Crude Oil, Fuels and organic chemistry

• What is crude oil?


  • A finite resource found in rocks, formed over millions of years from the remains of simple marine organisms
  • Contains complex mixture of hydrocarbons
• What are the processes in the fractional distillation of crude oil?


  • Crude mixture is put into the fractionating column at the bottom and heated
  • Hydrocarbons evaporate and rise up in the column
  • As the hydrocarbons rise, they eventually reach a fraction which is cool enough for them to condense into a black liquid
  • Mixture left at the bottom, which does not evaporate at all, is called bitumen

  *Sometimes more than 1 compound comes out in a fraction. This is because some compounds have different boiling points*
• What is a hydrocarbon?


  A compound made up of only hydrogen and oxygen
• What is crude oil classed as?

  Fossil fuel
• What are fractions in fractional distillation?

  Fractions contain mixtures of hydrocarbons (alkanes) with similar boiling points
• What does each fraction contain?

  A mixture of hydrocarbon compounds with similar boiling points
• As you go down the fractionating column what happens to the chain length and the boiling points?

  Both chain length and boiling points increase
• How is hydrocarbon chain length and usefulness as a fuel linked?

  The shorter the hydrocarbon chain length the more useful the fuel
• As you go down the fractioning column what happens to:

  Viscosity: Increases

  Ease of ignition: Decreases

  Cleanliness of burn: Decreases - less clean

  Colour: Gets darker
• Fraction - Petroleum Gases


  Uses:

  • Domestic heating
  • Cooking
• Fraction - Gasoline/ petrol


  Uses:

  • Cars
• Fraction - Naphtha


  Uses:

  • Solvents
• Fraction - Kerosene


  Uses:

  • Jet fuel
  • Plane fuel
• Fraction - Diesel


  Uses:

  • Trucks
  • Trains
  • Cars
• Fraction - Lubricating oil


  Uses:

  • Engine parts
• Fraction - Fuel oil


  Uses:

  • Oil central heating
• Fraction - Bitumen (tar)


  Uses:

  • Roads
  • Roofs
• What is the economic importance of the oil industry?

  • Oil companies set the price of oil so have an influence on the economy
  • Can be hard for poor countries to buy oil
  • Wars and intended crisis in a country can affect the flow of oil to the other countries they sell to
• What is the political importance of the oil industry?

  • Countries that are large producers of oil can cut of supplies to other countries (can be used as a political tool)
• What is the social importance of the oil industry?

  • Oil industry provides jobs which creates money for the economy
• What is the environmental impact of the oil industry?

  • Burning fossil fuels releases large amounts of carbon dioxide (a green house gas) into the atmosphere witch contributes to global warming and climate change
  • Building power stations and drilling for oil causes damage to landscapes and loss of habitats
  • Oil spillages in the ocean result in the death of marine life and birds
• What is catalytic cracking?

  Process of breaking down large hydrocarbon molecules into smaller ones using a catalyst. Lighter fractions produced are more useful then heavier ones in fractional distillation. Vapour containing unwanted fractions is passed over a very hot catalyst surface and this breaks up the long molecules into smaller fragments. Shorter chain compounds produced have lower boiling points so will burn more easily. Hydrocarbons produced are a mixture of alkenes and alkanes.

  A) decane

  B) octane

  C) ethene

  
• Why is it important for oil companies to carry out cracking?

  To make more useful compounds
• What is the combustion reaction of hydrogen and what are its uses?

  • Hydrogen burns in oxygen and forms carbon dioxide and water
  • Hydrogen is used as fuel in rockets and some cars
• What is a combustion reaction?

  A chemical reaction where a substance reacts with oxygen to produce heat, light and new products.

  A) Methane

  B) Oxygen

  C) Carbon dioxide

  D) Water

  
• What is the equations for the combustion of ethanol?

  C2H5OH + 3O2 -> 2CO2 + 3H2O

  Word equation:

  Ethanol + oxygen --> Carbon dioxide + water
• What is incomplete combustion?

  When the supply of oxygen is limited. Results in the formation of carbon (seen as soot), carbon monoxide, as well as carbon dioxide and water
• Many fuels can produce a variety of impurities, one of which is sulfur. Which can lead to acid rain which can result in what?

  Can wear away limestone buildings. Can alter the pH of lake rivers and pounds
• Advantages of using hydrogen as a fuel?

  • Produced from water; therefore, it is renewable
  • Water is the only product of its combustion so burning hydrogen does not contribute to global warming or acid rain
  • Ignites easily
• Disadvantages of hydrogen as a fuel

  • Requires large amounts of electricity to produce hydrogen from water by electrolysis
  • Storage requires bulky and heavy pressurised containers
  • Forms an explosive mixture with air