lecture 15: fossil fuels – oil and gas march 3, 2009petra/phys3150/lecture15.pdfplankton • two...
TRANSCRIPT
Energy&Sustainability
Lecture15:FossilFuels–OilandGas
March3,2009
Intro:Sources&Impact
• Wheredowegetourenergyfrom?
• A:FossilFuel(78%)
• “Features”:
1. Non‐renewable
2. Unevendistributed
Intro:Sources&Impact
• OilwellsonfireinKuwaitduringtheGulfWar
Intro:Sources&Impact
• TankersblocktheentrancetoaUKrefineryinSep’00,toprotestagainsthighfuelprices
Intro:Sources&Impact
• AfireonagasrigintheNorthSeain1988killed167people
Intro:Sources&Impact
• OilspillagefromanExxontankerin1989contaminated1300miofbeachesinAlaska.Theestimatedcostofcleanupwas$3billion
Intro:Sources&Impact
• Risingsealevelsduetoclimatechangecouldoverwhelmsomelow‐lyingnations
Tuvalu:agroupof9coralatollsinthePacific
Intro:Sources&Impact
• RisingtemperatureshavecausedsignificantmeltingoficearoundtheNorthPole
Introduction• fossil
– provideenergy‐relatedservices
– significantenvironmental&socialimpacts
• lowefficiency(fordelivery)
Sources&Sustainability
Wood Coal
Oil Natural Gas
• annualenergyconsumption
Sources&Sustainability
• percapitaconsumption
Sources&Sustainability
1. FossilFuels
✓ highlyconcentrated
✓ easytodistribute
- non‐renewable
- emissions
- health&safetyissues
Sources&Sustainability
• Coal
Sources&Sustainability
• Oil
Sources&Sustainability
• NaturalGas
Oil Mostscientistsagreethatoilcomesfromcreaturesthesizeofapinhead.Theseone‐celledcreatures,knownasdiatoms,aren'treallyplants,butshareoneveryimportantcharacteristicwiththem‐theytakelightfromthesunandconvertitintoenergy
Diatomsfloatinthetopfewmetersoftheoceans(andlakes‐whichispartofthereasonwhynotALLoilcomesfromoceandeposits!)andalsohappentobeamajorsourceoffoodformanyformsofoceanswimmers.
Plankton• Twotypes
– Phytoplankton:PlantsoftheSea– Zooplankton:SeaAnimals
• Planktoneitherfloatpassivelyinthewater,orpossesssuchlimitedpowersofswimmingthattheyarecarriedfromplacetoplacebythecurrents.
• Planktonrangeinsizefromtinymicrobes,whichareinvisibletothenakedeye,tojellyfishmeterslong.
• Apartfrombacteria,planktonicorganismsarethemostabundantlifeformonearth
• Theyareacriticalpartofthecarbonenergychain• Thetotalamountofcarbonintheoceanisabout50timesgreaterthantheamountintheatmosphere,andisexchangedwiththeatmosphereonatime‐scaleofseveralhundredyears.
• Atleast1/2oftheoxygenwebreathecomesfromthephotosynthesisofmarineplants.
GigaTons of Carbon/yr
Nutrienttraps:
theoriginoffossil‐fuel
deposits
Oil• Oilisformedfromthepreserved
remainsofprehistoricplankton(diatoms)andalgaewhichhavebeensettledtothesea(orlake)bottominlargequantitiesinwaterdepletedofoxygen.
• Terrestrialplants,ontheotherhand,tendtoformcoal.• Overgeologicaltimethisorganicmatter,mixedwith
mud,isburiedunderheavylayersofsediment.Theresultinghighlevelsofheatandpressurecausetheorganicmattertochemicallychange,first– intoawaxymaterialknownaskerogenwhichisfoundinvarious
oilshalesaroundtheworld,
– thenwithmoreheatintoliquidandgaseoushydrocarbons‐>OilandNaturalGas
• Dependingonthebalanceoffreshwaterversusevaporationthiscanchangewithtimeandreverseprovidingdifferentlayers
• Thisiswhyoilisoftenfoundjustoffshoreorinregionsthatusedtobewatercovered
SourceRock• Oilcomesfromrocks(sourcerocks)–notbigcaverns• Thereis"oilwindow"whichisthetemperaturerange
thatoilformsin—belowtheminimumtemperatureoilremainstrappedintheformofkerogen,andabovethemaximumtemperaturetheoilisconvertedtonaturalgas
• Thiscorrespondstoacertaindepthintheearth
• Threeconditionsmustbepresentforoilreservoirstoform:– asourcerockrichinorganicmaterialburieddeepenoughforsubterraneanheattocookitintooil;
– aporousandpermeablereservoirrockforittoaccumulatein;
– acaprock(seal)orothermechanismthatpreventsitfromescapingtothesurface.
• Thevastmajorityofoilthathasbeenproducedbytheearthhaslongagoescapedtothesurfaceandbeenbiodegradedbyoil‐eatingbacteria.
• Oilcompaniesarelookingforthesmallfractionthathasbeentrappedbythisrarecombinationofcircumstances.
• Oilsandsarereservoirsofpartiallybiodegradedoilstillintheprocessofescaping,butcontainsomuchmigratingoilthat,althoughmostofithasescaped,vastamountsarestillpresent‐morethancanbefoundinconventionaloilreservoirs.
• Ontheotherhand,oilshalesaresourcerocksthathaveneverbeenburieddeepenoughtoconverttheirtrappedkerogenintooil.
Fossilfuelavailabilty
Whichcountryhasthelargestoilreserves?
• Iran• Iraq• SaudiArabia• Canada• Venezuela
Whichcountryhasthesecondlargestoilreserves?
• Iran• Iraq• SaudiArabia• Canada• Venezuela
Whichcountryhasthesecondlargestoilreserves?
• Iran• Iraq• SaudiArabia• Canada• Venezuela
WhatfractionoftheknownOilreserveisinSaudiArabia?
1. 1%2. 5%3. 10%4. 20%5. 30%6. 40%
WhatfractionoftheknownOilreserveisinSaudiArabia?
1. 1%2. 5%3. 10%4. 20%5. 30%6. 40%
© 2003 John Wiley and Sons Publishers
Provenworldoilreservesin1998.
*
*Over 95% of these reserves are oil sands deposits in Alberta
© 2003 John Wiley and Sons Publishers
Majortraderoutesfortheworld’soil,emphasizingthecountriesthatuseMiddleEasternoil.
GasolinePrices
Howmuchwouldraisinggasprices$1/galloncosttheaverageUS
family?1. $500/yr2. $1000/yr3. $1500/yr4. $2000/yr5. $2500/yr
CosttoAverageConsumer• AssumeDrivergoes12,000miles/year• Cargets24mi/gallon
• 500gallons/year• Each$1/galloncost$500/year/car
CosttoAverageConsumer• Ifyouhave2driversperfamily$1,000year
CosttoAverageConsumer• TaxesareNOTalargepercentageofthecost
• Nowaround13%$0.45/gallon
O
© 2003 John Wiley and Sons Publishers
Taxesfor1galofgasolineinU.S.
dollarsequivalentforselectedcountries,
1995.
Improvements
• EnergyServices&EfficiencyImprovements
1. EnergyEfficiencyImprovements
1. Demand‐sideimprovements
– Transportsector
» motorvehicles
» rail
» air
» shipping
» non‐motorized
NaturalGas
• Sincethelate1990s,naturalgashasbeenthefuelofchoiceforthemajorityofnewgeneratingunits,resultingina99.0percentincreaseinnaturalgas‐firedcapacitysince1999.
• Theconstructionofnaturalgasplantsbeganincreasingin1999,peakedduring2002and2003,buthassincedeclinedconsiderably.
• In2006,naturalgas‐firedgeneratingcapacityrepresented388,294MWor39.4percentoftotalnetsummergeneratingcapacity.Althoughnewnaturalgas‐firedcombined‐cycleplantsproduceelectricitymoreefficientlythanolderfossil‐fueledplants,highnaturalgaspricescanworkagainstfullutilizationoftheseplantsifsuchpricesadverselyaffecteconomicdispatch
PeakCapacity(Summer)
CCGT
• EnergyServices&EfficiencyImprovements
• CombinedCycleGasTurbine
– ~50%efficiency
– more“climatefriendly”
HubbertMarionKingHubbert(October5,1903–October11,1989)wasageoscientistwhoworkedattheShellresearchlabinHouston,Texas
Hubbert’speak
WorldOil
HirschReportofDoE2005
• Worldoilpeakingisgoingtohappen,andwilllikelybeabrupt.
• Oilpeakingwilladverselyaffectglobaleconomies,particularlythosemostdependentonoil.
• Oilpeakingpresentsauniquechallenge(“itwillbeabruptandrevolutionary”).
• Theproblemisliquidfuels(growthindemandmainlyfromtransportationsector).
• Mitigationeffortswillrequiresubstantialtime.– 20yearsisrequiredtotransitionwithoutsubstantialimpacts
– A10yearrushtransitionwithmoderateimpactsispossiblewithextraordinaryeffortsfromgovernments,industry,andconsumers
– Lateinitiationofmitigationmayresultinsevereconsequences.• Bothsupplyanddemandwillrequireattention.
• Itisamatterofriskmanagement(mitigatingactionmustcomebeforethepeak).
• Governmentinterventionwillberequired.
– Economicupheavalisnotinevitable(“givenenoughlead‐time,theproblemsaresolublewithexistingtechnologies.”)
– Moreinformationisneededtomorepreciselydeterminethepeaktimeframe.