Fuels and Earth Science

• Primary methods for extracting crude oil include drilling, hydraulic fracturing, and mining.
• Crude oil - fossil fuel, formed over millions of years from ancient remains of marine organisms.
• hydrocarbons are compounds of carbon and hydrogen atoms only
• carbon atoms can form four covalent bonds, in a hydrocarbon molecule these can be: carbon-carbon bonds or carbon-hydrogen bonds
• • hydrocarbon bonds can consist of chains (with or without branches) or rings of carbon atoms
• crude oil is a complex mixture of hydrocarbons, with their carbon atoms in chains or rings
• crude oil is an important source of useful substances and it is a finite resource.
• Finite resource - no longer being made or are being made extremely slowly. Crude oil takes millions of years to form.
• The chemical symbols in the formulae for hydrocarbon molecules are: C for carbon, and H for hydrogen.
• In ball and stick models, atoms are usually modelled as: black for carbon atoms, and white for hydrogen atoms. 
• Familiar fuels such as petrol and diesel oil (used in cars) come from crude oil.
• A feedstock is a starting material for an industrial chemical process.
• The petrochemical industry involves the use and manufacture of substances from crude oil.
• Hydrocarbons from crude oil are useful as fuels and as feedstock for the petrochemical industry. 
• fractional distillation is used to separate crude oil into simpler, more useful mixtures
• crude oil can be separated by fractional distillation because its different hydrocarbons have different boiling points
• 1. during fractional distillation, oil is heated to evaporate it
• 2. during fractional distillation, vapours rise in a fractionating column
• 3. during fractional distillation the column has a temperature gradient - hot at the bottom, cool at the top
• 4. during fractional distillation, each fraction condenses where it becomes cool enough and is piped out of the column
• the gases fraction of crude oil does not condense and leaves out of the top
• the bitumen fraction of crude oil does not evaporate and leaves at the bottom
• the other fractions of crude oil are liquid at room temperature and are useful as fuels
• a fraction of crude oil is a mixture of hydrocarbons with similar boiling points
• number of C and H atoms decreases as you go up the fractionating column
• the boiling point of fractions decreases as you go up the fractionating column
• the ease of ignition increases as you go up the fractionating column
• the viscosity of fractions decreases as you go up the fractionating column
• Most of the hydrocarbons from crude oil are alkanes, a homologous series of compounds
• as the number of carbon and hydrogen atoms in a hydrocarbon molecule increases, the strength of the intermolecular forces increases
• as the number of carbon and hydrogen atoms in a hydrocarbon molecule increases, more energy must be transferred to overcome intermolecular forces
• as the number of carbon and hydrogen atoms in a hydrocarbon molecule increases, the boiling point increases
• gases fraction is used for domestic heating and cooking
• petrol fraction is used for fuel for cars
• kerosene fraction is used for fuel for aircraft
• diesel oil fraction is used for fuel for some cars and trains
• bitumen fraction is used for surfacing roads and roofs
• fuel oil fraction is used for fuel for large ships and some power stations
• alkanes are a homologous series of hydrocarbons
• a homologous series is a series of compounds in which molecular forces of neighbouring members differ by CH2