Natural gas is a fossil fuel found in marine and terrestrial sedimentary basins associated or not with oil. It consists of a mixture of light hydrocarbons, with a predominance of methane, and remains in a gaseous state under normal ambient temperature and pressure conditions.
This gas can undergo thermodynamic treatments to become liquid and so is called liquefied natural gas (LNG), being more easily transported. It is one of the most important energy sources in the world, second only to oil and coal.
Use
It represents a great fuel with several applications in cars and homes, businesses and industries, to provide electricity and heat. It is also used as raw material in the petrochemical industry (plastics, paints, synthetic fibers and rubber) and fertilizers (transformed into urea, ammonia and derivatives). In electricity generation, it has been widely used in thermoelectric plants and in industries.
Advantages and disadvantages
Natural gas is a non-renewable source, which was formed over millions of years in the planet's underground reservoirs. Its production process, from exploration, processing to transport, can generate
major impacts on the environment, such as oil tanker spills, platform and pipeline leaks. It also has the disadvantage of having highly toxic contaminants that have to be eliminated in the refining process.In addition, there are the problems generated by its use in thermoelectric plants, in particular the need for a cooling system, causing wasted water, and emissions of air pollutants: carbon dioxide carbon (CO2), nitrogen oxides (NOx) and, to a lesser extent, carbon monoxide and some low molecular weight hydrocarbons, including methane, due to combustion incomplete.
On the other hand, it presents some benefitsenvironmental as an energy source, compared to other fossil fuels (coal and petroleum derivatives), namely:
- it has fewer contaminants than other energy sources, such as diesel oil that produces emissions of sulfur oxide, soot and particulate matter;
- produces cleaner combustion with less CO emissions2 per unit of energy generated (about 20 to 23% less than fuel oil and 40 to 50% less than coal);
- contributes to reducing deforestation by replacing firewood;
- greater ease of transport and handling, compared to LPG (liquefied petroleum gas), which requires a large infrastructure;
- does not require storage, eliminating the risks of fuel storage;
- provides greater safety in case of leakage, because it is lighter than air and dissipates quickly through the atmosphere, favoring domestic use.
Origin and Composition
Natural gas originates from any organic matter degraded (algae, animal, vegetable remains) by anaerobic bacteria. The process takes millions of years.
Various natural factors define the composition of raw natural gas and it all depends, in large part, on the conditions under which the gas is accumulated underground, in the reservoirs.
See here everything about the Origin and Composition of Natural Gas.
