It's a Gas! Trivia Quiz

Answer:

Fossil fuels, which have been used as an energy source for thousands of years, are composed of carbon and/or hydrocarbons (containing carbon and hydrogen in their molecules) which have accumulated when organic matter (the remains of organisms that were once living) decays without being exposed to the atmosphere, and under conditions of heat and pressure that lead to the concentration of their carbon-containing portions. Although they are continually being produced, the time it takes to produce them (millions of years) is so long that they are considered a non-renewable resource: what we use up will not be replaced in our lifetime.

Coal, which is mostly carbon, starts as peat in the early stages of formation, and has been used as a fuel by those living near the area where it forms since before recorded history. If sufficient time is allowed to pass, this matter will become more purely carbon, with the other matter being eliminated. Coal is classified into different types depending on how pure the carbon in it is. The Industrial Revolution saw coal assume a major role as an energy source.

Petroleum, often just referred to as oil, is a liquid composed of (mostly) hydrocarbons whose molecules contain five or more carbon atoms, although some of the lighter molecules which are gaseous at room temperature may be included. Because it contains a wide range of different chemicals, it is processed to separate them from each other. This is the source of a large range of liquid fuels, as well as chemicals used in the petrochemical industry. Following the development of various types of engine based on liquid fuels (cars and aircraft spring immediately to mind), petroleum has become a valuable commodity. In North America, the liquid fuel used is called gasoline, or just gas; other parts of the world have other names, such as petrol.

Natural gas is, as the name suggests, a gas. It is mostly composed of methane, which contains a single carbon atom and four hydrogen atoms, but some slightly larger hydrocarbons (ethane, propane and butane, with 2, 3 and 4 carbon atoms respectively) are often in the mix. Like other fossil fuels, there are often traces of sulfur and nitrogen compounds which must be removed if the methane is desired to be pure. That is the case when it is being used as a feed material in the petrochemical industry, but less so when the planned use is as a fuel. Even then, some purification is needed, as the extraction process (often from an underwater source) frequently leads to the inclusion of water in the mixture - and water does not burn well.

Natural gas has been a popular source of domestic energy, for both heating and cooking, in places where it is readily available, and therefore relatively inexpensive. However, there are associated hazards, and in the 21st century there has been a strong movement to replace the domestic use of natural gas with electricity, often from solar panels that can be placed on the roof, allowing each house to provide its own power. This push to abandon the use of natural gas has been driven by the recognition that its use is a major contributing factor to the global warming that has occurred over the last few hundred years, and which endangers the viability of the lives of many people.

The need to replace fossil fuels as our main energy source is well recognized, but it is problematic. Something needs to replace them, and we do not yet have the appropriate technology in a number of areas. For instance, the Australian state of Victoria has been almost completely reliant on coal-fired power stations for its electricity, and industry still needs that externally-provided electricity, even as more and more houses transition to solar electricity. (In fact, from 2025 new houses will not be allowed to use natural gas, under current legislation.) The transition from coal, because not only is it running out, but the power plants are also getting so old they need to be replaced, requires some intermediate alternative. Some consider natural gas to be an appropriate transition fuel, others are in favour of developing nuclear power on the sites. Both plans have some significant drawbacks, and the question of the path along which central electricity generation is heading is not yet resolved. The ultimate destination is renewable energy! In mainland Australia, this means a combination of wind and solar power; in other parts of the world, hydroelectricity and geothermal power are more appropriate.

Natural gas is not just a fuel, as already mentioned. The methane (as well as some of the other chemicals, which can be collected as the gas is purified) is a useful chemical in the petrochemical industry. While one immediately thinks of plastics, and their impact on the environment when discarded, it should not be forgotten that petrochemicals include much more than that, including a range of medicines. Methane can be used to produce hydrogen (which has many industrial uses); it can be fed to bacteria that produce animal and fish feed; it can be used in the production of nitrogen, essential for fertilizers. With all these uses, it seems a shame to just burn it.