Section 9: Energy and Our World Ch.10 Energy Section 9: Energy and Our World

Energy and Our World Most of the energy produced comes from fossil fuels New alternatives: solar, wind, hydropower, nuclear, biomass, hydrogen

Fossil Fuels Def: decaying organic material Mostly from plants and ancient aquatic animals (yes, dinosaurs too) Ex: Petroleum (gasoline), Natural gas (cooking/heating), Coal (electricity production)

Petroleum Thick, dark liquid composed of various lengths of hydrocarbon chains Chains from 5-25 carbons long First oil well: 1859 in Pennsylvania First reason to drill: Kerosene (lamps) as a replacement for animal fats and whale oil

Petroleum Found to have many useful parts based on their length of their carbon chain Gasoline: C5-C10 Kerosene:C10-C18 Jet Fuel: C15-C25 Asphalt: C25-greater

Petroleum Different parts separated by Fractional Distillation Def: using different boiling points to extract substances according to their molecular structure Smaller structure=lower boiling point To get kerosene you need to extract gasoline first (see previous slide info).

Petroleum Another method of extraction is Cracking Def: breaking of carbon chains into smaller parts to “make” new substances Ex: Kerosene heated to 700oC will break into gasoline This allows for two different methods of refining gasoline

Petroleum Problems arose from using different methods of producing gasoline Not all molecules would be the same length, sometimes there would be an uneven distribution of gasoline in the product. Uneven distribution lead to knocking in the engine of a car. Solution: additive tetraethyl lead: (C2H5)Pb

Petroleum Leaded gasoline in 1960’s had as much as 3g of lead in one gallon Many environmental issues (lead is a neurotoxin) Now all gas is unleaded which has meant a more extensive refining process to ensure even distribution of gasoline

Coal Made from plants buried millions of years ago Over time cellulose (CH2O)x combines together to make deposits of coal Older the coal=more carbon atoms bonded together =more energy produced

Coal 4 types Lignite: 71%C : 23%O Subbituminous: 77%C : 16%O Anthracite: 92%C: 3%O * Contains the most sulfur (5%)

Coal Downfalls Expensive Dangerous to mine (deep underground) Strip mining; remove valuable top soil and scenic sites Produces high levels of greenhouse gases (CO2,etc.) and sulfur dioxide gas (SO2) which produces acid rain

CO2 and the Environment Radiant energy from the sun (70%) passes through our atmosphere This energy is used in photosynthesis in plants, oceans for evaporation, and to heat the surface of the Earth The energy that hits the surface is then radiated back into the atmosphere in the form of infrared radiation CO2 and H2O in the atmosphere reflect this infrared radiation

Greenhouse Effect The reflection of infrared radiation causes an increase in surface temperature This is much like the glass in a greenhouse trapping in heat to keep plants warm In the last 100 years carbon dioxide levels have increased 20% Over the next 100 years this could relate to an increase of 100C (500F) world wide

Future?? What alternative fuels could we use? How much are we willing to change our lifestyles? Does this even matter?

Sources of Energy Video List 6 sources of energy production List 10 main objectives/sources of learning Provide 3 questions to further your learning Sources of Energy Video