Please enable JavaScript.
Coggle requires JavaScript to display documents.
Fossil Fuels - Coggle Diagram
Fossil Fuels
-
Positives
-
-
-
-
Large reliance- It would take a long time for new technologies to change to renewables and fossil fuels provide an fuel source now.
-
Natural Gas
-
-
New Technology
Enhanced Gas Recovery (EGR) = injecting CO2 or N around the edges of the gas field to maintain pressure and gas flow.
Methane Hydrate (or methane clathrate) = a hydrocarbon gas, trapped in a solid ice like structure of water molecules. It is found frozen in permafrost, or on the sea bed.
-
Oil
Either produced through coalification (called dry natural gas’) or through maturation (called ‘wet natural gas’).
Extraction
Primary oil recovery involves the extraction of crude oil by natural pressure. A hole is drilled down to the oil, and it will rise to the surface. (Only 5-15% of oil is extracted with this simple technique)
Secondary oil recovery involves the injection of gas or water, which will displace the oil, force it to move from its resting place and bring it to the surface.
New Technology
Tertiary oil recovery seeks to alter the properties of oil, to make it easier to extract. This involves thermal recovery (heating the oil), gas injection (e.g. CO2 or Nitrogen) or chemical injection. This makes the oil less viscous, and reduces friction, so it can move to the surface more easily.
-
Tar Sands and Oil Shales
Tar Sands are sediments containing heavy, low viscosity oils
The sand is quarried, then treated with hot water, producing an emulsion of oil droplets that floats and can be separated. About 75% of oil is recovered.
Deep deposits can be injected with steam, solvents or controlled combustion to produce liquid oil that can be pumped to the surface. (Like tertiary oil recovery)
Oil shales = a rock containing solid hydrocarbons (kerogen) which can be turned into oil when heated.
Oil shales are mined, then the oil is extracted by heating the shales to drain off the fluid hydrocarbons.
Subsea production wells = wells located on the seabed, with no platform at the sea surface.
-
Fracking
Fracking is the process of drilling down into the earth before a high-pressure water mixture is directed at the rock to release the gas inside. Water, sand and chemicals are injected into the rock at high pressure which allows the gas to flow out to the head of the well.
More oil or gas will be available however there could be aquifer contimination or earthquakes which is why it is controversal.
Coal
New Technology
Coal gasification
Coal that is too deep to be mined can be burnt underground under controlled conditions to produce a mixture of fuel gases including hydrogen (H), carbon monoxide (CO) and methane (CH4).
Coal liquefaction
Solvents can be added to turn coal into liquid hydrocarbons directly.
Or after coal gasification, the gaseous hydrocarbons can be converted to liquid hydrocarbons.
-
Extraction
Open Cast mining
Open-cast mining can use large machinery but cannot access deeper coal. It also affects a larger area of land and causes more problems of noise, dust and visual impact.
Deep Cast mining
Deep mining involves extracting less non-coal material than open-cast mining, but it is relatively labour intensive, cannot use the largest equipment and suffers from problems of ventilation, overburden support, drainage and subsidence of the ground surface.