Ch. 9 RTB - Energy Sources & Conversions

Transcription

1 Ch. 9 RTB - Energy Sources & Conversions A. Types of Energy Sources 1. There are many different types of sources for energy 2. Energy comes from plants & Animals when living & Digested by another life form 3. Energy can come from plant & animal matter that is fossilized and turned to a carbon based material - Coal, Gas, or Oil 4. They are classified into 3 categories: a. Exhaustible b. Renewable c. In-Exhaustible 5. All must be understood in order to maintain their supply and how they can be used B. Exhaustible Sources of Energy 1. Coal - Black or brown in color found in the earth a. Obtained through Digging & Mining 1. Deep below ground or Close to surface b. It is the most abundant fossil fuel 1. Composed of plant & animal matter that is millions of years old 2. Pressure & heat forced the material to change it molecular structure to become coal we have today c. It is found in 2 form 1. Soft - High in sulfur - Very high pollutant a. Found close to the surface of earth b. Relatively safe & easy to mine c. Cheap to produce 2. Hard - Less pollution when burned a. Found deeper in earth b. Higher cost to mine c. More dangerous to mine as well d. At present rate of usage we have reserves of 500+ years 1. Question - Can technological advancement cause the supply to be used up faster? 2. Oil - During the last 60 years oil & natural gas have replaced coal as the main source of energy for energy in the home & transportation uses. a. Oil & gas have become the #1 source of energy over the past century due to their easy transport and storage. b. They are less polluting when burned c. They have a multitude of uses 1. Oil used to make plastics and other consumable goods 2. It is the world's most important fuel sources d. Oil can be found in many different places 1. Crude oil - Dark liquid trapped deep in the earth a. Obtained by drilling - in some places 4+ miles into the earths crust 2. Shale Oil a. Oil trapped in shale rock b. Over 3/4 of the oil in the US is in this form c. Obtained by digging the rock, Heating the rock and oil removed 1. Costly & Time consuming 3. Tar sands a. Oil trapped in sand b. Extracted through the use of heat

2 e. After oil is obtained it is refined 1. Fuels & Other materials f. The refining process 1. Oil is heated and boiled until it turns to a gas vapor 2. The gas vapor is collected & condensed a. This is where you get the various fuels from oil g. There are 2 main problems with using oil as a power source 1. there is a finite supply a. As the supply dwindles the cost will rise 2. It create pollution - Mainly that of the air 3. Natural Gas a. Most commonly found in pools under ground or with the crude oil b. The most common type of natural gas is METHANE c. Other types are ETHANE, PROPANE, & BUTANE d. Each type of gas has a different Btu rating - How hot they burn. 1. Propane is the hottest burning gas 2. The mixture of gasses sold is usually dependent upon the availability & cost e. It is stored & transported under pressure 1. The gas is heated to a high point then cooled to a liquid state 2. Though dangerous and highly flammable, the design of the containers & how we handle them makes it relatively safe to use f. It is the cleanest burning fuel 1. It creates the fewest pollutants when burned 2. Making it the cheapest & most used natural resource a. This has led to depleted reserves and thus harder to find b. There is not enough natural gas to meet our current needs 3. Geopressure reserves a. Gas is found in high pressure Brine (saltwater) pool under the ground 1. When tapped, they release the gas - Though expensive today technology is beginning to make the cost decrease 4. Tight sand reserves. a. Gas is trapped in hard dense sandstone generally found in the Rocky Mountain region of the US b. It is obtained by injecting high pressure water into the sand stone 1. The gas is released when the sandstone breaks apart c. After release, the gas needs to be processed to remove impurities d. Other gasses are drawn off to mix with the different gasses to create higher Btu rating gas when burned 4. Uranium a. A radioactive material found naturally in the earth 1. It is used by nuclear plants to create electrical energy 2. Though limited supplies exist in the US, There is enough reserves to last many years based upon our current usage 3. There are only about 100 nuclear plants in the United States today b. Mined from the earth, uranium is found in 2 basic types (isotopes) 1. Uranium 235 (U-235) and Uranium 238 U-238) 2. Though found together when mined, they are separated during processing c. Nuclear fission 1. Nuclear fission is generated in a power plant during a controlled nuclear fission.

3 a. The splitting apart of the nucleus of an atom 2. Atoms are bombarded with free neutrons causing the atom to split 3. When it splits, it forms 2 or more nuclei, more free neutrons, and gamma rays as well as a lot of energy 4. When a atom is split, a chain reaction takes place, when controlled it produces a steady flow of energy 5, The heat energy is released and water is heated to 580 degrees F 6. The water creates pressure as it evaporates and the steam is directed to turn turbines a. The turbines spin creating energy 7. The down side to nuclear fuels is that they are radioactive and harmful to animal cells 5. Renewable Energy sources 1. Ethanol - Ethyl-alcohol which id derived from plants (Corn) a. It is a mixed fuel b. 9/10 of the fuel is gasoline (unleaded) and 1/10 is Ethyl-alcohol c. This is called E10 d. "FLEX-FUEL" E85 - is an ethyl-alcohol mixed gas 1. 85% of the fuel is alcohol based 2. Movement to create a new fuel E95 - where 95% of the fuel is ethyl-alcohol e. Sources - Sweet Sorghum, Sugar Beets, grains & corn 1. Through distilling large quantities can be produced 2. Methanol - Methyl-alcohol a. Clean burning liquid fuel b. Can be used in vehicles c. Can be made from natural gas & coal - non renewable 1. Renewable can be made from wood, water, & waste d. By using methanol as transportation fuel - we produce less pollutants and reduce the cost be lessening the need for refined oil as fuels. 3. Biodiesel - Diesel fuel mixture with vegetable oils added. a. Cooking oil is heated to a temp of 130 degree F b. Then filtered, and additives are added c. This fuel is able to be made by industrial companies as well as private companies 1. Many people are making their own biodiesel fuel at home d. Because it is such a clean burning fuel, it loosens dirt & debris from fuel systems in vehicle essentially causing clogging d. Also the fuel isn't very good to use in cold weather, due to it thickening up 4. Waste Products a. Bioconversion is a method of obtaining energy from waste products b. Foods products, animal waste, paper, cardboard, and wood waste all included c. They can be burned or converted into fuels such as alcohol, oil, and methane gas d. The process is called thermal conversion or thermal depolymerization 1. Thermal depolymerization creates high quality fuel oil from turkey waste (parts and plastic bottles) e. The dispose of unwanted waste and can be located almost anywhere f. Fuels created are low pollutants g. They also help limit the waste that enters the waste stream 5. Wood a. Wood & wood waste are 2 of the oldest forms of energy b. Some communities still use it as a fuel today to create electricity c. Today there is a new way to use wood as a fuel

4 d. Problem it is not 1. By creating a liquid and gas e. New technologies are being sought to make work a more viable source of fuel 1. Problem, The amount of trees grown today doesn t supply enough raw material to make fuel and the number of tree farms would have to be increased C. Inexhaustable Energy Source 1. The Sun a. Solar energy collected from the sun, this source of energy is totally free, but it is expensive and inefficient to collect in large quantities b. Thermal Energy 1. Heat energy produced by the movement of molecules 2. Heat is conducted through a transfer from one material to another a. The faster the heat is transferred depends on the molecules of the material 3. The transfer generally takes place through liquid 4. The hot/heated water is then used to produce heat for homes, businesses, & factories a. Radiators 5. This process also is accomplished with solar energy. It is a large and complex system a. Mirrors are used to direct the sunlight to a central tower b. The tower has a salt that is heated and melted at high temperature from the directed light c. The heat is then used to generate electricity by heating water and causing steam to turn turbines d. This process is dependent upon the sun shining. And backup systems must be employed when the sun isn't shining c. Electricity 1. Through the use of PHOTOVOLTAIC cells, sunlight is collected and turned to electricity a. The process works in this way: 1. When photons strike materials in the Photovoltaic cells, electrons are released 2. The flow of these free electrons create the electricity 2. Coupled with a battery system, the system can produce & store energy 3. Much more efficient than solar panels 4. as technology changes, they are becoming cheaper to produce & Use. d. Flowing Water 1. Water has potential energy stored in it due to the mass of water that is held in place 2. Once the water begins to flow, it has kinetic energy that is ready to be used 3. The moving water is directed across turbines that turn and produce electricity 4. 20% of all energy produced today is from flowing water e. Wind 1. Very important source of energy in rural areas 2. Energy gathered through he use of windmills 3. The energy from wind was used to create direct mechanical energy to power pumps for water, to grind grain, and perform other useful tasks 4. Today Wind power is used to generate electricity 5. Specially designed propellers are used to capture the wind and drive the propellers a. The propellers provide mechanical energy to turn a generator that creates the Electricity b. This electricity is used to directly power equipment or is stored in batteries for later usage 6. Problems with this technology a. It is costly to store the energy created by the wind mills b. They are large and take up a lot of space and can be unsightly c. Affect wildlife in area

5 7. Though there are draw backs, wind power is becoming a source of backup energy for use by cities and factories a. Large wind farms are being constructed near source areas to provide this energy source f. Ocean Tides, Waves, & Currents 1. It is the natural resource that we know the least about. 2. The ones that we know the most about are the currents and tides 3. Tides a. The raising & lowering of water levels based upon the gravitational pull of the moon and the rotation of the earth b. High Tide is the point where water has risen to the highest level c. The effects of tidal change last about 6 hours each d. In some places around the world the difference between high & low tides is about 40 feet but the difference is much less on average. 4. Currents a. Are the movement of water in and out b. Based upon the topography of land and underwater features affect ho fast the currents move 5. We are able to collect energy from this movement of water by channeling it through an area and having it drive a turbine to generate electricity a. This practice is often practiced at hydroelectric plants. b. Dams are one common place where energy is collected in this fashion 6. The cost of operating a tidal hydroelectric plant is high, but very reliable 7. Ocean waves & currents are another source of energy. a. Devices, the Red Sea Snake, which floats on the surface of the ocean used the motion caused by waves to power generators which produce electric energy. b. Few countries use this technology, are supplementing their need for other sources of energy 1. two countries that use devices like this are Scotland & Portugal c. Researchers believe if fully implemented, it could produce 13% of the worlds energy g. Ocean Heat 1. Tropical oceans collect & store heat from the sun, Heating the water 2. The surface water is warm and the depth are cold 3. This difference is used to create electricity called Ocean Thermal Energy Conversion (OTEC) 4. OTEC systems are similar to a refrigerator a. Liquid ammonia is circulated through pipes, in cold water the ammonia remains a liquid, but as it moves to warm water it expands, becomes a gas, and the pressure is used to turn turbines thus producing electricity 5. The technology is simple enough, it is the application that isn't. $$$ and maintenance is needed 6. Still a plan but needs more research h. Solar Salt Ponds 1. Naturally found in the Western US are another source of electrical energy 2. Since the pools of salt water have little to no movement, the Sunlight passing through the top layers of heats the lower layer, since there isn't movement the heat builds and it can reach temps of 250 degrees 3. The heat is then used to operate a system similar to OTEC, but since there are few salt water ponds interest & research in the are has faded

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