Presentation on theme: "Energy from organic fuels"— Presentation transcript:
1 Energy from organic fuels Chapter 15Energy from organic fuels
2 The Need for Energyfuel: any substance from which energy is obtained.Examples:?How have things changes?Organic fuels: contain carbon compounds, examples:Hydrocarbon: compounds composed of only hydrogen and carbon, example: methane (a lot of them end in “ane”Methane, Ethane, Octane…. The octane rating of gasoline is derived from a formula based on the amount of energy contained in the gas compared to pure iso-octane.
3 Butane isomers: same number of atoms, different structure.
4 Organic fuels often contain other chemicals (the bad part usually for us anyhow), example: sulfur or leadCalled impurities, many contribute to pollution.Fossil FuelsWhen organisms die, not all of the energy they had stored was released.When buried, and you add pressure, typically the organisms energy is not loss.Therefore: fuels derived from the remains of organisms that lived long ago are fossil fuels. Examples: coal, petroleum, and natural gas.
5 CoalGenerated by organisms that died, covered in sediment, and with added pressure and heat formed coal.Chemically changed, and water removed (via pressure) become solid rock (coal)Over time, hydrogens and oxygen's are removed, concentrating the carbon (concentration of coal is directly related to the amount of energy available).This concentration is how we categorize different types of coal materials.PeatNot technically a type of coalLowest value of energy availableHigh water content, low percent of carbonFirst stage of coal formationLooks kind of like decaying woodThe youngest of these categoriesGives off a large amount of smoke (due to high water concentration)
6 LigniteSecond stage of coal formationSoft, brown coal composed of about 40% carbonBurns quickly, very little smoakMust be mined (peat does not have to be mined)Bituminous CoalSoft coal, 85 % carbonMust be minedEven more pure, burns hotterUsed by many power plantsMost abundant coal mined in USAnthracitePurest coal, 95% carbonShiny, black, often deeper underground than any otherBurns the hottest, least amount of smokeMost expensive to acquire as well.
7 Petroleum- crude oil, and a liquid fossil fuelnon-renewableFormed from microscopic protists, plants, and animalsMillions of years to formTrapped in pocked beneath nonporous rock (with water and natural gas)Can be under very high pressure (hence the term “gusher” when drilled into it.Worlds most important resource.Used to make a variety of products after being refinedHeat homesProduce electricityGrease and lubricantsAsphalt for roadsMany types of plastics
10 Natural GasOften found trapped above petroleum poolsMostly gaseous hydrocarbonsMethane is the primaryOthers include: propane, nitrogen, and heliumUsed instead of coal or oil because it burns cleaner (stoves, heaters, etc…)Really good because it does not have to be converted to electricity, can be burned directlyBecause of this, more efficient and less expensive to useOften NG is considered a waste product at the oil platform and is burned off.
12 Other organic fuelsBiomass Fuels (is a fuel formed from the products of living organisms)WoodStill relied on heavily in developing nationsAdvantages: renewableDisadvantages: lots of smoke that is high is carbon dioxide, tree reduction can cause more erosion.GarbageAbout 2/3 of the material in garbage can be burned.Some cities in the US already take advantage of this (using the heat to generate steam, thus produce electricity)Methane“swamp gas”Decaying garbage dumps also produce methane (both are being harvested and used same ways as natural gas)Cows are the number one releasing agent of methane (both ends) but this is much harder to use.
13 Alcoholbioconversion: converting organic materials into fuelsSugarcane and corn are used to make alcohol.Ethanol is the primary alcohol being produced right nowGood: renewableBad: not as much energy available as from regular gasGasohol: mixture of 4 parts gasoline to one part ethanol.