Industrial Search for Industrial Search for Greenhouse Greenhouse Gas ReplacementsGas Replacements

Zhuangjie LiZhuangjie Li

Department of Chemistry and BiochemistryDepartment of Chemistry and Biochemistry

California State University FullertonCalifornia State University Fullerton

Fullerton, CA 92834Fullerton, CA 92834

Outline Outline

IntroductionIntroduction

Global Warming Potentials Global Warming Potentials ((GWPsGWPs))

GHGGHG alternatives search strategy alternatives search strategy

Potential Potential GHGGHG replacement compounds replacement compounds

ConclusionConclusion

Global warming Global warming ((GWGW) - threats to our welfare) - threats to our welfare

- - draughts and floodsdraughts and floods, decrease food production, decrease food production

- - Sea level rise, Sea level rise, high tides, hurricanes, beach erosionhigh tides, hurricanes, beach erosion

Anthropogenic GW contributor – Greenhouse gases (Anthropogenic GW contributor – Greenhouse gases (GHGGHG))

- CO- CO22 – from fossil fuel usage – from fossil fuel usage

- non-CO- non-CO22 trace gases – trace gases – industrial industrial and and consumer consumer usageusage

Industrial Industrial – Solvents, cleaning, etching agents etc.– Solvents, cleaning, etching agents etc.

ConsumerConsumer – Refrigerators, air conditioners, spray products etc. – Refrigerators, air conditioners, spray products etc.

Ex. CFClEx. CFCl33, CF, CF22ClCl22, SF, SF66, C, C22FF66, NF, NF3 3 etc.etc.

To mitigate Global warming -

Reduce CO2 loading in the atmosphere - improve fuel efficiency; develop wind, solar, renewable energy etc.

For non-CO2 GHG – Develop new chemicals that are environmentally benign

(Solvents, cleaning agents, foam blowing materials, refrigerants, etc.)

Question: How do we know how much a newly

developed chemical would contribute to GW?

2CO of Potential WarmingGlobal Absolute-

GHG of Potential WarmingGlobal Absolute-

2

2

CO

GHG

CO

GHG

AGWP

AGWP

AGWP

AGWPGWP

constant rate -OH primarily

atmosphere the in stays molecule the long How 2.

forcing radiative

absorbs molecule a radiationIR much How 1.

on depend heavily

GWPs

Global Warming Potentials (GWPs) – A tool to

quantitatively measure the contribution of a compound to

global warming.

Sources: Brakkee et al. Int J LCA 13 191 (2008)Sources: Brakkee et al. Int J LCA 13 191 (2008)

Sources: NIST http://webbook.nist.gov/chemistry/form-ser.htmlSources: NIST http://webbook.nist.gov/chemistry/form-ser.html

molecules the of skeleton chain carbon the increase -

HFCs atoms H by atoms Cl ALLreplace -

HCFCs H by atom Cl replace -

)ClCF (ex. CFCs withStart

shortened lifetime catmospheri degrades compounds containing H the -

radicals OH the by extracted be can atom H the -

:atom(s) H contain CFCs the If -

lifetime catmospheri long radicals OH withreact not do CFCs -

atoms? H by atoms Cl substitute Why

lifetime catmospheriShort -

:compoundst replacemenGHG develop to Strategy

22

42

rd

nd

st

32

ClHFC ---- 1 4 - 1 - 1)2(2 Cl 4, F 1, H 2, C

214. 90 124 :124-HCFC Ex.

F - H - 1)2(C atoms Cl ofnumber

atoms F ofnumber -digit 3

atoms H ofnumber -digit 2

atoms C ofnumber -digit 1

:numberdigit three aget tonumber the to 90 Add

mean? etc. HCFC, CFC, behindnumber the doesWhat

CHClF)(CF 124-HCFC );(CHClF 22-HCFC :HCFCs

Summary of Atmospheric Lifetime and GWPs for HCFCs for 20, 100, and 500 Year Time Horizons_______________________________________________________________________________________

Global Warming PotentialsGas Atmospheric _________ years___________

Lifetime, years 20 100 500________________________________________________________________________________________

CFC- 12 100 7,900 8,500 4,200HCFC-22 12 4,662 1,900 535HCFC-123 1.4 303 120 28HCFC- 124 6.2 1,823 620 176HCFC-141b 9.1 1,701 700 177H CFC- 142b 18 4,396 2,300 610HCFC-225 ca 2.0 414 180 38HCFC-225cb 6.3 1,597 620 154______________________________________________________________________________________

Sources: WMO and IPCC reports (1999-2007)Sources: WMO and IPCC reports (1999-2007)

Summary of Atmospheric Lifetime and GWPs for HFCs for 20, 100, and 500 Year Time Horizons_______________________________________________________________________________________

Global Warming PotentialsGas Atmospheric _________ years___________

Lifetime, years 20 100 500________________________________________________________________________________________

HFC-32 5.2 2,920 880 276HFC- 125 29.4 5,738 3,800 1,083HFC- 134 10.4 3,288 1,200 356HFC- 134a 14 4,845 1,600 589HFC-143 3.7 1,017 370 94HFC- 143a 47 5,695 5,400 1,537HFC-152a 1.5 499 190 46HFC-161 0.3 22 10 2HFC- 227ea 35.7 5,395 3,800 1,172HFC-236fa 222 6,125 9,400 5,930HFC-245fa 7.67 3,094 995 309HFC-365mfc 10.7 2,709 910 296______________________________________________________________________________________

Sources: WMO and IPCC reports (1999-2007)Sources: WMO and IPCC reports (1999-2007)

Summary of Atmospheric Lifetime and GWPs for HFEs for 20, 100, and 500 Year Time Horizons_______________________________________________________________________________________

Global Warming PotentialsGas Atmospheric _________ years___________

Lifetime, years 20 100 500________________________________________________________________________________________

HFE-216 0.010 0.014 0.004 0.001HFE-227 11.3 3,000 1,100 300HFE-245fa 0.40 1,900 560 170HFE-245fb 0.36 850 250 79HFE- 134 0.43 9,400 4,300 1,300HFE- 125 0.42 12,100 14,400 9,400HFE-145 0.32 530 150 49HFE-227 0.28 370 110 35HFE-236fa 0.44 4100 1500 450HFE-236fb 0.34 1600 460 140HFE-263 0.20 37 11 3HFE-245fc 0.30 910 270 85HFE-329 0.49 2800 870 270HFE-338 0.43 1800 520 160HFE-349 0.41 1200 350 110__________________________________________________________________________________

Sources: WMO and IPCC reports (1999-2007); Sources: WMO and IPCC reports (1999-2007); Li et al. JGR 2000, 2001Li et al. JGR 2000, 2001

Additional requirements for a Additional requirements for a GHGGHG replacement compound:replacement compound:-Proper physical propertiesProper physical properties-non-flammable-non-flammable-low toxicitylow toxicity-low cost-low cost

All these requirements make the search All these requirements make the search for desirable GHG replacements for desirable GHG replacements challengingchallenging

ConclusionsConclusions

Key factors in searching Key factors in searching GHGGHG replacement: short atmospheric replacement: short atmospheric lifetimelifetime

Three groups of compounds are current focus:Three groups of compounds are current focus: HCFCsHCFCs, , HFCsHFCs, and , and HFEsHFEs..

Search for Search for GHG replacementsGHG replacements is on the way is on the way

Challenge:Challenge: Meeting all requirements: physical properties, safe to use, low cost, Meeting all requirements: physical properties, safe to use, low cost,

and benign to the environments.and benign to the environments.

Thank youThank you