IOT POLY ENGINEERING 3-3 DRILL 2 FEB 11 1)Why do they add odorant to Natural Gas? 2)How do they separate natural gas from other petroleum products?

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DRILL

2 FEB 11

1) Why do they add odorant to Natural Gas?

2) How do they separate natural gas from other petroleum products?

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1. What are the fossil fuels?2. What makes them non-renewable?3. Explain the formation of Coal, Natural Gas, and Petroleum.4. What are the methods of extraction for fossil fuels?5. What are hydrocarbons? What is methane formula?6. How are oil and natural gas transported?7. Why are fossil fuels processed prior to use?8. How is natural gas used in the home?9. What geographic region has largest oil reserves?

Topic 1 Energy Sources – Fuels

QUIZ REVIEW

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Non-Renewable Fuels – Petroleum

Oil Reserves

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Non-Renewable Fuels – Petroleum

Oil Reserves

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Non-Renewable Fuels – Petroleum

Oil Consumption Barrels per person per day

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Non-Renewable Fuels – Petroleum

Refining• Raw, unprocessed crude oil is mostly not useful• Varies in color – from clear to tar-black• Varies in viscosity – from water to almost-solid• Crude oil is processed and refined into more usable

forms – separated into parts• Distillation – purifying a liquid by successive

evaporation and condensation

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• Different components of crude have different boiling points.• When a vapor cools to its boiling point, the vapor become a liquid

again – like steamed water in a pot

Process:1. Crude is boiled2. Highest boiling points

condense first3. Lower boiling points

condense last

Non-Renewable Fuels – Petroleum

Refining

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Non-Renewable Fuels – Petroleum

Refining

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Non-Renewable Fuels – Petroleum

Refining

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Non-Renewable Fuels – Petroleum

Uses

• Primarily used to achieve mobility• Manufacture medicines, fertilizers, food, plastics,

building materials, paints, cloth, and to generate electricity

• Physical structure and way of life of suburban communities

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E is energym is massC is the speed of light

Mass and energy are interrelated

Non-Renewable Fuels – Nuclear

2mcE

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Non-Renewable Fuels – Nuclear

• Nuclear Fusion– Small atoms combine to create new atom and

give off energy– Power source for sun and other stars– Power source for hydrogen bombs– Main reaction is H + H ->He + energy

• Nuclear Fission– Large atom breaks apart to create two new

atoms and give off energy– Explosive force used in bombs dropped on

Nagasaki and Hiroshima– Energy source used in nuclear power

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Non-Renewable Fuels – Nuclear

1. Nucleus of a heavy element (e.g. Uranium) splits when bombarded by a free neutron

2. Two smaller atoms, 1-3 neutrons, plus energy3. Extra neutrons lead to chain reaction:

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Non-Renewable Fuels – Nuclear

Nuclear Fuel Cycle – Front End

Background Chemistry• The number of protons are the atomic number.

Uranium’s atomic number is 92• Atoms with different numbers of neutrons are called

isotopes – “same place”• Isotope U-235 is the only fissile isotope found in

nature

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Non-Renewable Fuels – Nuclear

Nuclear Fuel Cycle

Like coal, natural gas, and petroleum, Uranium (U) is an energy source that must be processed before use.

• Front End: preparing the fuel• Service Period: using fuel in reactor• Back End: safely manage, contain, reprocess/dispose

of spent fuel

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle

• Front End: preparing the fuel1. Exploration2. Mining and Milling3. Conversion4. Enrichment 5. Fabrication

• Service Period: using fuel in reactor • Back End: safely manage, contain, reprocess/dispose

of spent fuel

Non-Renewable Fuels – Nuclear

Nuclear Fuel Cycle – Service Period

27% Recycling

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Non-Renewable Fuels – Nuclear

Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Front End

1. Exploration:1) U is 500 times more abundant than gold2) Traces can be found everywhere – all rocks and

soils, rivers and oceans, food and human tissue2. Mining and Milling:

1) Mining – surface (strip) or underground mining2) Milling – grind up ore, use sulfuric acid to separate

U from waste rock – “yellow cake” U3O8

3. Conversion: U must be converted into a gas before it can be enriched (uranium hexafluoride – UF6 )

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Front End

Uranium Ore

Yellow Cake

UF6

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Front End

4. Enrichment: increase concentration of U-235 and remove 85% of U-238Depleted Uranium: removed U-238, which includes .25% U-235, is used in metal to form yacht keels, radiation shielding, and (controversially) weapons as ammunition.

Keel

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Non-Renewable Fuels – Nuclear

Nuclear Fuel Cycle – Front End

5. Fuel Fabrication:1) UF6 converted to UO2 powder

2) Powder converted to pellets3) Pellets stacked in tubes4) These are nuclear fuel rods5) Groups of rods make up fuel assembly6) Hundreds of assemblies make up reactor core

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Service Period

1. Electricity Generation1) Transport of radioactive materials2) In-core fuel management

Old fuel rods must be changed periodically (1/3 at a time)

2. Food and Agriculture1) FDA approved irradiation of food2) Kills bacteria, insects, and parasites

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Service Period

3. Nuclear medicine – Imaging1) Most medical imaging is anatomical – deals only

with structures2) Nuclear imaging shows physiological functioning

of organs3) Radiotracer injected into blood, inhaled, or

ingested4) “Gamma camera” detects energy given off

(PET scan – Positron Emission Tomography)

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Non-Renewable Fuels – Nuclear

4. Nuclear weapons1) Only two known uses of

nuclear weapons use – Hiroshima and Nagasaki during WW2

Nuclear Fuel Cycle – Service Period

“Fat Man” “Little Boy”

Nuclear Fuel Cycle – Service Period

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Back End

Two options for spent fuel: • Interim storage and final disposal• Reprocessing to recover usable portion

1. Interim Storage:1) Used fuel assemblies: hot and highly radioactive2) Stored in special ponds usually near reactor site3) Water is radiation barrier and cools fuel

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Back End

2. Reprocessing Reprocessing separates U and Pu from waste products – chop up fuel rods and dissolve them in acid to separate materials1) U enrichment

a) Spent fuel contains ~96% of original Ub) U-235 reduced to 1%c) Therefore, send back to enrichment

2) Plutonium (Pu)a) Spent fuel contains ~1% radioactive Pub) Can be blended with enriched U for new fuelc) One of the most highly toxic elements known

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Back End

Waste1. Low-level waste – radioactive isotopes decay 10-50 years

1. Material used to handle highly radioactive parts of reactorCooling water pipes, radiation suits

2. Waste from medical uses3. Processing nuclear fuel generates depleted uranium (DU)

DU used as heavy metal2. High-level waste – radioactive isotopes decay >100,000 years

Material from core of reactor/decommissioned weapons

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Back End

Waste Disposal1. Low-level waste – radioactive isotopes decay 10-50 years

1. Temporary storage2. Standard disposal methods or reuse (heavy metal)

2. High-level waste – radioactive isotopes decay >100,000 years1. Currently only short-term storage exists2. Geologic disposal. Requires:

1. Absolutely stable geological formations2. Unprecedented stability of human institutions

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Non-Renewable Fuels – NuclearNuclear Fuel Cycle – Back End

Waste Disposal2. High-level waste – radioactive isotopes decay >100,000 years

Yucca Mountain• 80 miles northwest of Las Vegas• Only proposed site in U.S. for high-level waste storage• 77,000 tons capacity

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Non-Renewable Fuels – Nuclear

Nuclear Fuel Cycle – Back EndWaste Disposal

2. High-level waste – radioactive isotopes decay >100,000 yearsSpace Disposal

1. Limited capacity on rockets2. Rocket malfunction is possible