AP Enviro 15.3-15.4: what are the advantages and disadvantages of natural gas, what are the advantages and disadvantages of coal
synthetic natural gas (SNG)
coal converted into a gaseous state. requires more mining, low net energy, expensive
coal liquefaction
converts coal into a liquid state. requires more mining, low net energy, expensive
liquefied natural gas (LNG)
low temp., high pressure natural gas that can be transported across oceans
natural gas
mixture of gases. mostly methane. lies above reservoirs of crude oil. needs pipeline.
liquefied petroleum gas (LPG)
propane and butane gases that are liquefied and removed when a natural gas field is tapped. stored in pressurized tanks. serves areas without pipelines (most rural areas)
use of coal in usa and china
usa and china are top 2 coal users, mostly for electicity
problems involved with increasing our LNG use
-we would become more dependent on countries we don't like, such as Russia and Iran -low net energy
pros and cons to natural gas as an energy resource
pros: ample supplies, high net energy, cheap, less air pollution and co2 emissions, easy to transport by pipeline, low land use, good for fuel cells, gas turbines, and motor vehicles
pros and cons of coal as an energy resource
pros: ample supplies, high net energy, cheap, we have good technology, air pollution could be improved with technology cons: severe land disturbance, air pollution, large govt subsidies
pros and cons of liquid and gas synfuels produced from coal
pros: large potential supply, vehicle fuel, moderate cost, less air pollution than coal cons: low to moderate net energy, more expensive than coal, requires more mining, large govt subsidies, high water use, higher co2 emissions than coal
coal
solid fossil fuel formed from plant remains that have been subjected to intense heat and pressure for 300-400 million years