Energy and the Environment Lecture 9 PHYS/ENVS 3070 Professor Dmitri Uzdensky Sept. 15, 2014 PHYS/ENVS 3070 1Announcements: • Read Chapter 2. • CAPA Homework #3 due Friday, Sept. 19, 11pm. • Midterm Exam I will be on Friday, Sept. 26, during our regular lecture time (3 -- 3:50) in G1B20. A practice exam will be posted on D2L. • Guest lecture next Monday, Sept. 22, by Andrew Revkin (science and environmental writer). • Short written Assignment #1 due Oct. 20 (see next slide). Sept. 15, 2014 PHYS/ENVS 3070 2Inquire/Inform,Assignment,1:!!!All!students!are!required!to!hand!in!a!short,!one1page!"inquire/inform"!assignment.!!This!may!have!the!form!of!wri;ng!a!le<er!to!a!newspaper!or!a!Congressperson/Senator/Governor/President!(you!don’t!have!to!actually!send!the!le<er);!or!touring!a!local!energy!facility!and!wri;ng!it!up,!etc.!!You!are!free!to!choose!the!topic!as!long!as!it!is!relevant!to!this!course.!!!The!key!is!to!use!some!scien;fic!knowledge!gained!in!this!course!to!!make!an!informed!point,!comment,!sugges;on,!supported!by!ra;onal,!logical!arguments,!not!just!expressing!an!opinion.!!Feel!free!to!check!with!me!if!you!have!a!good!idea.!!!!First,short,assignment,is,due,Mon.,October,20,,2014.,Sept.!15,!2014! PHYS/ENVS!3070! 3!Today’s,Lecture:,• Fossil!Fuels:!!– chemistry;!!– origin;!!• Oil!Sept.!15,!2014! PHYS/ENVS!3070! 4!FOSSIL,FUELS,> 80% of US energy supply comes from fossil fuels ! Sept.!15,!2014! PHYS/ENVS!3070! 5!Additional remarks: • NGL (Natural Gas Liquids) – not to be confused with LNG (Liquid Natural Gas). • Tar Sand and Oil Shale are sometimes considered separately from petroleum but are still fossil fuels. • Shale Oil (tight oil, e.g., Bakken) ≠ Oil Shale. • Oil (liquid), including shale (tight) oil • Natural Gas (gas): mostly methane • Coal (solid) TYPES,OF,FOSSIL,FUELS:,Sept.!15,!2014! PHYS/ENVS!3070! 6!Oil and Gas (“Hydrocarbons”): Molecules consisting of atoms of carbon (C) and hydrogen (H). Example: “Alkanes” with saturated single bonds (each carbon has 4 bonds) C H H H H Methane C H H H H Ethane C H H CHEMISTRY,OF,FOSSIL,FUELS,Coal:!!!Carbon!(C)!with!some!impuri;es!(e.g.,!sulfur)!Sept.!15,!2014! PHYS/ENVS!3070! 7!C H H H H C H H Methane (CH4) – one carbon atom Ethane (C2H6) – two carbon atoms Propane (C3H8) – three carbon atoms Butane (C4H10) – four carbon atoms And so forth…. How many carbon atoms in Octane? A) 2 B) 4 C) 7 D) 8 E) 10 C H H C H H C H H C H H C H H C H H Room!Frequency!DC!Clicker,QuesPon,Sept.!15,!2014! PHYS/ENVS!3070! 8!“Burning” Methane OH 2 CO O 2 CH2224+→+Chemical energy is released when burning. Provides 55.5 MJ/kg – a lot of energy! BURNING,FOSSIL,FUELS,Sept.!15,!2014! PHYS/ENVS!3070! 9!How!are!fossil!fuels!formed?!Origin is from plants and some animals. Mostly microscopic, early ocean life. ORIGIN,OF,FOSSIL,FUELS,Sept.!15,!2014! PHYS/ENVS!3070! 10!Cellulose Solar Energy as Input for Plants (Photosynthesis) Carbohydrates 2n510622O )OH(C Energy ... OH CO +⇒+++If you burn a piece of wood, you are reversing this process and freeing energy. Similar “burning” occurs via bacterial decomposition. However, in the absence of Oxygen, this does not happen. Sept.!15,!2014! PHYS/ENVS!3070! 11!Sometimes instead of bacterial decomposition or burning… Dead material sinks to the bottom of the water. If buried where there is no oxygen (e.g. in sand or mud), high pressure and temperatures can actually remove the oxygen from the molecules. Carbohydrates à Hydrocarbons The Production of Fossil Fuels Sept.!15,!2014! PHYS/ENVS!3070! 12!Plant material, wood, cellulose, … (C6H10O5) - (C6H10O5)- (C6H10O5) - (C6H10O5) Heat, Oxygen present CO2, H2O, … Heat, Pressure, Oxygen absent C H H H H H C C C C C C C C H H H H H H H H H H H H H H H H H Methane Octane H C C C C C H H H H H H H H H H C H H H Hexane Coal: C-C-C-C-C Plus impurities Sept.!15,!2014! PHYS/ENVS!3070! 13!HydrocarbonsLiquid!and!gas!(oil/gas)!hydrocarbons!flow,!un;l!they!are!trapped!in!a!natural!area!(impermeable!rock).!!Over!geological!;me!scales!(108!=!100!million!years),!reservoirs!may!end!up!under!LAND,!but!can!also!be!under!WATER!too.!!Sept.!15,!2014! PHYS/ENVS!3070! 14!• Coal formed relatively close to the surface Relatively low temperatures and lower pressures • Oil formation requires higher temperatures and pressures • Oil decomposes into natural gas at very high temperature Natural gas (CH4 = Methane) almost always present Sept.!15,!2014! PHYS/ENVS!3070! 15!OIL,Sept.!15,!2014! PHYS/ENVS!3070! 16!• Most versatile fuel, concentrated, easy to store and transport. • The foundation of modern land, sea, and air transportation. • Very important source of raw material for chemical industry (e.g., plastics).Origin,of,OIL,• ‘Rock!Oil’!=!Petra!Oleum!(la;n)!=!Petroleum.!• From!plant!and!animal!life!in!the!ancient!seas,!hundreds!of!million!years!ago.!• Buried!under!sediments!of!sand/mud.!• High!temperature!and!high!pressure!(loss!of!O2).!• Moves!large!distances!underground!un;l!trapped!in!impermeable!rock.!!!Sept.!15,!2014! PHYS/ENVS!3070! 17!ProperPes,of,Oil,Sept.!15,!2014! PHYS/ENVS!3070! 18!• Oil is not just one pure single substance! • There are different grades of oil, with different: • density (light/heavy), • viscosity (how easily it flows under normal conditions), • sulfur content (sweet/sour), etc., - governed by the oil composition as a mixture of hydrocarbons. • Oil density: oil is (usually) lighter than water, with density range of 0.75 - 1.05 of water density (1000 kg/m3 = 1 g/cm3).Measuring,and,Pricing,Oil,Sept.!15,!2014! PHYS/ENVS!3070! 19!• Amounts of oil are usually measured in barrels (bbl). The barrel is a unit of volume: 1 barrel = 42 U.S. gallons ≈ 159 liters • Oil production/consumption rate is usually given in bbl/day. • Current world oil production/consumption rate is about 1000 barrels/sec ≈ 86 million bbl/day ≈ 30 billion bbl/year ! • Oil is a globally-traded commodity. Two main oil price indicators: Ø (US) West Texas Intermediate (WTI), aka Texas light sweet; Ø (London) Brent crude • currently WTI price is $92/bbl and Brent is $97/bbl. •We1859: “Colonel” Drake at Titusville, PA. 1862: 75 wells in Pennsylvania, 3 x 106 bbl/year. 1870: John D.
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