Science 30 Unit D - Energy and the Environment Chapter 7 Worldwide Energy Demand

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1 Science 30 Unit D - Energy and the Environment Chapter 7 Worldwide Energy Demand Name Table of Contents 7.1 Global Energy Demand 7.2 Fossil Fuels (Non-Renewable Resources) 7.3 Combustion and Chemical Energy 7.4 Environmental Effects Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 1

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3 World Energy Use (EJ) World Population (Billions) 7.1 Global Energy Demand What is Energy Measured in? (p. 471) World Use of Energy World Energy Use (EJ) from *EJ = exajoule = 1 X J World Population from Per Capita Energy Use from Per capita for each person Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 3

4 Gross Domestic Product (GDP) the total market value for all goods and services produced by the country in one year. Considered a countries economic output. Energy Intensity The ratio of energy input (in joules) to economic output (in US$) World Bank Updated Info and GDP Graphs Latest Values and Energy Intensity What Factors Affect Energy Use in a Country? Looking at Home p.472 (Percent of New Car Sales). Why are Canadians buying more light-duty trucks than more efficient smaller cars? Energy Use in Alberta Alberta major sector are development of non-renewable energy resources of coal, petroleum, and natural gas. More focus in recent years on wind and hydroelectric power. Fossil fuels make up over half of the province s exports. Royalties paid to the Alberta government by energy companies that extract and process natural resources. ** Major focus in the past years has been to improve efficiency in our technologies in the energy sector. How does improving efficiency improve consumption?? ** Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 4

5 Energy Efficiency: The percent of input energy that has been transformed into useful output energy. Example Problems Calculate the energy efficiency of a toaster that uses 300 J of energy to increase the thermal energy of water 240 J. If an automobile engine is 15% efficient, calculate the useful output energy form 1 kg of gasoline containing 50.0 MJ of chemical potential energy (Answer to 3 significant digits). Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 5

6 7.1 Homework Comparing Energy Use Canada and Other Countries (p,473) p #9-12 Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 6

7 Lesson 7.2 Fossil Fuels (Non-Renewable Resources) Definitions Types of Energy Energy heat Energy Motion Energy Stored energy from the position in a system. Energy Potential and Kinetic Energy (when machines do work think of a turbine spinning) Energy Stored in the bonds of compounds (mostly hydrocarbons) Remember Energy is not created or destroyed only converted. Non-Renewable Resources (Textbook 1.2) The BIG THREE Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 7

8 Coal Society shifted from burning wood as a primary fuel source to burning coal during the industrial revolution. Coal is a combustible black or brownish-black sedimentary rock composed mostly of carbon and. It is the most abundant fossil fuel produced in the United States. Coal is a nonrenewable energy source because it takes millions of years to create. The energy in coal comes from the energy stored by plants that lived hundreds of millions of years ago, when the Earth was partly covered with swampy forests. Coal is cheap to surface mine and generates about half of the electrical power for North America. Coal surface mining can have negative impacts on the environmental landscape. Emissions produced from coal are. Research is going into scrubber technology to reduce the amount of pollutants going into the atmosphere. Petroleum (Crude Oil) Today by far, petroleum is the Over millions of years, the remains of animals and plants were covered by layers of sand and silt. Heat and pressure from these layers helped the remains turn into what we today call crude oil. The word "petroleum" means "rock oil" or "oil from the earth." Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 8

9 Crude oil is a smelly, yellow-to-black liquid and is usually found in underground areas called reservoirs. Oil derricks are built on an oil well that will bring a steady flow of oil to the surface. The Athabasca Oil Sands are not crude oil, but petroleum stuck in sand. It needs to be separated into useful There is an excellent source of energy; however there are a number of drawbacks. Pollutants form emissions include CO2, CO, SO2, NOx, VOC s, lead, benzene, and acetaldehyde. In addition to harmful effects to reclamation of the land, problems can ensue at oil wells. Natural Gas (Methane) Formation of natural gas is similar to petroleum, except natural gas requires more. It is used to heat our houses (furnaces), hot water, and the kitchen stove. Natural gas produces fewer emissions of sulphur, carbon, and nitrogen than coal or oil. It still produces. The footprint from natural gas is much less, but still impacts the land and marine habits where drilling occurs. Fossil Fuels Main source. In fossil fuel reactions the following occurs: Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 9

10 Fossil-Fuel Power Station In a coal-fired steam station water is turned into steam, which in turn drives turbine generators to produce electricity. Here s how the process works. 1. Heat is created The coal is crushed and mixed with hot air and blown into the firebox of the boiler. Burning in suspension, the coal/air mixture provides the most complete combustion and maximum heat possible. 2. Water turns to steam Highly purified water, pumped through pipes inside the boiler, is turned into steam by the heat. The steam reaches temperatures of up to 500 degrees Celsius and is piped to the turbine. 3. Steam turns the turbine The enormous pressure of the steam pushing against a series of giant turbine blades turns the turbine shaft. The turbine shaft is connected to the shaft of the generator, where magnets spin within wire coils to produce electricity. 4. Steam turns back into water After doing its work in the turbine, the steam is drawn into a condenser, a large chamber in the basement of the power plant. In this important step, millions of gallons of cool water from a nearby source (such as a river or lake) are pumped through a network of tubes running through the condenser. The cool water in the tubes converts the steam back into water that can be used over and over again in the plant. The cooling water is returned to its source without any contamination, and the steam water is returned to the boiler to repeat the cycle. Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 10

11 7.2 - Homework p.490 #1-6 Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 11

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13 7.3 Combustion and Chemical Energy Terms Combustion occurs in the presence of oxygen and results in the release of energy, carbon dioxide and water vapour. YOU MUST KNOW THIS REACTION! Exothermic release of energy. Endothermic absorbing energy. Temperature a measure of the average kinetic energy of the atoms or molecules of a substance. Heat the transfer of energy from molecules at a higher temperate to lower temperature. During a combustion reaction, the stored potential energy of a reaction decreases and the kinetic energy of the reaction increases. Like all chemical reactions, this reaction conserves energy (often released as heat). Since heat is just the transfer of energy, we can calculate how much heat was generated by measuring the temperature difference. This device is known as a calorimeter. This will allow us to find out exactly how much energy was generated during the reaction. This reaction is EXOTHERMIC because energy was released Potential Energy ch = fh = the heat of combustion (how much heat is released during a combustion reaction) Unit is often given in kj/mol (Data book p. 5) What is the fh of: Progress of Reaction Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 13

14 Glucose? 2 mols of Sucrose? Ethene? Water (l) and ethane combined? Single elements (i.e. Al, Ni, O2, H2, Ne, etc ) have a fh = 0. (If it s not listed, just give it a zero!) Hess Law Theoretical Heat of Combustion If we use the standard heats of formation from the data book we can calculate the energy generated by the products and the reactants. The standard heats don t equal one another where has the missing energy gone? In short, to find the heat generated by a chemical reaction Heat of reaction = (Theoretical Heat of Products) (Theoretical Heat of Reactants) Or (Data book bottom p.5) Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 14

15 Example Problem 1.1 (p.497) 1. Calculate the energy change of the reaction of methane gas. (Balance the equation and then use the formula) Practice Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 15

16 7.3 - Homework p.498 #22-23 and p.501 #1-5, 10 Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 16

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18 7.4 Environmental Effects of Combustion (textbook reference section 1.1, 1.3, 1.4 of Chem) Objectives: B1.8k outline the chemical reactions (e.g., combustion reactions) that produce air pollutants (i.e., sulfur dioxide and nitrous oxides) that, when combined with water, ultimately result in acid deposition 30 B1.9k describe impacts on the biotic and abiotic components of the environment caused by acid deposition Emissions Can React Products of combustion reacts, released as emissions can react with the water present in the atmosphere Oxides of carbon greenhouse gases Oxides of sulfur acid deposition Oxides of nitrogen acid deposition Note: rain water is naturally acidic and oxides of carbon, sulfur and nitrogen do exist naturally as well as anthropogenically (human produced) Dioxides react with water: SO2 + H2O ==> H2SO3 (sulphurous acid) NO2 + H2O HNO3 (nitric acid) Look at p. 161 where are the majority of sulphur dioxide and nitrogen monoxide emissions from? The main acid-forming pollutants are sulphur dioxide (SO2) and oxides of nitrogen (NOx). These substances interact with water in the atmosphere to form mild acids that return to the earth in wet (rain or snow) or dry (being absorbed in the atmposhere) deposits. Where do the Acids come From? Sulphur dioxide comes from electrical power stations, smelters (such as the nickel smelters in Sudbury, Ontario), gas processing plants, oil sands plants, coal-fired power plants, and transportation (trains and vehicles). Oxides of nitrogen come from the same sources with nearly half of it coming from transportation sources (cars, trucks, airplanes, etc.). The largest source of acid pollution in Alberta is from. It is a natural gas, which contains hydrogen sulphide (H2S) that must be removed before the gas can be used for other purposes or burned as fuel. In the process, large amounts of sulfur and sulfur dioxide can be produced. Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 18

19 Acid Deposition in Canada Acid deposition has different effects in different areas of Canada. Effects of Acid Rain Many parts of Eastern Canada and Western B.C. have naturally acidic soils. Acidic soils cannot neutralize acid; therefore acids build up faster in these soils. Other areas including parts of British Columbia, central and Alberta have large amounts of limestone in the rock beds and lakes. These lakes buffer the acid Limestone is (CaCO3). What would happen when limestone reacts with H3O+ ions of an acid? (Use acid-base reaction in data book) Minerals like calcium, magnesium, potassium and sodium are leached from the soil and carried away. (leaching loss of nutrients through dissolving with the liquid in soil) Toxic metals like aluminum, manganese, mercury, cadmium and lead become more soluble by the chemical action of the acids. This allows the toxic metals to be absorbed by the plant roots and can cause serious damage or death to the plant or microorganisms. Toxic metals like aluminum, mercury, lead, and cadmium are washed into the lakes from the soil. Collect in fish and other aquatic animals making them unsuitable or dangerous for people to eat (biomagnifcation). Ex. At a ph of 5.9, aluminum can start damaging the gills of some fish species and may eventually kill them. If the ph reaches 4.5, most of the fish, frogs, and insects will have died. Acid rain even affects historical monuments, such as the Parthenon in Greece, Westminster Abbey in England and the Taj Mahal in India turning the marble into a crumbly rock called gypsum. by Modern day works like steel bridges, vehicles and other metallic structures corrode or rust at a much faster rate because of acid rain. Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 19

20 Learning from Acid Deposition Reducing emissions is necessary for areas exposed to extreme acid deposition to recover The road to recovery is a LONG process Ability to be exposed to an acid or base and not change ph Soil/Limestone in lakes carbonate ion Blood hydrogen carbonate and carbonic acid Once too much of an acid/base is added, the buffering capacity is exceeded and the ph changes Titration Curves and Buffering The ph changes slowly in a titration due to buffering. Once the capacity is reached, a sharp change occurs. Smog Photochemical smog brownish-red haze produced by reaction of sunlight and automobile exhaust. Occurs in the atmosphere. Reaction of nitrogen oxides. Toronto, Montreal and Vancouver are cities where the ozone air quality objective is exceeded an average of 10 or more days in the summer. Reducing Emissions Process that removes one or more harmful components from a mixture of gases or liquids o See examples of electrostatic precipitator, scrubbers, and catalytic converters. (textbook) Different treaties and societal changes are needed to further reduce emissions. Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 20

21 Homework Questions??? Science 30 Unit D: Energy and The Environment Chapter 7 Worldwide Energy Demand Page 21