 10-12.

• Three refrigerants:– 134a– 1234yf– CO2 (R-744)

• Compact car – different climates• Cradle to grave analysis:

– Normal & abnormal leak rates– Service practice– End of life practice– Fuel consumption (& exhaust

emissions) for A/C operation• LCA: kg CO2 equivalent

– Direct contribution: refrigerant emission– Indirect contribution: CO2 exhaust

emission from fuel burned to run the A/C

27Nov 6, 2019

From The Website https://www.fluorineproducts-honeywell.com/climate-ticker/#

28Nov 6, 2019

Summary• Ozone layer has not fully healed yet, but it will recover due to HFC and

other non-ozone depleting technology development

• Greenhouse gas regulation is impacting HFC-user industries

• Multiple technology options are available to replace HFCs

• Technology choice should:

– Minimize total global warming impact, over the product life cycle

– Provide safety in use

– Be functional in the application

– Be economically viable

30Nov 6, 2019

Thank You