PHYS1003 ENERGY AND ENVIRONMENTAL ISSUES LECTURE 2 Fossil Fuels and Temperature 1 World Primary Energy Consumption Electricity Jet engine Containership Oil tanker Diesel engine Electric generator Electricity Global energy consumption 1850 2000 and corresponding technological inventions Nakicenovic and Grubler 2000 2 UNITS OF ENERGY AND POWER Energy is measured in BTU British Thermal Unit Joule J and kilowatt hour kWh barrel of oil bbl gallon liter toe tons of oil equivalent mt million t bt billion t calorie cal Calorie Cal kcal Power energy time is measured in Watt J s kW MW GW TW horse power hp 1hp 746 W e g kiloWatt hour kWh 1 kWh 1 toe 1 Cal 1 BTU 3 6 x106 J 42 x109 J 4184 J 1055 J ONE BARREL OF OIL 42 US gallons 159 liters 1700 kWh 6 12 GJ heat 680 kWh electricity MacKay s light bulb 1kWh a 40W light bulb runs for 24 hours 40 W 24 h 960 Wh 0 96 kWh 1kWh http www youtube com watch v oRQB2YXUxvY 3 OUR STANDARD ENERGY UNIT The energy consumption per capita in 2020 was 36 4 GJ per capita https www emsd gov hk filemanager en content 762 HKEEUD2022 pdf It is 10 111 kWh year per capita It is 28 kWh daily per capita Daily Energy Consumption 28 kWh 1 DEC Daily Food Calorie Intake 2400 Cal 2 79 kWh 10 of DEC 1 Cal 4 184 kJ 1 16 Wh 4 FOSSIL FUELS 5 What are fossil fuels Source Carbon and hydrocarbons from dead plants and micro organisms buried underground for 100 M years Coal Petroleum or crude oil Natural gas Heavy crude oil Tar sands Oil shale Shale gas 6 What are they used for Fossil fuels are main source of world energy ELECTRICITY GENERATION Coal oil and natural gas TRANSPORTATION Oil and natural gas FOOD PRODUCTION Oil natural gas and coal for fertilizer pesticide and chemical production 7 Fossil fuels Make 80 of Total Primary Energy Supply TPES SOURCE Key World Energy Statistics 2021 International Energy Agency 8 Fossil fuels Energy density Fuel Dried dung Air dried wood Charcoal Coal Crude oil Gasoline Natural Gas MJ kg 10 12 15 17 28 29 20 26 41 42 44 45 53 54 Source V Smil 2006 Energy UNITS Relevant quantities come in different units Energy J kWh Cal Oil in barrels 42 US gal For gas one uses MJ m3 energy per volume 9 WHY DO WE LOVE FOSSIL FUELS cheap and abundant high energy density easy to store and transport relatively safe low potential of catastrophic accidents 10 Coal READILY COMBUSTIBLE ROCK containing more than 50 percent by weight of carbonaceous material Most abundant fossil fuel Non renewable energy source because it takes millions of years to create FUELED THE 1st INDUSTRIAL REVOLUTION by powering steam machine SOURCE US EIA Energy Information Administration 11 Burning Coal Coal Oxygen Carbon Dioxide Heat Chemistry Basic Larger Molecules are formed by atoms smaller molecules bonding together To decompose a molecule energy is needed to break the bonds To form a molecule energy is released when a bond is formed Chemical Reaction C solid O2 CO2 C solid C free C free O2 CO2 Separating Carbon breaking a C C bond combination reaction Net Energy Release Energy in Bonds Formation Energy in Bond Breaking 12 Burning Coal Coal C Oxygen O2 Carbon Dioxide Heat Bond energy Separating 1C from others C C C 83 kcal mole O O 119 kcal mole C O 177 kcal mole 13 Burning Coal Coal C Oxygen O2 Carbon Dioxide Heat Bond energy Separating 1C from others C C C 83 kcal mole O O 119 kcal mole C O 177 kcal mole Breaking C C and O O Forming O C O 2 x C O bond 2 x 190 kcal mol 380 kcal mol Net release Bond formed Bond broken 178 kcal mole 24 178 butane chem uiuc edu cyerkes Chem104ACSpring2009 Genchemref bondenergies html 14 CHEMICAL BOND ENERGY TABLE 1 kcal 1 Cal 4 184 kJ 1 16 Wh 1 kJ 0 239 kcal 15 Burning Coal Energy from burning coal used in ELECTRICITY GENERATION About 41 of electricity worldwide is generated by coal Making Steel Heat Making cement Heat Making plastics tar synthetic fibers fertilizers and medicines with separated coal constituents methanol and ethylene of electricity generated by coal 2014 16 OIL PETROLEUM AND NATURAL GAS Hydrocarbons CnH2n 2 are organic compounds that are made of only hydrogen and carbon atoms They are found in crude oil and natural gas Burning of hydrocarbons 17 OIL AND NATURAL GAS Formation from ancient biomass SOURCE US EIA Energy Information Administration 18 http www youtube com watch v jk0WrtA8 T8 0 00 2 00 Oil Refinery Fractional Distillation separation of liquid mixture with different boiling temperature Fractional distillation http www black tides com uk oil oil everyday lives products obtained from crude oil php 19 19 WHAT WE USE OIL FOR Global crude oil consumption in 2018 Transportation 65 20 MANPOWER Video from the lectures of Prof W Lewin MIT https www youtube com watch v XJYY4jlwZzo 54 40 to end 21 WHAT IS TEMPERATURE Temperature and the zeroth law of thermodynamics Temperature and temperature scales Microscopic description of an ideal gas 22 TEMPERATURES EQUILIBRATE The Zeroth Law of Thermodynamics what does temperature mean Not in equilibrium TA TB In Equilibrium TA TB A B Heat A B No Heat Exchange Zero th Law If two objects A and C are each in equilibrium with a third object B then A and C are in thermal equilibrium with another Thermal Equilibrium Same Temperature A B A B in Equilibrium TA TB TA TC A C in Equilibrium A C B C B C in Equilibrium TB TC 23 Temperature measures the ability of a substance to release heat to other substances Hotter object releases heat to cooler one 24 MEASURING TEMPERATURE USING THERMOMETRIC MATERIAL PROPERTIES When temperature changes the physical properties of the matter changes too LIQUID THERMOMETER Based on thermal expansion of a liquid in a capillary BIMETAL THERMOMETER Based on different thermal expansion of metal strips 25 FUN FACT Temperature in empty space The Cosmic Microwave Background temperature over the full sky Average temperature 270 425 C http wmap gsfc nasa gov media 101080 How to measure Temp of space By thermal radiation An infrared thermometer or non contact thermometers or temperature guns is a thermometer which infers temperature from a portion of the thermal radiation sometimes called black body radiation emitted by the object being measured 26 Temperature Scales We Can Measure Temperature With Various Scales FAHRENHEIT SCALE Daniel Fahrenheit 1724 0 F is freezing point of ammonium brine 32 F is freezing point of water 212 F is boiling point of water CELSIUS SCALE Anders Celsius 1742 0 C is the freezing point of water 100 C is the boiling point of water measured at a pressure of 1atm TF