Fossil Fuels

Fossil Fuels

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Index

Oil

What are fossil fuel

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Coal

Natural gas

Pros and Cons

Enviroment

WHAT ARE FOSSIL FUELS?

Fossil fuels are energy sources derived from the decomposition of living organisms (plants and animals) that were formed millions of years ago in the absence of oxygen and under high pressure and temperature within the Earth's crust. The main fossil fuels are coal, oil, and natural gas. They produce a large amount of energy and made the Industrial Revolution possible.

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How fossil fuels are formed?

Living organisms

Millions of years ago, plants, algae, and animals lived on land and in the seas. When they died, their organic remains were deposited on the bottoms of lakes, swamps, and oceans.

Deposition and accumulation

These remains were covered by sand, clay, or silt. In this condition, microorganisms could not complete decomposition due to the lack of oxygen. Some of the organic matter did not rot completely, but was preserved in the sediment.

Burial and transformation

As millions of years passed, sediments accumulated , pressure and temperature increased. These conditions caused a slow, progressive chemical transformation.

Migration and accumulation

Oil and natural gas, which are lighter than water, migrate upward through porous rocks. When they encounter an impermeable layer, they are trapped, forming oil and gas reservoirs.

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COAL

WHAT IS COAL?

Coal is a carbon-rich, combustible sedimentary rock. It is composed primarily of carbon (50–98%), along with hydrogen, oxygen, nitrogen, and sulfur. Coal was a major energy source during the Industrial Revolution. Today the coal use is declining and is replaced by renewable sources and natural gas, although it remains important in some countries for electricity generation.

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OIL

WHAT IS OIL?

Oil is a liquid fossil fuel, dark and oily. It is made up of a natural mixture of hydrocarbons (molecules composed of carbon and hydrogen) and small amounts of sulfur, oxygen, nitrogen, and metals. It is found in porous underground rocks, trapped beneath impermeable layers that prevent it from escaping. To be used, oil must first be refined, and it is used to produce gasoline, diesel, plastics, lubricating oils, paints, and many other products. Oil is still the largest energy source, although many countries are trying to reduce its use due to pollution.

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NATURAL GAS

Natural gases are gaseous fossil fuels, composed mainly of methane. They are substances trapped underground within porous rocks covered by impermeable layers that prevent the gas from escaping. Natural gas is one of the most widely used energy sources in the world for: home heating, electricity generation, and vehicle fuel.

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I vantaggi principali nell'uso dei combustibili fossili sono:

• I combustibili fossili contengono molta energia per unità di massa o volume.

• A differenza di alcune fonti rinnovabili che dipendono da sole o vento, i combustibili fossili permettono di generare energia in qualsiasi momento.

• Molti paesi hanno riserve di petrolio, gas o carbone, o hanno accesso a mercati internazionali di questi combustibili, il che assicura una certa stabilità energetica.

• I combustibili fossili si prestano a molti utilizzi: produzione di elettricità, riscaldamento, trasporti, industria chimica, materie prime per plastica e altri prodotti.

PROS

The main advantages of using fossil fuels are:

• Fossil fuels contain a large amount of energy per unit of mass or volume.

• Unlike some renewable sources that depend on the sun or wind, fossil fuels allow energy to be generated at any time.

• Many countries have reserves of oil, gas, or coal, or have access to international markets of these fuels.

• Fossil fuels are versatile and can be used for electricity generation, heating, transportation or in the chemical industry.

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CONS

I vantaggi principali nell'uso dei combustibili fossili sono:

• I combustibili fossili contengono molta energia per unità di massa o volume.

• A differenza di alcune fonti rinnovabili che dipendono da sole o vento, i combustibili fossili permettono di generare energia in qualsiasi momento.

• Molti paesi hanno riserve di petrolio, gas o carbone, o hanno accesso a mercati internazionali di questi combustibili, il che assicura una certa stabilità energetica.

• I combustibili fossili si prestano a molti utilizzi: produzione di elettricità, riscaldamento, trasporti, industria chimica, materie prime per plastica e altri prodotti.

The main disadvantages of using fossil fuels are:

• Fossil fuels are formed over millions of years, so they cannot be regenerated.

• The fossil fuel market is subject to strong fluctuations due to geopolitical factors.

• Fossil fuels when they get burnt they release greenhouse gases which pollute the air and also increase the greenhouse effect.

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ENVIROMENT

Extraction and transportation activities lead to habitat loss, deforestation, soil erosion, and ecosystem fragmentation.

Fossil fuels are also very polluting because their combustion releases a lot of carbon dioxide and other greenhouse gases that end up in the atmosphere.

In addition to greenhouse gases, combustion also releases pollutants that can cause respiratory diseases.

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Chemical transformations

The first occurs at shallow depths (up to 1 km) and at temperatures below 50 °C. Here, bacteria decompose organic matter, producing methane gas, and a substance called kerogen is formed, which is the precursor of oil and natural gas.

Second phase: The second chemical transformation occurs at greater depths (1–4 km) and at temperatures between 50–150 °C. The kerogen breaks down into simpler molecules, giving rise to liquid oil if the temperature is moderate, or natural gas if the temperature is higher.

The third occurs at depths greater than 5 km and at temperatures above 150 °C. Almost all the organic material is transformed into natural gas and graphite.